4.5.1 Factors to consider when selecting flue-gas cleaning systems
4.5.1 选择烟气净化工艺需要考虑的因素
4.5.1.1 General factors
4.5.1.1 总的原则
[54, dechefdebien, 2003]
The following (non-exhaustive) list of general factors requires consideration when selecting flue-gas cleaning (FGC) systems:
如下列表(不限于)是考虑选择烟气净化工艺需要考虑的因素
•type of waste, its composition and variation;
废弃物类型,构成和种类
•type of combustion process, and its size;
焚烧工艺类型,规模
•flue-gas flow and temperature;
烟气流量和温度
•flue-gas content, including magnitude and rate of composition fluctuations;
烟气内容,包括组分的变化量和变化率;
•target emission limit values;
目标排放限制;(脱除效率)
•restrictions on discharge of aqueous effluents;
对废水排放的限制要求;
•plume visibility requirements;
对烟羽可视性的要求(是否要脱白)
•land and space availability;
土地和空间的大小
•availability and cost of outlets for residues accumulated/recovered;
回收副产物的可利用性和成本;
•compatibility with any existing process components (existing plants);
与现有工艺设备的可匹配性(现有工厂)
•availability and cost of water and other reagents;
水和其他物料的可获取性和成本;
•energy supply possibilities (e.g. supply of heat from condensing scrubbers);
是否能对外提供能源输出(如:湿法冷凝塔的热量对外输出)
•availability of subsidies for exported energy;
对外输出能源是否有补贴;
•tolerable disposal charge for the incoming waste (both market and political factors exist);
入场垃圾补贴费(包括:市场和政治因素)
•reduction of emissions by primary methods;
减少污染物排放使用的主要工艺手段;
•noise;
噪音;
•arrangement of different flue-gas cleaning devices if possible with decreasing flue-gas temperatures from boiler to stack.
规划不同的烟气工艺装置,尽可能地减少烟囱排烟温度;(从尾气中尽可能多地获取能量)
[ 74, TWG 2004 ]
4.5.1.2 Energy optimization
4.5.1.2 能源优化
Some flue-gas treatment techniques can add significantly to the overall energy requirements of the incineration process. It is necessary to consider the additional energy requirements imposed by applying lower ELVs(Emission limit values). The following key observations can be made:
一些烟气净化技术可以显著增加焚烧工艺的能源需求(消耗更多能源)。在有些低排放应用是必须要消耗更多能源的。关键点如下:
•Reducing dust emissions including boiler ash (and metals filtered with dust) generally requires additional filtration and increases energy consumption.
减少粉尘排放包括锅炉灰(以及粉尘中的金属过滤)通常会需要额外的过滤装置,从而增加能源消耗。
•Reducing NOX emissions to below 100 mg/Nm3 is most often achieved using SCR – which, due to the catalyst sensitivity to fouling and acid attacks, is generally used as a low-dust system in waste incineration, situated at the clean gas end of the FGC system. It therefore
usually requires some additional energy for flue-gas reheating. Very low SOX levels in the raw flue-gas may allow SCR to be used without reheating (see Section 2.5.5.2.2). The energy required for the additional flue-gas cleaning (to achieve very low emission levels)
will result in a reduction of the amount of energy generated by the incinerator that is available for export, or in the equivalent consumption of externally supplied energy. Although infrequent, high-dust SCR is used in some waste incineration plants.
减少NOx的排放至100mg/Nm3以下,通常使用SCR是比较适宜的。但是催化剂比较敏感容易受到污染和酸腐蚀的影响,其通常在垃圾焚烧中在低尘区域使用,布置于烟气净化系统的尾部。因此,通常需要额外的能源来对烟气进行再加热。如果原烟气中的Sox水平很低则可以允许SCR系统不进行在加热(详见2.5.5.2.2章节)。要实现额外的烟气净化目的(达到超低排放水平)所需要的能源将会使垃圾焚烧所产生的本来可以对外输出的能源进一步被消耗,或者消耗外部提供的等量的能源。虽然不常见,但是高尘布置的SCR在某些垃圾焚烧厂中也有使用。
•The boiler exit temperature has a major influence on FGC energy requirements – if it is below the acid dew point, additional energy input will be required to heat the flue-gas.
锅炉出口温度是决定烟气净化系统能源需求的主要决定因素,为了加热烟气使他不低于酸露点就需要消耗额外的能源。
•In general, placing the FGC components so that those requiring the highest operational temperatures precede those that operate at lower temperatures results in a lower overall
FGC energy demand (but this cannot be achieved in all cases, e.g. SCR usually requires
clean gas and is therefore placed after the lower temperature gas cleaning stages, as
implementing high-dust SCR avoids the use of energy to reheat the flue-gas but is challenging to implement).
[ 64, TWG(technical working group) 2003 ] [ 74, TWG 2004 ]
通常来说,在布置烟气净化各工艺段时,应当将那些最高运行温度的工艺段优先布置在那些低运行温度的工艺段上游,这样可以获得较低的能源需求(但是这个不可能在任何情况下都能实现,如:SCR通常需要布置在干净烟气区域,而导致需要布置在温度较低的净烟气段,布置在高尘段可以避免消耗能源去对烟气再热,但容易面临烟气中污染物组分对催化剂寿命影响的挑战)
4.5.1.3 Overall optimisation and the ‘whole system’ approach
4.5.1.3 整体优化及“全系统”方式
As well as considering the energy aspects (see sections on energy above), there is a benefit to considering the FGC system as a whole unit. This is particularly relevant to the removal of pollutants because the units often interact, providing primary abatement for some pollutants, and having an additional effect on others. Depending on the position in the cleaning sequence, different cleaning efficiency values are obtained. [ 74, TWG 2004 ] Multifunctional devices are common, and include the following:
基于能源因素的考虑(看上述能源章节),将烟气净化系统作为一个整体考虑是非常必要的,因为不同工艺段之间经常会相互影响,从而与实现最终的去除污染物的目的密切相关。(Sox高了会影响SCR的催化剂,从而影响寿命。预除尘效率过高会造成酸露点偏高从而影响系统的稳定性。HCL如果太低,会导致Sox在150度左右的脱除效率等等,很多密切相关的因素)基于在烟气净化系统中的不同位置布置,会获得不同的去除效率。多用途装置非常常见,包括如下:(如:布袋有除尘功能,还有二次脱酸功能。)
•If a bag filter (BF) is used downstream of reagent injection, in addition to its dedusting effect, it acts as a complementary reactor. The pressure drop through the fabric material distributes the flue-gas on the adhered cake which contains some deposited reagent and, due to the low velocity of the gases, the residence time is long. A BF can, therefore, contribute to the treatment of acid gases, gaseous metals such as mercury and cadmium, and POPs (persistent organic pollutants) such as PAHs, PCBs, dioxins and furans.
如果布袋除尘器被用于干粉喷射的下游,除了作为一个除尘装置外,它还将成为一个二次脱酸的反应器。通过滤料纤维的压降会将烟气分配到滤饼上与存留的反应剂进行接触,由于除尘器中的气体流速较低,会因此获得一个较长的停留时间。因此,除尘器有助于去除酸性气体,气态金属类如汞和镉以及POPs(持续性有机污染物)如PAHs,PCBs,二噁英和呋喃。
•In addition to acid gas treatment, wet scrubbers can help with capturing some dust and, if the pH is low enough and/or with the use of scrubber reagents, mercury.
除了脱酸功能外,湿法洗涤塔对粉尘捕捉也有一定功效,如果PH值够低或使用一些洗涤剂还能脱汞。( 在脱硫液中加入Fenton试剂可以促进单质汞氧化为二价氧化态汞,从而被脱硫液吸收,提高WFGD的脱汞效率。Lu和Tan等针对利用Fenton反应促进汞的脱除分别进行了实验室规模和中试规模的试验,试验发现,脱硫液中加入Fenton试剂时,实验室试验中,当H2O2质量分数为0.02%左右、Fe3+质量分数约为0.01%、pH为1.0~3.0条件下,烟气中单质汞的氧化率可达到75%;而中试试验中也能达到30%~40%的单质汞氧化率。)
• SCR de-NOX has an additional destruction effect on dioxins if designed (sized) accordingly.
SCR脱硝装置如果设计得当,还有一个额外功能,就是能破坏二噁英的能力。
•Adsorption by activated carbon and lignite coke has an effect on dioxins as well as on mercury and other substances.
[ 64, TWG 2003 ], [54, dechefdebien, 2003]
活性炭和褐煤焦(活性焦)吸附工艺能去除二噁英,汞和其他物质。
4.5.1.4 Technique selection for new or existing installations
4.5.1.4 新设备或现有设备的技术选择
Overall optimisation and the interface between FGC system components (as well as the rest of the incineration process) is important for both new and existing installations. With existing installations, the number of options may be more severely restricted than with new installations. Information regarding inter-process compatibility may be found in the sections that deal with individual FGC techniques.
烟气净化系统各工艺段(包括焚烧工艺的其余部分)的整体优化和内部接口对新上或现有设备来说都是同样重要的。重视现有的设备比新设设备更重要,有关工艺可以在其他章节找到。
4.5.2 除尘技术
The application of a system to remove dust from the flue-gas is generally considered essential for all waste incineration plants.
通常来说,垃圾焚烧厂都需要烟气除尘系统。
This section considers the locating of a dust removal stage before other subsequent FGC stages(i.e. upstream dedusting or pre-dedusting) or after other FGC systems (i.e. downstream dedusting).
本章节考虑了烟气净化系统的前置除尘(上游除尘或预除尘)和后置除尘(下游除尘)。
Upstream dedusting is used in combination with wet processes in order to protect the scrubbers.
上游除尘通常和湿法工艺相结合,为了保护洗涤塔。
Downstream dedusting is generally necessary for dry and semi-wet processes in order to capture at the same time as dust the salts produced by the reaction between acid gases and alkaline reagents. In some cases, double dedusting is applied, in which case the downstream deduster is sometimes called polishing deduster. [7, TWG 2017]
下游除尘通常和半干法(SDA)工艺相结合以同时便捕捉吸收塔中由酸性气体和碱性脱酸剂生成的副产物和粉尘。在有些应用案例中,会使用双除尘技术,下游除尘器通常被称为抛光除尘器。(就像湿法洗涤塔被称为抛光洗涤塔一样,用于最后的防守和精细脱酸)
4.5.2.1 Pre-dedusting stage before other flue-gas treatments
4.5.2.1 烟气净化系统的预除尘
Description
4.5.2.1.1 说明
This section refers to a dust removal stage located after the pre-dedusting in the boiler, [ 74,TWG 2004 ] but generally before other subsequent FGC stages.
本节是指锅炉后段的预除尘阶段,通常都布置在整个烟气净化系统之前。
Technical description
4.5.2.1.2 技术说明
The following pre-dedusting systems are used for waste incineration:
如下预除尘应用于垃圾焚烧:
•cyclones and multi-cyclones (generally in combination with other FGC components for the efficient capture of the finer dust fractions);
旋风或多管旋风(通常要和其他更高效的除尘工艺相结合<估计后面湿法洗涤是不是可以不再追加布袋或静电>,歌本山项目是个例外);
•electrostatic precipitators (ESPs);
静电除尘器;
•bag filters (BFs).
布袋除尘器。
(注:这里未提及陶瓷滤筒)
The individual techniques are described in Section 2.5.3.
单独的技术在2.5.3章节描述。
Wet ESPs are not generally applied to pre-dedusting on account of the flue-gas temperatures in the pre-dedusting area. [ 64, TWG 2003 ] In general, they are used for polishing after scrubbing. [ 74, TWG 2004 ]
湿式除尘器通常不作为预除尘使用是因为要考虑到温度因素。通常,他们布置在洗涤塔之后用于抛光处理。
Achieved environmental benefits
4.5.2.1.3 获得环境效益(该技术的优势)
Benefits include the reduction of emissions to the flue-gas stream by reducing the particulate
load on later FGC processes
这个利益包括减少了粉尘进入烟气净化系统的下游设备或工艺段。
Separation of the fly ash from the FGC residues allows:
将烟气净化系统中的副产物提前分离出来:
• reductions in the quantity of FGC residues produced;
减少了烟气净化系统副产物的数量
• separate treatment of fly ashes for possible recycling uses.
将飞灰单独提前分离出来,有利于循环利用(我们在山鹰公安和吉安项目都考虑作飞灰鉴别,以希望减少危废处理量,降低运行成本。)
Pre-dedusting reduces dust loads on subsequent FGC systems. These may then be reduced in capacity and will experience reduced clogging risks, and hence downstream units may be designed smaller and with some degree of reduced costs.
预除尘减少了下游烟气净化系统的粉尘负荷。这些将减少了粉尘量从而减少了系统堵塞的风险。(临淄项目因为没有布置预除尘,导致刮板机和灰斗堵塞的运行风险大大增加,这也是业主商务人员占主导决策地位的一个失败的案例。)同时,下游设备可以设计的更小以便降低一些成本。
Separate collection of the flue-gas components will not be of any environmental benefit if the separated residues are then remixed afterwards. Consideration of downstream aspects is therefore required to evaluate the possibility of real benefits. [ 64, TWG 2003 ]
在某些情况下,如果最终分离物需要再次混合,那就不必要再设计预除尘。所以,在设计预除尘时,需要考虑下游工艺的实际情况来评估是否需要设计预除尘。
ESPs and cyclones alone may have problems reaching the required dust emission levels. However, they are useful as pre-dedusters and contribute to meeting the lowest emission levels when applied in combination with other techniques.
单靠电除尘和旋风除尘是很难达到排放要求的。但是作为预除尘与其他工艺技术相结合,可以有效达到超低的粉尘排放水平。
Environmental performance and operational data
4.5.2.1.4 排放性能和运行数据
[ 2, InfoMil 2002 ] Cyclone collection efficiency increases directly as a function of the dust load, flue-gas flow rate, particle size and density. As the fly ash particles are fine, the density is low and the dust load and flue-gas flow rate change, so the dust removal efficiency of cyclones is limited. Normally, dust concentration values no lower than 200–300 mg/Nm3 can be reached. Multi-cyclones, which are based on the same removal principle, can reach somewhat lower values, but values below 100–150 mg/Nm3 are very difficult to achieve.
旋风除尘器的效率会随着粉尘入口浓度,烟气流量,粉尘颗粒的大小和密度的变化而显著提高。(遗漏翻译)
[ 2, InfoMil 2002 ] An ESP can reach substantially lower dust concentration values than (multi-) cyclones. Depending on the design and the siting in the flue-gas treatment system (pre- or downstream dedusting), and the number of fields, dust emission concentration values of 15–25 mg/Nm3 can normally be achieved. Achieving values below 5 mg/Nm3 is possible with more fields (two or three) and an increased ESP surface (and hence increased cost and space requirements).
静电除尘器的除尘效率显著高于(多管)旋风除尘器。根据其设计和其所在烟气净化系统中的布置位置(上游或下游布置)和设计电场数量,其粉尘排放可轻松达到15-25mg/Nm3。使用更多的电场(2-3个)和更大的通过面积(会因此增加成本和空间),静电除尘器也可以低于5mg/Nm3的排放水平。
Bag filters are generally very efficient dust removers. Where bag filters are used, most commonly reagents are also injected (although this is not always the case) to build a pre-coat layer over the bags to protect against corrosion and help filtration (especially for deep filtration). [ 74, TWG 2004 ] The reagents used are commonly hydrated lime and activated carbon. Activated carbon reduces the dioxin and mercury loads passing on to the subsequent flue-gas cleaning stages. For wet systems, this helps to reduce the memory-effect dioxin build-up in the scrubber materials.
布袋过滤方式在除尘方面有非常高的效率。当使用了布袋,通常也会选择干粉喷射工艺以便形成一层滤饼保护滤袋抵御腐蚀(特别是深层过滤)。通常会使用消石灰和活性炭作为干粉药剂。活性炭会通过吸附减少下游烟气设备的二噁英和汞的浓度。对湿法系统来说,这有助于减少洗涤塔填料等材料(我理解是包括填料,各类管道表面等)中的二噁英的累积记忆效应。
Care should be taken concerning the level of ash in the hopper as well as cinder (especially if bag filters are installed directly after the boiler) to prevent risk of fire.
应当注意灰斗和炉渣中灰分水平以防止火灾。(特别是直接布置在锅炉下游的布袋除尘器)
[ 2, InfoMil 2002 ] Cyclones are a relatively simple design without moving parts (except for the transport systems used for the removal of the fly ash from the bottom) and, therefore, can have high availability at relatively low costs. However, the pressure drop of the flue-gas stream is relatively high, resulting in an increased power requirement for the flue-gas fan and therefore in additional energy consumption.
旋风分离器是一种相对简单的设计,无需移动部件(用于清除底部飞灰的运输系统除外)。因此,可以以相对较低的成本获得高可用性。然而,烟气流的压降相对较高,导致对引风机的功率要求增加,从而增加了能耗。
[ 2, InfoMil 2002 ] For the proper functioning of an ESP, it is important that the flue-gas stream is evenly distributed over its total surface. The pressure drop of the flue-gas over an ESP is low, reducing energy consumption. However, some pre-dedusting equipment (e.g. ESPs, filters) require electricity for their operation. [ 74, TWG 2004 ].
为了使电除尘正常运作,除尘器内流程均匀分布是很重要的。电除尘的压降很低,可以减少能源消耗。但是一些预除尘设备需要使用电力(如:静电和布袋)。
Table 4.11: Operational data associated with the use of pre-dedusting systems
Table 4.11: 与使用预除尘相关的运行数据
The table below provides a comparison of dust removal techniques (used at the pre- and post- dedusting stages):
下表提供了各种除尘技术的比较(作为预除尘和主要除尘)
Table 4.12: A comparison of dust removal systems
Table 4.12: 除尘系统比较
Cross-media effects
4.5.2.1.5 跨介质影响(使用该技术而增加的能源消耗或其他影响)
Energy requirements of different pre-dedusting techniques are evaluated in the table below.
下表评估了不同的预除尘技术对能源消耗的需求。
Table 4.13:Energy requirements associated with the use of various pre-dedusters
Table 4.13: 不同预除尘使用所需要的能源需求
The most significant cross-media effects associated with this technique are:
当这些技术在不同介质方面最为显著的影响是:
•energy consumption due to pressure loss, which is higher with bag filters than for other systems;
布袋压损所需要的能源消耗高于其他系统;
•electricity consumption for ESP operation;
电除尘器的运行电耗
•flue-gas PCDD/F concentrations may increase during their residence time in the ESP, particularly when operated at temperatures between 200 °C to 450 °C.
烟气中的二噁英和呋喃的浓度可能会因为在静电除尘器停留的时间而升高,尤其是在200-450度之间运行时。(这是为什么歌本山在湿法洗涤中进行脱除的原因。)
Technical considerations relevant to applicability
4.5.2.1.6 技术适用性的考虑
Pre-dedusting requires space for the additional process unit, which may be a limiting factor for existing plants.
老厂改造可能会因为预除尘需要额外的布置空间而无法实现。
Economics
4.5.2.1.7 经济因素
The key aspects of this technique are:
这项技术的关键因素如下:
•increased capital and investment costs – for additional process units;
增加资本和投资成本—用于额外的工艺装置;
•increased energy costs, particularly for bag filtration;
增加能源消耗,特别是将布袋除尘作为预除尘时;
•possible cost reductions for disposal where outlets are available for segregated fly ash;
当飞灰可以单独处理时,设置预除尘可以减少处置成本。(如:吉安考虑飞灰鉴别,如最终确定不是危废,可以减少危废的处置成本)
•possible increased cost of handling additional residue streams (either for recovery or disposal).
由于预除尘需要额外的飞灰输送和处理装置(回收或处置),可能会增加投资成本。
Investment costs for a two-line MSWI with a total capacity of 200 000 t/yr are estimated as[12, Achternbosch, 2002]:
2条线年处理20万吨的市政垃圾焚烧厂的投资估算如下:(2x300t/d)
•ESP (3-field):EUR 2.2 million;
3电场的静电预除尘:220万欧元;
•ESP (2-field): EUR 1.6 million;
2电场的静电预除尘:160万欧元;
•bag filter:EUR 2.2 million (not clear if this includes an upstream flue-gas cooler).
布袋除尘:220万欧元(不确定是否包括上游的烟气冷却反应器)
The unit operational costs of a bag filter for pre-dedusting may be higher due to the higher energy use associated with the pressure drop and the reagent injection. However, the bag filter's greater removal capacity for dust and for other pollutants (particularly when used with reagent injection) can result in reduced costs for subsequent components of the FGC system.
布袋除尘作为预除尘的能耗应该是最高的,主要是由于压降和需要喷入药剂等因素。但是,布袋除尘的除尘和脱酸具有更好的去除率(特别是和干粉喷射一起使用时),这可以降低烟气净化系统下游设备的投入成本。
Driving force for implementation
4.5.2.1.8 实施动力(该技术的优势)
• The FGC residues and fly ash can be separated and treated/recycled separately.
烟气净化的副产物和飞灰可以分开处理和回收。
• Smaller capacity downstream FGC equipment is required (dust loads are reduced).
下游设备处理容量减少(如:选型可以适当减小,因为粉尘浓度已经降低了)
• Improvements in the operation of downstream FGC systems.
改善了下游设备的运行工况。
• Preference for the removal of PCDD/F before wet scrubbing to reduce the memory effect.
在湿法洗涤塔前能去除二噁英/呋喃,以减少记忆效应。
Example plants
4.5.2.1.9 工厂案例
Widely applied in many incineration plants.
在许多焚烧厂广泛应用
Reference literature
4.5.2.1.10 参考文献[ 2, InfoMil 2002 ], [ 55, EIPPCB 2002 ], [ 64, TWG 2003 ]
4.5.2.2 Downstream dedusting
4.5.2.2 下游除尘(主除尘、抛光除尘)
Description
4.5.2.2.1 说明
This technique relates to either one of the following cases:
该技术通常应用于如下某一种情况:
•dedusting associated with dry and semi-wet processes in order to capture at the same time as dust the salts produced by the reaction between acid gases and alkaline reagents.
下游除尘通常和干法或半干法(SDA)工艺相结合以同时便捕捉反应塔中由酸性气体和碱性脱酸剂生成的副产物和粉尘。
•the application of an additional flue-gas polishing system for the final reduction of dust emissions after other FGC components, before the final release of stack gases to the atmosphere.
应用作为一个额外的烟气抛光系统,为了最后在其他烟气净化系统工艺段后,通过烟囱排向大气前,实现粉尘排放的最后控制。(韩国麻蒲,荷兰代尔夫载尔。)
Technical description
4.5.2.2.2 技术说明
The main system used downstream of a dry or semi-wet FGC system is the bag filter.
干法或半干法烟气净化系统的下游通常使用的主除尘系统是布袋除尘。
The main systems used for flue-gas polishing are:
主除尘系统用于烟气抛光的主要有:
• bag filters;
布袋除尘器;
• wet ESPs;
湿式电除尘;
• electrodynamic Venturi scrubbers;
电动文丘里洗涤塔;
• agglo-filtering modules;
凝集过滤模块;
•ionising wet scrubbers. [ 74, TWG 2004 ]
离子湿法洗涤。
The individual techniques are described in Section 2.5.3.
单独的技术描述在2.5.3章节中。
The addition of a final wet flue-gas treatment system can also be considered a polishing treatment after other systems that deal with acid gases, etc. This addition is generally made to specifically control HCl and SO2 emissions where they are highly variable; PCDD/F and mercury can also be removed with the use of carbon-impregnated polymer (plastic) material and with the addition of hydrogen peroxide respectively. These additional techniques are described in Sections 4.5.5.7, and 4.5.6.5. [ 64, TWG 2003 ] [7, TWG 2017]
在其他脱酸等工艺后布置一道最终的湿式烟气处理系统,通常被认为抛光处理。这种设计是为了进一步控制HCL和SO2,因为他们的波动性较大。
Polishing devices are also implemented to remove droplets (especially fine ones). They are generally implemented to prevent fouling in downstream devices such as an SCR system. [ 74, TWG 2004 ]
抛光设施也用于去除细小颗粒物(特别是超细粉尘)。他们通常用于防止下游设备(如SCR系统)的污染。
Achieved environmental benefits
4.5.2.2.3 获得环境效益
In addition to the further reduction of dust emissions, emissions to air of the following substances can also be reduced:
除了进一步减少了粉尘排放外,如下物质也随之减少排放:
•metals – as their emission concentrations are usually associated with dust removal efficiency;
金属—因为他们的排放浓度通常与粉尘的去除效率相关;
•mercury and PCDD/F – where carbon (usually with alkaline reagent) is added as an absorbent on bag filters;
汞和二噁英/呋喃—活性炭(通常和碱性吸收剂一起)作为附在布袋表面的吸收剂。
• acid gases – where alkaline reagents are added to protect bag filters.
酸性气体—碱性吸收剂被加入除尘器用于保护布袋。
The benefits of these additional reductions may be small where upstream techniques are already being applied to reduce the concentrations in the flue-gas to a low level.
如果上游工艺措施已经将烟气污染物浓度降低到一个非常低的水平,那么这种抛光除尘器所起到的作用就是很有限的了。
以上述案例应该就是作用很有限的代表了。
Furthermore, the use of two different systems for the removal of solids from the flue-gas enables the separation of fly ash from the FGC residues (salts from acid gas neutralisation). This may then allow the recovery of one or other fraction where suitable outlets exist.
此外,使用二种不同的除尘系统可以将烟气固体颗粒物中的飞灰和脱酸副产物(主要是中和烟气酸性物质后得到的盐类)实现分离。这可以使得对飞灰或副产物进行有效回收得以实现。
Environmental performance and operational data
4.5.2.2.4 排放性能和运行数据
Generally, similar dust emission levels can be achieved with upstream and downstream dedusting.
一般来说,上游除尘和下游除尘可达到同等的粉尘排放水平。
In the case of double dedusting, further reductions of emissions to air beyond that already achieved by other FGC components are as shown in the table below.
如果使用双除尘技术,粉尘的减排能力将比其他烟气净化系统工艺段更好,正如下表所示。
Table 4.14: Emission levels associated with the use of BF flue-gas polishing systems
Table 4.14: 使用布袋除尘作为抛光系统(末端布置)的排放水平
Careful maintenance of bag filters is very important to ensure their effective operation and hence low emissions. The pressure drop across the bags is monitored in order to maintain a cake on the filter. It can also be used as a means to detect bag damage (such as irreversible fouling). Dust emissions can usually be controlled to a very low level, simply by observing the pressure drop more closely and adopting stricter criteria (i.e. less latitude allowed before maintenance action is taken) for bag replacement. Analysis of the filter media may also be used to assess the reagent dose rate required and to assess its condition and its remaining lifetime.
仔细对布袋除尘器进行维护对确保其运行效率和较低的排放水平是非常重要的。对布袋压差的监控是为了维持滤袋的滤饼层。这也是监测布袋是否损坏的一个方法(例如:糊袋),粉尘排放通常可以被控制在一个非常低的水平,只要密切关注压差和采用严格的换袋标准(在维护之前应当严格遵守)。滤料的化验分析可以用于评估吸收剂的给料率,评估其状况和剩余寿命。
Table 4.15: Operational data associated with the use of flue-gas polishing
Table 4.15: 与使用末端布置除尘相关的运行数据
Cross-media effects
4.5.2.2.5 跨介质影响(增加的能源消耗或其他影响)
The cross-media effects associated with double dedusting are identified in the following table.
下表列出了与双重除尘相关的跨介质效应。
Table 4.16: Cross-media effects associated with the use of additional flue-gas polishing
Table 4.16: 使用末端布置除尘在不同介质下的影响
For this technique, the most significant cross-media effect is the consumption of energy due to the pressure drop across the bag filters.
对于这个技术,最显著的跨介质影响(能源消耗)来自于布袋除尘器压降造成的能源消耗。
In particular, in the case of using two bag filters in series (even if separated), the potential benefits in terms of improved pollutant control need to be contrasted against the significantly higher fan power required to overcome the additional pressure drop caused by the second bag filter, and therefore higher electricity consumption.
特别是,在串联2个布袋除尘器时(即使是分开的),需要对比平衡选择“潜在地提高了污染物控制能力”和“克服由二级布袋除尘引起的额外的压降而引起的风机功率明显提高而造成的更多的电力消耗”。(这是个经济性问题,设计者需要考虑这一因素)
Technical considerations relevant to applicability
4.5.2.2.6 技术适用性的考虑
Flue-gas polishing (double dedusting) requires space for the additional process unit, which may be a limiting factor for existing plants
采用双除尘公司的烟气抛光设计,需要更多的额外场地来布置额外的工艺装置,这对老厂改造来说是有难度的。(还有引风机压头余量)
Economics
4.5.2.2.7 经济因素
The key cost aspects of double dedusting are:
采用双除尘技术的主要成本在于:
•increased capital costs due to the additional process unit;
因为增加了额外的工艺装置而增加了投资成本;
•increased operating costs – mainly due to energy requirements for the pressure drop, provision of compressed air for back pulsing of the bag filter (if used), and additional maintenance costs.
运营成本增加—主要是压降造成的成本,喷吹压缩空气和运行导致增加的成本。(如果是湿电的话,还有废水处理成本,电耗等。)
Driving force for implementation
4.5.2.2.8 实施动力(该技术的优势)
Downstream dedusting is generally necessary when using dry or semi-wet FGC systems. For the specific case of double dedusting, driving forces for its use may include:
通常采用干法或半干法系统的时候,下游除尘器是必须的。在这种情况下,仍采用双除尘的主要原因在于:
•compliance with legislation/local permit conditions that require additional reductions of dust, metals, dioxin and/or acid gas emissions;
依据法规或项目所在地的要求,进一步减少粉尘,重金属,二噁英和/或酸性污染物排放。
•need for effective dedusting for a subsequent SCR process;
基于下游的SCR工艺需要,必须确保除尘的可靠运行。(否则就会国内部分项目,出现催化堵塞或碱金属中毒等)
•possibility to recycle the salts arising from the removal of acid gases;
回收脱酸后的副产物的目的;(个人理解:可能考虑分段喷入活性炭,喷入活性炭后,副产物利用可能受到影响,所以需要在二段设置除尘,在二段喷活性炭等,这样一段捕捉下来的副产物就可以循环利用了。)
上面这个是不需要利用的返利,将消石灰和活性炭回喷到一级布袋,减少消耗量。
•where double bag filtration is used, recovering additional heat between the two bag filters enables operating the second filter at a lower, optimal temperature (around 140 °C) for activated carbon injection.
在使用双除尘的情况下,回收2个除尘之间的热量可以使二级除尘在更低的最佳温度(大约140度)下操作,有利于活性炭的喷射反应。
Example plants
4.5.2.2.9 工厂案例
Downstream dedusting is applied at all plants fitted with dry or semi-wet FGC systems
所有采用干法或半干法工艺的烟气净化系统的工厂都装有主除尘器。
There are examples of plants using double dedusting in Germany, Austria, France and the Netherlands.
德国、奥地利、法国和荷兰都有采用双除尘工艺的焚烧厂。
Reference literature
4.5.2.2.10 参考文献
[ 3, Austria 2002 ], [ 2, dedusting associated with dry and semi-wet processes in order to capture at the same time as dust the salts produced by the reaction between acid gases and alkaline reagents. ], [ 64, TWG 2003 ]
下游除尘通常和干法或半干法(SDA)工艺相结合以同时便捕捉反应塔中由酸性气体和碱性脱酸剂生成的副产物和粉尘。
4.5.3 Techniques to reduce acid gas emissions
4.5.3 脱酸技术
The sections that follow address:
以下各节说明:
•description and assessment of the performance generally achieved by the main techniques applied for acid gas reduction – including consideration of applicability to various situations;
对通常采用的主要脱酸技术进行描述和性能评估—包括各种应用情况下应考虑的问题;
•description and assessment of some other technological and procedural options relevant to acid gas removal.
与脱酸相关的其他技术和程序性因素的描述和评估。
4.5.3.1 Wet scrubbing systems
4.5.3.1 湿法洗涤系统
Description
4.5.3.1.1 说明
This technique is described in Section 2.5.4.
该技术的描述在2.5.4章节。
Technical description
4.5.3.1.2 技术说明
Wet scrubbers generally have at least two effective stages: the first at low pH removes mainly
HCl and HF as well as metals, the second stage is dosed with milk of lime, limestone suspension or sodium hydroxide and operated at a pH of 6–8 primarily for the removal of SO2. Scrubbers may sometimes be described as three or more stages – the additional stages generally being subdivisions of the first low pH stage for specific purposes.
湿法洗涤塔通常需要至少2个有效阶段:第一需要在非常低PH的阶段主要用于去除HCL和HF以及重金属,第二阶段是投加石灰乳,石灰石悬浮液或氢氧化钠,PH控制在6-8以便主要脱除二氧化硫。洗涤塔有时可描述为三个或更多阶段—附加段通常是第一个低pH阶段的细分,用于特定目的。(典型的案例可以参考德国的诺因基兴或丹麦lab做的4段洗涤塔,目前国内只有日系的2段洗涤塔。)
Achieved environmental benefits
4.5.3.1.3 获得环境效益
Wet FGC systems provide the highest removal efficiencies (for soluble acid gases) of all FGC
systems with the lowest excess stoichiometric factors. [ 74, TWG 2004 ]
湿法洗涤塔系统可以以“最低的过量化学计量比”(即钙酸比,钠酸比等)实现所有烟气净化系统中最高的去除效率(针对可溶性酸性气体)。
Whilst single-stage filtration-based FGC systems (e.g. semi-wet, dry) combine and collect residues together, this is not generally the case with wet systems. The wet systems can treat HCl, HF and SO2 separately from dust, which is usually removed before. That said, wet systems do provide some additional reductions of the following substances:
基于单机除尘的烟气净化系统(如设置一级布袋的半干法、干法工艺)会将副产物和飞灰结合在一起收集,但湿法系统通常不会这样。湿法系统可将HCl、HF和SO2与粉尘分开处理,通常粉尘在上游的除尘设施中就已经去除了。那就是说,湿法系统确实可以进一步减少以下物质:
•Dust - where the scrubber capacity is large enough to prevent clogging (most usually a pre- dedusting stage is used before the wet scrubber to reduce dust loads and prevent operational problems), by up to 50 % of the dust input. [ 74, TWG 2004 ]
粉尘(湿法洗涤还具有除尘功能)—如果洗涤塔的设计能力足够大就可以阻止系统堵塞(通常大部分情况下在湿法洗涤塔上游会设置预除尘以减少粉尘负荷避免出现操作问题),湿法洗涤塔可以具备高达50%的除尘效率。
•PCDD/F - if carbon-impregnated packing materials are used, a typical reduction of 70 % is achieved by a typical scrubbing system. However, multi-stage scrubbing systems packed with a sufficient volume of carbon-impregnated materials are able to guarantee emission levels well below 0.1 ng I-TEQ/Nm3 in MSWIs and HWIs. Activated carbon or coke may be added to the scrubber for a similar purpose, with similar removal efficiencies. In the absence of carbon additives, the removal rates are negligible. [ 74, TWG 2004 ] [7, TWG 2017]-Sweden
二噁英/呋喃(湿法脱除能力)—如果使用了“碳浸渍包装材料”(我baidu和google找了半天没找到准确的信息,估计是类似碳填充的封装好的一种填料类物品。
http://www.alibole.com/qynews/0198a492/article-452913386.html 这个可以拿来试试 http://www.dginfo.com/chanpin-242667495/ ),那么湿法洗涤的去除率能达到70%。然而装有足量 “碳浸渍包装材料”的市政垃圾焚烧厂及生活垃圾焚烧厂的多级洗涤塔系统能够保证排放水平低于0.1 ng I-TEQ/Nm3。可以通过加入活性炭或活性焦来使之具有相同的效率。如果没有添加此类碳添加剂,那么是没有什么去除效率的。
•Hg2+ - if a low pH (~1) first stage scrubber is used, and HCl concentrations in the waste provide for acidification of this stage, then mercury is removed as HgCl2; elemental mercury is in general not affected. [ 64, TWG 2003 ]
2价汞—如果使用一级低PH值的洗涤塔,废弃物中的HCL浓度足够在这段进行酸化,则汞可以通过形成HgCl2的化合物进行去除;元素汞通常不受影响。
•Other pollutants - when water-soluble pollutants like bromine and iodine are present in the raw gas, they may be condensed at the low temperatures in the scrubber and in this way enter the scrubber waste water.
其他污染物—当原烟气中存在溴和碘等水溶性污染物时,它们可能在洗涤器中低温冷凝,从而进入洗涤器废水。
Environmental performance and operational data
4.5.3.1.4 排放性能和运行数据
The air emission levels generally achieved by plants fitted with wet scrubbers are shown in
Table 4.17.
配置湿法洗涤塔的焚烧厂的常规可达到的排放水平见表4.17。
Table 4.17: Emission levels associated with the use of wet scrubbers
Table 4.17: 使用湿法洗涤塔的相关排放水平
Table 4.18: Operational data associated with the use of wet FGC
Table 4.18: 使用湿法烟气净化系统的运行数据
The main operational issues are as follows.
主要操作问题如下:
PCDD/F build-up in wet scrubbers can be a problem, in particular from maintenance and start- up periods, and may require specific measures to be taken.
二噁英/呋喃 在湿法洗涤塔中的富集(是否是指记忆效应?)可能是个问题,特别是从维护到启动的期间,需要采取具体的措施。(停机到下次启动之前,一定要进去清理。)
Effluent treatment requires highly skilled operation to achieve low emission levels.
废水处理需要高技术操作才能达到低排放的水平。
For effective operation, wet scrubbers require flue-gases that have already been dedusted using for example an ESP or BF. [ 64, TWG 2003 ]
为了有效地运行,在湿法洗涤塔上游的烟气净化系统需要先进行除尘,使用例如静电除尘或布袋除尘。
Wet scrubbing enables flexibility in terms of the variation in the inlet concentrations of HCl, HF and also SO2 owing to its high buffer capacity. Sometimes additional treatment is required for mercury, for example: the injection of a complex builder in the basic scrubber; injection of activated carbon in the acidic scrubber; injection of oxidising agent or abatement in the gas phase with adsorbent. [ 64, TWG 2003 ]
基于湿法洗涤塔非常强的抗波动能力,它对入口的HCL,HF以及SO2的波动具有较强适应性。有时候汞需要额外的处理(是不是当HCL浓度高的时候不需要,自动生成HgCl2),例如:在碱洗塔(欧洲分为 酸洗acidic scrubber 和 碱洗basic scrubber)里面喷入额外助剂;在酸洗塔中喷入活性炭;在气相阶段随吸附剂一起喷入氧化剂和消除剂;(???臭氧法?强制氧化法?)
Cross-media effects
4.5.3.1.5 跨介质影响(增加的能源消耗或其他影响)
Cross-media effects are identified in Table 4.19 below.
跨介质影响在下表4.19中确定。
Table 4.19: Cross-media effects associated with the use of wet scrubber FGC
Table 4.19: 与使用洗涤烟气净化有关的跨介质影响
For this technique, the most significant cross-media effects compared to other options are:
该技术与其他工艺相比,最显著的跨介质效果如下:
•lowest reagent consumption rates;
最低的吸收剂消耗率;
•lowest solid residue production rates;
最低的固体副产物排放率;
•higher water consumption;
最高的水耗;
•production of an effluent that requires management;
有废水产生,需要进行处理;
•increased plume visibility;
增加了烟羽的可视性;
•PCDD/F build-up (memory effect) on scrubber plastic components requires addressing;
二噁英/呋喃,在吸收塔内塑料部件上的积累(记忆效应)需要处理;(这个addressing有处理的意思,但这里是不是这个意思?)
•if the input temperature is too high the material used in the wet scrubber may be destroyed.
如果进入洗涤塔的烟气温度过高,可能塔内材料会遭到损坏。
[74, TWG 2004 ]
Technical considerations relevant to applicability
4.5.3.1.6 技术适用性的考虑
The technique is generally applicable as long as there is a sufficient water supply.
只要当地不缺水,该技术通常是普遍适用的。
Due to the low outlet temperature (approximately 70 °C), the flue-gas may need to be reheated for subsequent FGC systems, e.g. bag filters and SCR.
由于出口排烟温度低(大约在70度,国内如果脱白会更低),考虑到下游烟气净化系统,如:布袋除尘和SCR系统,烟气需要进行在加热。
Economics
4.5.3.1.7 经济因素
Estimated capital costs for the technique are as in the table below.
该技术的投资成本估算如下表所示。
Table 4.20: Estimated investment costs of selected components of wet FGC systems
Table 4.20: 湿法烟气净化系统的部件投资成本估算
The key cost aspects of this technique compared to the alternatives are:
与可替代的工艺相比这个技术的关键成本是:
•higher capital investment costs than other systems, mainly due to the effluent treatment plant and the higher number of process units required, which may be a limiting factor in particular at smaller non-hazardous waste incineration sites;
比其他系统更高的投资成本,是否废水处理装置和采用多少段(我理解为2段塔,3段塔或4段塔)工艺单元是影响成本的关键,也是小规模无害化垃圾焚烧场所无法使用的原因;
•operational costs associated with disposal of residues may be lower, due to the lower specific residue production [ 74, TWG 2004 ];
由于副产物外排量较低,处置副产物的运行成本较低;
•labour costs are higher due to the increased complexity of the system.
由于系统更为复杂,所以劳动力成本更高。
Driving force for implementation
4.5.3.1.8 实施动力(该技术的优势)
•Achievement of particularly low and stable acid gas emission levels.
实现特别低且稳定的酸性气体排放控制水平。
•Reduction of disposal costs for flue-gas treatment residues.
减少烟气净化系统副产物的处置成本。
•Possibility to recover HCl, salt, gypsum.
可以实现HCL,盐类和石膏的回收。
•Particularly difficult to predict/control input waste composition.
特别难预测和控制的废弃物组成。(个人理解为垃圾成分不确定,烟气系统要面对的就是污染物的波动和高入口浓度,湿法是最佳处理方案,国内浙江,特别是温州这个区域经常会有这个需求)。
•Input waste may contain high and variable loads of acid gas precursors or metals (e.g. ionic mercury) [ 74, TWG 2004 ].
输入废弃物可以适应浓度较高且波动较大的酸性气体的前驱物或金属(如:离子汞)。
•Reduction of ammonia emissions.
减少氨逃逸。
Example plants
4.5.3.1.9 工厂案例
Wet flue-gas scrubbing is widely used throughout Europe for the full range of waste types.
烟气湿法洗涤工艺广泛应用于整个欧洲的各类型废物处理工厂。
Reference literature
4.5.3.1.10 参考文献
[ 1, UBA 2001 ], [ 2, InfoMil 2002 ], [12, Achternbosch, 2002], [ 64, TWG 2003 ]
4.5.3.2 Semi-wet scrubbing systems
4.5.3.2 半干法系统
Description
4.5.3.2.1 说明
This technique is described in Section 2.5.4.
该技术在2.5.4章节描述。
Technical description
4.5.3.2.2 技术说明
The diagram below shows a typical semi-wet FGC system, with a reactor on the left and downstream deduster on the right.
下图显示了一个典型的半干法烟气净化工艺,左边是一个反应塔右边是一个下游除尘器。
Figure 4.6:Typical design of a semi-wet FGC system
Figure 4.6:半干法烟气净化系统的典型设计
Achieved environmental benefits
4.5.3.2.3 获得环境效益
There is no effluent discharge from semi-wet scrubbers as the amount of water used is generally lower than with wet scrubbers and it is evaporated with the flue-gases. If of suitable quality,
other site waste water (e.g. rainwater) may be sent to the FGC system. [ 74, TWG 2004 ]
半干法反应器没有废水排放,其用水量比湿法洗涤要小,水跟随烟气蒸发了。如果水的品质合适,其他部位的废水(如:雨水)可以拿来使用。
Semi-wet FGC systems provide high removal efficiencies (for soluble acid gases). Emission levels can be decreased by adjusting the reagent dosing rate and design point of the system, but generally at the cost of increased reagent consumption and residue production rates.
半干法烟气净化系统提供较高的去除效率(针对可溶性的酸性气体)。通过调节吸收剂的添加量和系统的设计点(是不是排烟温度?看4.5.3.9.4。),排放可以污染物排放水平,但是这通常会增加吸收剂的消耗量和副产物的排放量。
Semi-wet systems are used with fabric filters to remove the reagents added and their reaction products. Reagents, other than alkaline reagents, can also be added to adsorb other flue-gas components (e.g. activated carbon for mercury and PCDD/F).
半干法系统通常使用布袋除尘器去脱除吸收剂和反应副产物。除了碱性吸收剂外,其他试剂也可以被用于吸收其烟气污染物组分(例如:将活性炭用于汞和二噁英/呋喃)。
They are most commonly used as a single-stage reactor/filter for the combined reduction of:
他们通常采用单级反应器/布袋,然后组合在一起来减少如下污染物:
•acid gases- removed by the alkaline reagent;
酸性气体—通过碱性吸收剂去除;
•dust- filtered by the fabric filter;
粉尘—被布袋除器过滤;
•PCDD/F- adsorbed if activated carbon is injected as well as alkaline reagent;
二噁英/呋喃—喷入的活性炭与碱性吸收剂一起吸附;
•Hg- adsorbed if activated carbon is injected as well as alkaline reagent.
汞—喷入的活性炭与碱性吸收剂一起吸附;
Environmental performance and operational data
4.5.3.2.4 排放性能和运行数据
The air emission levels generally achieved by plants fitted with semi-wet scrubbers are as follows.
安装半干法工艺的焚烧厂可以达到如下排放水平。
Table 4.21: Emission levels associated with the use of semi-wet scrubbers
Table 4.21: 使用半干法工艺的排放水平
Table 4.22: Operational data associated with the use of semi-wet FGC
Table 4.22: 半干法工艺相关的运行数据
Most systems consist of only a reagent mixing unit (reagent plus water) and a spray tower, and then a bag filter – complexity is therefore lower than with wet FGC systems.
大部分系统组成仅仅是一个吸收剂制备单元(吸收剂加水)和喷雾干燥塔,然后一个布袋除尘—系统复杂性低于湿法烟气系统。
The reagent handling and dosing require good management to ensure effective and optimised operation, particularly where heterogeneous waste types are treated, e.g. merchant HWIs.
吸收剂制备和给料需要非常好的管理来确保有效和优化的运行操作,特别是复杂工况的垃圾,如:商业HWIs(是不是危险废弃无?吃不准。)
Upstream HCl monitoring (see Section 4.5.3.9) improves optimisation of reagent dosing in these systems and allows management of peak loads of HCl, HF and SO2 without high reagent dosing rates.
上游HCL监测(详见4.5.3.9章节)改进了这些吸收剂计量的优化和使得对HCL,HF和SO2的峰值负荷管理不再需要很高的吸收剂使用量。
Some installations produce the Ca(OH)2 for the FGC system on site by slaking of CaO. Effective lime preparation can be critical to good operation, as can be controlling the risk of fouling in the injection device. The injectors have to be located and designed such that they can be easily maintained and/or replaced for cleaning. [ 74, TWG 2004 ]
部分烟气净化系统通过在现场增设装置,用CaO熟化制备Ca(OH)2。有效的石灰制备对良好的运行是非常重要的,也可以有效控制喷射装置的堵塞风险。喷射器的位置和设计必须使其易于维护和/或更换以便清理。
Bag filters require close monitoring and management to address bag damage and consequent releases. Differential pressure monitors are commonly used to indicate bag damage and monitor operation in general.
布袋除尘器需要密切的监测和管理,以便解决布袋破损和随后的粉尘超标。压差监测仪通常用于指示破袋和监测操作。
Temperature requirements are critical. Care is required to ensure dew point corrosion in the bag filter is avoided – inlet gas temperatures of above 130–140 °C are usually used. At temperatures below 130 °C there may be problems due to the hygroscopic nature of the CaCl2 formed. Reagents usually require a specific temperature for optimal reaction conditions.
运行温度是非常关键的。需要关注避开滤袋的露点腐蚀—除尘器入口烟气温度通常要高于130-140度。如果温度低于130度就会出现吸湿性的CaCl2。(二水,四水氯化钠?参见一下Niro的培训手册)吸收剂通常需要一个特殊的温度来达到最佳反应条件。
It is reported that there may be operational problems when semi-wet FGC systems are used with very highly acidic polluted raw gases as this can lead to an increased risk of filter clogging.
报告称当入口原烟气中酸性污染物浓度非常高时,半干法烟气净化系统使用会遇到很多操作问题,这将导致布袋糊袋的风险增加。
The operational complexity of reactors and bag filters used in semi-dry systems can itself be decreased further by the use of a degree of pre-dedusting, e.g. use of a single-stage ESP, or by using non-sticky bag materials (see also Section 2.5.3.5). This avoids the problems of:
通过设置一些预除尘,半干法系统中的吸收塔和布袋除尘的操作难度会有所降低,如:使用一级电除尘,或使用防粘材料的布袋(详见2.5.3.5章节)。这可以避免如下问题:
• sticking of some zinc (and similar salts with low melting temperatures); and
部分锌的粘念(和类似的低熔点盐类);和
•hygroscopic salts forming sticky layers on the surface of the reactor. [ 64, TWG 2003 ]
在反应器表面形成粘性层的吸湿盐。
Cross-media effects
4.5.3.2.5 跨介质影响(增加的能源消耗或其他影响)
Cross-media effects are identified in the following table.
跨介质影响在下表中显示。
Table 4.23: Cross-media effects associated with the use of semi-wet acid gas treatment
Table 4.23: 使用半干法脱酸工艺的跨介质影响
For this technique, the most significant cross-media effect is higher residue production rates than for wet systems.
该技术的最主要的跨介质影响是会比湿法产生更多的副产物。
Separate collection of fly ash is possible if this system is preceded by an ESP. This then increases separation of fly ash and FGC residues, which can be beneficial if separate treatment/recycling options exist for these residues.
如果该系统前置了一个静电除尘器,那么飞灰可以单独进行收集。这就促进了飞灰和烟气净化系统副产物的分离,从而使得副产物的循环利用和分离处理的实现获得更多益处。
The semi-wet FGC system is often applied as a single-stage multi-reactor. Such systems usually have lower energy requirements than more complex multistage FGC systems.
该半干法系统通常作为一个单级多用途反应器使用。这类系统的能耗通常低于哪些多级复杂的烟气净化系统。
Technical considerations relevant to applicability
4.5.3.2.6 技术适用性的考虑
The technique is generally applicable.
该技术普遍适用。
Due to the outlet temperature (120–170 °C), the flue-gas may need to be reheated for some subsequent FGC systems, e.g. SCR.
由于其出口温度(120-170度),为了下游烟气净化系统(如:SCR系统)的需要,其烟气需要进行再加热。
Economics
4.5.3.2.7 经济因素
Capital cost information for the technique is shown in the table below.
该技术的投资成本如下表所示。
Table 4.24: Estimated investment costs of selected components of typical semi-wet FGC systems
Table 4.24: 典型的半干法烟气净化系统的选定部件投资成本估算
Key operational factors of this technique are:
该技术的关键操作点是:
•investment costs are lower than for wet FGC systems, especially for relatively small capacities [ 2, InfoMil 2002 ]; possible higher cost of disposal of the higher quantity of residues produced (than wet systems);
投资成本低于湿法烟气净化系统,对规模较小的焚烧厂而言更甚;副产物的量和处置成本相对较高(与湿法系统对比而言);
•reduced labour cost (compared to wet systems) due to the lower complexity, particularly because it avoids the costs of operating an effluent treatment plant;
由于复杂性相对较低,人员成本会减少(与湿法系统对比而言),特别是因为半干法系统避免了废水处理岛的运行成本。
•increased alkaline reagent cost due to higher stoichiometric ratios.
由于半干法需要更高的化学计量比,其碱性吸收剂的成本较高;
Driving force for implementation
4.5.3.2.8 实施动力(该技术的优势)
•Capability to deal with moderate and moderately variable inlet flue-gas loads.
适用于中等和中等波动的入口烟气负荷(个人理解包括:污染物浓度和烟气量波动)。
•No production of effluent.
无废水排放。
•Lower investment cost than for a wet scrubber.
比湿法洗涤塔投资要低。
•Water consumption lower than for a wet scrubber.
比湿法洗涤塔的水耗要低。
•Lower plume visibility than with wet systems. [ 64, TWG 2003 ]
比湿法洗涤的有色烟羽的程度要轻。
Example plants
4.5.3.2.9 工厂案例
Widely used in Europe, e.g. the UK, Germany, France and Denmark.
在欧盟广泛使用,如:英国,德国,法国和丹麦。
Reference literature
4.5.3.2.10 参考文献
[1, UBA, 2001] [ 2, InfoMil 2002 ] [3, Austria, 2002] [12, Achternbosch, 2002] [26, RSP 1999], [54, dechefdebien, 2003] [ 64, TWG 2003 ]
4.5.3.3 Dry FGC systems
4.5.3.3 干法烟气净化系统
Description
4.5.3.3.1 说明
This technique is described in Section 2.5.4.
该技术描述详见2.5.4章节。
Technical description
4.5.3.3.2 技术说明
Lime (e.g. hydrated lime, high specific surface area lime) and sodium bicarbonate are commonly used as the alkaline reagents. The addition of activated carbon provides for the reduction by adsorption of mercury and PCDD/F emissions.
石灰(例如:熟石灰,高比表面积石灰)和小苏打是通常使用的碱性吸收剂。通过加入活性炭吸收汞和二噁英/呋喃来实现减排。
Finely ground sodium bicarbonate, when injected into hot gases (above 160 °C), is converted to sodium carbonate of high porosity and hence is effective for acid gas absorption. [59, CEFIC
2002], [7, TWG 2017]- CEWEP-ESWET
研磨小苏打,当喷入到高温烟气(高于160度),转化为高孔隙率的碳酸钠,因此对酸性气体吸收有效。
Achieved environmental benefits
4.5.3.3.3 获得环境效益
With this technique, it is generally not possible to reach the same very low emission levels as with other FGC systems without increasing reagent dosing rates and consequent residue generation. Reagent recycling can reduce these cross-media effects to some degree, but can lead to operational difficulties related to reagent dosing systems.
使用该技术,很难如使用其他烟气净化工艺一样,达到非常低的排放水平,除非靠增加吸收剂给料率和进而副产物排出量也会增加。吸收剂循环可以在一定程度上减少跨介质影响,但是可能导致吸收剂给料系统的操作难度。
Environmental performance and operational data
4.5.3.3.4 排放性能和运行数据
Technical developments have enabled significant improvements over the last decade in the
performance of dry systems.
在过去十年中,技术的发展使干法烟气系统的性能有了显著的改善。
The air emission levels generally achieved by plants fitted with dry FGC are as follows.
安装干法烟气净化系统的工厂排放通常可以达到如下水平。
Table 4.25: Emission levels associated with the use of hydrated lime in dry FGC processes
Table 4.25: 使用消石灰干法烟气净化系统的的排放水平
Table 4.26: Emission levels associated with the use of sodium bicarbonate in dry FGC processes
Table 4.26: 使用小苏打干法烟气净化系统的的排放水平
Table 4.27: Operational data associated with the use of dry FGC
Table 4.27: 使用干法系统的相关运行数据
Dry reagents need to be handled in such a manner as to prevent dust emissions, e.g. emissions from loading silo breather vents.
干式吸收剂的处理应能防止粉尘的排放,如:装载粉仓通气孔的排放。
Some installations produce the Ca(OH)2 for the FGC system on site by slaking of CaO. Effective lime preparation can be critical to good operation, as can be controlling the risk of fouling in the injection device. The injectors have to be located and designed such that they can be easily maintained and/or replaced for cleaning. [ 74, TWG 2004 ], [7, TWG 2017]
一些装置通过现场熟化生石灰来为烟气净化系统制备消石灰。有效的石灰制备是良好运行的关键,也是控制干粉喷射装置堵塞风险的重要原因。喷射装置应该布置和设计在易于维护和/或清理更换。
It is reported that the use of operating temperatures above approximately 210 °C may give rise to a deterioration in the PCDD/F and mercury adsorption performance of injected carbon reagents. [7, TWG 2017]-CEFIC
有报道称,使用高于大约210度的运行温度可能导致活性炭吸附剂对二噁英/呋喃和汞的吸附能力减弱。
Cross-media effects
4.5.3.3.5 跨介质影响(增加的能源消耗或其他影响)
Cross-media effects are identified in the table below.
跨介质影响详见下表。
Table 4.28: Cross-media effects associated with the use of dry FGC
Table 4.28: 与使用干法烟气净化系统有关的跨介质影响
The most significant cross-media effect of this technique is the production of solid residues, which, all other parameters being equal, is generally greater than with wet systems. The excess may be reduced somewhat by residue recirculation.
该技术最显著的跨介质影响就是副产物的量,在边界条件相当的情况下,通常其副产物量是大约湿法系统的。当使用物料循环系统,副产物可能会减少。
With sodium bicarbonate, the solid residues are more soluble than with hydrated lime, but significantly lower in quantity. Residues from bicarbonate systems, if separated from the fly ashes, may be treated and recycled in the chemical industry (established practice in France and Italy). [ 74, TWG 2004 ], [7, TWG 2017]-CEFIC
在使用小苏打时,副产物比使用消石灰时更容易溶解,但是排放量明显减少。来自碳酸氢盐的副产物如果跟飞灰相分离后,还可以在化学工业中进行处理和回收(在法国和意大利有投产案例)。
Technical considerations relevant to applicability
4.5.3.3.6 技术适用性的考虑
The technique is generally applicable.
该技术普遍适用。
Economics
4.5.3.3.7 经济因素
Capital cost and system design considerations:
投资成本和系统设计需要考虑的因素:
•Lower capital costs than for semi-wet systems.
比半干法的投资成本更低。
•Higher possible operating temperatures can lead to savings for flue-gas reheating, e.g. for
SCR.
可以使用更高的运行温度从而降低了烟气再热的运行成本,如:下游要使用的SCR。
•Reagent slurry handling/mixing unit not required with dry systems.
干法烟气系统不需要吸收剂浆液制备系统。
Operating cost considerations relative to other techniques:
与其他烟气技术相比运行成本要考虑的因素:
• increased reagent consumption rates, compared to wet FGC;
与湿法烟气净化系统相比,增加了吸收剂的消耗率;
• increased disposal costs for residues, compared to other FGC systems;
与其他烟气净化系统相比,增加了副产物的处置成本;
• savings for treatment/disposal because of lack of effluent.
由于没有废水,省下了废水的处理和处置的成本。
Driving force for implementation
4.5.3.3.8 实施动力(该技术的优势)
The simplicity of such systems is the main reason for their use.
该技术简单是使用它的主要原因。
The lower energy consumption compared to other FGC options, and the lower possible boiler outlet temperatures allowed by the absence of a temperature drop in dry FGC, also make these systems attractive from the point of view of energy recovery.
与其他烟气净化系统技术相比,更低的能源消耗(电耗),可以适用更低的锅炉出口排烟温度因为干法烟气净化系统不需要温降段,从能源回收角度来讲使得该技术更具吸引力。
Restrictions on water supply and outlets make the use of dry FGC systems favourable. When water discharges are forbidden, dry (and semi-dry) systems are favoured.
对供水限制和限制排放废水的情况下,使用干法烟气净化工艺更为有利。在废水零排放时,干法(和半干法)工艺是最佳选择。
Dry systems provide further advantages where a visible plume has to be avoided.
采用干法系统还更有助于那些要求避免出现烟羽的地方。
Example plants
4.5.3.3.9 工厂案例
The technique is widely used throughout Europe. Over 240 plants are operating in more than 10
European countries, and Japan and the US.
该技术在欧洲广泛应用。在超过10个欧洲国家,日本和美国有240做焚烧厂采用了该技术。
There are examples of merchant HWIs using dry systems in France and Germany.
在法国和德国还有一些商业危险废弃物焚烧厂使用干法烟气净化系统的案例。
Reference literature
4.5.3.3.10 参考文献
[ 59, CEFIC 2002 ], [ 2, InfoMil 2002 ], [ 64, TWG 2003 ]
4.5.3.4 Addition of wet scrubbing as a flue-gas polishing system after other FGC techniques
4.5.3.4 在其他烟气净化技术末端增加湿式洗涤塔作为抛光系统
Description
4.5.3.4.1 说明
It is possible to consider that the addition of a final wet flue-gas treatment system, or flue-gas condensation, is a polishing treatment after other systems that deal with acid gases, etc. This
addition is generally made to control HCl and SO2 emissions where they are high or variable. [
74, TWG 2004 ]
可以认为,在其他系统之后追加一道湿法洗涤的烟气净化系统或者烟气冷凝系统,是一种处理酸性气体等的抛光处理方式(精细化处理)。这个额外装置通常可以用来处理入口浓度较高或者波动较大的HCL和SO2的。
Technical description
4.5.3.4.2 技术说明
Flue-gas polishing is typically performed in packed bed wet scrubbers. A usual feature of wet
scrubbing in the polishing position is that HCl, SO2, HF and possibly mercury can be removed in one common stage rather than in two separate stages. NaOH can be added to improve the removal of SO2 and HF. The process water may be injected into the furnace or into the upstream dry flue-gas cleaning system for waste-water-free operation. Energy recovery by condensation can be integrated into the system, and the occurrence of wet plume can be avoided by reheating the flue-gas by the addition of a steam heater or by a gas-gas heat exchanger without the need for an additional energy supply.
烟气抛光处理(高效脱除)通常是在填料塔中完成的。一个典型的特征是,当湿法洗涤在抛光处理的时候,HCL,SO2,HF以及可能的汞是在同一级塔中完成去除的,而不是在分开的二级塔中分别完成的。加入NaOH可以提高SO2和HF的去除率。废水可以喷入炉膛或在上游的干法烟气净化段,从而实现不需要废水的排放。从冷凝段回收的能源可以继续返回系统使用,通过使用蒸汽加热器或气气换热器再热(低温)烟气可以避免湿烟羽的出现,而不需要额外的能源消耗。(冷凝回收的热量够平衡这个烟气再热吗?没算过。)
Achieved environmental benefits
4.5.3.4.3 获得环境效益
Increased reliability in acid gas (HCl, HF, SO2) emission reductions down to levels at the lower end of the ranges achievable with wet scrubbing (see Section 4.5.3.1).
增加了酸性气体(HCL,HF,SO2)减排的可靠性,能达到使用湿法洗涤所能达到的最低限度。(详见4.5.3.1章节)
The consumption of sorbent and the related production of residues in the upstream dry system may be decreased due to the high efficiency and low stoichiometric factor of the polishing scrubber.
吸收剂的消耗量和上游干法脱酸系统中的副产物可以减少,因为抛光洗涤塔的高效脱除能力和较低的化学计量比(钙酸比,钠酸比等等)。
Environmental performance and operational data
4.5.3.4.4 排放性能和运行数据
See Section 4.5.3.1.
详见4.5.3.1。
Cross-media effects
4.5.3.4.5 跨介质影响(增加的能源消耗或其他影响)
See Section 4.5.3.1.
详见4.5.3.1。
Technical considerations relevant to applicability
4.5.3.4.6 技术适用性的考虑
See Section 4.5.3.1.
详见4.5.3.1。
Economics
4.5.3.4.7 经济因素
The typical investment cost reported for a scrubber sized for treating a 100 000 Nm3/h gas flow is EUR 2 million including circulation pumps. An additional investment of around EUR 100 000 may also be required for a reheater or fiberglass-reinforced plastic stack pipe.
报告称处理100000Nm3/h烟气量的湿法洗涤塔的典型投资成本在200万欧元,包括了循环泵。再加热器或玻璃钢烟囱再需10万欧元的额外投资。
Operating costs have been reported as EUR 10–15/h for electricity (additional fan pressure drop of typically 1 200 Pa) and circulation pump operation. The NaOH cost depends on the design.
报告称运行成本为10-15欧元/小时,用于电耗(额外的引风机压损通常为1200pa)和循环泵的运行。NaOH的运行成本基于设计情况。
See also Section 4.5.3.1.
详见4.5.3.1。
Driving force for implementation
4.5.3.4.8 实施动力(该技术的优势)
See Section 4.5.3.1 for the driving forces for the use of wet FGC in general.
详见4.5.3.1章节的湿法烟气净化的动因。
Where emissions of acid gases are high or variable, the addition of a polishing stage may be driven by legislation requiring improved flue-gas cleaning related to peak concentrations of pollutants. The technique is thus most suited to wastes that have high and variable concentrations of chlorine or other acid-forming components (e.g. hazardous wastes or MW that includes industrial wastes).
当酸性气体的入口浓度高且波动较大时,可以通过立法增加抛光(湿法)段来改善烟气净化应对峰值浓度的污染物。因此,该技术非常适合处理哪些具有高入口浓度且波动较大的含有氯化物或其他酸性化合物的垃圾(如:危险废弃物或包括工业废弃物的市政垃圾)。
The addition of a polishing stage may also be driven by savings in reagent costs in the upstream dry flue-gas cleaning system.
节约上游干法烟气净化系统的吸收剂运行成本也是增加抛光(湿法)段的动因之一。
Example plants
4.5.3.4.9 工厂案例
Many plants in Scandinavia and WTE ACCAM Busto Arsizio (IT) (IT01); Usine de Fort-De-
France (FR) (FR46); Halluin (FR) (FR92).
斯堪的纳维亚的很多焚烧厂(包含挪威、瑞典和丹麦)和意大利的ACCAM Busto Arsizio焚烧厂;法国Usine de Fort-De-France焚烧厂;法国Halluin焚烧厂;
Reference literature
4.5.3.4.10 参考文献
[ 64, TWG 2003 ], [ 97, Denmark et al. 2015 ]
4.5.3.5 Recirculation of FGC residues in the FGC system
4.5.3.5 物料循环流化烟气净化系统
Description
4.5.3.5.1 说明
Residues collected in the bag filters used for dry, semi-wet and similar (but not wet) FGC
systems (see also Sections 4.5.3.2, 4.5.3.3 and 4.5.3.8) usually contain a significant proportion of unreacted flue-gas treatment reagents, as well as the fly ash and other pollutants removed from the gas stream. A proportion of the accumulated residues can be reactivated and recirculated within the FGC system.
从干法,半干法或类似烟气净化系统(除了湿法)中布袋除尘收集下来的副产物(详见4.5.3.2,4.5.3.3.和4.5.3.8章节)通常包括了比例较高的未与烟气反应的吸收剂,以及从烟气中去除的飞灰和其他的污染物。一部分副产物可以通过烟气净化系统的再循环系统进行反应。
Technical description
4.5.3.5.2 技术说明
Because of the recirculation, the size of the FGC is generally increased to accommodate the
additional volume of recirculating material.
由于再循环,烟气净化系统的选型尺寸通常会放大以满足再循环物料的增量。(如:CFB烟气工艺我们的过滤风速通常会略低)
The technique is particularly beneficial in the case of techniques that operate with a higher stoichiometric excess, and less relevant for the more efficient once-through system in which little unreacted reagent remains without recirculation. Analyses of the FGC residues may be carried out to determine the proportions of reacted and unreacted reagent.
再循环技术对那些本身化学计量比特别高的烟气工艺特别有效,但是对那些单次通过就具有很高反应效率的技术没有作用,因为那类工艺下几乎没什么未反应的吸收剂还残留。(如:湿法洗涤工艺,对于钠碱法是否有需要还不清楚工程反馈数据,今后有纯小苏打干法项目可以试试副产物的成分化验。)可以对烟气净化系统的副产物取样分析以便确定反应完的和未反应完的吸收剂的比例。
The reactivation of unreacted reagents before reuse in the FGC process may take place by:
对未反应的吸收剂在烟气净化系统中在使用前的再活化可以通过以下方式进行:
• water addition and high residue recirculation rates;
通过加水和将副产物的循环倍率调到高倍率;
• low-pressure steam addition and medium residue recirculation rates;
通过加入低压蒸汽并将副产物的循环倍率调到中等倍率;
• maturation of unreacted reagents and fly ash before recirculation into the FGC process.
未反应完的吸收剂和飞灰在循环回烟气净化系统前进行熟化。(熟化是加水吗?不太确定)
Achieved environmental benefits
4.5.3.5.3 获得环境效益
The recirculation of reagents within the system, combined with water/low-pressure steam addition or maturation, has the following advantages:
在系统内的吸收剂再循环,与水/低压蒸汽或熟化相结合,具有以下优势:
• reduced reagent consumption (compared to dry and semi-wet systems);
减少吸收剂的消耗量(与干法和半干法系统相比);
• reduced solid residue production (contains less unreacted reagent);
减少固体副产物的产量(因为包含了更少的未反应的吸收剂);
• improved control of acid gas peaks (the recirculation results in a higher reagent buffer).
提高了对峰值酸性污染物排放的控制(物料循环导致了一个更高的吸收剂缓冲,也就是提高了与酸性气体的接触概率)。
These techniques are reported to be able to cope with the inlet concentrations associated with most waste types, including variable inlet concentrations that may arise for instance when incinerating merchant hazardous wastes.
据报道,这些技术能够处理大部分污染物类型的入口浓度,包括在焚烧商业危险废弃物时可能出现的波动较大的入口污染物浓度。
Environmental performance and operational data
4.5.3.5.4 排放性能和运行数据
Table 4.29: Operational data associated with the use of residue recirculation
Table 4.29: 使用再循环系统相关的运行数据
Reagent injection and residue bleed rates require optimisation to prevent adsorbent loading and eventual substance breakthrough (e.g. mercury and PCDD/F adsorbed on carbon).
吸收剂喷入和副产物排除的速率需要优化,以防止吸收剂的吸附能力过载和最终物质突破(个人理解是吸附饱和,进而超标)(例如:汞和二噁英/呋喃在活性炭上吸附)
Moisture levels require monitoring and control to maintain the acid gas adsorption efficiency. Upstream HCl and SO2 monitoring is used to optimise alkaline reagent/water/low-pressure steam dose rates.
烟气湿度水平需要进行检测和控制以便控制酸性气体的吸收效率。上游的HCL和SO2监测可以用于优化碱性吸收剂/水/低压蒸汽的给料率。
Some parts of the FGC system volume must be larger to incorporate the additionally recirculated material.
烟气净化系统的部分设备选型必须放大以便适应额外的循环物料。(如:布袋除尘器的选型。)
The reduction of emissions to air and emission levels achieved with these processes in combination with a bag filter and addition of reagent, are as follows.
将物料循环工艺与布袋除尘器和添加吸收剂相结合,可以减少空气污染物排放和降低排放水平,具体如下:
Table 4.30: Emission levels associated with the use of intermediate systems
Table 4.30: 使用中间系统的排放水平
Cross-media effects
4.5.3.5.5 跨介质影响(增加的能源消耗或其他影响)
This technique enables the reduction of the amount of solid residues produced, as it is lower than without recirculation.
该技术可以减少固体副产物的产生量,它比没有物料循环的排放量要低。
The reported reagent stoichiometry is in the range 1.5–2.5 depending on the implemented technology. A better stoichiometric ratio is achieved with low-pressure steam than with water addition or maturation.
据报告称该技术的吸收剂的化学计量比(钙酸比,钠酸比)范围在1.5-2.5,具体取决于所采用的技术(是指基于干法的物料循环,还是半干法的物料循环,个人理解半干法的物料循环化学计量比肯定更低)。通过加入低压蒸汽会获得比加水或熟化更好的化学计量比。
Water/low-pressure steam consumption depends on the inlet flue-gas temperature.
水/低压蒸汽的消耗量取决于入口的烟气温度。
Plume visibility is very low due to the minimal amount of water/low-pressure steam used for conditioning.
由于用于调节的水/低压蒸汽量最小,烟羽的可见度非常低。
In some cases, increases in mercury releases have been reported. Consideration of the mercury input rates and the provision of sufficient mecury removal may therefore be required to control this.
在有些案例中,有报告称采用物料循环后汞的排放量有所升高。因此需要控制和考虑汞的入口浓度和提供足够的汞的脱除能力。
Technical considerations relevant to applicability
4.5.3.5.6 技术适用性的考虑
The technique is generally applicable in combination with FGC systems other than wet systems.
该技术通常可应用于除湿法系统以外的其他烟气净化系统(如:干法,半干法)。
The recirculation of FGC residues requires a larger bag filter and additional space to accommodate the recirculation/reactivation/maturation equipment.
烟气净化系统物料再循环工艺需要一个选型较大的布袋除尘器和额外的空间来容纳再循环/再活化/熟化等设备。(活化设备是个啥?阿尔斯通的增湿活化器?有可能)
Economics
4.5.3.5.7 经济因素
Capital costs are reported to be somewhat lower than for wet and semi-wet systems due to the
reduced number of process components and consequently the smaller footprint, but slightly higher than for dry FGC without recirculation.
报告称,投资成本低于湿法和半干法系统,因为减少了工艺设备,因此占地面积也减少,但是投资比没有物料循环系统的干法烟气净化系统要稍微高些。
Operating costs, compared with dry FGC without recirculation, are reduced by the lower reagent consumption (improved stoichiometric ratio compared with dry systems) and the reduced residue disposal costs.
运行成本与没有物料循环系统的干法系统相比则更低,因为吸收剂消耗量减少(与干法系统相比改进了化学计量比,更低)和副产物处置成本降低。
Driving force for implementation
4.5.3.5.8 实施动力(该技术的优势)
• Reduction of reagent consumption.
吸收剂消耗量减少。
• Reduction of residue production.
副产物产量减少。
• Limited space requirements.
需要的占地共空间较少。
• Limited process complexity.
工艺复杂程度相对较低。(对于物料循环干法工艺而言我不认为负责程度低。)
Example plants
4.5.3.5.9 工厂案例
Existing plants incinerating MSW, RDF and wood wastes in France, the UK, Italy, Sweden, Norway, Germany, Denmark and Spain.
在法国,英国,意大利,瑞典,挪威,德国,丹麦,西班牙的现有生活垃圾,RDF(垃圾衍生燃料)和木材废料焚烧厂。
Reference literature
4.5.3.5.10 参考文献
[ 57, Alstom 2003 ], [ 64, TWG 2003 ], [7, TWG 2017]-CEWEP-ESWET
4.5.3.6 Direct addition of alkaline reagents to the waste (direct desulphurisation)
4.5.3.6 垃圾直接添碱工艺(直接脱硫工艺,流化床)
Description
4.5.3.6.1 说明
This technique is described in Section 2.5.4.4. It is generally only applied to fluidised bed furnaces.
该技术在2.5.4.4章节中描述。它通常适用于流化床焚烧炉。
The alkaline reagent reacts in the furnace with acid gases to reduce the acid loads in the raw flue-gas passing to subsequent flue-gas cleaning stages.
碱性吸收剂在熔炉里面和酸性气体反应,减少了烟气下游烟气净化段中原烟气的酸性负荷。(即减少了原烟气中的原始排放浓度)
Technical description
4.5.3.6.2 技术说明
Adsorption within the furnace at high temperatures is much more effective for SO2 than for HCl; the main applications are therefore processes with a relatively high SO2 content, e.g. sludge incineration.
[ 74, TWG 2004 ]
在炉内高温情况下,SO2的脱除效率要比HCL高;因此,主要适用于SO2含量相对较高的工艺,如:污泥焚烧。
Achieved environmental benefits
4.5.3.6.3 获得环境效益
Benefits include some reduction of raw gas loads and the reduction of emissions and reagent
consumption associated with the downstream FGC system.
该工艺获得的效益来自于原烟气中的污染物浓度减少导致的下游烟气净化设备的吸收剂消耗减少和污染物排放减少。
Environmental performance and operational data
4.5.3.6.4 排放性能和运行数据
The main advantage of this technique is that it may reduce corrosion problems in the boiler. As
the stoichiometric ratio is relatively high, it does not improve the overall FGC performance. [64, TWG 2003 ]
该技术的额主要优点在于它可以技术那好锅炉的腐蚀问题。因为其化学计量比相当高,所以它不会改善烟气净化系统的整体性能。(我理解是烟气出来的残余钙会进入下游烟气净化系统,导致下游烟气系统不缺钙,性能不会有啥变化和改善。也就是指下游烟气净化系统没什么潜力再可挖了。)
Cross-media effects
4.5.3.6.5 跨介质影响(增加的能源消耗或其他影响)
For this technique, the most significant cross-media effects are:
该技术,最重要的跨介质影响是:
• consumption of reagents in the furnace (but reduced consumption downstream);
炉内吸收剂的消耗量(但是减少了下游烟气设备的吸收剂消耗量);
• effects on the bottom ash quality since salts and the excess reagent are mixed with it;
由于炉内脱酸产生的副产物盐和过量的吸收剂,会混入锅炉底灰;
•changing the composition of the flue-gas (SO2 to HCl ratio) can affect the performance of downstream FGC systems, can alter the PCDD/F profile and can cause corrosion problems in the FGC.
改变了烟气组分(SO2和HCL的比例关系)会影响下游烟气净化系统的运行性能,也会改变二噁英/呋喃的属性和导致烟气净化系统中的腐蚀。(是否是Niro培训是提到的Sox和HCL的比例关系对脱硫效率的影响。详见:4.5.3.7.4,HCL的脱除率可能很低。)
The addition of hydrated lime will not only affect the bottom ash quality, but also the composition and resistivity of the fly ash (i.e. there will be more Ca and more sulphurous compounds and higher dilution of pollutants with an increasing amount of FGC residues). [ 64, TWG 2003 ]
加入消石灰不仅会影响锅炉底灰的品质,也会影响飞灰的组分和电阻率(即烟气净化系统会有更多含钙和更多含硫化合物和更高稀释度污染物的副产物产生)。
Technical considerations relevant to applicability
4.5.3.6.6 技术适用性的考虑
The technique is generally applicable to fluidised bed systems.
该技术通常适用于循环流化床锅炉系统。
Economics
4.5.3.6.7 经济因素
The reduced flue-gas treatment costs need to be considered against the costs of adding the
reagent at the earlier stage.
减少烟气处理的成本需要与上游添加(直接在垃圾中添加)吸收剂的成本相比较。
There are additional capital costs for the provision of reagent injection into the furnace/waste.
提供吸收剂喷入炉膛/垃圾,会产生额外的资金成本。
Driving force for implementation
4.5.3.6.8 实施动力(该技术的优势)
The technique is implemented as a retrofit at existing plants where there is only a limited possibility to increase the acid gas cleaning capacity of the FGC systems.
该技术通常适用于老厂改造,且该厂的烟气净化系统的脱酸能力增加的可能很有限。(个人理解老厂技改没空间,没资金之类的情况下,用用这种工艺。)
Example plants
4.5.3.6.9 工厂案例
SOGAMA, Cerceda (ES) (ES07.1/ES07.2); Area Impianti Bergamo (IT) (IT07); SNB, Moerdijk (NL) (NL06).
索加马,塞尔塞达(西班牙,后面也是用半干法工艺的,且看了一下好像是炉排,不知道是不是后来改造过)(焚烧厂相关参考信息:
https://pdfs.semanticscholar.org/b01c/d2f354d3bfaba74e2e8669ccc35934b73a3f.pdf
https://www.industryabout.com/country-territories-3/2160-galiza/waste-to-energy/33779-sogama-cerceda-incineration-plant
https://ec.europa.eu/regional_policy/sources/docgener/evaluation/pdf/projects/sogama_galicia.pdf );
Impianti Bergamo地区(意大利);
SNB, Moerdijk(荷兰)。
Reference literature
4.5.3.6.10 参考文献
[ 1, UBA 2001 ], [ 64, TWG 2003 ]
4.5.3.7 Boiler injection of alkaline reagents (high-temperature injection)
4.5.3.7 炉内喷碱工艺(高温喷射工艺,炉排和回转窑)
Description
4.5.3.7.1 说明
Direct injection of dedicated reagents into the boiler at high temperature, in the boiler post-
combustion area, to achieve partial abatement of the acid gases. Hydrated lime and dolime have been used as reagents.
直接向锅炉的燃烧后区域,在很高的下喷入专用吸收剂,实现酸性气体的部分脱除。消石灰和白云质生石灰(MgO·CaO)通常被用作吸收剂。
Technical description
4.5.3.7.2 技术说明
In this technique, the hydrated lime reagent is injected and reacts with the acid gases directly in
the furnace, at optimal temperatures of 800–1 200 ºC, to reduce the raw gas acid loads passing to subsequent flue-gas cleaning stages. Since adsorption at high temperatures is highly efficient
for SOX and HF removal, this reaction consumes significantly less reagent compared to achieving an equal removal rate at a lower temperature at the stage of the bag filter. The technique also flattens pollutant peaks, allowing the further reduction of reagent use in the
downstream flue-gas cleaning unit.
该技术,在800-1200度的最佳反应温度下,在炉内喷入消石灰吸收剂和烟气中的酸性气体直接反应,从而减少下游烟气净化段中烟气的酸性污染物负荷。因为对Sox和HF而言,高温吸附的效率是很高的,在同样的去除率下,其(高温段)吸收剂消耗量与布袋除尘器低温段的消耗量相比要明显减少。该技术还有助于解决峰值超标的问题,并可以减少下游烟气净化设备的吸收剂消耗。
Achieved environmental benefits
4.5.3.7.3 获得环境效益
Benefits are reduction of raw gas loads and reduction of acid gas peaks, and reduction of emissions and reagent consumption in the downstream flue-gas cleaning unit.
其好处在于减少了原烟气的酸性负荷和酸性烟气的峰值,减少了下游烟气净化设备中酸性气体的排放值和吸收剂消耗量。
Environmental performance and operational data
4.5.3.7.4 排放性能和运行数据
The reduction of SO2, SO3 and HF by 80–96 % and of HCl by 25–30 % (at the exit of the boiler) is reported with an injection rate of 3–8 kg hydrated lime per tonne of waste.
有报告称,对每吨垃圾喷入3-8公斤的消石灰,其脱除SO2,SO3和HF的效率可达80-96%,对HCL脱除效率为25-30%(在锅炉出口处的效率)。
Cross-media effects
4.5.3.7.5 跨介质影响(增加的能源消耗或其他影响)
Since an overall reduction in the use of reagents in the combined in-boiler and downstream flue-
gas cleaning systems is reported, no cross-media effects are expected.
据报告称,因为在锅炉和下游烟气净化系统中使用试剂的总体减少,预计不会产生跨介质影响。
Technical considerations relevant to applicability
4.5.3.7.6 技术适用性的考虑
The technique is generally applicable to grate and rotary kiln plants.
该技术通常适用于炉排和回转窑焚烧厂。
Economics
4.5.3.7.7 经济因素
Investment costs are reported to be in the range of EUR 100 000–300 000.
据报告称,该工艺设备的投资成本范围在10-30万欧元。
Operating costs, including maintenance and energy costs for the conveying system and reagent costs for for boiler injection, are EUR 0.4–2.20 per tonne of waste.
运行成本,包括维护,输送系统的能源消耗以及喷入锅炉的吸收剂成本(为何没考虑燃烧热量损失的成本?),是0.4-2.2欧元/吨垃圾。
Avoided operating costs in the case of downstream NaHCO3 sorbent injection are EUR 0.72–
2.04 per tonne of waste.
选择下游烟气净化系统使用小苏打作为吸收剂的成本是0.72-2.04欧元/吨垃圾。(上面的成本应该是都用消石灰)
Driving force for implementation
4.5.3.7.8 实施动力(该技术的优势)
• Allowance of increased input loads of acidic pollutants in the waste.
可以焚烧酸性污染物含量更高的废弃物。
• Reduction of boiler maintenance downtime.
减少锅炉维护停机时间。(减少检修频次)
• Reduction of the occurrence of acid gas emission peaks.
减少烟气中酸性污染峰值出现的概率。
• Increase of the reliability of the FGC system by adding an additional step.
增加了一个额外的步骤提高了烟气净化系统的可靠性。
•As a retrofit, the technique can provide a simple upgrade of the existing FGC unit to increase the removal rate of acidic pollutants while keeping the reagent dosage rate moderate.
作为一种技改手段,该技术可以对现有烟气净化设备提供一个简单的升级从而增加了酸性污染物的去除率,且仍可以保持吸收剂的给料量维持在中等水平。(也就是不以增加吸收剂消耗量为代价)
Example plants
4.5.3.7.9 工厂案例
ACSM S.p.A., Como (IT) (IT02); AMSA S.p.A. Milano (IT); REA Dalmine (IT) (IT10.1/IT10.2); Silea S.p.A, Valmadrera (IT) (IT11); Tecnoborgo S.p.A., Piacenza (IT) (IT12);
ACSM S.p.A., Como(意大利);AMSA S.p.A. Milano(意大利);REA Dalmine(意大利);Silea S.p.A, Valmadrera(意大利);Tecnoborgo S.p.A., Piacenza(意大利)
Ambiente 2000 Trezzo Adda (IT); Brianza Energia Ambiente-Desio (IT) (IT03); AEM Gestioni
Cremona (IT); ACCAM S.p.A., Busto Arsizio (IT) (IT01); Ecolombardia 4 Filago (IT); Schwandorf MWI (DE); Heringen RDF plant (DE) (DE50).
Ambiente 2000 Trezzo Adda(意大利 http://termotrezzo.it/ 看了一下它的排放还行);Brianza Energia Ambiente-Desio(意大利);AEM Gestioni
Cremona(意大利);ACCAM S.p.A., Busto Arsizio(意大利);Ecolombardia 4 Filago(意大利);Schwandorf 生活垃圾焚烧厂(德国);Heringen RDF 工厂(德国)。
Reference literature
4.5.3.7.10 参考文献
[ 99, EuLA 2015 ]
4.5.3.8 Combination of semi-wet absorber and dry injection system
4.5.3.8 半干法+干粉喷射系统
Description
4.5.3.8.1 说明
Combination of a semi-wet process (generally SDA) and of dry sorbent injection (DSI). The
technique is also known as the three-quarters dry system.
半干法工艺(通常为SDA)和干法吸收剂直喷工艺(DSI)相结合。该技术也被称之为四分之三干法系统。
Technical description
4.5.3.8.2 技术说明
The technique consists of the injection of a dry reagent (DSI) upstream or downstream of the semi-wet reactor.
该技术包括在半干法的上游(吸收塔入口)和下游(吸收塔出口,中国多采用这种工艺)喷射干式吸收剂(DSI)的方式。
The reagent of the DSI can be hydrated lime, high-surface hydrated lime, high-porosity hydrated lime or a blend of hydrated lime and carbonaceous or mineral materials.
干式吸收剂直喷工艺所采用的吸收剂可以是消石灰,高比表面积消石灰,高孔隙率消石灰或是石灰与碳质(矿物材料)的混合物。
The basic principle of operation is to keep the injection of milk of lime in the reactor constant at the optimal design rate to capture most of the pollutant load, while the DSI is used to remove the residual acidic gas load including peaks by means of direct regulation control.
基本操作是以最佳设计速率保持反应器中石灰浆液的注入量保持恒定,以捕获大部分污染物负荷,而干粉喷射则通过直接调节控制来去除残余的烟气中的酸性负荷(包括峰值的酸性污染物)。
Achieved environmental benefits
4.5.3.8.3 获得环境效益
•Reduction of the overall pollutant load released into air compared to a typical semi-wet process.
与典型半干法工艺相比,该工艺可以减少排放到空气中的污染物总量。
•Reduction of the quantity of residues generated thanks to improved stoichiometry compared to reaching the same removal rate with a semi-wet process alone.
与半干法工艺相比,达到同样的去除率,该工艺因为改进(减少)了吸收剂的化学计量比而减少了副产物的产生量。
Environmental performance and operational data
4.5.3.8.4 排放性能和运行数据
Reported removal efficiencies are > 98 % for SO2 and > 99 % for HCl.
报告称该工艺的SO2的去除效率大于98%,HCL的去除率大于99%。
Reported advantages are:
报告称该工艺的优势在于:
•constant operation of the milk of lime preparation;
石灰浆制备系统可以恒定运行;
•fast and accurate response of the DSI to peak pollutant loads;
干粉喷射工艺对峰值污染物负荷出现的反应快速而有效;
•redundancy of equipment for maintenance purposes;
从维护角度而言,多了备用设备;(就是半干法维护时候,还有干法还可以顶一下,有了备用系数)
•reduction of total reagent consumption (at equal acid gas removal rate) compared to the semi-wet process alone.
与单独使用半干法工艺相比(基于相同的酸性气体去除率为前提),减少了吸收剂的消耗总量。
Cross-media effects
4.5.3.8.5 跨介质影响(增加的能源消耗或其他影响)
Since an overall reduction in the use of reagents compared to the use of SDA alone is reported at the same pollutant removal rate, no cross-media effects are expected.
报告称,在相同的污染物去除率下,与单独使用半干法工艺相比其吸收剂使用总量减少了,因此预计没有跨介质影响。
Technical considerations relevant to applicability
4.5.3.8.6 技术适用性的考虑
The technique is applicable to new plants and to existing plants using SDA as the FGC process.
该技术适用于新厂建设和使用SDA半干法烟气净化工艺的老厂改造。
Economics
4.5.3.8.7 经济因素
Investment costs are EUR 100 000–200 000 for a DSI system.
干式吸收及直喷系统的投资成本在10万-20万欧元。
Operating costs, including maintenance and energy costs for the conveying system and reagent costs (1 kg hydrated lime per tonne of waste) for DSI, are EUR 0.17–0.29 per tonne of waste.
运行成本,包括干式吸收剂直喷系统维护成本,输送系统的能源消耗成本,吸收剂成本(吨垃圾1公斤消石灰消耗量),总计为0.17-0.29欧元吨垃圾。
Avoided operating costs by reducing reagent consumption in the SDA unit are EUR 0.33–0.38 per tonne of waste, based on reducing lime consumption from 10 kg to 7.5 kg per tonne of waste.
通过半干法+干法工艺实现比单独使用半干法工艺,从而将石灰消耗量从10公斤/吨垃圾减少到7.5公斤/吨垃圾,这减少半干法系统的吸收剂消耗成本是0.33-0.38欧元/吨垃圾。
Driving force for implementation
4.5.3.8.8 实施动力(该技术的优势)
•As a retrofit, to enable a plant fitted with SDA to further reduce emission levels.
作为技改技术,可以是装有SDA半干法工艺的焚烧厂进一步提高其污染物控制排放水平。
•Allowance of increased input loads of acidic pollutants in the waste.
可以焚烧酸性污染物含量更高的废弃物。
•Savings in operating costs.
省下了运行成本。(应该是吸收剂达到同等脱除率时,总耗量减少。)
Example plants
4.5.3.8.9 工厂案例
Intradel Uvelia-Herstal (BE) (BE04); SNVE, Rouen (FR); BSR, Berlin (DE); IPALLE,
Thumaide (BE); Vattenfall IKW, Ruedersdorf (DE) (DE84); SWB MHKW, Bremen (DE) (DE39); SERTRID Usine de Bourgogne (FR); IBW, Virginal (BE); Amagerforbraending, Copenhagen (DK); Slagelse Forbrændings Anlæg, Slagelse (DK) (DK03).
Intradel Uvelia-Herstal(比利时);SNVE, Rouen(法国);BSR, Berlin(德国);IPALLE,
Thumaide (德国); Vattenfall IKW, Ruedersdorf (德国); SWB MHKW, Bremen (德国); SERTRID Usine de Bourgogne (法国); IBW, Virginal (比利时); Amagerforbraending, Copenhagen (丹麦); Slagelse Forbrændings Anlæg, Slagelse (丹麦).
Reference literature
4.5.3.8.10 参考文献
[ 100, EuLA 2015 ]
4.5.3.9 Use of acid gas monitoring for FGC process optimization
4.5.3.9 酸性气体检测在烟气净化工艺中的优化
Description
4.5.3.9.1 说明
By using fast-response HCl, SO2, and possibly also HF monitoring upstream and/or downstream of dry and semi-wet FGC systems, it is possible to adjust the operation of the FGC system so that the quantity of alkaline reagent used is optimised for the emission set point of the operation.
使用在干法或半干法烟气净化系统的上游和/或下游设置的快速反馈的HCL,SO2以及HF在线监测信号,可以调节烟气净化系统的操作,这样碱性吸收剂的使用量可以根据操作的设置的排放值来进行优化(减少)。
Technical description
4.5.3.9.2 技术说明
The technique is generally applied as an additional method to control peak concentrations, with
the build-up of a layer of reagent on the bag filters also providing an important buffering effect for reagent fluctuations.
该技术通常作为一种控制峰值浓度的辅助方法使用,通过在滤袋表面形成一层滤饼同时当反应剂波动时,提供了一种重要的缓冲作用。
This technique is not relevant to wet scrubbers as the scrubbing medium is water and the supply of water to a wet scrubber is controlled by the evaporation and bleed rates, not by the raw HCl concentration. [ 64, TWG 2003 ]
该技术与湿法洗涤技术无关,因为洗涤的介质是水,给湿法洗涤塔供水是由蒸发和排放的速率所控制的,而不是依据氯化氢的浓度。(即我们湿法领域通常所说的脱硫是靠的水洗涤烟气中的酸性物质,而不是依靠的吸收剂的浓度多少。先用水洗下来,随后再考吸收剂去中和。)
Just preventing HCl breakthrough is not always sufficient to ensure for all FGC systems that enough reagent is available to also provide for SO2 and/or HF control and, therefore, reduce peak emissions. [7, TWG 2017]-EuLA
仅仅防止HCl的峰值超标并不总是足以确保所有烟气净化系统有足够的试剂可用于控制SO2和/或HF,从而减少峰值排放。
Achieved environmental benefits
4.5.3.9.3 获得环境效益
Benefits of the technique are that:
该技术的好处是:
• peak raw gas loads are anticipated and therefore do not result in elevated emissions to air;
原烟气的峰值(通过设置cems反馈)可以被提前得知,因此不会出现相应的超标排放;
• neutralisation reagent consumption can be reduced by matching the demand;
脱酸的中和剂的耗量可以通过匹配需要量来减少。
• the amount of unused reagent in residues is reduced.
副产物中未使用的吸收剂的数量减少。
These environmental benefits are highest where waste quality control at the input to the furnace is limited, and lower where wastes are homogenised and subjected to good-quality control by means of selection, mixing or pretreatment operations.
这些环境效益是最高的,因为入炉的垃圾质量得到了控制,通过分选,混合或预处理操作使得垃圾均质化,从而得到更好的品质管理。
Smaller plants may benefit the most as rogue waste inputs can exert a larger influence on smaller throughput systems.
小型焚烧厂的得益是最大的,因为较小吞吐量的系统对垃圾的品质波动影响最大。
Environmental performance and operational data
4.5.3.9.4 排放性能和运行数据
The response time of the monitor needs to be fast to pass the control signal to the reagent dosing
equipment in time to provide an effective response.
在线监测的反馈速度要求及时快速地把信号传输给吸收剂给料设备,从而提供有效分反馈。
Where the monitors are located upstream of the FGC system, their resistance to corrosion is essential because of the extremely aggressive environment. Fouling can also be a problem.
当在线监测位于烟气净化系统的上游,他们的耐腐蚀性是至关重要的,因为入口区域的环境是非常恶劣的。积灰也是一个问题。
The variation in the absorption capacity in the FGC system can be achieved by:
烟气净化系统中的吸收容量的变化可以通过以下方式实现:
•changing the flow rate using variable speed pumps or variable speed dosing screws;
使用变频泵或可变速给料的螺旋来改变给料量;
•changing the reagent concentration in semi-wet systems – where the mixing tank volume is small enough to ensure an adequate concentration change rate;
改变半干法系统的吸收浆液浓度—制备罐的容量足够小以便确保足够的浓度变化率;(个人理解,因为制备罐太大,导致制备完一次要等很长时间才能用完,会导致调节能力下降。)
•adjusting the ratio of the reagents in FGC systems where multiple reagents or multiple FGC
steps are used.
调整烟气净化系统中的吸收剂剂量,如果有多段烟气净化系统使用的那么调整各种对应的药剂给料量。
Cross-media effects
4.5.3.9.5 跨介质影响(增加的能源消耗或其他影响)
None reported.
没有报道。
Technical considerations relevant to applicability
4.5.3.9.6 技术适用性的考虑
The technique is generally applicable.
这个技术是普遍使用的。
Economics
4.5.3.9.7 经济因素
No information provided.
无信息可提供
Driving force for implementation
4.5.3.9.8 实施动力(该技术的优势)
•As a retrofit at existing plants, to avoid exceeding short-term emission limits.
作为一种现有工厂的改造手段,可以解决短期排放值超标的问题。
•In the design of new plants, to optimise reagent consumption while ensuring compliance with short-term emission requirements.
在新厂设计时,在确保短期排放值(如:小时均值,半小时均值,15分钟均值等)的同时还可以减少吸附剂的耗量。
Example plants
4.5.3.9.9 工厂案例
Applied at incinerators across the EU, e.g.Vitre (FR) (FR002); Cergy, Saint-Ouen L’Aumône
(FR) (FR075); MHKW Bremerhaven, Breme (DE) (DE39); MKVA Krefeld (DE) (DE55.2R); UTE-TEM, Mataró (ES) (ES04); Allington Incinerator (UK) (UK07); Lincoln (UK) (UK12).
适用于全欧盟的的焚烧厂,如:法国Vitre焚烧厂(FR002);法国Cergy焚烧厂(FR075);德国Breme焚烧厂;德国MKVA Krefeld焚烧厂;西班牙UTE-TEM焚烧厂;英国Allington焚烧厂;英国Lincoln焚烧厂;
Reference literature
4.5.3.9.10 参考文献
[ 17, ONYX 2000 ], [ 64, TWG 2003 ]