吸收方式对燃煤电厂模拟烟气碳捕集的影响

采用散堆填料塔研究了循环吸收及单程吸收两种方式对模拟燃煤电厂烟气碳捕集的影响。结果表明循环吸收条件下当贫液中NaOH浓度较高时,CO₂吸收过程主要受气体扩散过程控制,捕集率较高,贫液中NaOH浓度降低至一定值时,CO₂吸收过程逐渐转化为反应速率控制,捕集率迅速降低,吸收液气比为10 L/m³时,贫液中NaOH浓度在1.5 mol/L时CO₂捕集率出现转折点,转折点捕集率为97.2%,吸收剂转化率85.7%,单程吸收条件下液气比7.5 L/m³捕集效果最佳,CO₂捕集率98.4%,吸收剂转化率87.9%。     

基于碳捕集系统半闭式S-CO2布雷顿循环性能分析

针对高温钙基碳捕集技术回收储存过程中未利用CO₂的超临界、流量大等特点的问题,采用半闭式超临界二氧化碳(S-CO₂)布雷顿循环系统取代传统CO₂回收系统,以降低由于碳捕集系统所造成的热量损失。利用Aspen Plus软件搭建耦合钙循环碳捕集的燃气轮机发电模型,在其CO₂回收系统中耦合S-CO₂布雷顿循环系统和跨临界二氧化碳(T-CO₂)布雷顿循环系统,使用精准度更高的REFPROR物性方法研究主压缩机出口压力、透平入口温度、透平入口压力及分流系数对循环系统净做功的影响。结果表明：CO₂回收系统中耦合S-CO₂布雷顿循环系统可以使全厂热效率提升1.7%,全厂■效率为26.98%;采用分流纯净烟气的方法作为S-CO₂布雷顿循环系统的热源,可使同一热源的热效率提升6.7%。     

计及电转气和碳捕集的数据中心微电网“源-荷”低碳优化调度方法

为促进数据中心多能互补以及低碳化,基于随机规划,提出了考虑电转气和碳捕集的数据中心微电网“源-荷”低碳优化调度模型。模型综合考虑了发电约束、数据负荷约束、电转气系统及碳捕集等约束,在发电侧引入碳捕集电厂-电转气-燃气机组(CCPP-P2G-CHP),将捕集的CO₂作为电转气系统合成甲烷的燃料;在负荷侧考虑即时型和可延迟型两种数据负荷,构建了数据中心功耗和数据负荷分配模型。仿真结果表明,所提模型在考虑碳排放的基础上,通过发电和数据中心数据负荷的优化调度,实现了数据中心微电网运行成本的最小化。     

计及碳交易和碳税的碳捕集技术经济性研究

采用经济学成本分析法对集成碳捕集封存技术(CCS)的1 000 MW超超临界燃煤机组进行技术经济性分析,以供电成本、净现值、动态回收期及内部收益率为评价指标,探究了煤炭价格、碳配额交易价格、碳税、通货膨胀率及CO₂售卖价格的影响。结果表明：CCS碳捕集装置建设成本较高,较常规机组总投资增加约24.54%,CCS系统能效惩罚较大,厂用电率增加19.31百分点;常规机组供电成本为0.307 5元/(kW·h),CCS机组的供电成本增加35.87%;CO₂减排成本为171.47元/t; CCS机组净现值为138.06亿元,为常规机组的2.23倍;CCS机组的动态回收期为4.15 a,较常规机组提前1.94 a;综合考虑碳税、碳配额交易及CO₂售卖时,CCS机组的供电成本为0.196 4元/(kW·h),较常规机组低43.17%;在碳交易、碳税政策和CO₂循环再利用市场完善建立后,CCS机组具有更强的盈利能力。     

基于富液分流改进工艺的混合胺法燃煤电厂烟气碳捕集过程模拟研究

  [目的]  工艺流程优化是降低燃煤电厂烟气胺化学吸收法碳捕集过程能耗的重要方法。  [方法]  通过Aspen plus软件模拟研究了MEA吸收剂和混合胺MDEA/PZ吸收剂在三种不同富液分流改进工艺下的烟气二氧化碳捕集性能,分析了贫液负荷和分流比对二氧化碳再生过程热负荷和冷负荷的影响,同时通过浓度驱动力和温度驱动力分析揭示了解吸过程特性。  [结果]  研究结果表明,三种富液分流工艺均能有效降低二氧化碳再生热负荷和冷负荷,其中方案3效果最为显著,因为该方案可获得更为均衡更低的驱动力分布,有效减少了不可逆损失。  [结论]  相比常规MEA碳捕集系统,结合了MDEA/PZ吸收剂和富液分流改进工艺方案3的碳捕集系统再生热负荷和冷负荷可降低35.36%和71.42%,具有较好的应用前景。     

高炉煤气碳捕集对钢铁联合企业碳排放的影响

为了探究高炉煤气碳捕集对钢铁联合企业碳排放的影响,通过建立钢铁联合企业的CO₂排放核算模型,用来计算钢铁产品以及企业的CO₂排放量。最后以高炉煤气CO₂捕集率作为情景假设,计算不同情景下高炉煤气CO₂排放系数及高炉煤气的热值,分析不同情景下钢铁产品以及企业CO₂的减排效果。结果表明捕集率为75%时,高炉煤气的热值提高了17.6%,钢铁联合企业的CO₂减排幅度约为14.5%,钢铁产品中的铁水的碳减排幅度最大,降低了15.33%。高炉煤气的碳捕集可以有效降低钢铁联合企业的CO₂排放,对钢铁联合企业碳中和提供有效的实施路径。     

烟气二氧化碳捕集胺类吸收剂研究进展

  [目的]  胺类化学吸收法是目前燃烧后捕集烟气CO₂最成熟的技术,但存在捕集能耗过高的问题,开发新型吸收剂替代传统MEA吸收剂是降低能耗的重要途径。  [方法]  根据近些年公开文献报道的胺类吸收剂组成,将其分成单一吸收剂、混合胺吸收剂、两相吸收剂和非水吸收剂四类,并对这四类吸收剂的技术特点、研究现状和存在问题进行了介绍。  [结果]  混合胺结合了不同单一胺类的优点,能较好满足高吸收速率,高吸收容量和低能耗的要求;而相变吸收剂和无水吸收剂为新一代吸收剂,潜力巨大,但仍需深入研究改进。  [结论]  相比而言,混合胺型吸收剂更为成熟,短期内进行工业化应用更具优势。     

燃气-超临界CO2联合循环发电系统

  [目的]  燃气轮机排气温度高,可增加底循环,利用排气的余热发电,从而提高燃料总的能量利用率。鉴于超临界CO₂循环热效率高,并且具有系统简单、结构紧凑、运行灵活等潜在优势,可与燃气轮机组成新型的燃气-超临界CO₂联合循环。  [方法]  为了充分利用燃气轮机排气余热,提出在简单回热超临界CO₂循环的基础上,再嵌套一个简单回热循环的布置方式,并以PG9351(FA)型燃气轮机为例,对其热效率进行了计算分析。同时,在系统中增加余热利用装置,可将剩余热量用于供热、转换为冷量或发电。  [结果]  结果表明:对于选定的燃气轮机,超临界CO₂循环最高温度可达约600 ℃,循环发电效率约32%,获得余热温度为170 ℃以上,余热热量占燃气轮机排气热量9%,联合循环发电效率约54%。  [结论]  燃气-超临界CO₂联合循环发电系统具有较高的热效率,并且保留部分较高品位的余热,可进一步用于电厂运行。     

H2O和SO2对钙循环捕集CO2碳酸化过程协同效应的研究

采用自制恒温热重系统研究了H₂O和SO₂对钙循环捕集CO₂的协同效应,并结合吸收剂的孔径进行了机理分析。结果表明：气氛中的H₂O加速了碳酸化快速反应阶段的反应速度,改善了CaO颗粒的孔结构,从而提高了碳酸化转化率;气氛中的SO₂阻碍了CO₂的捕集,使碳酸化转化率下降,且随循环进行碳酸化转化率下降更加明显;当H₂O和SO₂协同作用于碳酸化过程时,钙循环特性受H₂O和SO₂的协同效应影响：加入0.05%体积分数的SO₂后,当H₂O体积分数从0%增加至20%时,吸收剂孔容积逐步上升,CO₂捕集能力得到改善;加入10%体积分数的H₂O后,当SO₂体积分数从0%增加至0.1%时,吸收剂孔隙堵塞更加严重,CO₂捕集能力下降,但是相较于无H_2<...     

二氧化碳捕集技术研究进展

CO₂是造成温室效应的主要气体,如何有效解决CO₂引起的气候问题越来越受到人们的关注。近年来,通过大力发展可再生能源和清洁能源试图从源头上降低碳排放,但由于短期内人类生产生活离不开对能源的消耗,要做到完全脱碳是不现实的。事实上,二氧化碳不仅是一种温室气体,也是一种潜在的碳资源。因此,如何捕集并有效利用CO₂成为业界一直在探索关注的研究方向。通过介绍和分析化学吸收法、多孔固体吸附法、膜分离法、深冷分离法、水合物法和微生物法等各类CO₂捕集技术的研究现状、适用场景和技术发展重点,总结对比不同CO₂捕集方法的优点和局限性,并针对不同技术的未来前景和建议方向进行了展望。以期为CO₂捕集和利用途径提供有益的借鉴和参考,推动CO₂捕集技术实现大规模商业化应用。     

集成小型堆和可再生能源的超临界CO2循环发电系统

  [目的]  小型模块化压水堆(小型堆)核电站由于温度参数低,其发电效率不到30%,为了提高小型堆的核能利用效率,可将小型堆与可再生能源组合,并以先进的超临界CO₂循环作为热能转换为电能的装置。  [方法]  基于简单回热模式的超临界CO₂循环,并在此基础上增加一次间冷和一次再热,将小型堆与太阳能、生物质能热源集成为新型混合发电系统,对其发电效率进行了分析。  [结果]  结果表明:对于高压透平入口温度390 ℃的系统,发电效率34.13%,对于高压透平入口温度550 ℃的系统,发电效率41.22%。此外,对系统的安全性分析表明:CO₂本身是具备核安全属性的工质,并且超临界CO₂循环还可以作为反应堆的非能动余热排出系统,确保在严重事故工况下,反应堆持续排出衰变热。  [结论]  集成小型堆和可再生能源的超临界CO₂循环发电系统具备良好的发电效率和核安全性。     

The long-term life cycle private and external costs of high coal usage in the US

Using four times as much coal in 2050 for electricity production need not degrade air quality or increase greenhouse gas emissions. Current SO_x and NO_x emissions from the power sector could be reduced from 12 to less than 1 and from 5 to 2 million tons annually, respectively, using advanced technology. While direct CO₂ emissions from new power plants could be reduced by over 87%, life cycle emissions could increase by over 25% due to the additional coal that is required to be mined and transported to compensate for the energy penalty of the carbon capture and storage technology. Strict environmental controls push capital costs of pulverized coal (PC) and integrated coal gasification combined cycle (IGCC) plants to $1500–1700/kW and $1600–2000/kW, respectively. Adding carbon capture and storage (CCS) increases costs to $2400–2700/kW and $2100–3000/kW (2005 dollars), respectively. Adding CCS reduces the 40–43% efficiency of the ultra-supercritical PC plant to 31–34%; adding CCS reduces the 32–38% efficiency of the GE IGCC plant to 27–33%. For IGCC, PC, and natural gas combined cycle (NGCC) plants, the carbon dioxide tax would have to be $53, $74, and $61, respectively, to make electricity from a plant with CCS cheaper. Capturing and storing 90% of the CO₂ emissions increases life cycle costs from 5.4 to 11.6 cents/kWh. This analysis shows that 90% CCS removal efficiency, although being a large improvement over current electricity generation emissions, results in life cycle emissions that are large enough that additional effort is required to achieve significant economy-wide reductions in the US for this large increase in electricity generation using either coal or natural gas.     

燃煤电厂全过程低碳节能技术路径探讨

  目的  燃煤电厂的低碳节能路径是缓解我国能源危机与环境污染的重要策略。  方法  文章评述了当前燃煤电厂在燃料供应设计阶段和节能运行维护阶段的低碳节能技术以及低碳技术潜在的发展方向。  结果  对于电厂燃料供应设计阶段的低碳技术应优化生物质/氨与煤的掺烧比例,良好的掺烧比例有利于炉内充分燃烧,降低碳排;电厂节能运行维护阶段吸收技术、吸附技术和气体分离技术是碳颗粒捕集的常用手段,同时储能技术、深度调峰技术、柔性直流供电技术对于CO₂减排具有重要作用。  结论  对电厂低碳技术发展进行展望,认为采用综合互补低碳协同方式,并结合电厂运行过程中的监管反馈调控措施,将是促进电厂可持续能源发展的重要发展方向。     

Performance modelling of a carbon dioxide removal system for power plants

In this paper, a carbon dioxide removal and liquefaction system, which separates carbon dioxide from the flue gases of conventional power plants, was modelled. The system is based on an amine chemical absorption stripping system, followed by a liquefaction unit to treat the removed CO₂ for transportation and storage. The effect of the main parameters on the absorption and stripping columns is presented. The main constraints set for the model are a capture efficiency of 90% and the use of an aqueous solution with a maximum 30% amine content by weight. The goal of this study is to remove the CO₂ with minimum energy requirements for the process when it is integrated in a fossil fuel fired power plant. Results of the simulation are compared to experimental and literature data from feasibility studies and existing plants.

The power plant to which the removal system is connected is a 320 MW steam power plant with steam reheat and 8 feedwater heaters. Two different fossil fuels were considered: coal and natural gas. The effect of the modifications necessary to integrate the CO₂ removal system in the power plant is also studied.

The capital cost of the removal and liquefaction system is estimated, and its influence on the cost of generated electricity is calculated.     

双碳背景下IGCC系统的发展趋势及研究方法

  目的  在“双碳”背景下,IGCC技术耦合低成本燃烧前CO₂捕集技术具有较大的应用潜力。  方法  文章首先综述了近年来IGCC发电系统的研究现状以及开拓研究的重点方向,其次分别从燃料多样性、系统形式的优化设计以及系统仿真软件应用等三个方面评述了现有研究的特点以及相关优化建议,最后着重介绍了结合“双碳”背景下IGCC发电系统进行深度优化的潜在优势,进而对IGCC发电系统进行了展望,重点分析了多能耦合及储能技术的应用前景与数值模拟在IGCC系统优化方面的优势。  结果  结果表明:通过多能耦合系统、多联产系统等方式,新型IGCC发电系统在低碳领域发展潜力巨大。  结论  研究结果将对IGCC发电系统的进一步研究研究提供了参考。     

A coal-fired power plant integrated with biomass co-firing and CO2 capture for zero carbon emission

A promising scheme for coal-fired power plants in which biomass co-firing and carbon dioxide capture technologies are adopted and the low-temperature waste heat from the CO₂ capture process is recycled to heat the condensed water to achieve zero carbon emission is proposed in this paper. Based on a 660 MW supercritical coal-fired power plant, the thermal performance, emission performance, and economic performance of the proposed scheme are evaluated. In addition, a sensitivity analysis is conducted to show the effects of several key parameters on the performance of the proposed system. The results show that when the biomass mass mixing ratio is 15.40% and the CO₂ capture rate is 90%, the CO₂ emission of the coal-fired power plant can reach zero, indicating that the technical route proposed in this paper can indeed achieve zero carbon emission in coal-fired power plants. The net thermal efficiency decreases by 10.31%, due to the huge energy consumption of the CO₂ capture unit. Besides, the cost of electricity (COE) and the cost of CO₂ avoided (COA) of the proposed system are 80.37 $/MWh and 41.63 $/tCO₂, respectively. The sensitivity analysis demonstrates that with the energy consumption of the reboiler decreasing from 3.22 GJ/tCO₂ to 2.40 GJ/ tCO₂, the efficiency penalty is reduced to 8.67%. This paper may provide reference for promoting the early realization of carbon neutrality in the power generation industry.     

Engineering economic analysis of biomass IGCC with carbon capture and storage

Integration of biomass energy technologies with carbon capture and sequestration could yield useful energy products and negative net atmospheric carbon emissions. We survey the methods of integrating biomass technologies with carbon dioxide capture, and model an IGCC electric power system in detail. Our engineering process model, based on analysis and operational results of the Battelle/Future Energy Resources Corporation gasifier technology, integrates gasification, syngas conditioning, and carbon capture with a combined cycle gas turbine to generate electricity with negative net carbon emissions. Our baseline system has a net generation of 123 MW_e, 28% thermal efficiency, 44% carbon capture efficiency, and specific capital cost of 1,730 $ kW_e⁻¹. Economic analysis suggests this technology could be roughly cost competitive with more conventional methods of achieving deep reductions in CO₂ emissions from electric power. The potential to generate negative emissions could provide cost-effective emissions offsets for sources where direct mitigation is expected to be difficult, and will be increasingly important as mitigation targets become more stringent.     

Natural gas fired combined cycle power plant with CO2 capture

A natural gas (NG) fired power plant is designed with virtually zero emissions of pollutants, including CO₂. The plant operates in a gas turbine-steam turbine combined cycle mode. NG is fired in highly enriched oxygen (99.7%) and recycled CO₂ from the flue gas. Liquid oxygen (LOX) is supplied by an on-site air separation unit (ASU). By cross-integrating the ASU with the CO₂ capture unit, the energy consumption for CO₂ capture is significantly reduced. The exergy of LOX is used to liquefy CO₂ from the flue gas, thereby saving compression energy and also delivering product CO₂ in a saleable form. By applying a new technique, the gas turbine efficiency is increased by about 2.9%. The net thermal efficiency (electricity out/heat input) is estimated at 45%, compared to a plant without CO₂ capture of 54%. However, the relatively modest efficiency loss is amply compensated by producing saleable byproducts, and by the virtue that the plant is pollution free, including NO_x, SO₂ and particulate matter. In fact, the plant needs no smokestack. Besides electricity, the byproducts of the plant are condensed CO₂, NO₂ and Ar, and if operated in cogeneration mode, steam.