Hydrate-based carbon dioxide capture from simulated integrated gasification combined cycle gas

The equilibrium hydrate formation conditions for CO2/H2 gas mixtures with different CO2 concentrations in 0.29 mol% TBAB aqueous solution are firstly measured.The results illustrate that the equilibrium hydrate formation pressure increases remarkably with the decrease of CO2 concentration in the gas mixture.Based on the phase equilibrium data,a three stages hydrate CO2 separation from integrated gasification combined cycle （IGCC） synthesis gas is investigated.Because the separation efficiency is quite low for the third hydrate separation,a hybrid CO2 separation process of two hydrate stages in conjunction with one chemical absorption process （absorption with MEA） is proposed and studied.The experimental results show H2 concentration in the final residual gas released from the three stages hydrate CO2 separation process was approximately 95.0 mol% while that released from the hybrid CO2 separation process was approximately 99.4 mol%.Thus,the hybrid process is possible to be a promising technology for the industrial application in the future.

DESIGN OF COMBINED CYCLE GENERATION SYSTEM WITH HIGH TEMPERATURE FUEL CELL AND STEAM TURBINE

For environment protection and high efficiency, development of new conceptpower plant has been required in China. The fuel cell is expected to be used in a power plant as acentralized power Station or distributed power plant. It is a chemical power generation device thatconverts the energy of a chemical reaction directly into electrical energy and not limited by Carnotcycle efficiency. The molten carbonate fuel cell (MCFC) power plant has several attractive featuresi.e. high efficiency and lower emission of NO_x and SO_x A combined cycle generation system withMCFC and steam turbine is designed. Its net electrical efficiency LHV is about 55 percent.

Current status of national integrated gasification fuel cell projects in China

Coal has been the main energy source in China for a long period.Therefore,the energy industry must improve coal power generation efficiency and achieve near-zero CO_(2) emissions.Integrated gasification fuel cell(IGFC)systems that combine coal gasification and high-temperature fuel cells,such as solid oxide fuel cells or molten carbonate fuel cells(MCFCs),are proving to be promising for efficient and clean power generation,compared with traditional coal-fired power plants.In 2017,with the support of National Key R&D Program of China,a consortium led by the China Energy Group and including 12 institutions was formed to develop the advanced IGFC technology with near-zero CO_(2) emissions.The objectives of this project include understanding the performance of an IGFC power generation system under different operating conditions,designing master system principles for engineering optimization,developing key technologies and intellectual property portfolios,setting up supply chains for key materials and equipment,and operating the first megawatt IGFC demonstration system with near-zero CO_(2) emission,in early 2022.In this paper,the main developments and projections pertaining to the IGFC project are highlighted.

Numerical Calculation of a 3000MWt MHD-steam Combined Cycel System with Tail Gasification

A numerical calculation of a 3000MWt MHD steam combined cycle system with tail gasification is described . The research scheme has been set up and the parameters of this system have been designed. Then the efficiency of the combined cycle system has been calculated which is up to 53.9%.

Assessment of Operational Performance in a Power Generation/Selling Integrated Company Using a Dynamic Proportional Adjustment Coefficient

Currently,the operational performance assessment system in the power market primarily focuses on power generation and electricity retail companies,lacking a system tailored to the operational characteristics of power generation/selling integrated companies.Therefore,this article proposes an assessment index system for assessing the operational performance of a power generation/selling integrated company,encompassing three dimensions:basic capacity,development potential,and external environment.A dynamic proportional adjustment coefficient is designed,along with a subjective and objective weighting model for assessment indexes based on a combined weightingmethod.Subsequently,the operational performance of an integrated company is assessed using extension theory.The results in the case study demonstrate the feasibility and effectiveness of the proposed dynamic proportional adjustment coefficient.

计及氢能高效利用和热电灵活输出的综合能源系统源荷灵活运行策略

为进一步发挥氢能高效利用优势,构建绿色低碳能源系统,提出一种计及氢能高效利用和热电联产灵活输出的综合能源系统源荷灵活运行策略。首先,对源侧供能模型进行两方面改进:一是引入含风电制氢、燃气混氢、多能用氢和储氢的氢能利用模型,并考虑到电解水和甲烷化反应过程中的热量散失情况,引入热量回收装置,构建计及热量回收的氢能高效利用模型;二是针对常规热电联产灵活性不足的问题,构建含电锅炉和有机朗肯循环的热电灵活输出模型,以解耦常规热电联产“以热定电”和“以电定热”限制。其次,在荷侧引入含可转移、可削减和可平移的电、热柔性负荷,以缓解电、热负荷峰谷差,并与源侧相结合,形成源荷灵活运行模型。最后,综合考虑阶梯型碳交易成本、设备运行维护成本、弃风成本以及购能成本,建立综合能源系统源荷灵活优化运行模型。采用CPLEX求解器对所提综合能源系统源荷灵活运行模型进行求解,并设置不同场景进行对比。结果表明,相比常规氢能利用模型,考虑所提计及热量回收的氢能高效利用模型时,系统的总成本、碳排放量分别降低了1.92%、4.22%,并且引入热电联产改进模型后,其总成本、碳排放量可进一步降低4.08%、7.32%,实现系统低碳、经济和灵活运行。

基于Aspen Plus的气流床煤气化炉建模及其变工况特性研究

【目的】研究整体煤气化联合循环(integrated gasification combined cycle,IGCC)电站中煤气化炉的运行机理,分析和优化煤气化炉的关键运行参数。【方法】基于Aspen Plus建立了气流床煤气化炉的稳态热力学模型,并与文献中数据进行比对,验证了模型准确性,在此基础上,开展了对煤气化炉关键参数敏感性的研究。【结果】热力学模型适合对稳态的煤气化过程进行模拟,具有模拟结果准确、建模简单和计算量不大的优点。【结论】敏感性分析的结果表明:氧煤比是影响煤气化过程的最主要的运行参数,氧气不足和氧气过多都会造成合成气有效成分的产量减少,建立的Shell气化炉模型的最佳氧煤比在0.85左右;水煤比也是影响煤气化过程的关键参数,气化炉内能量充足时,增加输入水的量可使合成气中含有更多的氢气,而能量不足时过多的水也会导致合成气有效成分的减少。

考虑多重不确定性的电-热-气综合能源系统协同优化方法

综合能源系统(IES)中风-光出力和负荷不确定性对系统的运行安全和规划提出了挑战。以包含光伏、生物质气化热电联产等设备的IES调度过程为例,提出一种集成随机规划-信息间隙决策理论(IGDT)的方法应对系统优化运行过程中源-荷侧的多重不确定性。随机规划方法处理光伏出力不确定性,并将优化结果作为IGDT处理负荷不确定性的基准值。其中,IGDT中的风险规避和风险寻求策略反映了系统管理者面对不确定性带来运行风险时的态度。结果表明,风险规避策略下生物质气化热电联产日电能输出总量高于风险寻求策略下生物质气化热电联产日电能输出总量的50%。不同策略下的调度结果差异性为系统管理者提供了灵活的选择。

整体煤气化联合循环汽轮机三改联动改造方案

整体煤气化联合循环(IGCC)发电站的主要燃料依然是煤炭。为了适应新形势下国家对煤电机组“三改联动”的要求和用户的实际需求,针对某IGCC电站汽轮机节能降耗改造、供热改造和灵活性改造等方案进行了研究。通过对比不同改造方案的技术路线和经济性,最终确定双转子互换循环水供热改造方案为优选方案,其主要包括非供暖季的通流改造和供暖季的高背压循环水供热改造。该方案实施后,机组各项性能指标将明显提高,纯凝热耗率验收工况下的热耗设计值将降低约5.15%,出力设计值比改造前增加约8.4%,对外供热功率约为186.67 MW。所提改造方案具有良好的经济效益和社会效益,可为类似机组的“三改联动”改造提供参考。

Recent Developments in Integrated Solar Combined Cycle Power Plants

Global concern for depleting fossil fuel reserves have been compelling for evolving power generation options using renewable energy sources. The solar energy happens to be a potential source for running the power plants among renewable energy sources. Integrated Solar Combined Cycle(ISCC) power plants have gained popularity among the thermal power plants. Traditional ISCC power plants use Direct Steam Generation(DSG) approach. However, with the DSG method, the ISCC plant’s overall thermal efficiency does not increase significantly due to variations in the availability of solar energy. Thermal Energy Storage(TES) systems when integrated into the solar cycle can address such issues related to energy efficiency, process flexibility, reducing intermittency during non-solar hours. This review work focuses and discusses the developments in various components of the ISCC system including its major cycles and related parameters. The main focus is on CSP technologies, Heat Transfer Fluid(HTF), and Phase Change Material(PCM) used for thermal energy storage. Further, study includes heat enhancement methods with HTF and latent heat storage system. This study will be beneficial to the power plant professionals intending to modify the solar-based Combined Cycle Power Plant(CCPP) and to retrofit the existing Natural Gas Combined Cycle(NGCC) plant with the advanced solar cycle.

Off-design Characteristics of IGCC System Based on Two-stage Coal-slurry Gasification Technology

整体煤气化联合循环（integrated gasification combinedcycle,IGCC）机组在一定情况下处于非设计工况运行。为了研究IGCC系统变工况特性,采用ThermoFlex软件建立基于两段式水煤浆气化技术的200 MW级整体煤气化联合循环系统模型,主要考查燃气轮机负荷、整体空分系数Xas、大气温度、大气压力对系统性能的影响。研究结果表明,降低燃气轮机负荷或者提高大气温度系统效率均呈先升高而后降低的趋势。整体空分系数Xas增加,机组发电效率降低。大气压力对系统效率影响较小。上述条件下采用两段水煤浆气化技术,系统性能可以得到有效改善。研究结果可为采用两段式水煤浆气化技术的IGCC系统的设计、运行提供参考。

Prime Energy Challenges for Operating Power Plants in the GCC

There is a false notion of existing available, abundant, and long lasting fuel energy in the Gulf Cooperation Council (GCC) Countries;with continual income return from its exports. This is not true as the sustainability of this income is questionable. Energy problems started to appear, and can be intensified in coming years due to continuous growth of energy demands and consumptions. The demands already consume all produced Natural Gas (NG) in all GCC, except Qatar;and the NG is the needed fuel for Electric Power (EP) production. These countries have to import NG to run their EP plants. Fuel oil production can be locally consumed within two to three decades if the current rate of consumed energy prevails. The returns from selling the oil and natural gas are the main income to most of the GCC. While NG and oil can be used in EP plants, NG is cheaper, cleaner, and has less negative effects on the environment than fuel oil. Moreover, oil has much better usage than being burned in steam generators of steam power plants or combustion chambers of gas turbines. Introducing renewable energy or nuclear energy may be a necessity for the GCC to keep the flow of their main income from exporting oil. This paper reviews the GCC productions and consumptions of the prime energy (fuel oil and NG) and their role in electric power production. The paper shows that, NG should be the only fossil fuel used to run the power plants in the GCC. It also shows that the all GCC except Qatar, have to import NG. They should diversify the prime energy used in power plants;and consider alternative energy such as nuclear and renewable energy, (solar and wind) energy.

Evaluation of Palladium-Based Sorbents for Trace Mercury Removal in Electricity Generation

The development of warm-gas cleanup (WGCU) systems for synthesis gas (syngas) cleanup in in- tegrated gasification combined cycle (IGCC) power plants has the potential to lower the costs of generating power. WGCU includes the removal of mercury (Hg), present in coal, from the syngas. Carbon-based sorbents used for Hg removal are not suitable for high-temperature Hg removal in conjunction with the WGCU. The US Department of Energy’s National Energy Technology Laboratory’s (DOE/NETL) Office of Research & Development (ORD) has been developing various sorbent alternatives to address the problem of high-temperature Hg removal. This study presents analysis of the capture of Hg from syngas streams as a polishing step to attain US Environmental Protection Agency (EPA) Mercury and Air Toxics Standards (MATS) requirements for Hg (0.003 lb/GWhgross for new IGCC plants) using palladium (Pd) adsorbent being tested by DOE/NETL in association with Johnson Matthey (JM). For the present study, it was assumed that syngas is already cleaned to 5 parts per billion by weight (ppbw) Hg, and the Pd sorbent technology is used as a polishing step to achieve the EPA MATS requirements (0.003 lb/GWhgross, equivalent to 2 ppbw given representative process configuration and material flows). The incremental cost of Hg polishing and the additional capital cost needed were estimated for several scenarios/cases. These cases were differentiated by variance in the following parameters, which are important because they have direct im- pacts on additional capital costs ($/kW), and in turn impacts on the levelized cost of electricity (LCOE): 1) Pd cost (varied from $4,000 to $12,000/lb Pd);2) Gas hourly space velocity (SV) (varied from 500 to 13,500 h-1);3) Pd loading (varied between 2 w/w% Pd and 5 w/w% Pd);4) Sorbent make-up rate (varied between 3%, 1%). The ranges were chosen in order to reasonably reflect, in the cases that are analyzed, the actual fluctuations that have been observed in past *Corresponding author. experience in these important parameters that affect cost (e.g., the Pd cost has kept to within the $4 to 12 k/lb range in recent years). In the case of SV, the high and low points of the range are extremes beyond which costs would either be unreasonable, or increase in cost benefit would be negligible. For a typical case (i.e., using mid-range values of the parameters, including SV of 8000 h-1, 2% Pd loading, 3% make-up rate, $9500/lb Pd cost), the increase in LCOE due to the Pd-polishing system is approximately 0.4% and the additional capital cost is ~$10/kW. As a comparison, the incremental capital cost of conventional Hg removal in an IGCC plant is ~$4 to 8/kW, and the increase in the LCOE is less than 0.4%. Results indicate that in the range of SVs from 3500 h-1 to 10,000 h-1, the Hg-polishing step is expected to function adequately and with increase of LCOE limited to about 1% - 2%. The use of a Pd sorbent-based polishing system to reduce trace Hg levels to the EPA MATS requirements for new IGCC power generation appears to be feasible and reasonably cost-effective.

基于动态仿真系统的空分及高压氮气管路节能优化研究

针对国内首台整体煤气化联合循环电站,建立了关于该电站空分设备和全厂主要高压氮气使用设备及管路的实时动态仿真系统。在不同负荷下稳态运行的仿真测试表明,建立的实时动态仿真系统对于现场运行状态的仿真结果误差小于5%,表明该仿真系统具有较高的精度,能够用于对实际物理过程的仿真。利用该实时动态仿真系统对新增氮气储罐布置于原有空分至高压氮气缓冲储罐之间的管路来收集放空氮气同时平稳原有高压氮气管路压力波动的改造方案进行了研究,结果表明改造方案相比现有方案可以减少高压氮气管路系统压力波动范围,且串联布置方式优于并联布置方式。

以气化煤气为燃料的固体氧化物燃料电池热电联供系统设计

煤炭在相当长一段时间内仍将是我国的主要能源,提高其利用效率对减碳具有重要意义;固体氧化物燃料电池(SOFC)是最高效的能量转化装置,二者结合将实现煤炭资源的最大化利用,助力新老能源的平稳过渡。但传统煤炭气化工厂产出的煤气中灰分、硫等杂质含量高,不能直接作为SOFC燃料,针对煤炭气化和净化过程以及燃料电池发电和热回收系统进行设计与模拟。使用Aspen Plus软件建立煤炭裂解、煤炭气化、煤炭净化、煤气冷却热回收、SOFC发电、尾气燃烧、蒸汽轮机发电、热水供应模块,使用软件内置Fortran模块对煤炭气化和SOFC发电的电化学过程进行建模,最终得到一种适合固体氧化物燃料电池的煤炭气化模块,气化效率为70.1%,该煤气主要含58%CO、32%H_(2),可直接通入燃料电池进行发电。模拟结果显示,该系统在拟定工作条件下,SOFC净发电效率可达37.54%,热水效率为35.11%,系统总体能量利用率可达78.58%。经灵敏度分析发现,采用适当的燃料利用率和燃料流量可有效降低系统运行成本,空气过量比在可选择范围内尽量选大。可实现煤炭的绿色、清洁高效应用。对煤炭气化燃料电池发电技术热电联供系统(IGFC-CHP)的全部过程进行了模型搭建,对IGFC-CHP的实现具有借鉴意义。

基于“双碳”目标的中国火力发电技术发展路径研究

火力发电是中国最主要的电力来源和CO_(2)排放来源,火力发电行业的CO_(2)减排是顺利实现“碳达峰、碳中和”目标的重要保证。为了探究“双碳”背景下中国火力发电技术发展路径,结合中国火力发电行业发展历程以及中长期电力消费结构展望,预测中国火力发电技术将从注重高参数、高效率向调峰灵活性转变。针对超高参数火力发电技术、灵活性调峰技术,以及整合煤气化联合循环发电(integrated gasification combined cycle,IGCC)/煤气化燃料电池(integrated gasification fuel cell,IGFC)联合循环技术进行了探讨和研究,发现超高参数火力发电技术发展受限于耐高温材料,灵活性改造能有效延展火力发电技术的生命周期,认为IGCC/IGFC发电技术是兼具高效率、灵活性的洁净煤发电技术,并提出煤气(油)电一体化能源基地的应用场景。展望2060年,建议加强煤气化/净化技术、燃料电池发电技术、IGFC系统集成控制技术的研发,助力中国顺利实现碳中和。

与生物质气化联合循环系统耦合的压缩空气储能系统性能分析

为提高压缩空气储能系统的性能,该文提出一种生物质气化联合循环系统与压缩空气储能系统集成的新方案。储能过程中,利用联合循环系统的给水冷却高温压缩空气。释能过程中,在联合循环系统中的余热锅炉部分布置旁路烟道。来自储气罐的压缩空气经旁路烟道加热后,直接通入至联合循环系统的燃烧室。该耦合方案采用能量梯级利用的原理,可以实现系统效率的提升;同时还可以节省常规压缩空气储能系统中的蓄热罐、蓄冷罐和膨胀机等设备。采用Ebsilon软件对耦合系统进行模拟,并对耦合系统进行热力学分析和经济性分析。结果表明:新方案中压缩空气储能系统的循环效率和能量密度分别为86.14%和7.48MJ/m^(3),整个集成系统的总效率为37.20%。此外,新方案的动态投资回收期为3.73年,净现值为89.65万元。该研究为提高压缩空气储能系统的性能提供了新的技术选项。

与燃煤电站和S-CO_(2)循环耦合的生物质气化发电系统性能分析

为充分利用生物质资源,提出了与燃煤机组和超临界二氧化碳循环的生物质气化系统概念,该系统的生物质气化利用过程与燃煤机组及超临界二氧化碳循环的高度耦合。合成气经二氧化碳冷却后,经净化后送入燃气轮机燃烧。烟气经燃气轮机,超临界二氧化碳循环,锅炉给水逐步回收热量,提升了生物质的利用率,进而提高了发电效率。以660 MW燃煤机组和16 t/h生物质气化炉为例,通过对系统仿真,对其进行了热力学和经济性分析。结果表明,所提出的耦合系统引入了46.66 MW的生物质能,额外发出了21.09 MW功率,生物质能效率可达45.20%,[火用]效率可达41.67%,可充分利用生物质中能量。系统净现值约40 468万元,且约需2.94 a即可收回成本,具有良好的经济效益。

A New Cleaner Power Generation System Based on Self-Sustaining Supercritical Water Gasification of Coal

A new cleaner power generation system(IPGS) is proposed and investigated in this paper. Integrating combined cycle with supercritical water gasification of coal, the thermodynamic energy of the produced syngas is cascade utilized according to its temperature and pressure, both sensible and latent heat of the syngas can be recycled into the system, and thereby the net power efficiency can be about 6.4 percentage points higher than that of the traditional GE gasification based power plant(GEPP). The exergy analysis results show that the exergy efficiency of the proposed system reaches 52.45%, which is 13.94% higher than that of the GEPP, and the improvement in exergy efficiency of the proposed system mainly comes from the exergy destruction decline in the syngas energy recovery process, the condensation process and the syngas purification process. The syngas combustion process is the highest exergy destruction process with a value of 157.84 MW in the proposed system. Further performance improvement of the proposed system lies in the utilization process of syngas. Furthermore, system operation parameters have been examined on the coal mass fraction in the supercritical water gasifier(GF), the gasification temperature, and the gasification pressure. The parametric analysis shows that changes in coal concentration in the GF exert more influence on the exergy efficiency of the system compared with the other two parameters.

IGCC机组厂级监控信息系统搭建方案及数据一致性研究

近几年来随着厂级信息监控系统(SIS)研究的不断深入,SIS系统在企业的应用越来越广泛。SIS系统能够对生产过程中产生的数据进行采集与处理,并建立实时、历史数据库,为电厂管理信息系统(MIS)提供过程数据、计算分析结果,实现了设备运行情况在线监视与分析、机组经济性能指标分析、各类报表自动生成等功能,真正做到检修、运行、生产各部门之间的数据共享,满足了电厂对生产过程管控一体化需求,为机组安全、高效运行提供强大支撑。介绍了一种基于IGCC(整体煤气化联合循环)机组厂级信息监控系统搭建方案,并对DCS与SIS的数据一致性进行研究,给类似机组或工程提供参考。