不同煤气化过程的FT合成油-电多联产模拟计算

设计并模拟了以Shell, GSP, Texaco煤气化为气头的FT合成油-电多联产系统,考察了三者的系统特性. 结果表明,在入炉煤量为1000 t/h的条件下,其合成油(包括柴油、石脑油和LPG)产量分别为318.56, 318.42和285.79 t/h,但FT合成96%的CO转化率使其发电量均不足以满足系统自身的用电,尾气发电仅相当于回收了原料煤热值近2%的能量. 以Shell技术为气头的多联产系统具有最高的系统热效率(47.65%),Texaco技术为气头的多联产系统具有最低的系统热效率,比前者低6.5%左右. 3种方案捕获的CO2分别相当于回收了进入系统全部碳含量的58.69%, 58.65%, 59.55%.     

“双气头”多联产系统CO2减排特性方程研究

以煤气化为核心的多联产能源系统是有效解决温室气体CO2排放的手段之一,其中,“双气头”多联产系统将气化煤气富碳、焦炉煤气富氢的特点相结合,实现了生产过程的CO2减排。笔者在与传统煤制甲醇生产过程相比的基础上,得到了“双气头”多联产系统CO2减排特性方程,从而定量的描述了“双气头”系统生产过程的CO2排放量,为方案设计和将其纳入“清洁发展机制”项目提供了基础的理论指导。     

“双气头”多联产洁净煤示范项目奠基

<正>气化煤气和热解煤气共重整制合成气多联产技术,简称"双气头"多联产技术,是我国自主创新的煤基多联产节能减排创新技术。2009年8月11日,"双气头"多联产洁净煤示范项目在山西忻州禹王煤化工循环经济园区奠基。该项目以醇醚燃料和电力为最终产品,设计能力1 000t/a醇醚燃料,总投资2 863万元。     

不同工艺路线FT合成油-电多联产模拟计算

设计并模拟了以Shell煤气化为气头的FT合成油-电多联产串联型和并联型案例,研究了不同工艺路线的系统特性. 结果表明,在CO总转化率0.96、摩尔比H2/CO=1.5的条件下,串联型多联产具有最多的合成油产量,分别为柴油205.2、石脑油73.24及液化石油气(LPG) 40.12 t/h,但发电量不足以满足自身用电消耗;并联型多联产随合成气分流比降低,合成油产量下降而发电量大幅上升,但系统热效率降低,分别为47.55%(FT-100), 46.85%(FT-75)及44.98%(FT-25). 3种方案的C捕集率分别为58.7%(FT-100), 44%(FT-75)和14.7%(FT-25).     

以Shell气化为气头的二甲醚-电多联产系统分析

设计了以Shell气化为气头的两步法生产二甲醚(DME)、联合循环发电的多联产系统,并对带尾气循环和一次通过的2个案例进行了模拟计算.结果表明,带尾气循环使煤化学能的60.87%用以生产DME,具有较高的热效率,但发电量低,不能满足系统自身的用电需求;一次通过以发电为主,煤化学能的24.93%转化为电能,DME产量低,热效率较带尾气循环的方案低5.24%.可以通过调节尾气循环比在生产DME和发电之间取得平衡.2种方案可捕获CO2 1682.26 t/h,占进入系统总碳量的57.82%.     

双气头多联产系统的Aspen Plus实现及工艺过程优化(Ⅰ) 模拟流程的建立及验证

通过流程模拟对煤基多联产系统进行过程优化是一种低成本、高效率的研究方法。通过稳态流程模拟软件Aspen Plus建立了二甲醚和电力为主要目标产品并副产甲醇的煤基多联产系统流程。采用气化煤气与焦炉煤气混合气作为气头,以达到利用焦炉煤气中高浓度甲烷、下一步工艺调整氢碳比并实现温室气体减排的目的。模拟流程中包括了空分、煤气化及净化、CH4/CO2重整、产品合成、燃气轮机联合循环发电等多联产系统中的5个主要工艺单元,涉及化学反应的CH4/CO2重整单元和二甲醚合成单元通过嵌入包含特定反应动力学参数的动力学子程序进行模拟。多联产系统综合考虑了化学反应的动力学和热力学,系统总体及各工艺单元物料、能量衡算一致,各个单元模拟数据与文献实验数据吻合。在建立流程的基础上,计算比较了热值加和效率与当量发电效率,发现考虑能量品质的当量发电效率更适合联产液体燃料和电能的多联产系统的评价。     

化工中试装置性能化设计思路探讨

中试装置在设计中存在着"标准真空"问题,国内外均无针对中试装置的专业标准规范,造成中试装置在设计时出现无规范可依的状况。本文首先对化工中试装置设计现状及其特点进行了了解,并在此基础上对中试装置的设计采用了一种新的设计思路,即性能化设计的思路,建立起了中试装置性能化平面布局设计框架,并对框架的步骤进行了简要说明。     

“双气头”甲醇-电多联产系统的设计与优化

为使焦炉煤气得到有效利用,设计了基于气化煤气与焦炉煤气的“双气头”多联产工艺流程,建立了系统配置最优化判据,计算发现在分流比为0.802时,低位热值效率具有最大值为48.7％.借助Aspen Plus和GT Pro模拟软件设计了年产12～32万t甲醇和274～ 496 MW电力等不同等级规模的多联产系统,并对系统整体性能和单元过程操作参数等方面进行了分析与讨论,通过模拟得到的最佳低位热值效率与系统配置最优化判据得到的数据十分吻合.     

双气头多联产中醇醚燃料合成流程的经济评价

采用Aspen Icarus Process Evahator(Aspen IPE)软件对双气头多联产流程中关键工艺段--洁净气化煤气/焦炉煤气合成醇醚燃料单元进行了经济评价,以估算多联产系统中化工产品生产部分的经济性.经济评估计算以焦炭产能5 000 t/a的焦化厂为例,原料气按照气化煤气/焦炉煤气体积比1∶1进行输入,化学品合成工艺按一步法合成二甲醚(386 t/a),副产甲醇(242t/a).应用Aspen IPE软件计算该流程的投资费用、操作费用和利润率,并在此基础上分析了原料和产品价格变化对该项目经济性的影响.     

天然气基多联产系统研究进展

分析了天然气基化工和动力分产系统的能源利用特性,指出多联产系统是进一步提高能量利用率的突破口,概括总结了天然气基化工动力联产系统的集成原则思路;在此基础上对并联和串联两种多联产系统基本流程的集成特性与节能潜力进行了对比分析,并对不同化工产品对联产系统集成特性的影响进行了探讨,最后对天然气基多联产系统的经济性进行了初步分析.研究结果表明,多联产系统能够进一步提高化石能源的利用效率,并具有较好的经济性,是一种具有广阔发展前景的新型能源系统.     

双气头多联产系统的Aspen Plus实现及工艺过程优化(Ⅱ) 工艺操作参数分析

在所建立的以二甲醚和电力为主要目标产品并副产甲醇的多联产系统流程基础上,以化工产品产率优化及二氧化碳减排为目的,以甲醇当量产率、二甲醚产量和CH4/CO2转化率作为全流程优化的目标函数,对包括CH4/CO2催化重整单元和二甲醚(甲醇)合成单元在内的两个关键单元流程进行整体优化处理,同时分析了一步法二甲醚合成反应体系间的协同作用,得到了重整反应器和合成反应器的优化操作参数和最佳焦炉煤气与气化煤气进料流量比。     

一种煤基多联产碳循环系统的设计及评价

将高密度三塔式循环流化床(TBCFB)应用于串并联综合型多联产系统,提出一种基于碳循环的流程与参数共优化的煤基多联产系统,促进低阶煤资源的高质高效转化。碳循环体现在两方面,一是系统以热解煤气循环作为热解气氛,提高了焦油产率,实现低阶煤高质化转化;二是在TBCFB使用富氧燃烧,提高了烟气中二氧化碳浓度,将烟气替代氮气直接用于燃气轮机发电工质,减少了氮气消耗。利用Aspen Plus对全系统进行模拟,对多联产系统进行物料、能量和?衡算,研究未反应合成气循环比和烟气注入量对过程的影响;以能量利用效率为优化目标,对煤基多联产碳循环系统的操作条件寻优。结果表明,动力单元注入气体使用烟气时,煤基多联产碳循环系统的能量利用效率达49.7%,高于用氮气作为热解气氛的传统煤基多联产系统,相比传统的单产系统,煤基多联产系统的能量可节约13%,对于年处理30万吨煤的系统,折合减少二氧化碳排放量为14.9万吨/年。     

Pilot Development of Polygeneration Process of Circulating Fluidized Bed Combustion combined with Coal Pyrolysis

A pilot polygeneration process of a 75 t h^–1 circulating fluidized bed (CFB) boiler combined with a moving bed coal pyrolyzer was developed based on laboratory‐scale experimental results. The process operation showed good consistency and integration between boiler and pyrolyzer. Some critical operating parameters such as hot ash split flow from the CFB boiler to the pyrolyzer, mixing of hot ash and coal particles, control of pyrolysis temperature and solid inventory in the pyrolyzer, and pyrolysis gas clean‐up were investigated. Yields of 6.0 wt‐% tar and 8.0 wt‐% gas with a heating value of about 26 MJ m^–3 at 600 °C were obtained. Particulate content in tar was restrained less than 4.0 wt‐% by using a granular filter of the moving bed. Operation results showed that this pilot polygeneration process was successfully scaled up.     

Simulation of a Lignite‐Based Polygeneration System Coproducing Electricity and Tar with Carbon Capture

Lignite‐based polygeneration systems for coproducing tar and electricity with and without carbon capture and storage (CCS) were proposed and simulated. Predried lignite was pyrolyzed into coal gas, tar, and char. Coal gas was fired in a gas turbine after the cleanup process, while char was combusted in circulating fluidized‐bed (CFB) boilers. The polygeneration plant without CCS turned out to be more efficient than the conventional CFB power plant, suggesting that the former is a promising and efficient option to utilize lignite resources. Moreover, the performance and emissions of polygeneration plants with and without CCS were compared. It was shown that the more CO₂ is captured, the larger energy penalty it will cost. Therefore, a trade‐off should be made between low emissions and high efficiency.     

Modeling and optimization of polygeneration energy systems

The forecasted shortage of fossil fuels and the ever-increasing effect of greenhouse gas (GHG) emissions on global warming and environmental stability are two international problems with major technical, economic and political implications in the 21st century. Therefore, it is urgent to restructure present energy production and utilization systems in order to ensure that fossil fuels are used with high efficiency and low to zero emissions. Polygeneration energy systems combine power generation and chemical fuel synthesis in a single plant (producing both electricity and fuels) and thus provide a promising alternative pathway towards achieving sustainable and flexible economic development. Mixed-Integer programming (MIP) is useful in constructing long-term decision models that are suitable for investment planning and design of polygeneration infrastructure systems. This paper presents a model for the investment planning of a polygeneration energy system and a case study addressing a system for production of methanol and electricity in China during the period from 2010 to 2035. It contains five different feedstocks and twelve polygeneration technologies.     

煤气化多联产系统研究现状与进展

文章综述了国内外煤气化多联产系统及其关键技术的研究现状和进展,对当前煤气化多联产系统研究的重点和存在的问题进行了总结。     

Optimal design and operation of a steel plant integrated with a polygeneration system

A process integration approach has been applied to integrate a traditional steelmaking plant with a polygeneration system to increase energy efficiency and suppress carbon dioxide emissions from the system. Using short‐cut models and empirical equations for different units and available technologies for gas separation, methane gasification, and methanol synthesis, a mixed integer nonlinear model is applied to find the optimal design of the polygeneration plant and operational conditions of the system. Due to the complexity of the blast furnace (BF) operation, a surrogate model technique is chosen based on an existing BF model. The results show that from an economic perspective, the pressure swing adsorption process with gas‐phase methanol unit is preferred. The results demonstrate that integration of conventional steelmaking with a polygeneration system could decrease the specific emissions by more than 20 percent. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3659–3670, 2013