几种二甲醚合成工艺的技术经济分析

为了比较新型二甲醚单产系统和联产系统的技术经济特性，构造了以LPDME浆态床二甲醚反应器为核心的一步法二甲醚合成系统及其模型。并对3种二甲醚合成系统进行了技术经济分析。结果表明，相对于LPDME二甲醚单产系统，新型二甲醚／动力联产系统的相对节能率为0．34％。对于20万t／年二甲醚产量规模，当天然气价格在0．66元／Nm^3、电价在0．25元／kWh情况下，二甲醚／动力联产系统的二甲醚成本最低。分析结果表明：在天然气资源丰富而价廉地区，新型二甲醚系统具有一定的经济优势。图6表3参15     

多联产系统中合成气一步法制取二甲醚的热力学分析

二甲醚具有良好的物理化学性质,市场前景广阔,合成气一步法制取工艺因其成本低而受到普遍关注,而多联产系统联产二甲醚可有效降低初投资。构建了合成气一步法制取二甲醚工艺的化学平衡计算模型,研究了在多联产系统中反应温度、压力和原料气配比对二甲醚平衡产率的影响,得到的优化温度为220~260℃,压力为4~6M Pa,使得二甲醚平衡产率取极大值的H2/CO<1,对于晋城9#无烟煤产生的合成气,优化H2/CO是0.75~0.8。     

煤基氨-动力多联产系统的设计和分析

煤基氨-动力多联产系统是一种建立在能量梯级利用概念基础上,融合了煤气化联合循环发电系统和合成氨流程的化工-动力多联产系统.利用大型化工流程模拟软件Aspen Plus对各系统进行了流程模拟,分析比较了分产系统和多联产系统的性能,指出该多联产系统可节能9.1%.借助于图像分析法,揭示了系统性能改善的内部机理.图11参10     

新型二甲醚-发电多功能系统的设计与分析

由于从偏远地区长距离输送天然气的成本较高,将天然气就地转化为高附加值且易运输的化工产品,比如甲醇、二甲醚等,是西部天然气资源利用的重要途径之一.论文以天然气空气部分氧化制合成气与二甲醚合成工艺为基础,针对合成尾气不同利用方式,提出二甲醚单产工艺和二甲醚/动力联产工艺.与单产二甲醚的工艺相比,联产系统的相对节能率为8.94%.文中还探讨了合成气的氢碳比对于联产系统性能的影响.图8表1参13     

以煤气化为核心的甲醇、电的多联产系统分析(上)

以煤气化为核心的多联产系统是一条解决我国能源领域可持续发展的重要途径。由于是刚刚兴起。多联产系统的详细分析还未见诸文献。基于流程模拟，对甲醇、电的多联产系统的多种设计进行了模拟计算和初步优化，提供的数据将为多联产系统的进一步全面评价和系统选择打下重要的基础。图6表7参5     

结合冶金的煤基多联产系统及其数字仿真平台框架

以煤气化为核心的多联产思想是实现未来中国能源可持续发展的重要思路．文中将该前沿思想进一步推广至冶金领域，结合世界钢铁领域先进的熔融还原COREX炼铁工艺，分析了COREX联产电力的经济环境效益．提出了未来煤基多联产系统概念模型及开展复合大系统优化集成研究的平台软件框架解决方案。具有丰富动力工程、化工、冶金等重要煤基工业过程模型资源的，可用于灵活配置各种多联产流程的优化集成平台将为未来多联产系统的真正实现提供科学分析和开发工具。图6参3     

多联产配置是推进我国IGCC系统发展的重要途径

分析了IGCC电站在我国及世界的发展形势,并从经济和技术角度分析了影响其发展的主要因素,重点对多联产系统相对IGCC电站具有更好的经济性和操作灵活性进行分析。提出通过多联产系统来推进IGCC这种清洁煤发电技术发展的观点。     

多联产系统的能值评估

为了扩展能值分析方法的应用范围,根据能值分析的基本思想,并以能量守恒和能值守恒为依据,提出了能反映多联产系统特点的能值评价指标,该能值评价指标将多联产系统的成本结构、排放影响和节约的资源置于同样重要位置考虑.以煤基燃料-电力多联产系统（甲醇-电力,氢-电力）为案例进行了能值分析.结果表明：该能值评价指标能全面度量多联产系统及其可持续性;多联产系统的连接模式、技术配置等因素均影响着多联产系统的可持续性;合适的燃料-电力比例的多联产系统的可持续性与单产系统相比有明显改善.图4表3参11     

费托合成*在我国发展的新机遇

目前我国液体燃料严重短缺，环境污染形势也十分严峻，以煤气化核心的多联产能源系统是解决我国未来能源可持续发展的一个重要方向，以煤为原料经“一步法”费托合成生产液体燃料，同时与燃气－蒸汽联合循环结合联合发电是多联产系统的一种方案，文中综述了国外以煤，天然气或生物质为原料生产液体燃料的流程和经济性，论述了费托合成采用“一步法”流程，生产液体燃料同时与燃气－蒸气联合循环结合联产发电是降低成本的有效方法。图4表2参11。     

以煤热解为基础的多联产系统的热效率分析

多联产作为高效、环保的化工能源系统,特别是以联产甲醇和电为代表的多联产是最典型的多联产系统,具有显著的节能功能。本文以热力学方法研究了以煤热解为基础的多联产系统的热效率,进一步将联产和分产进行了节能效果比较。     

System study on natural gas-based polygeneration system of DME and electricity

An innovative system for the polygeneration of dimethyl ether (DME) and electricity was proposed in this paper. The system uses natural gas as the raw material. Polygeneration is sequential, with one-step and once-through DME synthesis. Syngas is made to react to synthesize DME first, and then the residual syngas is sent to the power generation unit as fuel. The exergy analysis from the view of cascade utilization was executed for individual generation and for polygeneration. The analysis results showed that both chemical energy and thermal energy in polygeneration were effectively utilized, and both chemical exergy destruction and thermal exergy destruction in polygeneration were decreased. The cause of the decrease in exergy destruction was revealed. The analysis showed that hydrogen-rich (natural gas-based) polygeneration was as desirable as carbon-rich (coal-based) polygeneration. The energy saving ratio of polygeneration was about 10.2%, which demonstrated that high efficiency natural gas-based polygeneration is attainable, and the cascade utilizations of both chemical energy and thermal energy are key contributors to the improvement of performance. Copyright © 2007 John Wiley & Sons, Ltd.     

Exergoeconomic assessment of a biomass-based hydrogen,electricity and freshwater production cycle combined with an electrolyzer,steam turbine and a thermal desalination process

Since biomass resources can be found with different contents in most regions of the world, biomass/gasification (Biog) coupling processes can be considered as an attractive and useful technology for integrating in polygeneration configurations. In this regard, a new polygeneration energy configuration based on Biog process is proposed and its conceptual analysis is presented. In the new energy process, a Rankine cycle, a water electrolysis cycle (based on solid oxide electrolyzer, SOE), and a multi-effect desalination (MED) unit are embedded to generate electricity, hydrogen fuel, and freshwater, respectively. The considered polygeneration configuration is comprehensively investigated and discussed utilizing a parametric evaluation and from thermodynamic, energetic and exergoeconomic points of view. Relying on the proposed system can provide a new approach to produce carbon-free hydrogen fuel and freshwater in order to achieve an efficient, modern and green polygeneration configuration. The results indicated that the electrical power generated by the considered polygeneration configuration is close to 1735 kW. In addition, the system is capable of producing almost 9880 kg/h of freshwater and 12.3 kg/h of hydrogen. In such a context, the energy efficiency and total products unit exergy cost were 36.4% and 16.6 USD/GJ, respectively. Also, the system could achieve an exergy efficiency of nearly 17.1%. Moreover, about 8.9 MW of process's exergy is destroyed. The performance of the proposed polygeneration configuration using four different biomass fuels is compared. It was determined that the total products unit exergy costs under paddy husk and paper biomass are approximately 14.8% and 8.6% higher than MSW, respectively.     

Economic analysis of coal-based polygeneration system for methanol and power production

Polygeneration system for chemical and power co-production has been regarded as one of promising technologies to use fossil fuel more efficiently and cleanly. In this paper the thermodynamic and economic performances of three types of coal-based polygeneration system were investigated and the influence of energy saving of oxygenation systems on system economic performance was revealed. The primary cost saving ratio (PCS) is presented as a criterion, which represents the cost saving of polygeneration system compared with the single-product systems with the same products outputs, to evaluate economic advantages of polygeneration system. As a result, the system, adopting un-reacted syngas partly recycled to the methanol synthesis reactor and without the shift process, can get the optimal PCS of 11.8%, which results from the trade-off between the installed capital cost saving and the energy saving effects on the cost saving, and represents the optimal coupling relationship among chemical conversion, energy utilization and economic performance. And both of fuel price and the level of equipment capital cost affect on PCS faintly. This paper provides an evaluation method for polygeneration systems based on both technical and economic viewpoints.     

Thermochemical production of liquid fuels from biomass: Thermo-economic modeling,process design and process integration analysis

A detailed thermo-economic model combining thermodynamics with economic analysis and considering different technological alternatives for the thermochemical production of liquid fuels from lignocellulosic biomass is presented. Energetic and economic models for the production of Fischer–Tropsch fuel (FT), methanol (MeOH) and dimethyl ether (DME) by means of biomass drying with steam or flue gas, directly or indirectly heated fluidized bed or entrained flow gasification, hot or cold gas cleaning, fuel synthesis and upgrading are reviewed and developed. The process is integrated and the optimal utility system is computed. The competitiveness of the different process options is compared systematically with regard to energetic, economic and environmental considerations. At several examples, it is highlighted that process integration is a key element that allows for considerably increasing the performance by optimal utility integration and energy conversion. The performance computations of some exemplary technology scenarios of integrated plants yield overall energy efficiencies of 59.8% (crude FT-fuel), 52.5% (MeOH) and 53.5% (DME), and production costs of 89, 128 and 113 € MWh^?1 on fuel basis. The applied process design approach allows to evaluate the economic competitiveness compared to fossil fuels, to study the influence of the biomass and electricity price and to project for different plant capacities. Process integration reveals in particular potential energy savings and waste heat valorization. Based on this work, the most promising options for the polygeneration of fuel, power and heat will be determined in a future thermo-economic optimization.     

化工动力多联产系统设计优化理论与方法

化工动力联产备受关注,文章概述作者团队对多联产系统设计优化理论与方法的研究。从领域交叉层面探讨联产系统集成理论,阐明了能的综合梯级利用和控制CO2一体化原理;基于新原理,诠释了多联产系统类型和集成特征,凝练了系统集成的三个一般性原则思路和体现这些原则的优化整合途径和手段。然后,构建了相关的联产系统设计优化方法：基于相对节能率和基于化学能梯级利用机理的设计方法。实例研究验证了所提出理论与方法的有效性、实用性。     

甲醇缸内直喷热氛围燃烧的试验研究

在单缸直喷式柴油机上进行了二甲醚(dimethyl ether,DME)气道喷射和甲醇缸内直喷的甲醇热氛围燃烧试验研究．结果表明,该燃烧方式呈现分布式放热规律,燃烧过程可分为DME低温放热、高温放热和甲醇扩散燃烧 3个阶段．随负荷的增加,实现稳定燃烧的最小DME比例减小．随DME比例减小,DME高温放热和甲醇燃烧滞后．在稳定燃烧的情况下,随DME比例的增大,燃烧效率和热效率降低,HC和NOx排放呈上升趋势,而CO排放先升高后降低．综合考虑,采用最小比例DME有利于提高其热效率、降低排放．此时热效率、HC排放与原柴油机相当, NOx降低约50％,但CO排放相对原柴油机有较大幅度的增加．     

层次分析法在多联产系统综合性能评价中的应用

按照系统工程方法进行多联产系统的优化设计，应用层次分析法建立了多联产系统综合评价模型，对多种甲醇．电多联产系统方案进行了单项效益和综合效益的计算、分析和评价，进一步证明了多联产方案比单产方案在节能、经济、环境保护方面有较大优势，并指出：在年产甲醇20万t，发电容量300MW的规模下，富CO气体一次通过并联多联产系统（E1）和富CO气体一次通过串联多联产系统（F1）综合效益较高，可以根据实际情况来选取，为系统进一步优化指明了方向。图1表8参10     

Design of a hybrid polygeneration system with solar collectors and a Solid Oxide Fuel Cell: Dynamic simulation and economic assessment

Solid Oxide Fuel Cells (SOFC) are very promising energy conversion devices, producing electricity and heat from a fuel directly via electrochemical reactions. The electrical efficiency of SOFCs is particularly high, so that such systems are very attractive for integration in complex polygeneration systems. In this paper, the integration of SOFC systems with solar thermal collector is investigated seeking to design a novel polygeneration system producing: electricity, space heating and cooling and domestic hot water, for a university building located in Naples (Italy), assumed as case study. The polygeneration system is based on the following main components: concentrating parabolic through solar collectors, a double-stage LiBr-H₂O absorption chiller and an ambient pressure SOFC fuel cell. The system also includes a number of additional components required for the balance of plant, such as: storage tanks, heat exchangers, pumps, controllers, cooling tower, etc. The SOFC operates at full load, producing electric energy that is in part self-consumed for powering building lights and equipments, and in part is used for operating the system itself; the electric energy in excess is eventually released to the grid and sold to the public Company that operates the grid itself. The system was designed and then simulated by means of a zero-dimensional transient simulation model, developed using the TRNSYS software; the investigation of the dynamic behavior of the building is also included. The results of the case study were analyzed for different time bases, from both energetic and economic points of view. Finally, a thermoeconomic optimization is also presented aiming at determining the optimal set of system design parameters. The economic results show that the system under investigation may be profitable, provided that it is properly funded. However, the overall energetic and economic results are more encouraging than those claimed for other similar polygeneration systems in the recent literature.     

Polygeneration and efficient use of natural resources

The consumption of natural resources has been increasing continuously during recent decades, due to the growing demand caused by both the economic and the demographic rise of global population. Environmental overloads that endanger the survival of our civilization and the sustainability of current life support systems are caused by the increased consumption of natural resources—particularly water and energy—which are essential for life and for the socio-economic development of societies. While not yet well utilized, process integration and polygeneration are promising tools which reach the double objective of increasing the efficiency of natural resources, and also minimizing the environmental impact. This paper discusses the concepts of polygeneration and energy integration and various examples of polygeneration systems: (i) sugar and energy production in a sugarcane factory; (ii) district heating and cooling with natural gas cogeneration engines and (iii) combined production of water and energy. It is clearly evident that polygeneration systems which include appropriate process integration significantly increase the efficient use of natural resources.