啤酒领域循环经济新技术——广州珠啤集团污水处理后的沼气回收综合利用

广州珠江.集团公司污水处理过程中会产生大量沼气,每天有大约10000～12000m3沼气直接燃烧排放.分析和介绍珠啤集团将该部分沼气回收综合利用的情况,将沼气回收脱硫预处理后用于发电和制冷,即将高品位能源用于发电,发电机组排放的低品位能源(烟气余热、热水余热)用于制冷,达到充分利用能源的目的,同时每年减少18吨SO2,的排放,产生较好的经济效益和积极的社会效益.     

啤酒领域循环经济新技术

广州珠江．集团公司污水处理过程中会产生大量沼气，每天有大约10000—12000m^3沼气直接燃烧排放。分析和介绍珠啤集团将该部分沼气回收综合利用的情况，将沼气回收悦硫预处理后用于发电和制冷，即将高品位能源用于发电．发电机组排放的低品位能源（烟气余热、热水余热）用于制冷．达到充分利用能源的目的，同时每年减少18吨SO，的排放，产生较好的经济效益和积极的社会效益。     

实例分析大中型沼气工程能源效益

以扬州某畜禽养殖场大中型沼气工程为例,从各种能源替代类别差异的视角,利用等效能量替代的方法对大中型沼气工程产生沼气的能源替代效益进行分析,同时计算沼气发电余热回收利用所节约的能源量,为分析计算畜禽养殖场大中型沼气工程能源效益和经济效益提供了方法和案例.     

大中型沼气工程增温及控制系统运行管理策略

针对北方地区大中型养殖场沼气工程,制定一套发酵罐体增温及控制系统的运行管理策略,它分为供暖期与非供暖期两种模式。阐述两种系统的工作原理,对系统的热负荷、发电余热回收、沼气锅炉采暖及锅炉回水余热回收进行理论计算,并进行设备选型。计算可得:发酵系统平均每日热负荷为3.26 GJ,余热锅炉每日可提供的发电尾气余热回收量为3.64 GJ,发电量为1300 k Wh/d;通过板式换热器与沼气锅炉回水换热,每日集热量为4.41 GJ,可满足维持发酵罐体正常发酵温度的要求,从而保证厌氧发酵系统的稳定运行。     

获能式制冷及其在工业冷却中的应用

在制冷装置中,利用简易的汽轮发电机取代其冷却系统,制冷中吸收的热能和剩余动能用于发电反馈回电网,从而将制冷由耗能变为获能。采用获能式的制冷装置对工业生产中余热进行冷却,从而获取热能用于发电以提高设备效率。     

钢铁企业佘热蒸汽利用状况的研究

余热回收和利用是钢铁企业节能减排的重要措施。分析了钢铁企业余热蒸汽回收利用系统的特点,研究表明,做好余热蒸汽的回收和科学利用可以使钢铁企业对一次能源的需求量减少约8％。余热蒸汽利用系统要根据“按质用能,温度对口,梯级利用,热和能尽其利用”的原则进行统一的规划。开发先进的余热蒸汽调控和利用技术,是目前余热蒸汽回收利用的关键,随着钢铁企业余热蒸汽回收量的增加,应该大力发展蒸汽制冷、余热蒸汽发电等技术。     

发动机余热回收技术的研究现状及发展趋势

综述了国内外发动机余热回收技术的研究现状和发展趋势.从用途上把发动机余热利用技术分为废气涡轮增压、制冷空调、发电、采暖和改良燃料等五种,并分别探讨这些技术的可行性.阐述了有关余热回收的新技术及新理论.最后指出了利用有机工质循环系统将废气余热转化为电能,是汽车余热利用的发展趋势.     

燃气分布式供能项目经济性研究

1综述分布式能源系统,是指将燃料同时转换成多种产品:电力、热水、蒸汽、冷水或除湿后的新鲜空气。具体就是将小型化、模块化的发电系统布置在用户附近,利用城市管道天然气为燃料发电供用户使用,同时把发电过程中发电机组产生的冷却水和排气中的余热用热交换器回收生产热水或蒸汽供用户采暖、洗浴、制冷或除湿。通过对一次能源的多级利用,能源总利用率可达80%以上,节能效果明显。同时还具备环保、建设周期短、投资回收快、保证用电可靠性等优点。     

钢铁企业余热蒸汽利用状况的研究

余热回收和利用是钢铁企业节能减排的重要措施。分析了钢铁企业余热蒸汽回收利用系统的特点,研究表明,做好余热蒸汽的回收和科学利用可以使钢铁企业对一次能源的需求量减少约8%。余热蒸汽利用系统要根据"按质用能,温度对口,梯级利用,热和能尽其利用"的原则进行统一的规划。开发先进的余热蒸汽调控和利用技术,是目前余热蒸汽回收利用的关键,随着钢铁企业余热蒸汽回收量的增加,应该大力发展蒸汽制冷、余热蒸汽发电等技术。     

低品质余热回收利用热经济性分析

回收低品质余热用于制冷,减少制冷机组所需的低压蒸汽,节省煤量,同时自备电厂供热机组供汽量减少,热电比减小,煤耗增加,两者的差值是余热利用后净节省煤量。通过计算发现,考虑余热回收利用对自备电厂的影响．回收制冷机组投资成本需3a的时间,而按以往计算只需1a,其两者数据结果偏差较大。因此,分析余热回收利用实际问题时,需考虑多方面因素对企业的影响。     

联合太阳能沼气的冷热电供能系统的集成及经济性分析

冷热电联供是一种先进、高效的能源系统,目前在我国应用的主要问题是天然气成本高,导致系统经济性差。太阳能和沼气是非常清洁的可再生能源,在我国来源广泛且廉价。将冷热电联供系统与太阳能、沼气完美地结合起来,集成为联合太阳能沼气的冷热电供能系统。该系统较为合理的组合方式是采用太阳能沼气池作为燃料提供装置,采用微型燃气轮机、余热锅炉、溴化锂吸收式制冷机、蒸汽换热器等作为供电、供冷和供热机组,采用太阳能集热器、换热器等装置为沼气池加热,太阳能不足时采用尾气加热。该系统能够实现能量的梯级利用,提高一次能源利用率,达到综合用能的目的,同时可有效治理环境。以某酒店作为该系统的用户对象,分析其经济性并与常规模式进行对比。结果表明,该系统一次能源利用率为74.8%,而常规模式为62.3%;综合能源价格为0.3398元/(k W·h),而现阶段电网电价约为0.6元/(k W·h);环境与减排评价指标也具有明显优势。     

Biogas derived from municipal solid waste to generate electrical power through solid oxide fuel cells

Depleting fossil fuels and the pollution resulting from their consumption indicate an urgent need for clean and dependable alternatives such as renewable energies. Biomass is a free and abundant source of renewable energy. Municipal solid waste (MSW) as one of the main categories of biomass has always been an issue for metropolitan cities. It has, however, a high potential for biogas production. In this study, the technical and economic aspects of generating electrical power through solid oxide fuel cells (SOFCs) powered by injecting biogas derived from Tehran's MSW, as a case study, are investigated. The main objectives of the current study are to identify the power generation capability of the process and find out if it can result in a competitive energy resource. The total amount of obtainable methane through anaerobic digestion of MSW and then the achievable power generation capacity by using the obtained biogas are computed using the electrochemical relations inside the SOFC. The economic calculations are carried out to estimate the final price of the generated electricity, taking into account the major capital and ongoing costs of the required equipment. The effect of variations of MSW composition on the power generation capability and final electricity price is also studied. Moreover, the application of a gas turbine (GT) with the SOFC as a hybrid SOFC–GT system to recover the produced heat by SOFC and its effect on the power generation capability and the final electricity price are investigated. Results indicate that around 997.3 tons day^?1 biomethane can be generated using Tehran's MSW. By using the SOFC, the produced biogas can generate 300 MW_AC electrical power with a final cost of Depleting fossil fuels and the pollution resulting from their consumption indicate an urgent need for clean and dependable alternatives such as renewable energies. Biomass is a free and abundant source of renewable energy. Municipal solid waste (MSW) as one of the main categories of biomass has always been an issue for metropolitan cities. It has, however, a high potential for biogas production. In this study, the technical and economic aspects of generating electrical power through solid oxide fuel cells (SOFCs) powered by injecting biogas derived from Tehran's MSW, as a case study, are investigated. The main objectives of the current study are to identify the power generation capability of the process and find out if it can result in a competitive energy resource. The total amount of obtainable methane through anaerobic digestion of MSW and then the achievable power generation capacity by using the obtained biogas are computed using the electrochemical relations inside the SOFC. The economic calculations are carried out to estimate the final price of the generated electricity, taking into account the major capital and ongoing costs of the required equipment. The effect of variations of MSW composition on the power generation capability and final electricity price is also studied. Moreover, the application of a gas turbine (GT) with the SOFC as a hybrid SOFC–GT system to recover the produced heat by SOFC and its effect on the power generation capability and the final electricity price are investigated. Results indicate that around 997.3 tons day^?1 biomethane can be generated using Tehran's MSW. By using the SOFC, the produced biogas can generate 300 MW_AC electrical power with a final cost of $0.178 kWh^?1. By using the hybrid SOFC–GT, the electrical power capacity is increased to 525 MW_AC, and the final electricity cost drops to $0.11 kWh^?1, which indicates its competitiveness with other common energy resources in the near future, especially by considering different governmental subsidy policies that support renewable energy resources. The considerable environmental benefits of the proposed procedure, from both MSW management and CO₂ emission reduction points of view, make it a promising sustainable energy resource for the future. Copyright © 2016 John Wiley & Sons, Ltd.     

Sustainable biogas energy in Poland: Prospects and challenges

The article investigates prospects and challenges for expanding of sustainable biogas energy in Poland. The number of Polish biogas fuelled power plants and installed electrical power during the 2001-2010 decade is presented. Current economical incentives for biogas energy are discussed. It is emphasized that some revisions to the Polish tradable certificate system are urgently needed in order to encourage energy crop cultivation and the use of best available power technologies. Further, promising, but mostly unexplored feedstocks, such as energy crops, grasses and sorted municipal organic wastes are analyzed. It is also revealed that agrobiogas is characterized by a unique feature of ‘negative net’ CO₂ atmospheric emissions and thus the role of agrobiogas in solving Polish CCS dilemmas is discussed. In regard to biogas energy systems it is stressed, that the cost of electricity from biogas is almost independent on the size of agrobiogas CHP power plants in the range of 0.2-5 MW_e. Therefore agrobiogas energy is well suited for distributed energy systems involving small-scale agrobiogas power plants offering more green jobs and improved local waste management characteristics. Finally, reliable technologies suitable for biogas energy conversion and upgrading of biogas fuel to marketable gaseous fuels are briefly characterized.     

Strategies to improve the performance of a spark ignition engine using fuel blends of biogas with natural gas,propane and hydrogen

This work presents the strategies applied to improve the performance of a spark ignition (SI) biogas engine. A diesel engine with a high compression ratio (CR) was converted to SI to be fueled with gaseous fuels. Biogas was used as the main fuel to increase knocking resistance of the blends. Biogas was blended with natural gas, propane, and hydrogen to improve fuel combustion properties. The spark timing (ST) was adjusted for optimum generating efficiencies close to the knocking threshold. The engine was operated on each blend at the maximum output power under stable combustion conditions. The maximum output power was measured at partial throttle limited by engine knocking threshold. The use of biogas in the engine resulted in a power derating of 6.25% compared with the original diesel engine (8 kW @ 1800 rpm). 50% biogas + 50% natural gas was the blend with the highest output power (8.66 kW @1800 rpm) and the highest generating efficiency (29.8%); this blend indeed got better results than the blends enriched with propane and hydrogen. Tests conditions were selected to achieve an average knocking peak pressure between 0.3 and 0.5 bar and COV of IMEP lower than 4% using 200 consecutive cycles as reference. With the blends of biogas, propane, and hydrogen, the output power obtained was just over 8 kW whereas the blends of biogas, natural gas, and hydrogen the output power were close to 8.6 kW. Moreover, a new approach to evaluate the maximum output power in gas engines is proposed, which does not depend on the engine % throttle but on the limit defined by the knocking threshold and cyclic variations.     

太阳能吸收式制冷系统夏季运行方式分析

介绍一个典型太阳能吸收式制冷系统,讨论了其在夏季的各种运行方式及相应运行特性,提出了各运行模式的控制方案。     

CO2双蒸发器压缩/喷射式跨临界制冷循环

为减小CO_2跨临界循环系统节流部分的膨胀功损失,提高系统性能,可在小型制冷系统中采用喷射器代替节流阀,部分回收工质从高压到低压过程的膨胀功。在对系统进行热力学分析的基础上,建立了CO_2跨临界压缩／喷射制冷循环的效率分析模型。计算结果表明：在合理的喷射器出口背压下,CO_2跨临界压缩／喷射制冷循环可以得到较高的循环性能。蒸发温度和气体冷却器出口温度两工况的变化对该系统性能的影响程度相对较大。在较低蒸发温度下,该系统可以明显降低压缩机出口温度,有利于系统稳定运行。     

Use of waste for heat,electricity and transport—Challenges when performing energy system analysis

This paper presents a comparative energy system analysis of different technologies utilising organic waste for heat and power production as well as fuel for transport. Technologies included in the analysis are second-generation biofuel production, gasification, fermentation (biogas production) and improved incineration. It is argued that energy technologies should be assessed together with the energy systems of which they form part and influence. The energy system analysis is performed by use of the EnergyPLAN model, which simulates the Danish energy system hour by hour. The analysis shows that most fossil fuel is saved by gasifying the organic waste and using the syngas for combined heat and power production. On the other hand, least greenhouse gases are emitted if biogas is produced from organic waste and used for combined heat and power production; assuming that the use of organic waste for biogas production facilitates the use of manure for biogas production. The technology which provides the cheapest CO₂ reduction is gasification of waste with the subsequent conversion of gas into transport fuel.     

Local acceptance of existing biogas plants in Switzerland

After the Swiss government's decision to decommission its five nuclear power plants by 2035, energy production from wind, biomass, biogas and photovoltaic is expected to increase significantly. Due to its many aspects of a direct democracy, high levels of public acceptance are necessary if a substantial increase in new renewable energy power plants is to be achieved in Switzerland. A survey of 502 citizens living near 19 biogas plants was conducted as the basis for using structural equation modeling to measure the effects of perceived benefits, perceived costs, trust towards the plant operator, perceived smell, information received and participation options on citizens’ acceptance of “their” biogas plant. Results show that local acceptance towards existing biogas power plants is relatively high in Switzerland. Perceived benefits and costs as well as trust towards the plant operator are highly correlated and have a significant effect on local acceptance. While smell perception and information received had a significant effect on local acceptance as well, no such effect was found for participation options. Reasons for the non-impact of participation options on local acceptance are discussed, and pathways for future research are presented.     

Application of Anaerobic Digestion Model No. 1 for describing an existing biogas power plant

Pragmatic approach was adopted in order to reduce the amount of parameters necessary for determination, prior to simulation with Anaerobic Digestion Model No. 1 (ADM1). As a result common kinetic constants describing hydrolysis phase, applicable for a wide range of substrates, were determined and tested. Afterwards, this simulation methodology was tested against industrial scale biogas power plant, with 7 dam³ fermenter size, and feed with cattle manure and food waste. The result confirmed the applicability of ADM1 with modified kinetic constants in describing an existing biogas power plant.     

Technical–economical analysis of the Saveh biogas power plant

The resource limitation of fossil fuels and the problems arising from their combustion has led to widespread research on the accessibility of new and renewable energy resources. Solar, wind, thermal and hydro sources, and finally biogas are among these renewable energy resources. But what makes biogas distinct from other renewable energies is its importance in controlling and collecting organic waste material and at the same time producing fertilizer and water for use in agricultural irrigation. Unlike other forms of renewable energy, biogas neither has any geographical limitations and required technology for producing energy and nor is it complex or monopolistic. Considering the ever increasing amount of different types of organic waste materials (about 15 million tonnes) in Iran, working on the control of waste material and biogas production becomes inevitable.In this paper, biogas and the benefits from its production are discussed, as is the technical-economic analysis of the Saveh biogas power plant as a case study.