农作物秸秆固化成型燃料生产企业投资分析

将农作物秸秆及其废弃物压制成长方体或圆柱体成型燃料,就能将农作物秸秆变成替代原煤的燃料。通过对农作物秸秆固化成型燃料生产企业建设的选址、工艺装备、生产规模、生产运营成本、经济效益等分析,为投资建设农作物秸秆固化成型燃料生产企业提供帮助和启示,以提高投资效益,促进我国农作物秸秆能源化事业快速稳步发展。     

中国和瑞典将合作开发生物质能源项目

据中国-瑞典利用木薯秸秆开发生物质能源高效热电联产项目研讨会透露的消息,2010年,中国和瑞典将充分利用广西丰富的木薯秸秆资源,合作开发发电、产热和生产固体颗粒成型燃料生物质能源高效热电联产项目。     

秸秆成型燃料气化气作为车载燃料的试验研究

以改变进入气化炉空气的温度,从而改变当量比的方法研究了秸秆成型燃料气化产出气的成分变化规律.研究结果表明:气化气成分变化明显,热值大幅度提高,达到了改变气体成分的目的.初步研究了秸秆成型燃料气化气作为机动车燃料的适应性和动力性能,着重分析了尾气中CO,HC及NOx的排放规律及主要影响因素.研究结果表明:秸秆成型燃料气化气对汽车发动机有良好的适应性;尾气排放完全符合GB18285-2005的相关规定,其中,CO,HC的排放量仅为排放限值的5.56%和1.11%.     

高热值垃圾制备RDF成型特性及可行性

为高效能源化处理城市废物,文章提出了城市生活垃圾分质收集、分别处理、以废治废的新理念,即将高热值垃圾与其它废物联合制取RDF(垃圾衍生燃料)为工业应用提供能源;研究不同水分含量、不同塑料含量及不同附加物(生物质)对RDF成型特性的影响,对RDF制取过程进行部分能耗分析。结果表明:随着塑料含量增加RDF颗粒热值明显增大,但颗粒变得松散易破碎,堆积密度和颗粒长度降低,塑料含量小于50%为宜;随着含水率的增加热值有下降趋势,但利于颗粒压缩成型,堆积密度和颗粒长度降低,含水率控制在10%¹4%时,颗粒成型效果较好;锯末作为辅料制备的RDF成型效果比秸秆好。     

水洗预处理对甜高粱茎秆酵渣燃料性能改善试验研究

对水洗预处理后的甜高粱茎秆酵渣进行工业分析、元素分析,热值、燃烧特性、灰分组分和灰熔融特性测试,研究常温下水洗固液比对甜高粱茎秆酵渣燃烧性能的影响。试验结果表明:水洗有助于脱除灰分,增大低位热值,大幅减小原料中的Cl、N元素的含量,降低燃料结渣指数。在常温情况下,采用固液比1∶30进行水洗预处理,确保燃料的各项性能得到提升,减少NO_x和二恶英(PCDD/F)的污染排放。另外,建议进行酸洗以减轻燃料中的碱性化合物含量,进一步减轻结渣趋势。     

秸秆成型燃料加工装备与掺烧发电研究

将农作物秸秆加工成成型燃料用于掺烧发电等,既可增加农民收入,保护生态环境,又能有效解决我国能源紧缺的矛盾.在分析了国内外秸秆成型燃料掺烧发电技术与装备、秸秆成型燃料加工技术与装备的发展现状、存在问题的基础上,对秸秆成型燃料掺烧发电技术和装备、秸秆成型燃料加工技术的发展前景进行了探索,并就秸秆成型燃料掺烧发电与加工技术装备行业的健康发展提出了保障措施.     

中国农作物秸秆能源化潜力估算

农作物秸秆中含有丰富的有机质,是个巨大的能源库,对其的准确定量是秸秆综合利用的前提条件.文章以2005年中国农作物秸秆资源为例,结合农作物秸秆的能源转化方式,定量估算了中国农作物秸秆能源化的潜力,为秸秆综合利用提供参考资料.结果表明,中国每年约有3.995×108 t农作物秸秆可作为能源利用,这些秸秆若全部以直接燃烧、锅炉燃烧、压缩成型燃烧、沼气供热、沼气发电、气化供热以及气化发电等不同转化方式加以利用,则其能源化产品可分别替代化石燃料0.291×108,0.5×108,2.039×108,0.815×108,0.258×108,2.217×108和0.5987×108 t标煤.其中气化供热能源转化效率最高,可达60.37%,其次为压缩成型燃烧,能源转化效率达58.26%.秸秆资源用于气化供热和压缩成型燃烧潜力巨大.     

我国秸秆成型燃料掺烧发电与加工技术前景探讨

农作物秸秆是宝贵的资源,但利用率很低。将农作物秸秆加工成成型燃料用于掺烧发电等,既可增加农民收入,保护生态环境,又能有效解决我国能源紧缺的矛盾。分析国内外秸秆成型燃料掺烧发电技术与装备、秸秆成型燃料加工技术与装备的发展现状、存在问题和发展前景,提出秸秆成型燃料掺烧发电与加工技术装备行业的健康发展保障措施。     

成型生物质流化床气化及结渣影响因素研究

为提高生物质气化产物的品质,采用成型桉树皮和成型玉米秸秆2种典型农林废弃物,并选取稻壳和木屑作为对比,在中试规模的流化床实验台上进行气化实验,得到成型桉树皮、成型玉米秸秆、稻壳和木屑的最佳空气当量系数,分析了成型生物质在气化中出现结渣现象的原因。结果表明：在实验条件下,成型桉树皮、稻壳和木屑的最佳空气当量系数为0.20,其燃气热值分别为5.5 MJ/m³、5.5 MJ/m³、6 MJ/m³,气化效率分别为60%、45%、52%;成型玉米秸秆由于其高灰分、低热值,所需空气量更大,最佳空气当量系数为0.24,燃气热值为4 MJ/m³,气化效率为35%;气化温度提高可促进不同生物质的气化反应,碱金属、碱土金属含量较多的成型生物质在气化过程中更易结渣。     

秸秆成型燃料锅炉的设计及试验研究

根据秸秆成型燃料高挥发性和燃烧稳定的特点,完成了输出热负荷200 kW的秸秆成型燃料锅炉的设计。其炉膛可分为热解区、炭燃烧区与挥发分燃烧区3部分,实现了秸秆成型燃料的分段燃烧。以直径不同的5种玉米秸秆成型燃料进行了试验研究,分别对其输出热负荷、燃气中CO含量及热利用效率进行了测试,发现利用直径为40～50 mm成型燃料时,锅炉的输出热负荷最大,热利用率较高,烟气中CO含量较低。     

Biomass from agriculture in small-scale combined heat and power plants - A comparative life cycle assessment

Biomass produced on farm land is a renewable fuel that can prove suitable for small-scale combined heat and power (CHP) plants in rural areas. However, it can still be questioned if biomass-based energy generation is a good environmental choice with regards to the impact on greenhouse gas emissions, and if there are negative consequences of using of agricultural land for other purposes than food production.In this study, a simplified life cycle assessment (LCA) was conducted over four scenarios for supply of the entire demand of power and heat of a rural village. Three of the scenarios are based on utilization of biomass in 100 kW (e) combined heat and power (CHP) systems and the fourth is based on fossil fuel in a large-scale plant. The biomass systems analyzed were based on 1) biogas production with ley as substrate and the biogas combusted in a microturbine, 2) gasification of willow chips and the product gas combusted in an IC-engine and 3) combustion of willow chips for a Stirling engine. The two first scenarios also require a straw boiler.The results show that the biomass-based scenarios reduce greenhouse gas emissions considerably compared to the scenario based on fossil fuel, but have higher acidifying emissions. Scenario 1 has by far the best performance with respect to global warming potential and the advantage of utilizing a byproduct and thus not occupying extra land. Scenario 2 and 3 require less primary energy and less fossil energy input than 1, but set-aside land for willow production must be available. The low electric efficiency of scenario 3 makes it an unsuitable option.     

Evaluation of energy efficiency of various biogas production and utilization pathways

The energy efficiency of different biogas systems, including single and co-digestion of multiple feedstock, different biogas utilization pathways, and waste-stream management strategies was evaluated. The input data were derived from assessment of existing biogas systems, present knowledge on anaerobic digestion process management and technologies for biogas system operating conditions in Germany. The energy balance was evaluated as Primary Energy Input to Output (PEIO) ratio, to assess the process energy efficiency, hence, the potential sustainability. Results indicate that the PEIO correspond to 10.5–64.0% and 34.1–55.0% for single feedstock digestion and feedstock co-digestion, respectively. Energy balance was assessed to be negative for feedstock transportation distances in excess of 22 km and 425 km for cattle manure and for Municipal Solid Waste, respectively, which defines the operational limits for respective feedstock transportation. Energy input was highly influenced by the characteristics of feedstock used. For example, agricultural waste, in most part, did not require pre-treatment. Energy crop feedstock required the respect cultivation energy inputs, and processing of industrial waste streams included energy-demanding pre-treatment processes to meet stipulated hygiene standards. Energy balance depended on biogas yield, the utilization efficiency, and energy value of intended fossil fuel substitution. For example, obtained results suggests that, whereas the upgrading of biogas to biomethane for injection into natural gas network potentially increased the primary energy input for biogas utilization by up to 100%; the energy efficiency of the biogas system improved by up to 65% when natural gas was substituted instead of electricity. It was also found that, system energy efficiency could be further enhanced by 5.1–6.1% through recovery of residual biogas from enclosed digestate storage units. Overall, this study provides bases for more detailed assessment of environmental compatibility of energy efficiency pathways in biogas production and utilization, including management of spent digestate.     

Anaerobic fermentation technology increases biomass energy use efficiency in crop residue utilization and biogas production

A biomass energy utilization project (Corn stalk→Cattle→Cattle dung→Biogas digester→Biogas/Digester residues→Soil) was conducted in a typical temperate agro-village of China from 2005 to 2010. The present study focused on two key approaches of the ecological loop: (1) increasing corn stalk use efficiency by improving anaerobic fermentation technology; and (2) enhancing biogas productivity by optimizing fermentation conditions. Our results showed that crude protein and fat of corn stalks significantly increased, while crude fiber content and pH decreased considerably during anaerobic fermentation. The cattle digestion rate, forage consumption and increases in cattle weight were higher in cattle fed fermented corn stalks than in those fed non-fermented corn stalks. The rate of biogas production was higher (78.4%) by using cattle dung as a substrate than using crop residues. Heat preservation measures effectively enhanced the biogas production rate (12.3%). In 2005, only two cattle were fed in this village, with only 1.1% corn stalk utilized as forage. No more than three biogas digesters existed, and the proportion of biogas energy used in total household fuel was only 1.7%. At the end of the 5-year experiment, the number of cattle capita reached 169 with 78.9% corn stalk used as forage. Biogas digesters increased to 130, and the proportion of biogas energy used in total household fuel was up to 42.3%. A significant positive correlation was noted between the increasing rate of farmers’ incomes and the proportion of corn stalks used as forage. Available nutrients were higher in fermented cattle dung than in fresh cattle dung. Our findings clearly suggest that anaerobic fermentation technology is important in enhancing crop residue use efficiency, biogas productivity and soil fertility. Fermentation technology may help reduce the use of fossil fuels and improve the environment in rural areas.     

北方农村复合颗粒燃料取暖全生命周期评价研究

以秸秆和煤为原料制备复合颗粒燃料,利用全生命周期评价方法,研究颗粒燃烧取暖全生命周期过程中的能源消耗和环境影响。结果表明：颗粒燃料取暖全生命周期过程中能量投入为908 MJ/t,燃烧释放热量15490 MJ/t,能量产出投入比为17.1,能源转化效率较高。颗粒燃料的能量投入主要来自玉米种植,种植过程中的氮肥使用消耗较多能量。对气候变化（GWP）和酸化（AP）贡献较大的清单数据为颗粒燃料的燃烧,其中燃烧污染物排放的直接贡献最大,贡献率分别为53.22%和46.08%;对水资源消耗（WU）贡献较大的清单数据为颗粒燃料的压制,贡献率为71.56%;对富营养化潜值（EP）贡献较大的清单数据为颗粒燃料燃烧后的废渣排放,贡献率为43.40%。     

生物质气化技术面临的挑战及技术选择

生物质气化可实现低品位生物质能的深层次利用,不同地区、不同行业有不同的能源需求和产业结构,应合理选择生物质气化技术。固定床气化技术针对的是中小规模应用,该技术存在的问题包括焦油含量高、规模小、机械化和自动化程度较低、发电效率低等。流化床气化技术针对的是中等及以上规模应用,目前需要解决的问题是热效率低,发电效率低,需要开发高气化效率和无焦油的燃气型气化炉、低热值燃气轮机、高效燃气净化系统,以便采用BIGCC技术。沼气技术是一项生物质综合高效清洁利用的多联产工艺,目前急需开发高效高浓度厌氧消化的沼气发酵工艺和配套的集成设备,培育和筛选高效沼气发酵微生物菌群,简化沼气净化工序,解决沼液、沼渣的利用难题等。生物质快速热解技术是一种高温处理过程,其最大的优点是产物生物油易于储存运输,不存在产品规模和消费的地域限制问题。从工艺特点、经济效益和规模化生产来看,沼气技术更适合处理高含水的养殖业粪便,快速热解技术更适合农作物秸秆的规模化转化,燃气型气化技术更适合社区生活垃圾和农林产品加工废弃物的处理。     

Technical, economic and environmental analysis of energy production from municipal solid waste

Four technologies are investigated which produce energy from municipal solid waste (MSW): incineration, gasification, generation of biogas and utilisation in a combined heat and power (CHP) plant, generation of biogas and conversion to transport fuel.Typically the residual component of MSW (non-recyclable, non-organic) is incinerated producing electricity at an efficiency of about 20% and thermal product at an efficiency of about 55%. This is problematic in an Irish context where utilisation of thermal products is not the norm. Gasification produces electricity at an efficiency of about 34%; this would suggest that gasification of the residual component of MSW is more advantageous than incineration where a market for thermal product does not exist. Gasification produces more electricity than incineration, requires a smaller gate fee than incineration and when thermal product is not utilised generates less greenhouse gas per kWh than incineration. Gasification of MSW (a non-homogenous fuel) is, however, not proven at commercial scale.Biogas may be generated by digesting the organic fraction of MSW (OFMSW). The produced biogas may be utilised for CHP production or for transport fuel production as CH₄-enriched biogas. When used to produce transport fuel some of the biogas is used in a small CHP unit to meet electricity demand on site. This generates a surplus thermal product.Both biogas technologies require significantly less investment costs than the thermal conversion technologies (incineration and gasification) and have smaller gate fees. Of the four technologies investigated transport fuel production requires the least gate fee. A shortfall of the transport fuel production technology is that only 50% of biogas is available for scrubbing to CH₄-enriched biogas.     

Integration of biogas plants in the building materials industry

The paper quantifies the synergy-effects of an areal combination of biogas-plants with plants of the building materials industry (e.g. cement works) from the energetic and economical point of view. Therefore an overall process model based on energy and mass flow balances is developed to determine the effects of a combination of both plants in terms of energetic efficiency, investment and operating costs, greenhouse gas emission reduction and overall energy production costs. The results and the calculation procedure for a combination of biogas plants with cement works are presented in detail. The main benefits of this combination are the utilisation of low temperature excess heat sources from cement works for fermenter heating and the direct thermal utilisation of unprocessed biogas as a valuable, CO₂-neutral fuel for combustion processes for instance clinker burning. Due to the combination, the energetic efficiency of the biogas plant, defined as utilisable energy output in relation to the energy content of the produced biogas, significantly increases from 63.0% to 83.8%. Concurrently the energy production costs are reduced, turning biogas into a competitive source of energy without the need for federal sponsorship. Calculations show, that production costs in combined plants for plant sizes larger than 90 m³_STP/h biogas are even lower than the actual market prize of natural gas.     

反馈系统在池炉燃气热值调节中的应用研究

为了提高超白玻璃的生产质量并降低能耗,要求对玻璃炉窑燃用的天然气的热值进行精确控制。利用对空气流加热的方法在线测量燃气的热值,通过给燃气加入空气调整燃气热值,设计了燃气热值反馈调节系统。系统采用前馈和双闭环的调整方法,有效地保障了池炉燃气供应系统良好的热值调节质量。试验表明:反馈控制系统控制精度为1.0%,重复性为0.3%,响应时间为6 s,采用热值反馈系统后燃气热值波动范围由原来的40.9~42.8MJ/m3减小为34.5~34.7MJ/m3,满足了玻璃熔化质量的要求,提高了窑炉燃烧效率。     

低热值燃气-柴油双燃料发动机动力性能计算

推导了低热值燃气-柴油双燃料发动机动力性能计算公式,并对由单缸、四冲程、水冷、直喷式柴油机改装的生物制气-柴油双燃料发动机的动力性能进行了计算分析。结果表明：双燃料发动机能够达到原柴油机的动力水平;其动力性能随引燃油量的减小而降低;在新鲜空气充足的前提下,供给更多的燃气,双燃料发动机的动力性能增强;燃气替代率有一最大值,超过该值后,随替代率增大,动力性能急剧下降;燃气低热值越高,替代率便可越大。计算得出的生物制气-柴油双燃料发动机在标定点和最大转矩点的最大生物制气替代率和对应的燃气进气比,与试验结果相吻合。     

Investigation of performance and emission characteristics of a biogas fuelled electric generator integrated with solar concentrated photovoltaic system

Integration of renewable energy systems with the appropriate technology plays a pivotal role in resolving the problem of sustainable energy supply. This paper is aimed to describe the concept of integration of biomass and solar concentrated photovoltaic (CPV) energy system. The present study focused particularly on the investigation of performance and emission from a 1.4 kVA Spark Ignition, constant speed generator using raw biogas integrated in hybrid energy system. The experiments are conducted at different fuel flow rates under varying electric loading conditions. Comparing with LPG as fuel, the power deterioration is observed to be 32% on raw biogas, due to its low calorific value. The maximum power output and brake thermal efficiency using biogas is witnessed to be 812 W and 19.50% respectively. The exhaust emission analysis of generator using biogas displays considerably reduced carbon monoxide and hydrocarbons whereas there is no significant difference in nitrogen oxides concentration levels while comparing with LPG, ascertaining it to be an eco-friendly fuel. The biogas fuelled electric generator integration with CPV system can attain sustainable rural energy supply.