浅谈我国生物质锅炉对节能减排的影响

本文主要从节能减排方面探讨使用生物质锅炉的必要,能源是人类社会生存与发展的物质基础,世界各国在高速发展经济的同时对环境保护的要求也越来越高,全世界都在从保护人类自然资源和生态环境出发寻求一种新的清洁、安全、可靠的可持续发展能源体系。,     

生物质合成气制备及合成液体燃料研究进展

主要介绍了国内外生物质气化制备合成气工艺以及国内外生物质合成气合成液体燃料的工艺技术.生物质直接气化技术在早期得到了较好的发展,但生物质收集困难,限制了其发展.近几年国内外开发了生物质两段气化工艺技术.该技术通过快速裂解把生物质裂解为能量密度相对较高的快速裂解油(生物油),通过收集生物油制备合成气路线可以降低整个系统的...     

中国东北地区发展生物质型煤理论与实践的探讨

从分析生物质型煤比传统型煤具有的优势入手,对生物质型煤的用途进行了阐述,并预测了其市场需求。针对东北地区丰富的原料来源,设计出生产生物质型煤的工艺方法。结合生物质型煤的节能减排效应,对年产100万t项目进行投资估算及经济分析,其结果表明该项目具有较强的盈利能力。     

中国生物质炉灶技术和应用进展

回顾了我国生物质炉灶的发展历程,介绍了我国生物质炉灶的推广应用现状和技术水平,分析了生物质炉灶性能评价标准和方法;阐述和分析了生物质炉灶开发CDM项目的发展现状、开发方法以及未来发展的巨大潜力;最后提出了生物质炉灶技术和应用发展的建议.     

生物质能源开发利用的现状研究

能源是人类活动的物质基础。近些年来随着工业的蓬勃发展,非可再生能源消耗越来越严重,这让我们不得不考虑将眼光转投其他替代能源,特别是生物质能源。     

生物质气化制取合成气的模拟

阐述了利用串行流化床制取生物质合成气的技术,该技术将生物质气化过程与燃烧过程分开,气化反应器和燃烧反应器之间通过床料进行热量传递,并通过生物质补燃实现自供热。利用ASPEN PLUS软件建立了串行流化床制取合成气的模型,通过将模拟数值与实验结果相比较,验证了模拟研究的可行性。重点研究了气化温度、水蒸汽与生物质的质量配比(S/B)对制取生物质合成气的影响。结果表明,为获取较高品质的生物质合成气并得到较高的碳转化率、气化份额和合成气产率,气化温度以650～800℃为宜,S/B应在0.2～1.0之间。     

生物质对降低煤制合成氨综合能耗的应用价值

简要介绍一种完全不同于传统中小合成氨的新原料路线工艺,对生物质炭块替代无烟块煤可操作性进行了分析、论证。认为从合成氨原料这一源头变革原料路线将使降低煤制合成氨综合能耗迎刃而解,带来超预期经济、技术、社会效益。     

生物质合成气合成二甲醚的研究

在加压固定床反应装置上进行了生物质合成气合成二甲醚(DME)的研究.采用机械混合法制备二甲醚合成双功能催化剂.考察了组成为V(H_2):V(CO):V(CO_2):V(CH_4)=52:24:23:1的生物质合成气在不同反应温度、空速、压力下对合成二甲醚反应的影响.同时进行了102 h的催化剂的稳定性实验.结果表明,在260-300℃范围内,随反应温度的升高,CO转化率和二甲醚的选择性均先增大后减小;随反应压力的升高,CO转化率和二甲醚选择性都随之升高;原料气中高浓度的CO_2可导致铜基催化剂较快的失活.     

生物质合成气一步法合成二甲醚的反应器及温度控制系统

本发明公开了一种生物质合成气一步制二甲醚的反应器,包括有固定床反应器,沿该反应器内纵向平行分布有多根反应列管;在所述固定床反应器的     

低劣生物质厌氧产甲烷过程的模拟研究进展

低劣生物质厌氧消化可以减少温室气体的排放并且生产生物甲烷作为能源。介绍了关于厌氧消化过程、底物的相关理论,还对目前主要用于厌氧产甲烷过程研究的数学模型以及碳氮磷转化的模拟研究进行了综述。其中,一级动力学模型是最为简单的数学模型,其可以通过简单的计算得到整个过程中甲烷产量随着时间的变化曲线,但是只限于较准确模拟甲烷产率的ADM1模型相对发展最为全面、应用最为广泛,且能够针对具体要研究的对象进行模型的修改。同时总结了较为常见的底物厌氧产甲烷研究模型、研究对象及结果、已有碳/氮/磷转化模拟研究及相关研究,并对开展针对厌氧产甲烷过程中碳氮磷转化的模拟研究进行了展望。     

硫化钠节能生产工艺探索

随着我国工业化的发展,建设资源节约型、环境友好型社会是当今经济发展对工业化的必然要求。节能减排工作任重道远,能够有效缓解经济发展与资源环境之间的矛盾。我国硫化钠生产大多采用煤还原芒硝法,此种工艺资源利用率低,能耗较大,生产成本高,经济效益不佳。加快硫化钠生产工艺和生产设备的改造升级,有效实现节能减排,社会效益、经济效益明显。     

Simulation of biomass char gasification in a downdraft reactor for syngas production

A steady state, one‐dimensional computational fluid dynamics model of wood char gasification in a downdraft reactor is presented. The model is not only based on reaction kinetics and fluid flow in the porous char bed but also on equations of heat and mass conservation. An original OpenFOAM solver is used to simulate the model and the results are found to be in good agreement with published experimental data. Next, a sensitivity analysis is performed to study the influence of reactor inlet temperature and gas composition on char conversion, bed temperature profile and syngas composition. In addition, the evolution of the complex reaction mechanisms involved in mixed atmosphere gasification is investigated, and the most suitable operating parameters for controlling syngas composition are evaluated. Our simulation results provide essential knowledge for optimizing the design and operation of downdraft gasifiers to produce syngas that meets the requirements of various biofuel applications. © 2015 American Institute of Chemical Engineers AIChE J, 62: 1079–1091, 2016     

生物质粗燃气自热重整调变的热力学分析

运用吉布斯自由能最小化方法对生物质粗燃气自热重整过程进行了热力学分析,研究了重整反应过程中的温度,O2/CH4摩尔比及焦油摩尔分数等因素对平衡产物组成的影响规律。研究结果表明:低温有利于CO歧化与加氢反应,而高温促进了CH4和CO2的转化,提高合成气H2+CO摩尔分数,降低H2/CO摩尔比。O2/CH4摩尔比的增加有利于生物质燃气从部分氧化反应向完全氧化反应转变,促进了CH4的重整反应而抑制了CO2的转化;O2/CH4摩尔比的增加降低了合成气H2+CO摩尔分数,降低了H2/CO摩尔比,在重整后的生物质粗燃气中,n(H2)/n(CO)≈1。积碳量随温度升高和O2/CH4摩尔比的增加逐渐减少,随着焦油(C10H8)物质的量的增加而增加。焦油物质的量增加提高了合成气中H2与CO摩尔分数,是重整反应的重要原料。优化的生物质燃气自热重整反应条件为温度1 023 K,O2/CH4摩尔比0.7,焦油摩尔分数<1%。     

基于CoFe2O4载氧体的生物质化学链气化反应特性

在热重分析仪和固定床反应器上对基于CoFe₂O₄载氧体的生物质化学链气化反应特性进行了研究，考察了载氧体与生物质质量比、水蒸气、反应温度对生物质化学链气化反应特性的影响，同时也对载氧体的循环反应性能进行了研究。通过XRD及SEM对新制备的和反应后的载氧体进行了表征。热重结果表明：CoFe₂O₄能够提供晶格氧，有效促进生物质气化。当CoFe₂O₄与生物质质量比为0.8，水蒸气体积分数为50%，温度为900 ℃时，气化反应效果最好。5次循环反应后，仍能获得较高品质的合成气，载氧体能够循环再生且未出现明显烧结团聚。     

生物质合成气甲烷化与变换反应串联偶合新工艺

以模拟生物质合成气为原料,在固定床反应器中,对合成气甲烷化反应工艺条件进行优化,并在此反应中串联偶合水煤气变换反应,以此提高生物质合成气中碳氢的比例,从而弥补生物质合成气碳氢比较低的不足,使生物质合成气甲烷化反应更彻底,进而提高甲烷的收率。实验结果表明,在水煤气变换空速为15 000 h~(-1)、进水量0.02 m L·min~(-1)和还原温度为450℃条件下,甲烷化催化剂的性能最优,CO转化率100%,甲烷选择性对于整个偶合反应为50%,但就单一甲烷化反应高达99%。     

清洁生物质秸秆能源研究进展

秸秆生物质是一种洁净的可再生能源,具有硫、氮含量低,环境污染小等优点。目前,国内外秸秆生物质主要有裂解制取汽柴油、水解生产乙醇、燃料甲醇、厌氧消化制取沼气、固化生物性煤、秸秆发电、生物质制氢等方面技术的研究及应用。阐述了各种技术的特点和存在的问题,提出了清洁秸秆生物质能源应加强裂解液化技术的研究以及工艺过程的开发,并对其未来的应用前景作了一定的预测。     

源江水厂快滤池提升泵变频控制调节

通过PID控制方式对提升泵进行变频控制,达到确保进水渠水位恒定在(2±0.1)m的范围内的目标。为此,采用工程整定法,经过逐级调试逼近的方式,确定比例增益(P增益):K_p=18、积分增益(I增益):K_i=0、微分增益(D增益):K_d=20的参数组合,同时,也确定了PID控制参数CV的控制上限为60%,控制下限为10%,控制阈值DV为0.03。PID控制循环周期为200ms,同时,介绍了PID控制的数学模型。运行结果表明,通过逐级逼近法确定的控制增益参数组,PID控制效果明显,进水渠水位控制在(2±0.1)m的范围内,达到了恒水位控制目标。     

Co-firing of coal and cattle feedlot biomass (FB) fuels. Part II. Performance results from 30 kWt (100,000) BTU/h laboratory scale boiler burner

The use of cattle manure (referred to as feedlot biomass, FB) as a fuel source has the potential to both solve waste disposal problems and reduce fossil fuel based CO₂ emissions. A co-firing technology is proposed where FB is ground, mixed with coal, and then fired in existing, pulverized coal-fired boiler burner facilities. A research program was undertaken in order to determine (i) fuel characteristics, (ii) combustion characteristics when fired along with coal in a small scale 30-kW_t (100,000 BTU/h) boiler burner facility, and (iii) combustion and fouling characteristics when fired along with coal in a large pilot scale 150-kW_t (500,000 BTU/h) DOE-NETL boiler-burner facility. Part I presented a methodology for fuel collection, fuel characteristics of the FB, its relation to ration fed, and the change in fuel characteristics and volatile oxides due to composting. Part II addresses the pyrolysis characteristics of coal, FB, and blend and presents results on the performance of 90:10 coal:FB (PC) blend as fired in a 30-kW_t boiler-burner unit. The boiler-burner unit is made of steel and lined with a cast ceramic liner for long duration operation and a commercial feeding system is used for firing the coal and the blend. Thermogravimetric analyses (TGA) performed on coal, FB, and 90:10 coal:FB blend reveal that biomass will start releasing gases at 273 °C (523  °F) which is about 100 °C (212 °F) lower than that of coal. The maximum rate of volatile release is about 0.000669 kg/s kg for FB while that of coal is 0.000425 kg/s kg. The experiments revealed that the 90:10 blend burns more completely in the boiler, due to the earlier release of biomass volatiles and higher amount of volatile matter in FB. The NO_x emission for coal was 290 ppm, 0.162 kg/GJ (0.3768 lb/mm BTU) and 260 ppm, 0.1475 kg/GJ (0.343 lb/mm BTU) for the 90:10 blend at 10% excess air. Even though the effective N content of the blend increased by 18%, compared to coal the NO_x emission decreased which is attributed to the higher VM of FB and more N in the form of NH₃. However, due to limited residence time and higher VM, the CO emission increased from 15,582 ppm, 5.29 kg/GJ (12.305 lb/mm BTU) to 22,669 ppm, 7.81 kg/GJ (18.16 lb/mm BTU) when fuel was switched from coal to 90:10 blend. Large scale pilot plant tests performed at the 150-kW_t facility (DOE-NETL) reveal increased falling potential for the blend compared to coal (Part III), emissions were negligible.     

Production of high grade fuels and chemicals from catalytic pyrolysis of biomass

The potential offered by biomass and solid wastes for solving some of the world's energy problems is widely recognised. The energy in biomass may be realised either by direct use as in combustion, or by upgrading into a more valuable and usable fuel such as fuel gas, fuel oil, transport fuel or higher value products for the chemical industry. This paper is concerned with conversion and upgrading by pyrolysis and briefly describes the technologies of fast pyrolysis with particular reference to the use of catalysts in chemicals production and the use of catalytic processes in upgrading the primary pyrolysis products to higher quality and higher value fuels and chemicals. There are natural catalysts in biomass which substantially influence the production of high yielding chemicals. Removal or reinforcement of these catalysts has a dramatic effect on product yield and composition. The pyrolysis vapours can be catalytically cracked over zeolites to give aromatics and other hydrocarbon products which can be further converted into gasoline and diesel and the condensed liquid can be hydrotreated to a naphtha like product also for upgrading into transport fuels. There is, however, considerable uncertainty over the ability of the upgrading technology to be scaled up to commercial feasibility most notably in terms of catalyst performance and life. Considerably more research and development is needed to develop and prove suitable catalyst systems. There is also considerable uncertainty over the cost of upgrading in terms of capital costs, operating costs and performance and some preliminary estimates are included.