共查询到18条相似文献,搜索用时 140 毫秒
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生物质焦油裂解的技术关键 总被引:21,自引:0,他引:21
生物质焦油是生物质气化过程中有害的副产物,它会降低气化效率,影响设备运行,所以必须加以有效利用和处理。本文介绍了国内外焦油催化裂解的研究现状,详细地分析了讨论了催化裂解的关键过程和工艺件,总结出了焦油催化裂解的最佳条件和比较有前景的工艺路线。 相似文献
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建立了基于热力学平衡的生物质气化模型,利用平衡模型分析了气化过程的特性,研究了气化过程的反应规律及各种因素对气化性能指标的影响,详细分析了当量比及物料湿度对气体产物成分及气化产物热值的影响.同时,建立了以生物质气为燃料的固体氧化物燃料电池的数学模型,该模型考虑了燃料电池的能斯特电动势及各种极化损失.利用建立的模型分析了操作参数以及物料湿度和生物质种类对生物质气化—燃料电池发电系统性能的影响.结果表明,生物质气化—燃料电池发电系统的发电效率可达30%,热电联产效率最高可达95%以上. 相似文献
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CaO催化裂解生物质气化焦油实验研究 总被引:4,自引:0,他引:4
以谷壳气化发电产生焦油为研究对象,考查了CaO作为焦油裂解催化剂对其催化裂解的影响。实验研究结果表明:CaO作为焦油裂解催化剂可使焦油裂解率明显提高,在800℃时,其裂解率可由热裂解的28.66%提高到65.60%,焦油催化裂解后可使燃气成份中的H2、CO、CH4以及CO2含量提高。但焦油裂解过程中,其积炭率可达30.51%;扫描电镜显示:因焦油裂解积炭包裹CaO催化剂,易使其催化活性失效,同时由于积炭,使床层压降增加,给焦油催化裂解运行带来困难。 相似文献
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生物质气化发电技术讲座(3)生物质焦油裂解技术 总被引:12,自引:1,他引:12
1生物质焦油的特性生物质气化的目标是得到尽可能多的可燃气体产物。但在气化过程中,焦炭和焦油都是不可避免的副产物。焦油在高温时呈气态,与可燃气体完全混合,而在低温(一般低于200℃)时凝结为液态。对于燃气需要降温利用的情况(如燃气用于内燃机发电时),焦油的分离问题显得尤为重要。焦油的存在对生物质气化及其利用会产生不利的影响。首先它降低了气化炉气化效率,气化气中焦油产物的能量一般占总能量的5%~15%,这部分能量在低温时难以与可燃气体一道被利用,大部分被浪费;其次焦油在低温时凝结为液态,容易和水、焦炭等结合在一起,堵塞输… 相似文献
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The use of biomass for energy generation is getting increasing attention. At present, gasification of biomass is taken as a popular technical route to produce fuel gas for application in boilers, engine, gas turbine or fuel cell. Up to now, most of researchers have focused their attentions only on fixed-bed gasification and fluidised bed gasification under air-blown conditions. In that case, the producer gas is contaminated by high tar contents and particles which could lead to the corrosion and wear of blades of turbine. Furthermore, both the technologies, particularly fixed bed gasification, are not flexible for using multiple biomass-fuel types and also not feasible economically and environmentally for large scale application up to 10–50 MWth. An innovative circulating fluidised bed concept has been considered in our laboratory for biomass gasification thereby overcoming these challenges. The concept combines and integrates partial oxidation, fast pyrolysis (with an instantaneous drying), gasification, and tar cracking, as well as a shift reaction, with the purpose of producing a high quality of gas, in terms of low tar level and particulates carried out in the producer gas, and overall emissions reduction associated with the combustion of producer gas. This paper describes our innovative concept and presents some experimental results. The results indicate that the gas yield can be above 1.83 N m3/kg and the fluctuation of the gas yield during the period of operation is 3.3% at temperature of 750 °C. Generally speaking, the results achieved support our concept as a promising alternative to gasify biomass for the generation of electricity. 相似文献
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生物质能源是一种环境友好的可再生能源,但也存在能量密度低、含水率高、碱金属含量高等缺点,导致其在热利用的过程中存在易结渣、堵灰及腐蚀、热效率不高等问题。本文结合生物质气化、炉内碱金属/硫固定、两级焦油裂解、蓄热式燃烧,以及冷凝热回收等多项先进技术,设计并搭建了连续蓄热式生物质气化/燃烧供热系统。以海洋贝壳类废弃物作为生物质成型燃料的添加剂和生物质焦油裂解过程的催化剂,在实现海洋废弃资源高值化利用的同时,克服了生物质热利用过程中的多项障碍,能够显著提高生物质能热利用效率,同时大幅度降低当前工业及民用供热过程中CO2、SOx、NOx及烟尘的排放,具有良好的经济性与环保性。 相似文献
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以桉木为原料,对1.5 t/h生物质混流式固定床气化炉运行特性进行了测试分析与评价,与文献报导报道的相关炉型包括上吸式、下吸式、两段式等炉型运行结果进行了比较。实验以气化炉空气通入量作为主要控制变量,对有或无水蒸气条件下的气化炉温度及压力分布、燃气组成、焦油与飞灰含量、气体产率等参数进行了较长周期的测试,结果表明:气化炉运行效果符合设计要求,各项指标相当于或优于传统的下吸式气化炉;气化炉运行温度与压力比较稳定;以冷燃气计算的燃气热值一般约为4 900 ~ 5 500 kJ/Nm3;气化效率约为70% ~ 78%;燃气焦油含量约600 ~ 3 500 mg/Nm3,运行负荷在50%以上时,焦油含量一般低于1 500 mg/Nm3。研究结果有望为混流式气化炉的改进和操作提供优化建议,同时可为其他气化工艺设计提供参考依据。 相似文献
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V. Skoulou E. Kantarelis S. Arvelakis W. Yang A. Zabaniotou 《International Journal of Hydrogen Energy》2009
The effect of biomass water leaching on H2 production, as well as, prediction of ash thermal behavior and formation of biomass tar during high temperature steam gasification (HTSG) of olive kernel is the main aim of the present work. Within this study raw olive kernel samples (OK1, OK2) and a pre-treated one by water leaching (LOK2) were examined with regard to their ash fouling propensity and tar concentration in the gaseous phase. Two temperatures (T = 850 and 950 °C) and a constant steam to biomass ratio (S/B = 1.28) were chosen in order to perform the steam gasification experiments. Results indicated that considering the samples' ash thermal behavior, it seemed that water leaching improved the fusibility behavior of olive kernel; however, it proved that water leaching does not favour tar steam reforming, while at the same time decreases the H2 yield in gas product under air gasification conditions, due to possible loss of the catalytic effect of ash with water leaching. 相似文献
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Bing-Shun Huang Hsin-Yi ChenKui-Hao Chuang Ren-Xuan YangMing-Yen Wey 《International Journal of Hydrogen Energy》2012
Biomass gasification for hydrogen production was performed in a continuous-feeding fluidized-bed with the use of Fe/CaO catalysts. The relationship between catalyst properties and biomass gasification efficiencies was studied. The findings indicated that only CaO was involved in the enhancement of char gasification, resulting in an increased hydrogen production. However, CaO was also easily deactivated by biomass tar. The characterization results indicated that when CaO was impregnated with Fe, Ca2Fe2O5 formed on the surface of the support. Ca2Fe2O5 decomposed polyaromatic tar but was not effective in char gasification. The synergistic effects between Fe and CaO that effectively enhanced biomass gasification mainly involved combustion and pyrolysis, and the biomass gasification products, i.e., char and tar, were further gasified, indicating that tailor-made Fe/CaO catalysts prevented CaO deactivation by tar, thus promoting biomass gasification and hydrogen production. 相似文献