摘要
生物质能具有CO_2零排放、普遍易得、价格低廉等优势。生物质成型处理有利于其远距离运输与长时间储存。但是,生物质细胞壁高分子聚合物形成了物理和化学抗降解屏障,严重阻碍了生物质成型燃料品质的提高,因此,采用预处理技术是实现生物质能源高效利用的必要手段。目前,生物质预处理技术主要分为物理法、物理-化学法、化学法和生物法四大类。由于各种预处理技术对生物质化学组分占比以及结构的影响不同,预处理后的生物质成型燃料所体现出的物理性质和燃烧特性各有特点。本文介绍了生物质原料中的纤维素、半纤维素以及木质素等主要化学成分的结构特点及其对成型过程的影响,并从提升生物质成型燃料的物理性质和燃烧特性角度总结了蒸汽爆破预处理、低温热解预处理及水热预处理3种预处理技术的研究进展。总体而言,水热预处理技术使处理后生物质成型燃料在燃烧热值、能量密度、耐久度以及机械强度等各方面性能得以全面提升,但是水热预处理成本较高且对环境有影响。未来生物质成型燃料预处理技术的研究方向应从平衡生物质燃料品质与预处理成本之间的关系、减少污染物排放、预处理过程流程配置差异性集成和精确工艺参数匹配等方面为基础,开发适于规模化灵活生产的节能高效生物质预处理技术。上海理工大学碳基燃料洁净转化实验室利用水热预处理技术制备高机械强度生物质成型燃料及成型炭燃料,并获得过程副产物——木醋液,开发了多产品、环境友好的生物质综合利用技术。
Biomass energy is characteristic of CO2 zero emission,easy obtaining and low cost. Biomass briquetting favors its long distance transportation and long period store.The cell wall of biomass consists of macromolecule polymers,which are physical and chemical antidegradation barriers to the further improvement of the quality of biomass briquettes.Therefore,the pretreatment process is necessary for the efficient utilization of the biomass energy. The main biomass pretreatment techniques can be classified into physical,physicochemical,chemical or biological processes.The different effects of the various pretreatment process on the proportion of chemical components and the structure of the biomass lead to the differences in the physical properties and combustion characteristics of the resulted biomass briquettes.In this article,the structural characteristics of the main chemical components( celluloses,hemicelluloses and lignins) presenting in the biomass feedstock and their influences on the biomass briquetting process were introduced.Steam explosion pretreatment,low temperature pyrolysis pretreatment and hydrothermal pretreatment has been used and researched for the improvement of the physical properties and combustion characteristics of the resulted biomass briquettes and the research progress of the three kinds of the pretreatment techniques was summarized.In general,hydrothermal process is an outstanding pretreatment technology to overall enhance biomass feedstock into high-quality biomass briquettes with excellent heating value,energy density,durability and mechanical strength.However,hydrothermal process with high costs maybe has a bad impact on the environment.Therefore,the further research and development of the energy-efficient pretreatment process should be carried out to meet the requirement of the large-scale and flexible biomass briquette production techniques with high fuel quality and low operating costs,low pollutant emissions. Moreover,the high level of the system integration and parameter matching between the biomass briquetting and pretreatment processes should be accomplished.Laboratory of clean carbon-based fuel conversion,USST has been engaged in high-strength biomass briquette and charcoal briquette preparation from hydrothermal pretreated biomass for nearly ten years and a green biomass utilization technology with multi-products including biomass briquette,charcoal briquette and wood vinegar has been developed.
作者
曹忠耀
张守玉
黄小河
宋晓冰
吴渊默
CAO Zhongyao;ZHANG Shouyu;HUANG Xiaohe;SONG Xiaobing;WU Yuanmo(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)
出处
《洁净煤技术》
CAS
2019年第1期12-20,共9页
Clean Coal Technology
基金
国家科技支撑计划资助项目(2012BAA04B01)
上海理工大学科技发展资助项目(16KJFZ094)
关键词
生物质
成型燃料
预处理
蒸汽爆破
低温热解
水热
biomass
briquette
pretreatment
steam explosion
low temperature pyrolysis
hydrothermal
