响应面法优化油菜秸秆真空热解液化工艺及生物油分析1

以油菜秸秆为原料,采用真空热解系统进行了制取生物油的中心组合实验研究,以热解终温、体系压力和升温速率为实验因子,生物油产率为实验指标,利用响应面法(RSM)对制备生物油的工艺参数进行了优化,并对在最优条件下制取的生物油进行了理化特性和化学组成分析。研究结果表明,热解终温、体系压力和升温速率对生物油产率有显著影响,热解终温和升温速率之间的交互作用显著;获得最佳热解液化工艺条件为:热解终温490.0℃、体系压力5.0 k Pa、升温速率20.0℃·min-1,在此条件下,生物油产率可达41.65%。与预测值42.00%较为接近。油菜秸秆真空热解所得生物油的含水量为33.85%,热值为18.65 MJ·kg-1,常温下的运动黏度为4.16 mm2·s-1,密度和p H值分别为1.14g·cm·3和2.32;生物油成分较为复杂,其中多种有机物可被进一步提取用作化工原料;生物油中羧酸、醛、酮类等腐蚀性和不稳定组分含量较高,需对其进一步精制,以提高其稳定性。     

稻壳快速热解制备生物油条件探索及产物分析

以稻壳为原料,通过流化床快速热解的方式制备生物油。初步考察了螺旋进料速率对流化床反应参数的影响。当进料速率由 4 kg/h 提高至 5 kg/h 时,床层温度明显下降,床层压差明显增加,燃气流量也明显增加,表明热解产物更多地发生了二次裂解反应。采用GC-MS对快速热解所得生物油的组成进行分析,采用TG-DSC考察生物油的热稳定性,表明在250~400℃ 之间,出现较强的放热现象,缩聚现象严重,并对其重要的燃料性能进行表征,pH值2.33,水分 24.0%,热值 16.3 MJ/kg,密度 1.17 g/mL,黏度 45 mm²/s(30℃)。     

生物质快速热解与生物油精制研究进展

本文综述了生物质快速热解与生物油精制工艺。阐述了快速热解的机理、工艺以及影响因素;介绍了生物油的组分与特性;概括了目前生物油精制的3种工艺:催化加氢、催化裂化以及乳化技术,评价了这3种工艺的机理、效果以及优缺点,并从3个方面预测了该课题未来的研究方向。     

Thermochemical Processing of Miscanthus through Fluidized‐Bed Fast Pyrolysis: A Parametric Study

Thermochemical processing of agriculture waste not only provides surrogates for combustion fuel but also reduces the environmental issues of waste. Miscanthus has been viewed as one of the largest agriculture wastes in Taiwan and a proper process for turning Miscanthus into a valuable product has become a significant subject. Here, fluidized‐bed fast pyrolysis was applied to convert Miscanthus into bio‐oil, bio‐char, and pyrolytic gases as the products. The product distributions were examined depending on various reaction parameters such as reaction temperature, carrier gas flow rate, feedstock feeding rate, and feedstock size. The chemical compositions of the bio‐oil, bio‐char, and product gases were analyzed and the properties of the bio‐oil were also tested via standard methods. So far, bio‐oil derived from Miscanthus is unfavorable for application in combustion engines without further upgrading processes.     

Influence of Operating Conditions for Fast Pyrolysis and Pyrolysis Oil Production in a Conical Spouted‐Bed Reactor

Fast pyrolysis experiments of larch sawdust were conducted in a conical spouted‐bed reactor to study the influences of reaction temperature, inlet gas velocity, feeding rate, and particle size on the product yield and pyrolysis oil quality. For the first time, the optimal conditions were determined for various pyrolysis operations of such reactor to increase the yield and quality of pyrolysis oil. The results demonstrate that the biomass particle size, reaction temperature, biomass feeding rate, and inlet gas velocity all affected the quality and yield of the pyrolysis oil, in this order.     

Fast Pyrolysis of Fresh Bio Waste and Ensiled Municipal Green Cut

The aim of the work was to estimate the feasibility of utilizing fresh bio waste and ensiled green cut for the bioliq process, which includes downstream entrained flow gasification in a GSP gasifier. Fast pyrolysis experiments are carried out after leaching and mechanical dewatering. The solid and liquid products of the green cut waste contained up to 94 % of the energy content of the starting material. The pyrolysis products are chemically similar to those of other biomasses, except for a distinct share of fatty acids due to the variability of the feedstock. The results show that the use of these leached and dried waste materials in the bioliq process is possible.     

Hydrodynamics of a Novel Biomass Autothermal Fast Pyrolysis Reactor: Flow Pattern and Pressure Drop

A novel biomass, autothermal, fast pyrolysis reactor with a draft tube and an internal dipleg dividing the reactor into two interconnected beds is proposed. This internally interconnected fluidized beds (IIFB) reactor is designed to produce high‐quality bio‐oil using catalysts. Meanwhile, the pyrolysis by‐products, i.e., char, coke and non‐condensable gases, are expected to burn in the combustion bed to provide the heat for the pyrolysis. On the other hand, the catalysts can be regenerated simultaneously. In this study, experiments on the hydrodynamics of a cold model IIFB reactor are reported. Geldart group B and D sand particles were used as the bed materials. The effects of spouting and fluidizing gas velocities, particle size, static bed height and the total pressure loss coefficient of the pyrolysis bed exit, on the flow patterns and pressure drops of the two interconnected beds are studied. Six distinct flow patterns, i.e., fixed bed (F), periodic spouted/bubbling bed (PS/B), spouted bed with aeration (SA), spout‐fluidized bed (SF), spout‐fluidized bed with slugging (SFS) and spouted bed with backward jet (SBJ) are identified. The investigations on the pressure drops of the two beds show that both of them are seen to increase at first (mainly in the F flow pattern), then to decrease (mainly in the PS/B and SA flow patterns) and finally to increase again (mainly in the SA and SF flow patterns), with the increase of the spouting gas velocity. It is observed that a larger particle size and lower static bed height lead to lower pressure drops of the two beds.     

基于显微组分化学键特征的宁夏庆华煤热解特性及动力学分析

通过X射线光电子能谱和傅里叶红外光谱表征宁夏宁东庆华煤不同显微组分的官能团种类、表面结构元素价态分布及化学键赋存特征。采用热重-质谱联用考察庆华煤镜质组和惰质组在不同热解温度下的失重行为和关键气体组分变化。进一步基于Coats-Redfern模型从化学键断裂特征和反应动力学角度探讨煤镜质组和惰质组的热解行为差异。结果表明,庆华煤显微组分的热解失重峰与相应化学键断裂信息能够很好地吻合。不同显微组分的热重曲线变化趋同,但相同热解温度下镜质组的失重率始终高于惰质组。快速热解阶段镜质组较惰质组表现出更大的失重率和最大失重速率。其主要原因在于镜质组的脂肪族官能团相对含量更高,快速热解阶段会发生更多的C_al—C_al断裂。不同热解温度下庆华煤显微组分三个主要热解阶段的活化能和频率因子大小次序为：快速热解阶段>快速缩合阶段>缓慢热解阶段。在快速热解阶段,镜质组和惰质组的平均活化能均约为75 kJ/mol,但镜质组的频率因子更高。     

Synthesis of derivatives of alkylamino alkyloxy propanol structures by N-alkylation, acylation, and nitration. Application as fuel additives

Polyfunctional compounds were prepared by alkylation, acylation, and nitration of hydroxyl and amine functions of the following alkanolamine ether structures: (di)alkylamino alkyloxy propanol, hydroxy alkyloxy (di)alkylamino propanol, and their dimer compounds. The resulting compounds were characterized by conventional spectroscopic methods, and complete nuclear magnetic resonance data are given. These reactions extented the application of these propanic compounds to use as multipurpose fuel additives. In particular, they enhance phase stability and improve the cetane number in ethanol-diesel fuel blends.     

Synthesis of alkyloxy (di)alkylamino propanols, hydroxy alkyloxy (di)alkylamino propanols, and the dimer compounds for use as fuel additives

Alkyl glycidyl ethers and bis glycidyl ethers, synthesized in a heterogeneous weakly hydrous medium, were condensed with primary or secondary amines to obtain 3-alkyloxy propanolamines or bis alkyloxy propanolamines in a regioselective manner. The compounds were characterized by conventional spectroscopic methods, and complete nuclear magnetic resonance data are given. Their high-temperature stability, their good emulsifying power, their oxidation, and corrosion inhibition make these compounds suitable for solubilizing ethanol-diesel fuel blends.