共查询到17条相似文献,搜索用时 60 毫秒
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《精细化工原料及中间体》2014,(3)
正吉林石化研究院和北京化工大学合作承担的利用蒸汽渗透技术实现生物质燃料乙醇的原位发酵-分离过程研究项目通过了中国石油科技管理部组织的专家验收。采用该项目成果建设的乙醇发酵-蒸汽渗透耦合中试装置评价表明:渗透液中乙醇浓度在340~480g/L,发酵液中乙醇浓度保持在54~66g/L,分离性能稳定,效果显著,各项指标均达到要求。该项目组在国内首次提出了一种利用蒸汽渗透技术原位分离乙醇的方法,将生物乙醇发酵过程与蒸汽渗透技术相 相似文献
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生物基(正)丁醇是一种重要的化学品和替代燃料,其主要制备途径为糖质底物的丙酮-丁醇-乙醇(ABE)发酵。受制于发酵副产物多、溶剂浓度低、产物共沸等因素,传统的生物丁醇分离过程存在分离能耗大、成本高等问题,制约其产业化制备。为解决生物丁醇分离的技术瓶颈,近年来,应用新型分离技术实现与ABE发酵过程的耦合成为研究的热点。本文综述了生物丁醇分离技术的最新研究进展,讨论了基于汽液平衡、相转移、膜分离技术等新型分离方式的技术特点;并针对多级分离级联系统开发、面向终产物的精馏技术的新趋势、新特点进行剖析和讨论。随着分离技术的发展和进步、生物炼制工艺开发和集成,生物丁醇的制备成本可望进一步降低,提升市场竞争力。 相似文献
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采用合成气生物发酵法制乙醇具有反应条件温和、产物选择性高、原料来源广泛、低碳可持续发展等优势,是一种具有前景的可再生能源新型生产工艺。文章综述了合成气发酵法制乙醇的微生物种类及对应的适宜操作条件,分析了合成气发酵法制乙醇的Wood-Ljungdahl代谢途径;总结了合成气的广泛来源;分析讨论了过程工艺参数如合成气组成及压力、pH、温度、培养基组分、气液传质对合成气发酵的影响;指出合成气发酵法制乙醇面临的底物传质性能差、乙醇收率低等关键问题,比较了典型反应器在传质方面的差异,归纳了传质强化方法;总结了合成气发酵法制乙醇的工业化进展, 并提出了未来的发展方向。 相似文献
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一体化生物加工过程(consolidated bioprocessing,CBP)指通过对理想底盘微生物的开发和利用来实现一步转化木质纤维素为生物产品的生物加工程序。本文回顾了一体化生物加工过程的研究背景,简述了其开发理念和技术路线,全面综述了近年来该技术在转化木质纤维素生产二代生物乙醇研究中的不同策略及最新的研究进展。分析了CBP系统中自然菌株、重组菌株和共培养菌株在转化木质纤维素生产生物乙醇时的优点和瓶颈因素。研究了基因工程、代谢工程等工程手段和技术在克服此技术中的阻碍性因素及提升乙醇得率等方面的应用价值和潜力。最后,论述了组学及合成生物学等新兴生物技术对CBP生物乙醇的贡献和二代生物乙醇的商业化发展现状及CBP乙醇未来所面临的机遇与挑战。 相似文献
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分子印迹技术(MIT)是一种新的、很有发展潜力的分离技术。分子印迹聚合物因其具有预定性、识别性和实用性的优点,已广泛应用于分离技术中,显示出良好的应用前景,引起了人们的广泛关注。介绍了分子印迹技术的产生、原理及其在分离技术方面的应用,并对其进行了展望。 相似文献
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Xi Lan Jintao Gao Huanhuan Xu Zhancheng Guo 《Journal of the American Ceramic Society》2022,105(9):5966-5974
Bayan Obo ore has abundant rare earth (RE) reserves, and RE elements (REEs) are mainly transferred into the RE-bearing slag. However, the utilization of RE-bearing slag is greatly limited due to the serious lack and ambiguity of RE crystals. In this study, in situ separation of RE crystals from RE-bearing slag via supergravity was developed, and the high-purity crystals of britholite with various REEs contents were selectively separated from the CaO–SiO2–CaF2–P2O5–Ce2O3 system with a high REEs recovery ratio of 95.58%–98.65%. On this basis, the chemical formula, the crystal structure, and the formation mechanism of britholite were characterized from the high-purity crystals through a combination of the Rietveld refinement and DFT calculation. It was found that the britholite was verified to be evolved from Ca5(PO4)3F, there would be an SiO44− instead of a PO43− when a Ce3+ replaced a Ca2+, the chemical formula changed from Ca5(PO4)3F to Ca4.377Ce0.623Si0.6P2.4O12F, Ca3.956Ce1.044Si1.01P1.99O12F, and Ca3.176Ce1.824Si1.93P1.07O12F with the increase of REEs content, and the substitution range of REEs was between 0 and 2. This study supplements some necessary basic data of RE crystals, which provides the theoretical reference for efficient recovery of RE resources and sustainable utilization of RE-bearing slag. 相似文献
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The kinetics of formation of a mixture of two polymers [poly(methyl methacrylate) and polyurethane] in situ in the course of two simultaneously proceeding reactions was studied in the presence of various amount of a filler (fumed silica). It was shown that the filler affects the rates of both reactions. In addition, the filler exerts an influence on the phase separation induced by the chemical reaction increasing the amount of a filler increases the time for the onset of phase separation. The effects observed may be explained both by the increase in the viscosity of the reaction system due to introduction of a filler and by selective adsorption of reaction system components at the interface with filler particles. In all cases, phase separation in the early stages of reaction proceeds in a four‐component system (two polymers formed and two initial compounds) and obeys the spinodal mechanism. It is also shown that the final morphology is determined far from the end of the reaction and before establishing the equilibrium state. © 2003 Society of Chemical Industry 相似文献