A review of the current state of biofuels production from lignocellulosic biomass using thermochemical conversion routes

The rapid increase in energy demand, the extensive use of fossil fuels and the urgent need to reduce the carbon dioxide emissions have raised concerns in the transportation sector. Alternate renewable and sustainable sources have become the ultimate solution to overcome the expected depletion of fossil fuels.The conversion of lignocellulosic biomass to liquid(BtL) transportation fuels seems to be a promising path and presents advantages over first generation biofuels and fossil fuels. Therefore, development of BtL systems is critical to increase the potential of this resource in a sustainable and economic way.Conversion of lignocellulosic BtL transportation fuels, such as, gasoline, diesel and jet fuel can be accomplished through various thermochemical processes and processing routes. The major steps for the production of BtL fuels involve feedstock selection, physical pretreatment, production of bio-oil, upgrading of bio-oil to transportation fuels and recovery of value-added products. The present work is aiming to give a comprehensive review of the current process technologies following these major steps and the current scenarios of biomass to liquid facilities for the production of biofuels.     

Separation of ethylene glycol, 1,2-butanediol and 1,2-propanediol with azeotropic distillation

1,2-butanediol (1,2-BDO) and 1,2-propanediol (1,2-PDO) are inevitably side produced in the ethylene glycol (EG) production processes from non-petroleum routes, but are very difficult to separate by the ordinary distillation method because of the closeness of their boiling temperatures to EG, thus compromise the economy of these processes. The azeotropic distillation process using 1-octanol (CPO) as an entrainer to separate EG and 1,2-BDO mixture with or without 1,2-PDO was studied in this paper. Four binary vapour–liquid equilibrium data of EG-1,2-BDO, EG-CPO, 1,2-BDO-CPO, and 1,2-PDO-CPO were measured using an Ellis equilibrium kettle and regressed with the thermodynamic model of non-random two liquid to obtain the corresponding binary interaction parameters. On this basis, azeotropic distillations with CPO as an entrainer were designed to separate EG and 1,2-BDO with or without 1,2-PDO. The complete separation processes, including the azeotropic distillation and CPO recovery process consisting of extraction with H₂O and subsequent distillation, were simulated and optimized with Aspen Plus for both the EG-1,2-BDO binary mixture and the EG-1,2-BDO-1,2-PDO ternary mixture. The simulation results show that the azeotropic distillation method with CPO as an entrainer can effectively separate the mixture of EG-1,2-BDO and EG-1,2-BDO-1,2-PDO, achieving EG of 99.90% purity with 99.98% recovery and 1,2-BDO of 99.30% purity with 99.45% recovery for the binary mixture, and achieving EG of 99.90% purity with 99.80% recovery, 1,2-BDO of 99.35% purity with 99.35% recovery, and 1,2-PDO of 90.59% purity with 94.38% recovery for the ternary mixture. These processes are promising for industrial application and can significantly improve the economy of non-petroleum EG production.     

New methods for the one-pot processing of polysaccharide components (cellulose and hemicelluloses) of lignocellulose biomass into valuable products. Part 2: Biotechnological approaches to the conversion of polysaccharides and monosaccharides into the valuable industrial chemicals

Part 2 of the review discusses modern processes for biotechnological conversion of lignocellulosic biomass into the valuable chemicals. It also recognizes the new approaches toward the development of more efficient enzymes for the depolymerization of biomass and the properties of the microorganisms employed in the fermentation of the biomass-derived sugars. Various biotechnological approaches to the fermentation of the depolymerized biomass products are described, including SHF, SSF, NSSF, SSFF, SSCF, and CBP. It is demonstrated that that the main tendencies for development of the new technologies for biotechnological biomass processing are the application of genetic engineering, synthetic biology and reduction of the number of processing steps. Application of one-pot processing of lignocellulosic biomass is promising for development of the new and efficient manufacturing technologies for production of valuable chemicals.     

Sustainable ammonia production through process synthesis and global optimization

Current ammonia production technologies have a significant carbon footprint. In this study, we present a process synthesis and global optimization framework to discover the efficient utilization of renewable resources in ammonia production. Competing technologies are incorporated in a process superstructure where biomass, wind, and solar routes are compared with the natural gas-based reference case. A deterministic global optimization-based branch-and-bound algorithm is used to solve the resulting large-scale nonconvex mixed-integer nonlinear programming problem (MINLP). Case studies for Texas, California, and Iowa are conducted to examine the effects of different feedstock prices and availabilities. Results indicate that profitability of ammonia production is highly sensitive to feedstock and electricity prices, as well as greenhouse gas (GHG) restrictions. Under strict 75% GHG reductions, biomass to ammonia route is found to be competitive with natural gas route, whereas wind and solar to ammonia routes require further improvement to compete with those two routes. © 2018 American Institute of Chemical Engineers AIChE J, 65: e16498 2019     

环保型替代物：1-氯-3,3,3-三氟丙烯的合成与应用

综述了1-氯-3,3,3-三氟丙烯（HCFO-1233zd）的合成路线和应用。在合成路线方面,以1,1,1,3,3-五氯丙烷（HCC-240fa）为原料经气相氟-氯交换合成HCFO-1233zd(E)的路线具有原料易得、转化率高、选择性高等优点,具有工业化价值;以HCFO-1233zd(E)为原料经气相异构化合成HCFO-1233zd(Z)的路线具有催化剂使用寿命长、选择性高等优点,易于实现工业化。在应用方面,HCFO-1233zd(E)主要用作发泡剂和传热流体,HCFO-1233zd(Z)主要用作清洗剂。提出了今后HCFO-1233zd领域的研究重点在于高活性非铬催化剂的开发和HCFO-1233zd新应用技术的开发。     

二元醇混合物汽液相平衡的GEMC模拟与微观结构分析

采用Gibbs蒙特卡罗模拟方法和OPLS-AA力场计算了乙二醇（EG）/1,2-丁二醇（1,2-BDO）、乙二醇/1,3-丁二醇（1,3-BDO）、乙二醇/1,4-丁二醇（1,4-BDO）三组二元醇混合物的汽液相平衡数据,通过与实验数据及Wilson状态方程计算数据的比较验证了方法和力场对体系汽液相平衡预测的适用性。对混合体系饱和液相的径向分布函数分析可知,各二醇间存在与羟基官能团位置近似无关的强氢键作用和作用范围不同的范德华作用。经体系O-O平均数目的统计及氢键缔合比例分析发现,随乙二醇组成增大,3种体系的微观结构由主要包含较大的BDO-BDO、BDO-EG缔合结构（>6）向包含较小的EG-BDO、EG-EG缔合结构（2～4）转变,且缔合比例下降。Molclus+Gaussian09对小分子EG、1,2-BDO缔合结构进行能量优化与构型搜索,由此提出了二醇缔合比例随EG组成变化的可能原因：1,2-BDO间缔合结构稳定于其他缔合结构,随缔合分子数增大,各缔合结构稳定性增加,但EG自缔成大分子结构的稳定性与其和BDO缔合成小分子结构稳定性差异减小。     

生物质制备乙酰丙酸酯类转化路径的研究进展

乙酰丙酸酯类是比较重要的一类平台化合物,具有广泛的应用。本文首先介绍了乙酰丙酸酯类的生物炼制途径,然后综述了目前国内外制备乙酰丙酸酯类的研究现状和最新进展。乙酰丙酸酯类的主要制备方法包括乙酰丙酸合成法、糠醇转化法以及生物质醇解法,并对3种方法的优劣进行说明,指出今后乙酰丙酸酯类的制备方法将以生物质直接醇解法为主。建议着力建立生物质直接醇解法反应过程中的热力学性质等相关数据,并加强与此相关的交叉学科的研究,以构建生物质醇解法制备乙酰丙酸酯类的理论基础。     

低级焦油酚下游精细化学品产业链技术进展

焦油酚产业链技术开发和相关产业向高端、精细化发展,是传统煤化工产业转型的方向。以低级焦油酚为基础的甲基酚合成具有催化体系近似、工艺过程通用、多产物共生的特点。开发单系统甲基酚多联产技术,有助于减少投资,增强市场适应能力。2,3,5-三甲基氢醌是该产业链走向高端化的重要产品路线。2,3,6-三甲基苯酚催化空气氧化-催化加氢还原法是氢醌合成技术方向,但需解决氧化催化剂效率与易分离性的矛盾,以及相关中间及最终产品的分离效率问题。     

Superstructure optimization of integrated fast pyrolysis‐gasification for production of liquid fuels and propylene

Motivated by the apparent advantages of fast pyrolysis and gasification, a novel integrated biorefinery plant is systematically synthesized for coproducing premium quality liquid fuels and propylene. The required heat and fluidization promotion of the fast pyrolyzer are provided by hot syngas from the gasifier. Light gas and syngas from the fast pyrolyzer are finally converted to hydrocarbons via Fischer‐Tropsch synthesis. Multiple syngas production technologies, hydrocarbon production and downstream upgrading routes are incorporated within a superstructure optimization based process synthesis framework. This is the first article to investigate the benefits associated with the introduction of conventional catalytic cracking and dewaxing from a systems engineering perspective. Surrogate models describing the gasifiers and rigorous equations for Fischer‐Tropsch effluents validated by our experimental collaborator are introduced. Through investigation of five scenarios the primary parameters affecting overall economic performance are identified through ranking of the relevant candidates. Comparisons of the hybrid conversion route and stand‐alone routes are made. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3155–3176, 2016     

对二甲苯选择性氧化合成对甲基苯甲酸

使用1,4-二氨-2,3-二氯蒽醌(DACAQ)与N-羟基邻苯二甲酰亚胺(NHPI)非金属催化剂实现了对二甲苯空气选择性氧化合成对甲基苯甲酸。分别加入NHPI4%(n/n)和DACAQ1%(n/n,以反应物总量计)为催化剂,在氧气压力0.9MPa、温度为120℃的条件下,反应2h,对二甲苯转化率达59%,对甲基苯甲酸产品选择性达70%。与传统金属催化剂相比,采用该非金属催化体系产品选择性大大提高,为对甲基苯甲酸的工业化生产提供了一条更具吸引力的途径。     

A review of Canadian wood conversion technologies for the production of fuels and chemicals

Canada has 347 million ha of forest cover, contributing to the potential large availability of wood-based resources. Although Canada's forest sector contributed $23.7 billion to the national nominal gross domestic product (GDP) in 2019, the GDP contribution of the wood product manufacturing subsector shrank by 6%. To reposition the Canadian forest industry, new forest management practices and wood-based conversion technologies should be applied. In this context, the use of woody biomass in biorefineries to produce clean energy, fuels, and chemicals is becoming increasingly significant. There is a need to understand the current status and challenges of the wood-based biomass conversion technologies that have been and are being developed in Canada. This information will help decision-makers in formulating and implementing forest sector-related policies for a sustainable bioeconomy in Canada. This study is focused on a review of Canadian woody biomass conversion technologies. Our critical review identified considerable potential biomass conversion technologies specialized for woody feedstock, all in the Canadian setting. We focused on the prospects of revitalizing Canada's pulp and paper industry through the integration of pre-treatment processes and biochemical technologies. The thermochemical conversion pathway was identified as the dominant route for woody feedstock valorization. The review also identified pathways with the potential to diversify the existing product mix that generate products from wood streams, such as chemicals and biomaterials. Most of the biochemical and thermochemical research done in institutional and multi-institutional research collaborations from laboratory scale to industrial scale will boost the chances of the commercialization of a wood-based biorefinery in Canada.     

以褐煤干馏提质为基础的多联产技术分析

褐煤干馏提质技术可以实现气-液-固产品的分级转化利用,是一种资源节约型、环境友好型的资源转化途径。在已有的技术基础上,提出了褐煤提质技术多联产综合利用的构想,根据目标产品的不同,详细论述了以下几种可能实施的多联产耦合实例:褐煤干馏提质技术分别与煤洁净发电、合成化工产品、煤制天然气、煤间接制油等优化组合的多联产系统。     

多晶硅生产技术发展方向探讨

还原高频电源技术、硅烷流化床法和气液沉积法,可与改良西门子法工艺技术有机结合生产多晶硅,对解决目前国内多晶硅所面临的生产成本高、产品质量低下等问题具有非常重要的意义。本文总结了改良西门子法、硅烷流化床法和气液沉积法生产多晶硅的工艺技术,分析了各自的优缺点和发展方向。指出了目前的改良西门子法核心设备的改进方向和应用还原高频电源技术、硅烷流化床技术需在加热方式上做进一步开发研究,气液沉积法可与现有的多种工艺技术相结合形成多种工艺路线,其中二氧化硅经碳热氯化法制备四氯化硅后,与氢气还原四氯化硅法相结合制备多晶硅,是值得研究开发的一种新工艺路线。该工艺路线不仅工艺流程大大缩减,而且四氯化硅的提纯比其他氯硅烷更容易,生产的多晶硅产品质量更高、成本更低。     

甲醇制芳烃催化剂及相关工艺研究进展

当前我国芳烃生产面临石油资源短缺等困难，而我国丰富的煤炭资源和当前过剩的甲醇产能为煤基甲醇制芳烃提供了价格低廉的原料，对于我国的能源安全具有重要意义。本文综述了近年来国内外甲醇制芳烃（MTA）技术的相关研究进展，分别介绍了MTA固定床、流化床技术；针对传统MTA过程产物复杂，分离能耗大，经济效益差等不足，归纳总结了更具经济性的甲醇一步法制对二甲苯（MTPX）以及甲醇一步法制对二甲苯联产低碳烯烃（MTO&PX）技术；针对传统MTA催化剂稳定性差等不足，对比介绍了甲醇直接制芳烃以及低碳烯烃制芳烃路线，结果表明甲醇经低碳烯烃制芳烃工艺路线具有催化剂寿命长、产品组成易调节等优势。最后，本文认为分子筛限域效应、分子筛表面修饰新技术、金属-酸双活性中心协同效应是未来MTA研究的重要方向。     

草甘膦合成工艺研究进展

综述了国内外合成草甘膦的各种工艺路线和最新研究成果,重点介绍了甘氨酸路线和亚氨基二乙酸（IDA）路线,并结合国内外的实际情况,深入分析比较了这两种路线的优缺点。以氢氰酸为原料的IDA-空气（氧气）催化氧化工艺路线最具竞争优势,国外由于氢氰酸价格低廉而普遍采用这种路线。我国受氢氰酸原料的限制,草甘膦生产目前仍以甘氨酸-亚磷酸二甲酯路线为主,IDA路线为辅,但是随着氢氰酸生产技术的突破,IDA路线终将成为我国草甘膦生产的主流工艺路线。文章还简要介绍了一些新型的具有原子经济性的草甘膦合成工艺,如生物催化法和光化学法等,这些方法都有望在未来得到突破。     

PBO的合成及其纺丝技术研究进展

概述了聚对苯撑苯并二(?)唑(PBO)及PBO纤维国内外的发展现状;详述了PBO的合成方法:对苯二甲酸法、对苯二甲酰氯法、三甲基硅烷基化法、对苯二甲酸盐法、对羟基苯甲酸酯法等,以及PBO纤维的制备:液晶纺丝法和静电纺丝法;建议今后国内PBO纤维的发展应开发具有自主知识产权的高性能PBO纤维生产技术。     

二氧化碳转化为合成气及高附加值产品的研究进展

由于二氧化碳（CO₂）过度排放导致全球变暖日益严峻,发展零碳技术已成为人类社会面向可持续发展的战略选择。将CO₂捕集并转化为高附加值化学和能源产品,可以优化化石能源为主体的能源结构、有效缓解环境问题,并实现碳资源的充分利用,是一项可以大规模实现低碳减排的技术。本文重点介绍了CO₂高效利用新途径,通过二氧化碳-合成气-高附加值化学品的产品工艺路线,实现CO₂的资源化利用。对比综述了热催化法、电催化法和光催化法高效转化合成气的最新进展,总结了热、电、光催化制备合成气过程中催化剂的设计原理和方法以及目前工业化应用前景;简单概述了合成气作为重要平台分子,进一步通过费托合成路线或接力催化路线转化为低碳烯烃和液态燃料或芳烃等化学品过程中催化剂设计研究进展。最后,总结了大规模工业化CO₂转化为合成气及高附加值产品过程催化剂设计和反应器优化的技术难题,并对未来CO₂高效转化利用方向进行了展望。同时指出目前各技术还普遍存在反应机理不清晰、催化剂成本高以及缺乏大规模合成等问题,未来开发出高效、高活性、低成本且稳定的催化剂是各技术推广应用的关键。     

C1～C4含氧化合物的煤化工生产工艺

综述和分析以煤为原料生产含氧化合物的工业路线。以煤炭加工利用方式和含氧化合物的碳原子数为主线,探讨了主要C_1～C_4含氧化合物的煤化工生产及相互转化工艺路线,并列举了甲醇、甲醛、乙酸、乙二醇、丙烯酸、环氧丙烷、正丁醇/异丁醇、1,4-丁二醇和乙酸乙酯共10种代表性低碳含氧化合物的煤化工生产途径。在煤气化制合成气的基础上,采用适宜催化剂,可以经一步或多步合成大部分C_1～C_4含氧化合物,相关合成路线基本都有工业应用实例。适度发展现代煤化工,高效、清洁、高值化利用煤炭资源具有重要的现实意义。     

Molecular Evolution of a Steroid Hydroxylating Cytochrome P450 Using a Versatile Steroid Detection System for Screening

Molecular evolution is a powerful tool for improving or changing activities of enzymes for their use in biotechnological processes. Cytochromes P450 are highly interesting enzymes for biotechnological purposes because they are able to hydroxylate a broad variety of substrates with high regio- and stereoselectivity. One promising steroid hydroxylating cytochrome P450 for biotechnological applications is CYP106A2 from Bacillus megaterium ATCC 13368. It is one of a few known bacterial cytochromes P450 able to transform steroids such as progesterone and 11-deoxycortisol. CYP106A2 can be easily expressed in Escherichia coli with a high yield and can be reconstituted using the adrenal redox proteins, adrenodoxin and adrenodoxin reductase. We developed a simple screening assay for this system and performed random mutagenesis of CYP106A2, yielding variants with improved 11-deoxycortisol and progesterone hydroxylation activity. After two generations of directed evolution, we were able to improve the k (cat)/K (m) of the 11-deoxycortisol hydroxylation by a factor of more than four. At the same time progesterone conversion was improved about 1.4-fold. Mapping the mutations identified in catalytically improved CYP106A2 variants into the structure of a CYP106A2 model suggests that these mutations influence the mobility of the F/G loop, and the interaction with the redox partner adrenodoxin. The results show the evolution of a soluble steroid hydroxylase as a potential new catalyst for the production of steroidogenic compounds.     

生物质化学转化产品谱系及研究进展

生物质生物精炼是替代化石精炼维持社会和化学工业发展的必然趋势.未来生物精炼体系将采用平台精炼方式生产谱系产品,其精炼产品能同时满足社会对能源和化学品的需求.生物精炼主要采用生物转化和化学转化方式进行炼制,化学转化具有更高的可设计性和应用范围.甘油、3 -羟基丁内酯、乙酰丙酸、2,5-呋喃二甲酸、葡萄糖二酸及山梨醇是6种...