Progress in the hydrolysis of lignocellulosic biomass for fuel-thanol production

以木质纤维素生产燃料乙醇具有原料可再生性和环境友好的优点而备受重视。本文介绍了国内外木质纤维素制取燃料乙醇中的水解工艺过程,包括浓酸水解、稀酸水解和酶水解工艺,分析了各工艺的技术特点,同时指出稀酸预处理-酶水解工艺将成为近几年国内外研究和开发的重点。     

木质纤维素水解制取燃料乙醇研究进展

以木质纤维素生产燃料乙醇具有原料可再生性和环境友好的优点而备受重视.本文介绍了国内外木质纤维素制取燃料乙醇中的水解工艺过程,包括浓酸水解、稀酸水解和酶水解工艺,分析了各工艺的技术特点,同时指出稀酸预处理-酶水解工艺将成为近几年国内外研究和开发的重点.     

木质纤维素制取燃料乙醇水解工艺技术进展

以木质纤维素生产燃料酒精因为具有原料可再生性和环境友好的优点而备受重视。本文介绍了木质纤维素制取燃料乙醇中的水解工艺过程,包括浓酸水解、稀酸水解和生物酶水解,讨论了各个工艺的关键技术问题。     

纤维素燃料乙醇生产技术研究进展

纤维素燃料乙醇已成为下一代燃料乙醇的必然发展方向。文章综述了近年来以木质纤维素为原料生产燃料乙醇的关键技术,重点对物理法、化学法、蒸汽爆破法、生物法等木质纤维素原料预处理技术,酸水解、酶水解等水解(糖化)技术,以及直接发酵法、水解发酵两步法、同步水解发酵法等发酵工艺进行了总结,并指出了未来纤维素乙醇的产业化过程中必须解决的关键问题和发展趋势。     

木质纤维素生产燃料乙醇的研究现状

介绍了近年来国内外木质纤维素生产燃料乙醇的技术现状。评述了纤维素原料生产乙醇的预处理及水解为葡萄糖和发酵成酒精的各生产工艺。分析了各工艺的技术特点和经济性。提出应进一步加强纤维素生产燃料乙醇的研究。     

木质纤维素原料生产燃料酒精开发技术研究进展

在分析美国、日本、加拿大等国关于纤维素制取乙醇技术发展的基础上,对木质纤维素原料生产乙醇的预处理及水解为葡萄糖技术和纤维素原料发酵生产酒精生产技术、酒精废糟的处理利用进行了述评与讨论,对木质纤维素原料不同的预处理、水解和发酵方法进行了比较,展望了木质纤维素原料生产燃料酒精的前景.     

甜高粱生产燃料乙醇的研究进展

以甜高粱为原料生产燃料乙醇具有广泛的应用前景.主要介绍了国内外利用甜高粱生产燃料乙醇的研究现状、工艺路线及存在的主要问题,并指出今后由甜高粱生产燃料乙醇的发展方向是利用其纤维素成分进行乙醇发酵.     

纤维乙醇产业化研究进展

利用纤维素类物质资源生产燃料乙醇是纤维素物质工业转化的一个重要方面.本文对国内外纤维燃料乙醇生产中的重要工艺,如原料预原理、纤维素水解、五碳糖与六碳糖发酵等研究情况进行了综述,并对国内外产业化情况进行了介绍.     

国外纤维素燃料乙醇研究动态

综述了近几年来燃料乙醇在原料预处理、纤维素水解及发酵环节中的研究进展,指明了这3个环节的研究方向.并介绍了3种国外比较接近实用化的纤维素制燃料乙醇的技术工艺.     

木质纤维素乙醇原料预处理技术的研究进展

近十年来,随着石油价格的上涨以及化石燃料使用对全球变暖的影响,利用木质素纤维素制取燃料乙醇日益成为国内外研究的热点。木质纤维素制取乙醇的主要步骤包括:原料的预处理、纤维素的糖化、发酵、产品分离。木质纤维素的组成包括木质素、半纤维素和纤维素,其中木质素和半纤维素对纤维素的水解具有阻碍作用。因此,在木质纤维素制取乙醇的工艺过程中,原料的预处理是非常关键的步骤,影响整个木质纤维素乙醇的生产过程。文章回顾了木质纤维素原料主要的预处理技术的最新进展,并结合后续的水解与发酵工序,对各种预处理技术的优缺点进行了对比。     

浅谈秸秆类废弃物制备燃料乙醇的工艺

秸秆类废弃物类物质是地球上一种含量极其丰富的可再生资源,其主要由纤维素、半纤维素和木质素组成。这种废弃物类物质在经过预处理、水解和发酵工艺后,可以用来生产变性燃料乙醇。文章针对这几个关键工艺步骤进行了描述,并探讨了目前有关方面的最新进展。     

木质纤维素燃料乙醇生物转化预处理技术

由丰富的木质纤维素资源制备乙醇有利于缓解能源紧缺、减少环境污染、实现可持续发展.然而某些物理、化学因素阻碍了木质纤维素中纤维素和半纤维素的转化和利用.预处理引起物理和/或化学上的变化,主要目的是改变或去除各种结构和(或)化学障碍,增加纤维素酶解率和转化效果,是一系列纤维素乙醇转化技术中的关键和核心.本文就纤维素乙醇生物...     

生物质水解发酵生产燃料乙醇的研究进展

生物质原料丰富多样,用其发酵生产燃料乙醇,能缓解当今世界日益凸显的能源问题.本文综述了这一领域国内外的研究概况,纤维素原料水解发酵制取燃料乙醇的生产工艺,重点介绍了水解液的脱毒,发酵有关的微生物,菌种选育和几种典型的发酵工艺;对发酵乙醇的几种典型微生物如酿酒酵母、管囊酵母、树干毕赤酵母、休哈塔假丝酵母和运动单胞菌等进行了介绍,并对当今存在的问题进行了分析和展望.     

秸秆生产乙醇预处理的研究现状分析

利用农作物秸秆生产乙醇,由于原料来源广,不存在与民争粮,与粮争地的问题,是全球生物燃料乙醇的研究重点。由于秸秆的组成比较复杂,一般不易被降解,在发酵之前要进行预处理,预处理是利用秸秆生产乙醇的一个关键部分,预处理的好坏对后续的酶解和发酵有很大的影响。本文在分析农作物秸秆的组成后,对目前各种预处理方法进行了综述,并对利用秸秆生产乙醇的前景进行了展望,为选出合理的处理方法提供了依据。     

Innovative and intensified technology for the biological pretreatment of agro waste for ethanol production

Lignocellulosic biomass is an abundant, renewable resource, but the structural and chemical complexity of biomass acts as a hindrance in its effective utilization for cellulosic ethanol production. Hence, effective pretreatment is always necessary to remove the surrounding matrix of lignin prior to the enzymatic hydrolysis. Pretreatment of rice straw by Pleurotus florida was found to be effective and resulted in 49% lignin degradation, whereas fungus along with grape leaves resulted in 99% lignin degradation. This method not only explores a pathway for utilizing the solid agro waste but also results in a value-added product of edible mushrooms that has proved to be the best pretreatment technology for ethanol production. FTIR and SEM analysis confirmed the structural transformation taking place during the pretreatment. The components of grape leaves were also analyzed using GC-MS.     

生物基产品制备关键过程及其生态产业链集成的研究进展——生物基产品过程工程的提出

生物质原料可以转化为能源、材料和化工产品,是国内外研究的热点. 目前生物基产品制备过程中存在原料组分利用和转化技术单一、缺乏系统技术集成等问题. 本工作从生物质的原料特点、转化过程和产品工程关键问题入手,综合多学科知识,提出了生物基产品过程工程这一理念. 从全新的面向原料、过程、产品的角度,建立生物质分层多级转化技术体系,并以无污染汽爆及其组分分离技术、节水节能固态纯种发酵技术、秸秆固相酶解-液体发酵乙醇耦合技术和汽爆秸秆膜循环酶解耦合发酵技术4个关键技术为平台,形成生物基产品生态产业新模式,为实现生物质资源高值化利用和生物基产品生态产业化提供研发思路和技术平台.     

Different process configurations for bioethanol production from pretreated olive pruning biomass

BACKGROUND: In Mediterranean countries, olive tree pruning provides a widely available renewable agricultural residue with, currently, no industrial application. This residue could provide feedstock for the bioethanol industry. In the present study, olive tree pruning biomass pretreated with both ‘liquid hot water’ and ‘dilute‐sulfuric acid’ was tested as a substrate for ethanol production. Three different process configurations, separate hydrolysis and fermentation (SHF), simultaneous saccharification, fermentation and prehydrolysis (PSSF), and simultaneous saccharification and fermentation (SSF), were compared at different water‐insoluble solids concentrations. RESULTS: High ethanol concentration of about 3.7% (v/v) was obtained by separate hydrolysis and fermentation or prehydrolysis and simultaneous saccharification and fermentation of liquid hot water pretreated at 23% (w/w) substrate loading. CONCLUSION: The nature of the pretreated residue allows high substrate concentration (≥17% w/w) to be used in the enzymatic hydrolysis step. Substrate loading of 17% DM has been shown to provide a compromise between hydrolysis efficiency and glucose concentrations for the same enzyme/substrate ratio. Prehydrolysis prior to simultaneous saccharification and fermentation facilitated SSF performance at high substrate loading on liquid hot water pretreated olive pruning residue. This effect was not observed with dilute‐acid pretreated substrate. Copyright © 2011 Society of Chemical Industry     

Enzymatic hydrolysis from carbohydrates of barley straw pretreated by ionic liquids

BACKGROUND: Lignocellulosic biomass offers many potential advantages in comparison with the traditionally used sugars or starchy biomass since it is very widely available and does not compete with food and feed production. The abundance and high carbohydrates content of barley straw make it a good candidate for bioethanol production in Europe. Since biomass must be pretreated before enzymatic hydrolysis to improve the digestibility of both the cellulose and the hemicellulose biomass, the use of ionic liquids (IL) has been proposed as an environment‐friendly pretreatment of biomass. RESULTS: Different pretreatment conditions were investigated to determine the effects of the experimental conditions (temperature and time) on the enzymatic digestibility of pretreated material. The pretreatment of barley straw with 1‐ethyl‐3‐methyl imidazolium acetate treatment resulted in up to a 9‐fold increase in the cellulose conversion and a 13‐fold increase in the xylan conversion when compared with the untreated barley straw. CONCLUSION: Ionic liquid pretreatment of barley straw at 110°C for 30 min, followed by enzymatic hydrolysis, leads to a sugar yield of 53.5 g per 100 g raw material. It is then ready available for conversion into ethanol and is equivalent to more than 86% from potential sugars. The increase in saccharification was possible due to rupture of the lignin–hemicellulose linkages by treatment with 1‐ethyl‐3‐methyl imidazolium acetate. © 2012 Society of Chemical Industry     

Acid hydrolysis of olive tree biomass

Olive tree cultivation generates a great amount of biomass residues which have no industrial application. Pruning residues are usually grindered or burnt on fields, causing economical costs and environmental concerns. An alternative issue for these renewable sugar-containing feedstocks may be the conversion into fuel ethanol by hydrolysis and fermentation.As a first step in the bioconversion process, the acid hydrolysis of olive tree pruning is studied and a mathematical model predicting both fiber content and sugar release as a function of operation variables is proposed. Sulphuric acid concentration in the range 0–32% (w/w), process temperature between 60 and 90 °C and hydrolysis time from 0 to 240 min were used as hydrolysis conditions. The process was modelled by first-order reaction kinetics. The apparent kinetic constant relating acid concentration to fiber hydrolysis and sugar release shows a potential dependence; on the other hand, an Arrhenius-type equation has enabled the evaluation of activation energy values of 26.4 and 25.9 kJ/mol for fiber hydrolysis and sugar generation, respectively.