Butanol production in a sugarcane biorefinery using ethanol as feedstock. Part I: Integration to a first generation sugarcane distillery

Butanol production from renewable resources has been increasingly investigated over the past decade, mostly for its use as a liquid biofuel for road transportation, since its energy density is higher than that of ethanol and it may be used in gasoline driven engines with practically no changes, but also for use as a feedstock in the chemical industry. Most of the research concerning butanol production focuses on the ABE process (fermentation of sugars into a mixture of acetone, butanol and ethanol), which has several drawbacks regarding microorganism performance and product inhibition. An alternative to ABE fermentation, ethanol catalytic conversion to butanol can produce a higher quality product with less retrofitting than ABE in existing ethanol producing facilities. There are different types of catalysts for the chemical conversion of ethanol to butanol being developed in laboratory scale, but their actual use in a sugarcane processing plant has never before been assessed. Butanol production from ethanol in a sugarcane biorefinery, using data from the literature, was assessed in this study; different technological alternatives (catalytic routes) were evaluated through computer simulation in Aspen Plus (including production of electricity, sugar, ethanol and other products) and economic and environmental impacts were assessed. Results indicate that vapor-phase catalysis presents higher potential for industrial implementation, and commercialization of butanol for use as a chemical feedstock has an economic performance similar to that of current, optimized first generation sugarcane distilleries, but can potentially contribute to cost reduction that will allow commercialization of butanol as a fuel in the future.     

Evaluation of technological alternatives for process integration of sugarcane bagasse for sustainable biofuels production—Part 1

Nowadays, there is a tremendous global interest in the biofuels production. However, first generation biofuels have been debated about that energy-crop compete with food crops and thus cause food deficiency and price increases. In this sense, researchers have started looking for potential feedstock for ethanol such as lignocellulosic biomass (e.g., sugarcane bagasse), which does not affect food security. In this paper, the integrated use of sugarcane bagasse is analyzed as raw material for second generation of biofuels production. This case study implements a design and process integration to compare several biorefinery topologies using the typical mass flow rate of residual biomass produced by the sugar industry (1200 ton per day). Based on evaluation of chemical composition of bagasse (cellulose, hemicellulose, and lignin) several process schemes for integral utilization of biomass were proposed. This paper is the first part of the study on the exergy, life cycle analysis (LCA) and economic analysis of sugarcane bagasse for sustainable biofuels production using Aspen Plus™ software. Part 1 presents the exergy and life cycle analysis developed while part 2 describes economic analysis and selection of an optimal configuration with minimal environmental impact, by means of the combined use of raw material and energy integration.     

Cogeneration in integrated first and second generation ethanol from sugarcane

Sugarcane bagasse and trash are used as fuels in cogeneration systems for bioethanol production, supplying steam and electricity, but may also be used as feedstock for second generation ethanol. The amount of surplus lignocellulosic material used as feedstock depends on the energy consumption of the production process; residues of the pretreatment and hydrolysis operations (residual cellulose, lignin and eventually biogas from pentoses biodigestion) may be used as fuels and increase the amount of lignocellulosic material available as feedstock in hydrolysis. The configuration of the cogeneration system (boiler pressure, lignocellulosic material consumption and steam production, turbines efficiencies, among others) has a significant impact on consumption of fuel and electricity output; in the integrated first and second generation, it also affects overall ethanol production. Simulations of the integrated first and second generation ethanol production processes were carried out using Aspen Plus, comparing different configurations of the cogeneration systems and pentoses use (biodigestion and fermentation). Economic analysis shows that electricity sale can benefit second generation ethanol, even in relatively small amounts. Environmental analysis shows that the integrated first and second generation process has higher environmental impacts in most of the categories evaluated than first generation.     

燃料乙醇发展现状及思考

自20世纪70年代以来,生物燃料乙醇作为车用燃料的研究和产业化受到广泛重视,被认为是未来最重要的可再生燃料之一。本文介绍了燃料乙醇的发展概况,综述了近年来国内外研究开发历程、产业政策和最新进展,对化学合成乙醇路线（合成气催化制乙醇、乙酸加氢制乙醇工艺）和生物发酵制乙醇路线（粮食发酵、非粮原料发酵、合成气发酵工艺）的技术特点、纤维素燃料乙醇产业化存在的困难和问题进行了分析,并对影响燃料乙醇产业发展的因素进行了分析,提出了我国燃料乙醇技术研发和产业发展的相关建议,认为我国应加强非粮原料供应体系建设,积极进行技术研发,加强工业示范并优化燃料乙醇使用环节,促进非粮燃料乙醇产业发展。     

Investigation of Ionic Liquids for the Separation of Butanol and Water

Abstract

With the continual rise in the cost of fossil fuel based energy, research into economic and sustainable alternatives is of increasing importance. One significant source of increased cost and demand is the consumption of fossil fuels for automotive fuels. While ethanol has received the most attention as a fuel additive; butanol could be a better direct fuel alternative owing to its physical properties and energy value when compared to ethanol. Commercial butanol is nearly exclusively produced from petroleum feedstocks currently; however, some recent interest has begun to refocus on its generation via fermentation. Unfortunately, this production is limited due to the nature of the process and the use of energy-intensive separation techniques. Ionic liquids are novel green solvents that have the potential to be employed as an extraction agent to remove butanol from the aqueous fermentation media. A hurdle to this potential is the limited availability of solubility data for ionic liquids. This research investigates the phase behavior of two ionic liquids, butanol, and water. Additionally, issues related to the implementation of the investigated ionic liquids are discussed.     

Agro Food Wastes and Innovative Pretreatments to Meet Biofuel Demand in Europe

The use of agricultural residues (AR) and agro‐food waste (AFW) as potential feedstocks for the production of second‐generation ethanol and butanol is reviewed. The maximum biofuel production rate from AR and AFW was estimated on the basis of the feedstock availability rate, the average composition, and the biofuel yields reported in the literature. According to the estimations, the contribution of ethanol and butanol to current European biofuel accounts could be 32 and 23 % if traditional pretreatments are applied, and 40 and 19 % if they are produced by innovative pretreatments, respectively. Finally, the analysis was applied to a local scenario (Campania, Italy), with a view to potential decentralized exploitation of AR and AFW.     

The role of butanol in the development of sustainable fuel technologies

OVERVIEW: The development of innovative methods to efficiently convert biomass to fuels and industrial chemicals is one of the grand challenges of the current age. n‐Butanol is a versatile and sustainable platform chemical that can be produced from a variety of waste biomass sources. The emergence of new technologies for the production of fuels and chemicals from butanol will allow it to be a significant component of a necessarily dynamic and multifaceted solution to the current global energy crisis. IMPACT: The production of butanol from biomass and its utilization as a precursor to a diverse set of fuel products has the potential to reduce petroleum use worldwide. In concert with other emerging renewable technologies, significant reductions in greenhouse gas emissions may be realized. The rapid incorporation of renewables into the world fuel supply may also help to offset predicted increases in transportation fuel prices as the supply of oil declines. APPLICATIONS: Recent work has shown that butanol is a potential gasoline replacement that can also be blended in significant quantities with conventional diesel fuel. These efforts have transitioned to research focused on the development of viable methods for the production of an array of oxygenated and fully saturated jet and diesel fuels from butanol. The technologies discussed in this paper will help drive the commercialization and utilization of a spectrum of butanol based sustainable fuels that can supplement and partially displace conventional petroleum derived fuels. Published 2010 by John Wiley and Sons, Ltd.     

Experimental determination of laminar burning velocity for butanol and ethanol iso-octane blends

The potential of butanol as an additive in iso-octane used as gasoline fuel was characterized with respect to laminar combustion, and compared with ethanol. New sets of data of laminar burning velocity are provided by using the spherical expanding flame methodology, in a constant volume vessel. This paper presents the first results obtained for pure fuels (iso-octane, ethanol and butanol) at an initial pressure of 0.1 MPa and a temperature of 400 K, and for an equivalence range from 0.8 to 1.4. New data of laminar burning velocity for three fuel blends containing up to 75% alcohol by liquid volume are also provided. From these new experimental data, a correlation to estimate the laminar burning velocity of any butanol or ethanol blend iso-octane-air mixture is proposed.     

晋城市煤层气综合利用发展初探

介绍了晋城市煤层气资源储量状况及煤层气的开发利用现状,对晋城市煤层气的开发利用提出了建议:可用于发电,可作为工业燃料和化工原料等。煤层气具有广阔的发展前景,其开发利用会带来很好的经济效益和社会效益。     

燃料乙醇生产技术路线分析及产业发展建议

对化学合成乙醇路线(合成气催化制乙醇、乙酸加氢制乙醇工艺)和生物发酵制乙醇路线(粮食发酵、非粮原料发酵、合成气发酵工艺)及其技术特点进行了分析,重点阐述了纤维素乙醇生产工艺、核心技术及国内外开发现状,并对我国燃料乙醇产业发展提出了有关建议.     

生物法制取纤维素乙醇技术

以纤维素为原料生产燃料乙醇,由于其原料来源广泛及环保效益良好而被认为是最有前景的生产燃料乙醇的方法之一。在阐述我国发展纤维素乙醇必要性的基础上,综述了纤维素乙醇的浓酸水解、稀酸水解、酶水解及生物质合成气等发酵工艺及研究进展。分析了各工艺优缺点,并讨论了各工艺过程需要解决的关键技术问题,展望了纤维素乙醇的产业化前景。     

Liquid–Liquid Extraction of Butanol from Dilute Aqueous Solutions Using Soybean-Derived Biodiesel

Liquid–liquid extraction (LLE) of mixtures of butanol, 1,3-propanediol (PDO), and ethanol was performed using soybean-derived biodiesel as the extractant. The composition of the mixtures simulated the product of the anaerobic fermentation of biodiesel-derived crude glycerol, which has recently been reported for the first time by the authors. Using a biodiesel: with an aqueous phase volume ratio of 1:1, butanol recovery ranged from 45 to 51% at initial butanol concentrations of 150 and 225 mM, respectively. Less than 10% of the ethanol was extracted, and essentially no PDO was extracted. The partition coefficient for butanol in biodiesel was determined to be 0.91 ± 0.097. This partition coefficient is less than that of oleyl alcohol, which is considered the standard for LLE. However, butanol is suitable for blending with biodiesel, which would eliminate the need for separating the butanol after extraction. Additionally, biodiesel is much less costly than oleyl alcohol. If biodiesel-derived glycerol is used as the feedstock for butanol production, and biodiesel is used as the extractant to recover butanol from the fermentation broth, production of a biodiesel/butanol fuel blend could be a fully integrated process within a biodiesel facility. This process could ultimately help reduce the cost of butanol separation and ultimately help improve the overall economics of butanol fermentation using renewable feedstocks.     

Ethanol—the primary renewable liquid fuel

This perspective paper establishes that ethanol has a long history of very good performance as a renewable liquid fuel blended with gasoline and can be used in over 80% of the automobile and other light duty transportation vehicles. It fits very well into the future of the combination of electricity and renewable liquid fuel for such transportation. It has also been established that renewable biomass feedstock is highly oxygenated and ethanol can be produced with high yields and efficiency with some conversion technologies—particularly the ‘Hybrid’ of gasification with bioconversion—that have been developed to the commercial implementation stage. Recent major studies conducted by the USDA, DOE and major National Laboratories have projected that large and sustainable biomass feedstock supplies are available and are going to be available to efficiently produce this ethanol in very large quantities of around 340 billion liters per year in the USA. The experience gained over the past 70 years in the south‐eastern USA has been summarized to further support the fact that efficient and sustainable biomass supply can be developed and maintained to support much increased usage. Copyright © 2011 Society of Chemical Industry     

Membrane process opportunities and challenges in the bioethanol industry

Increasing oil prices and growing environmental concerns in recent years have driven the development of renewable biofuels. Until now, most of the bioethanol production concepts are based on sugar and starch crops as feedstock, while research on second generation of bioethanol concepts is investigating the use of cellulosic biomass such as straw, wood, etc. as feedstock. The first part of the paper will review membrane opportunities in the present bioethanol production concepts, while the second part will provide an outlook on the future potentials of membrane technologies in the second generation concepts. For both production concepts, application opportunities for conventional membrane processes such as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) as well as the emerging membrane processes pervaporation (PV) and vapour permeation (VP) will be presented. Overall, this paper demonstrates that membrane technology as a highly selective and energy-saving unit operation has a great potential in the bioethanol industry of today and in future. Hence, membrane technology will contribute to solving future energy and environmental problems.     

Biobasiertes Glycerin – ein neuer Rohstoff für die chemische Industrie?

Glycerol that originates as a by‐product from the production of biodiesel is a bio‐based feedstock, which neither has the disadvantages of fossil resources nor can be used as food. It was studied in a life cycle assessment whether a use in the chemical industry leads to environmental advantages. The life cycle assessment of options of use of glycerol from the biodiesel production shows that a conventional material use without conversion is the environmentally most advantageous option. However, it is to be expected that not all glycerol can be used this way if the biodiesel production increases. In this case, innovative biotechnological conversions of glycerol to n‐butanol or 1,3‐propanediol as well as the use for energy production can be environmentally advantageous if especially the energy and resource efficiencies are further optimized.     

燃料乙醇生产用生物原料的土地使用、能耗、环境影响和水耗分析

在引入生物质分配比率的基础上,从土地使用率、能耗、环境和耗水量4个方面分析了玉米秸秆、木薯和甜高粱3种生物质原料生产燃料乙醇的过程,得到了3种生物质发展潜力数据. 结果表明,玉米秸秆作为原料,按产出乙醇能计,土地使用率最高可达563.40 GJ/ha,投入能量最低,仅为22.68 MJ/GJ,环境影响最小,耗水量最少,只有8 m3/GJ,是最有开发前景的原料. 甜高粱总体上优于木薯,但耗水量太大,不利于长远发展.     

Selective separation of n‐butanol from aqueous solutions by pervaporation using silicone rubber‐coated silicalite membranes

BACKGROUND: To use butanol as a liquid fuel and feedstock, it is necessary to establish processes for refining low‐concentration butanol solutions. Pervaporation (PV) employing hydrophobic silicalite membranes for selective recovery of butanol is a promising approach. In this study, the adsorption behavior of components present in clostridia fermentation broths on membrane material (silicalite powder) was investigated. The potential of PV using silicone rubber‐coated silicalite membranes for the selective separation of butanol from model acetone–butanol–ethanol (ABE) solutions was investigated. RESULTS: The equilibrium adsorbed amounts of ABE per gram of silicalite from aqueous solutions of binary mixtures at 30 °C increased as follows: ethanol (95 mg) < acetone (100 mg) < n‐butanol (120 mg). The amount of butanol adsorbed is decreased by the adsorption of acetone and butyric acid. In the separation of ternary butanol/water/acetone mixtures, the enrichment factor for acetone decreased, compared with that in binary acetone/water mixtures. In the separation of a model acetone–butanol–ethanol (ABE) fermentation broth containing butyric acid by PV using a silicone rubber‐coated silicalite membrane, the permeate butanol concentration was comparable with that obtained in the separation of a model ABE broth without butyric acid. The total flux decreased with decreasing feed solution pH. CONCLUSION: A silicone rubber‐coated silicalite membrane exhibited highly selective PV performance in the separation of a model ABE solution. It is very important to demonstrate the effectiveness of PV in the separation of actual clostridia fermentation broths, and to identify the factors affecting PV performance. Copyright © 2011 Society of Chemical Industry     

氢能源的利用现状分析

氢能是公认的清洁能源,它具有储运方便、利用途径多样、高利用率及来源广泛等特点,可为解决能源危机、全球变暖和环境污染提供帮助。当前,一些发达国家已将氢能列为国家能源体系中的重要组成部分,我国在氢能的研究及产业化方面也投入巨大。本文综合考虑氢能在能源和化工领域的应用,较为全面地总结了氢能作为清洁能源在燃料电池汽车、分布式发电、燃料电池叉车和应急电源,作为能源载体在可再生能源消纳以及作为重要化工原料在油品质量升级和煤制清洁能源各方面的国内外利用现状,分析明确了氢清洁能源的利用是目前推动氢能发展的主要动力,氢能源载体的利用有助于可再生能源和氢能的协同发展,而氢化工原料的利用则是目前最有希望实现氢能规模化利用的有效途径,同时指出氢的制取、储运和燃料电池技术依然是制约氢能发展的关键因素。     

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.     

后石油经济时代中国能源化工的选择

中国面临总能耗和总碳排放的巨大压力,但人均能耗和人均碳排放增长是中国发展的合理诉求.现代社会的交通燃料和多种重要基础化工材料均以石油为主要原料,而石油资源短缺和可持续发展理念要求寻找石油经济的替代模式.本丈对后石油时代能源化工的主要问题,即交通燃料和重要基础化工原料的生产工艺替代,从技术层面探讨了中国能源化工的发展如何面对资源与碳排放的双重挑战.