Gasohol Production Research Articles

Production of gasohol by azeotropic distillation

AbstractA new azeotropic distillation process is presented to produce gasohol in an adequate concentration of bioethanol and isooctane, which emulates the properties of gasoline ready to use in conventional combustion engines. Since the mixing step is eliminated, there are significant economic savings which imply a competitive price of bioethanol. A comparison is provided with the traditional bioethanol dehydration process, extractive distillation. Both processes were simultaneously designed and optimized with differential evolution with a Tabu list algorithm (DETL) in order to reduce the total annual cost (TAC). Results showed that when obtaining E10 biofuel, a blend of up to 10% ethanol and 90% unleaded isooctane, via azeotropic distillation, over 40% of the TAC is saved compared to obtaining pure alcohol dehydrating through extractive distillation. Moreover, the reduction in carbon dioxide emissions results in an average of 27%.

Process Simulation-based Net Energy Analysis for Future Bioethanol Production as Commercial Biofuel from Waste Rice Straw in Sri Lanka

As the staple food crop in Sri Lanka, paddy rice occupies around 34% (over 0.87 million hectares of land) of the total arable area in the country, corresponding to an average rice production of 3,774,344 t/year. Rice straw is the major biomass waste from rice cultivation, which approximates to an average of 2,830,758 t/year generation at a theoretical straw/grain ratio of 0.75. Open burning of rice straw in paddy fields is the common practice, which could result in an average GHG emissions of 92 kg CO2 eq/t of dry rice straw and other harmful airborne emissions. Application of rice straw into soil as an organic fertiliser is also an inefficient practice, compared to bioenergy generation using rice straw. The average composition of the Sri Lankan rice straw (i.e. 30.0 wt.% cellulose, 3.9 wt.% hemicellulose, 38.2% lignin, 16.1 wt.% wax, and 12.3 wt.% silica) shows the possibility to be used as a second-generation bioethanol feedstock. Existing studies indicate that bioethanol production from rice straw is more environmentally-benign, compared to alternative options, such as gasification for combined heat and power and dimethyl ether (DME) production. This study analyses the net energy indicators of a possible bioethanol production process from rice straw in Sri Lanka. Chemical process simulations using Aspen Plus software were utilised to evaluate the bioethanol production process from rice straw, with a plant output capacity of 1,000 litres/hr of dehydrated bioethanol (99.7 vol.% ethanol) that can be blended with gasoline as a commercial fuel (e.g. E10: 10% bioethanol+gasoline) without any vehicle engine modification. The cradle to gate bioethanol production process from waste rice straw, considered for net energy analysis consists of three major stages: 1. Rice straw preparation, 2. Rice straw transportation, and 3. Bioethanol conversion. The results show that the considered bioethanol production process has a positive net energy gain and increased renewability factor. Detailed analysis indicates that only around 8% of the total process energy consumption is utilised for the bioethanol dehydration operation that is favourable for converting any existing rice straw ethanol plant into commercial gasohol production plant. The sensitivity of bioethanol yield and process energy parameters for the net energy indicator results are further analysed and discussed. The findings from this study can support decision making for a future waste-to-biofuel plant using waste rice straw in Sri Lanka.Keywords: Rice straw, Bioethanol production, Net energy analysis, Process simulation, Waste-to-biofuel

A comparison of process alternatives for energy-efficient bioethanol downstream processing

Ethanol is a biofuel used to reduce fossil fuel consumption and the greenhouse gases emissions associated with road transportation. Bioethanol is obtained from diluted fermentation broths, and various technological solutions are available for its recovery and dehydration prior marketing, usually blended with gasoline (gasohol). This work explores an ethanol purification approach where gasoline is used as a separation agent towards the direct production of gasohol. This alternative replaces part of the purification steps in common ethanol downstream processing, providing significant reductions on the operating costs required to produce bioethanol. Two configurations for the direct manufacture of E10 gasohol are analyzed. Process Iincorporates a liquid-liquid extraction stage, while Process IIuses an extractive distillation arrangement. The energy requirements of both configurations are compared against each other and with a benchmark process where ethanol dehydration is carried out by molecular sieves (Process MS).The results show that both alternatives are energetically advantageous since they can be optimized to reduce their equivalent energy requirements by 33% compared to Process MS, for ethanol concentrations in the fermentation broths between 2 and 10 wt%. Further improvements could be achieved with a multi-effect distillation system in the ethanol concentration step, allowing total energy savings of 68% relatively to the benchmark, for a fermentation broth containing 5 wt% ethanol. Estimated ethanol separation costs are approximately $0.15/kg ·ethanol, making these technological alternatives especially attractive for large scale industrial application.

Production of gasohol from isobutanol

Butanol is a four carbon chain alcohol compound of a non-polar used as a solvent and as an intermediate in several consumer products. It can be produced from petrochemical process route as well as biochemical process. A common petrochemical route to produce butanol is hydroformylation of propylene as primary feedstock followed by hydrogenation. The increasing demand for butanol and the scarcity of petrochemical basestock has put the urgent need for a renewable resource of butanol production. Biobutanol is butanol produced from renewable, biological feedstock through fermentation of plant materials types of food, non-food and biomass. One isomer of butanol which is more similar with gasoline property is isobutanol. The use of isobutanol is commonly as solvent in coatings industry, as lacquers, melamine or phenolic resin. Isobutanol can be potentially used as a gasoline blending component, and it is better than ethanol due to its higher heating value, lower volatility and less corrosive. A brief review of process technology for butanol production is outlined in this paper. The benefit of isobutanol over ethanol was also overviewed. In order to prove the compatibility on fuel application, the production of gasohol was carried out by mixing isobutanol and base gasoline, then evaluated according to commercial fuel specification. From the research work, it has been shown that the addition of isobutanol in base gasoline by certain volum fraction has met the typical fuel specifications used for spark-ignition engine. The physical and chemical properties of the mixture was quite similar to gasoline 88 and gasoline 92 specifications.

Synthesis and Testing of Zeolite from Industrial-Waste Coal Fly Ash as Sorbent For Water Adsorption from Ethanol Solution

In the present work, zeolite was prepared from industrial-waste coal fired ash (CFA) by fusion technique with and without acid-washing pretreatment under various conditions. The synthesized materials were then tested for water adsorption from bioethanol solution with an aim to produce a high purity ethanol (>99.5%) for later utilization in gasohol production manufacturing. From our studies, it was found that the impurities (i.e., Fe 2 O 3 , TiO 2 , MgO, CaO, K 2 O and SO 3 ) in CFA could be efficiently removed by acid-washing pretreatment. Among three different acids studied (i.e. HCl, HNO 3 , and H 2 SO 4 ), HCl exhibited the highest pretreatment performance, while the most suitable pretreatment conditions to enhance high purity raw material (up to 85% purity) were by using 20%HCl with the acid to CFA ratio of 25 mlHCl/gCFA at 80°C for 3 h. After fusion at 550oC with NaOH/CFA mass ratio of 2.25 and further crystallization at 90oC for 4 h, the pretreated CFA was converted to zeolite; from which the main phases were sodium aluminum silicate hydrate (1.08Na 2 O•Al 2 O 3 •1.68SiO 2 •1.8H 2 O) and faujasite-Na (Na 2 Al 2 Si 2 .4O8.8•6.7H 2 O). Regarding water adsorption testing, the synthesized zeolite provided comparable adsorption performance with the commercial grade molecular sieve. Under three adsorption cycles testing at 85oC, high ethanol purity (99.8%) could be achieved without deactivation being observed.

Effects of synthesis parameters on zeolite membrane formation and performance by microwave technique

AbstractRecently, zeolite membranes on porous supports have been extensively studied in the ethanol–water separation process for further use for gasohol production. This work focuses on a NaA membrane synthesized on an α‐Al2O3 support via microwave hydrothermal treatment. Synthesis temperature and time, type of substrate, seed amount and seeding time for the layer growth of the membrane are considered. The formation of as‐synthesized membranes is discussed according to observations by SEM and XRD. In addition, a preliminary study of the performance of the synthesized NaA zeolite membrane was conducted using the pervaporation technique. It was found that, for the synthesized continuous NaA membranes prepared using a 0.5 µm NaA crystal seed concentration of 3 g/l via vacuum seeding, the optimum conditions were 363 K synthesis temperature for 15–20 min via microwave heating. The flux and the separation factor obtained were 1.6 kg/m2 h and 1760.5, respectively, for the substrate without an intermediate layer. Interestingly, the substrate with an intermediate layer showed better flux and separation factor at 1.7 kg/m2 h and 6532.7, respectively. Copyright © 2007 John Wiley & Sons, Ltd.

The Production of Gasohol: The Environmental and Economic Implications of Growing Our Own Fuel

The Production of Gasohol: The Environmental and Economic Implications of Growing Our Own Fuel

4490153 Process for the production of gasohol: Morgan C Y Sze, George D Suciu assigned to Lummus Crest Inc

4490153 Process for the production of gasohol: Morgan C Y Sze, George D Suciu assigned to Lummus Crest Inc

4523928 Gasohol production from thermochemical conversion of biomass to ethanol: Melville E D Hillman, William J Huffman, Edward S Lipinsky, Edgel Stambaugh assigned to Battelle Development Corporation

4523928 Gasohol production from thermochemical conversion of biomass to ethanol: Melville E D Hillman, William J Huffman, Edward S Lipinsky, Edgel Stambaugh assigned to Battelle Development Corporation

Identification of Additives to Render Mixtures of Gasoline and the Ethanol-Water Azeotrope Hiscible

SUMMARY The economical production of gasohol, in terms of both energy and dollars, is dependent upon th e use of pure, water-free ethanol. Since a small amount of water will cause phase separation in the gasohol, the ethanol must be completely water free. Rather than using pure ethanol, it was proposed to use the ethanol-water azeotrope and some kind of modifier to remove the phase splitting that would occur from using the azeotrope, thus removing the burden of producing water-free ethanol. A thermodynamic analysis of a set of mixtures containing the gasoline, ethanol azeotrope, and an additive was performed. Each system was evaluated using a computer algorithm which interfaced liquid-liquid equilibrium calculations with the UNIFAC ac tivity coefficient prediction model. The amount of each additive necessary to produce a single phase in the mixture was then determined. Thirty six compounds were evaluated as possible additives and, of these, six were found to require less than 10% by volume added in order ...

Gasohol production by extraction of ethanol from water using gasoline as solvent

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGasohol production by extraction of ethanol from water using gasoline as solventStephen A. Leeper and Phillip C. WankatCite this: Ind. Eng. Chem. Process Des. Dev. 1982, 21, 2, 331–334Publication Date (Print):April 1, 1982Publication History Published online1 May 2002Published inissue 1 April 1982https://doi.org/10.1021/i200017a018RIGHTS & PERMISSIONSArticle Views286Altmetric-Citations23LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (509 KB) Get e-Alerts