摘要:

Biogas has been recognized as one of the best available renewable and decentralized sources of energy and organic fertilizer for a country like India. There is enough evidence to prove that temperature has a profound influence on the rate of biogas production. In temperate climates, where the winters are mild, solar energy systems can be effectively used to increase the temperature of the biogas digester to the desired level. This paper examines various techniques, such as a solar greenhouse on the biogas digester, a shallow solar pond water heater, insulation, and a heat exchanger, and their technoeconomic viability.

ISSN:0090-8312    

DOI:10.1080/00908318808908930

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A two-stage, low-temperature, ambient pressure, acid hydrolysis process that utilizes separate unit operations to convert hemicellulose and cellulose in agricultural residues and crops to fermentable sugars is being developed and tested by the Tennessee Valley Authority and the U.S. Department of Energy (DOE) in Muscle Shoals, Alabama. In laboratory and bench-scale evaluations, the conversion and recovery efficiencies of sugars from hemicellulose and cellulose fractions of corn stover were greater than 90%percnt;. Sugar product concentrations of more than 10%percnt; glucose and 10%percnt; xylose were achieved. In these tests, furfural and hydroxymethyl furfural levels in the sugar solutions never exceeded 0.02gll00 mL, which is far below the levels shown to inhibit fermentation. Based on the results of the bench-scale tests, TVA built a one-of-a-kind acid hydrolysis experimental plant to demonstrate the concepts of low-temperature acid hydrolysis on a much larger scale. The experimental plant was coupled to an existing 10 gal/h fermentation and distillation facility. Plant tests using corn stover have been conducted for more than a year and conversion efficiences have equaled those achieved in the laboratory. Laboratory tests to determine the potential for low-temperature acid hydrolysis of other feedstocks-including red clover, alfalfa, kobe lespedeza, winter rape, and rye grass-are being conducted. Where applicable, process modifications to include extraction before or after hydrolysis also are being studied. This paper describes the experimental plant and process, results obtained in the plant, results of alternative feedstocks testing in the laboratory, and a plan for an integrated system that will produce other fuels, feed, and food from crops grown on marginal land.

ISSN:0090-8312    

DOI:10.1080/00908318808908931

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

There are significant quantities of low-quality or subquality natural gas in the United States that have not been entered into the resource data base. The fields encountered have been shut in or abandoned for lack of a market. Such gas fields notably contain nitrogen in higher concentrations and also may contain carbon dioxide and/or hydrogen sulfide. There are, in fact, high-nitrogen-content natural gas occurrences in southwest Arkansas, northern Texas, West Texas and the Panhandle region, eastern New Mexico and eastern Colorado, western Kansas and north central Oklahoma—not to mention central California and other locales. A detailing of this subquality reserve would be most useful, as would new and improved methods for gas separation, particularly of nitrogen.

ISSN:0090-8312    

DOI:10.1080/00908318808908932

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A new analytic technique for the prediction of temperature profile of buried gas pipelines is developed based on the corresponding states principle. The resulting equations are tested through prediction of the actual experimental data. It is demonstrated that the new technique can predict temperature profile quite accurately without using any additional chart or table. This technique can also be used for prediction of gas mixture temperature profile flowing in a buried pipeline.

ISSN:0090-8312    

DOI:10.1080/00908318808908933

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A study on the distribution of isoprenoid structures in the five fractions obtained by mild Na2Cr2O7/AcOH stepwise oxidation of Green River kerogen is presented. Gas chromatography-mass spectrometry analysis of the fractions resulted in the identification of a homologous series of isoprenoid acids ranging from C14-C21with C16as the largest and C18entirely absent, as well as the two isoprenoidal ketones: 6,l0-dimethyl-2-undecanone and 6,10,l4-trimethyl-2-pentadecanone. A semiquantitative analysis of these components was performed using an INCOS 2300 data system. On the basis of the results obtained, it is suggested that isoprenoid structures do not constitute more than 4% of the kerogen matrix. The results also substantiate previous assumptions that the phytol side chain of chlorophyll is the most likely pre-genitor to the chain isoprenoids found in Green River kerogen.

ISSN:0090-8312    

DOI:10.1080/00908318808908934

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0090-8312    

DOI:10.1080/00908318808908935

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0090-8312    

DOI:10.1080/00908318808945382

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor