摘要:

Data concerning organic petrology and thermal maturity of Lower Karoo coal measures (Lower Permian) are of considerable importance in determining the hydrocarbon potential of sediments in the rift-valley and half-graben complexes of the Luangwa and Zambezi valleys of eastern and southern Zambia, respectively, and in the extensive sedimentary basin developed on relatively stable Precambrian basement in western Zambia, a total area in excess of 3000 km2. Samples from seven outcrop and subsurface localities situated in the northeast (northern Luangwa Valley), east (mid-Luangwa Valley), south (mid-Zambezi Valley), and the Western Province of Zambia were studied. The coal measures are from 9 to 280 m thick, but individual coal seams are generally less than 6 m. The coal macerals contain an average of 60% vitrinite and 9 % liptinite, enough to have potential to generate hydrocarbon. A few samples contain twice this amount of liptinite. Reflected-light microscopy and the thermal alteration index of spores were used to determine the thermal maturity. The organic matter in samples studied is within the oil generation zone (thermal alteration index 2— to 2 + ; %R0max = 0.5-0.9). Considerable differences in depth of burial of the coal measures, such as might be expected in rift valleys or half-grabens, have probably resulted in varying degrees of thermal maturity elsewhere. For example, in localities with significant thickness of younger Karoo and post-Karoo rocks (approximately 3500 m in some localities) the thermal maturity at depth (no samples available) is probably higher than %R0= 1.35 and falls within the gas generation zone. The penological and palynological data indicate that the organic matter consists of Types II (generally approximately 25% in carbonaceous shale samples), III, and IV, indicating source rock potential. Late Karoo(?) and post-Karoo fault blocks with differential vertical displacements may have produced structural traps suitable for oil and gas accumulation.

ISSN:0090-8312    

DOI:10.1080/00908319208908731

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The objective of this work is to develop control techniques for the efficient operation of fuel cells generating electric power. The system to be controlled consists of a network of multiple fuel cells. The proposed control system structure is a multilevel implementation. The first level deals with dedicated feedback control to keep the parameters of a cell at set-point values with minimized error. The desired values (set points) of feedback controls are adjusted by supervisory controls corresponding to a minimized energy production cost. The dynamics and the steady performance of a cell are utilized to determine the first-level control functions. The operational values of performance parameters such as conversion factor, efficiency, cell potential, power density, fuel utilization, temperature, current, electrolyte concentration, and power are determined to arrive at an overall maximum efficiency and minimum operational cost.

ISSN:0090-8312    

DOI:10.1080/00908319208908732

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

At present, the total installed electricity generating capacity of Thailand is 7500 MW. According to an official forecast, the average annual growth of electricity demand will be 725 MW during 1992-1996 and 800 MW during 1997-2001. To satisfy this demand, it would be necessary to invest approximately $7 billion during the next 10 years. Because this level of investment will take an unacceptably large part of total foreign borrowing, the government plans to encourage participation of the private sector in electricity generation. Among the various technology options for power production, cogeneration appears to be the most promising technology due to its very high effectiveness of fuel utilization. Therefore, in the first phase of private power generation, the Thai government is encouraging cogeneration systems

ISSN:0090-8312    

DOI:10.1080/00908319208908733

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A geographical information system known locally as the Hawaii Natural Resources Information System (HNRIS) was utilized to identify potential biomass plantation sites by matching biomass species requirements with appropriate environmental conditions. The HNRIS database contains the essential information, such as soil type, elevation, temperature, solar radiation, rainfall, land zoning, ownership, and present use, for the six major islands of the state of Hawaii. Its use facilitates a biomass energy resource assessment efficiently and economically, in contrast to conducting expensive and time-consuming large field trials at many independent locations. The site selection process includes analyses of land suitability and land availability factors. Maps generated by HNRIS show land parcels with environmental conditions and land zoning similar to experimental field sites. An integrated methanol-from-biomass system model is described.

ISSN:0090-8312    

DOI:10.1080/00908319208908734

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The effects of hydraulic retention time and alkali treatment on methane production rate from the semicontinuous anaerobic digestion of 2% sunflower-head/ water mixtures were investigated. The experiments were carried out in laboratory-scale fermenters, fed with I liter of untreated, 2 g NaOH/l00 g total solids (TS), and 5 g NaOH/100 g TS alkali-treated sunflower-head/water mixtures, respectively, and maintained at 55 °C. Digestion experiments were performed for hydraulic retention times of 8, 10, and 15 days. The amount and composition of produced gas were measured until steady state was attained in each run. The steady-state methane production rates were found to decrease with hydraulic retention time and increase with alkali dosage used for pretreatment.

ISSN:0090-8312    

DOI:10.1080/00908319208908735

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Kenya's heavy dependence on petroleum has had an adverse effect on its economy, making it difficult to achieve its development goals. Furthermore, the use of fossil fuels is accompanied by emissions of large quantities of carbon dioxide into the atmosphere—a process that is enhancing the greenhouse effect and subsequent global warming and climate change. This article gives an analysis of the Kenya's current energy scene and discuses its alternative energy resources. Although renewable energies are at present not viable substitutes for oil, the development and exploitation of these energy resources will not only reinforce conservation measures but also promote new trends in technology development.

ISSN:0090-8312    

DOI:10.1080/00908319208908736

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A current political topic is the request for increasing use of wind energy. The objectives of this paper are to evaluate this call in more detail in some parts of the Federal Republic of Germany by analyzing possibilities, restrictions, and production costs of electricity generation from wind energy in Baden-Württemberg, an inland state in the southwest of Germany. Based on zones with similar average wind velocities, the theoretical potential to install converters is assessed for each municipality, considering among other things residential areas, highways, roads, rivers, and nature conservation areas as not usable territories. The result is a technical area potential suitable for the installation of wind energy converters. Based on this area potential, a methodological approach is presented that allows the definition and the analysis of strategies of a wind energy use on a high spatial and timely resolution. On the basis of measured hourly mean wind velocities at different locations, a method is shown that allows the calculation of representative wind speed time series for any possible site correlated with the general weather situation. Then the most cost-efficient spatial distribution of the wind turbines is calculated. After the simulation of the electricity generation corresponding to the wind energy supply and the calculation of the annual investment costs, the energy generation costs for one unit electricity can be determined. Using this model two strategies of an wind electricity generation in Baden-Württemberg are analyzed. They are evaluated on the amount of electricity generation, the regional supply distribution, and the resulting energy production costs.

ISSN:0090-8312    

DOI:10.1080/00908319208908737

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Approximately 130 core and drillhole cuttings samples taken from the Palaeozoic and Mesozoic of northwestern Melville Island were examined using reflected-light microscopy and Rock-Eval pyrolysis. The Triassic Schei Point marine silty shales, known to be good-quality source rocks in certain parts of the Sverdrup Basin, are dominated by kerogen Types I and II, have hydrogen index (HI) values as high as 625 mg hydrocarbon (HC)/g organic carbon, a total organic carbon (TOC) content as high as 8.07o, but are marginally mature at best. Source potential decreases drastically in the Jurassic and Cretaceous parts of the succession

ISSN:0090-8312    

DOI:10.1080/00908319208908738

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Over the last three decades the V. S. geothermal power-generation industry has grown to be the largest in the world, with over 2700 MW of installed electrical capacity. Growth during the first two decades (1960-1980) was characterized by a single utility's development of one dry-steam resource. After 1983, growth shifted toward independent power producers, and development of water-dominated geothermal resources at several locations. In the absence of significant changes in demand, incentives, or the regulatory process, new geothermal generating capacity, through 1995, will probably not exceed 500 MW. The U.S. geothermal industry must increase its inventory of characterized geothermal reservoirs in order to meet the expected demand for rapid geothermal development before the year 2000.

ISSN:0090-8312    

DOI:10.1080/00908319208908739

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The results of a study on the effect of oxidation on the AP index and acidity of three Nigerian coals are reported. The coals were oxidized in air over a period of 35 days at both 100 and 50°C. The heating value, slurry pH (acidity), and the ΔP index of three Nigerian coal sample were monitored as a function of oxidation time. The results revealed a decrease in ΔP index and an increase in the acidity of all three coals with increase in oxidation time. The heating value of the coals was also reduced by the oxidation.

ISSN:0090-8312    

DOI:10.1080/00908319208908740

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor