Showing papers on "Substitute natural gas published in 1994"

Apparatus for producing substitute natural gas

Abstract: PURPOSE:To obtain an apparatus capable of providing a substitute natural gas at inexpensive cost of equipment by reforming a fossil-based hydrocarbon with steam at low temperature and high temperature, separating hydrogen from a gas obtained by conversion of carbon monoxide, mixing the hydrogen with low-temperature reformed gas and carrying out methanation of the mixture. CONSTITUTION:In an apparatus for producing a substitute natural gas for city gas consisting essentially of methane by carrying out steam reforming using a fossil-based hydrocarbon as a raw material, when a lean gas producing apparatus for city gas consisting of desulfurizing process (1), low-temperature reforming process (2), high- temperature reforming process (3) and carbon monoxide conversion process (4) is diverted into the apparatus for producing the substitute natural gas, PSA(Pressure Swing Adsorption) process (5) for separating hydrogen gas by treating a gas discharged from the carbon monoxide conversion process (4) is newly equipped and a methanation process (6) for receiving a mixed gas consisting of a gas obtained by partly discharging a gas output from the low-temperature reforming process (2) and hydrogen obtained from the PSA process (5) and then methanating carbon monoxide and carbon dioxide in this gas is newly equipped to provide the objective apparatus for producing the substitute natural gas, capable of installing at inexpensive cost of equipment.

Alternate routes for the production of fuels from coal and natural gas.

Abstract: Almost all transportation worldwide is powered by high energy density liquid hydrocarbon fuels produced from crude oil. Transportation fuels currently use over 50 percent of total world petroleum demand of 66 million barrels per day. Prior MlTRE studies indicate that crude oil supply will become severely limited after the year 2030 as increasing world energy demand, dnven by population growth and economic development, depletes oil resources. If conventional liquid hydrocarbon fuels that can use existing production and distribution infrastructures are still needed for transportation in the future, then alternate sources of these fuels will have to be utilized. Two such sources are natural gas and coal. Natural gas reserves worldwide are expected to last well into the 21st century, and coal resources are enormous. This paper examines the technologies for producing environmentally superior liquid transportation fuels from coal and natural gas using modern conversion technologies. Estimates of the costs of fuels from these sources are given, and the potential environmental impacts of these fuels are examined. INTRODUCTION: High energy density liquid fuels are the predominant form of energy used for transportation worldwide. The existing infrastructure for production, refining, distribution, and use of liquid fuels represents an enormous investment worldwide, especially so for the Organization of Economic Cooperation and Development (OECD) countries that are transportation rich The pressures of potential resource limitations for petroleum and the drive toward a cleaner environment have aroused considerable interest in developing alternative fuels for transportation. These alternatives include non-liquid fuels like natural gas and, perhaps in the future, hydrogen. If it is considered to be economically and technically expedient to continue to use the existing liquid fuels infrastructure rather than to change to a gas-based system, liquid fuels could still be produced from non-petroleum sources. The most abundant fossil fuel source worldwide is coal and this can be used to produce high quality liquid fuels. Natural gas can also be used as a source of liquid transportation fuels. Previous studies at MITRE have examined potential world energy supply and demand scenarios till the year ZlOO(1). These hypothetical scenarios show that total world energy demand increases from the current annual use of 360 exajoules to about 1,100 exajoules by 2 100. This projection assumes that energy conversion and end-use efficiency increase such that after 33 years existing equipment is replaced by new equipment that saves 33 percent of the energy. This 33 cycle continues for another two cycles of continuing efficiency improvements saving an additional 16.6 and 8.3 percent respectively. Recoverable oil and gas resources are assumed to be 10,000 exajoules each(*). and they will be essentially depleted by 2100. The purpose of this look into the future is to demonstrate that after 2030 oil production will be in decline and an alternative to petroleum-based fuels will have to be found. Coal as an alternative feedstock for transportation fuels: The key to converting solid coal to liquid fuel is hydrogen. Liquid fuels typically contain ahout 14 percent hydrogen whereas coal contains around 5 percent. This hydrogen deficit can be made up by forcing hydrogen into the coal under pressure (so-called direct liq~efaction(~)), or by gasifying the coal with oxygen and steam to a synthesis gas containing hydrogen and carbon monoxide that is then passed over catalysts to form hydrocarbons (so-called indirect liq~efaction(~)). For direct liquefaction, coal is slurried with a recycle oil and heated under a high pressure of hydrogen to produce a synthetic crude oil that can be upgraded into specification transport fuels by existing petroleum

Money down the chute: A new coal liquefaction process

Abstract: This paper describes the efforts in France beginning in the 1970's to diversify its energy sources used to produce transportation fuels. The objective of this effort was to develop an original scheme for the simultaneous production of gasoline and substitute natural gas via hydroliquefaction of coal. Catalyst studies, pilot plant evaluation, and economics of the final process are described. The essential conclusion of the economic study was that the absolute value of production cost was about twice as high as the mean price of the crude-oil-based products. The project and further research was finally abandoned in 1990.