Showing papers on "Substitute natural gas published in 1977"

Production of substitute natural gas

Abstract: Synthesis gases containing carbon monoxide, eg above 40% volume, and hydrogen are methanated to produce substitute natural gas, after CO2 removal, wherein the synthesis gas is simultaneously saturated with water, further heated and divided into first and second feed gas streams. The first feed gas stream is catalytically methanated at a temperature of from 250 to 550° C, and the reaction product mixed with said second feed gas stream. The mixture is methanated over a second catalyst at a temperature of from 250 to 550° C and the product is divided into a second product gas stream and a recycle gas stream and the recycle gas stream is admixed with the first feed gas stream, prior to the first catalytic methanation. The second product gas stream is subjected to a carbon dioxide removal process to produce SNG.

Process for the catalytic gasification of coal

Abstract: A process for the production of synthetic natural gas from a carbon-alkali metal catalyst or alkali-metal impregnated carbonaceous feed, particularly coal, by reaction of said feed with water (steam) in the presence of a mixture of hydrogen and carbon monoxide, in a series of staged fluidized bed gasification reactors (or gasification zones). The first reactor, or main reactor, of the series is operated as an entrainment reactor and entrained solids are carried over to the second reactor, or reactors, of the series. A carbonaceous feed, or coal, is thus partially gasified in a fluidized bed in the main reactor to form a product gas and a char, and char is entrained within the effluent gases, separated therefrom and then fed into the secondary gasification reactor, or reactors, of the series, the entrained char constituting feed to a secondary reactor, or reactors. Some char is also passed via dense phase transfer from the main reactor to the secondary reactor to maintain catalyst balance. More effective ultilization of the feed carbon is possible by use of the reactor system operated in such a manner than is possible by the sole use of the main reactor, even when the latter is operated at the same or at more optimum conversion conditions.

Production of low sulfur fuels from coal

Abstract: A general method for producing low-sulfur gas and solid fuel is disclosed. Such method involves partial gasification of coal, using steam and an oxygen-containing gas, to produce low-B.t.u. fuel which can be used as a feedstock for power plants and industrial boilers. Also disclosed is a method for simultaneously producing low-sulfur gas, liquid, and solid fuels from coal in a single reaction vessel using a multi-stage fluidized gasification and desulfurization system. Synthesis gas produced in a first stage gas generator by reaction of steam, an oxygen-containing gas, and auxiliary carbonaceous fuel, is reacted with high-sulfur coal in a second stage desulfurization unit forming a solid phase consisting of low-sulfur fuel and a fluid phase consisting of sulfur-containing gaseous and liquid fuels. After disengagement of solid and fluid phases present in the second stage reaction zone, a solid fuel of reduced sulfur content is recovered.

Converting fossil fuel and liberated water constituents to electrical energy, synthetic natural gas or miscellaneous hydrocarbons while avoiding befoulment of environment

Abstract: An abstract of my disclosure envisions a continuously repeated series of treatments a gaseous and fluidized powder stream is subjected to after it is made and unceasingly renewed from fossil fuel, oxygen and steam in a gasifier at slagging temperatures; and then impelled to flow through connected steam making, processing and electricity generating units forming a closed circulatory system; producing a stream of carbon monoxide and hydrogen while generating electrical energy.

Thermal stability of some aircraft turbine fuels derived from oil shale and coal

Abstract: Thermal stability breakpoint temperatures are shown for 32 jet fuels prepared from oil shale and coal syncrudes by various degrees of hydrogenation. Low severity hydrotreated shale oils, with nitrogen contents of 0.1 to 0.24 weight percent, had breakpoint temperatures in the 477 to 505 K (400 to 450 F) range. Higher severity treatment, lowering nitrogen levels to 0.008 to 0.017 weight percent, resulted in breakpoint temperatures in the 505 to 533 K (450 to 500 F) range. Coal derived fuels showed generally increasing breakpoint temperatures with increasing weight percent hydrogen, fuels below 13 weight percent hydrogen having breakpoints below 533 K (500 F). Comparisons are shown with similar literature data.

Biological conversion of biomass to methane

Abstract: The importance of natural gas as a fuel in the United States and the shortage of long term supplies has fostered interest in processes capable of producing substitute natural gas. A system for producing this gas from a renewable source is presented. In photosynthesis, plants have the capacity to capture and store solar energy in the form of plant tissue. This energy can be recovered as methane by employing an anaerobic fermentation process. Factors that determine the quantity of energy that can be obtained are discussed. These factors range from the photosynthetic efficiency, or dry matter yield, to process conversion efficiency. Experimental results of the fermentation process applied to plant fibers are presented. Those factors affecting process conversion efficiency are discussed in detail.

Silvicultural biomass farms, volume V: conversion processes and costs.

Abstract: An assessment of the products and processes that appear to be the candidates for the conversion of wood biomass to energy forms suited to the national energy scene is presented. Identification was achieved by comparing market-oriented selling prices of competitive products projected for the future with estimations of production-oriented selling prices utilizing wood-biomass feedstocks needed to make the production attractive to the investor. The products assessed include: electricity from combustion of wood, wood and wood charcoal in combustion with oil or coal, ammonia, methanol, medium-Btu fuel gas, substitute natural gas, and ethanol. Conversion technologies are reviewed and data and information gaps for ultimate design of viable processes are identified as an input to the formulation of research and development needs.

Process for making substitute natural gas

Abstract: A process, having high thermal efficiency, is provided for the production of substitute natural gas from fossil fuels such as crude oil, by non-catalytic hydrogenation High thermal efficiency is obtained by using cryogenic systems for separating hydrogen from (a) the product of the hydrogenation reaction and (b) from products produced by partial oxidation in the production of hydrogen required for the hydrogenation reactions Other products from the partial oxidation reaction may be used either as fuel or as feedstocks for catalytic steam reforming to produce SNG

Synthetic fuels from coal or coke - preimpregnated with catalyst by hydrothermal treatment

Abstract: Solid carbonaceous fuels (coal or coke) are converted into synthetic fuels by (a) mixing particles of the solid fuel with an aq. soln. contg. at least one catalytically active cation; (b) heating the mixt. under high pressure at 125-375 degrees C for a time sufficient to modify the structure of the particles and impregnate them with the cation(s); and (c) reacting the particles with one or more of H2, H2O, steam, O2, air, CO, CO2 and organic solvents at a manometric pressure of >10.5 kg/mc2 and a temp. at least equal to the impregnation temp. The process esp. applies to the prodn. of synthesis gas or synthetic natural gas (SNG). The hydrothermal treatment step (b) activates the coal or coke to a greater extent than simple impregnation or mechanical mixing with the catalyst, and (when one of the cations is Ca2+ or Mg2+) reduces the S content of the end product; it also renders caking coals non-caking.

A Long-Range Approach to the Natural Gas Shortage Utilizing Nonfossil Renewable Carbon*

Abstract: Based on our present knowledge, the only long-term practical solution to sustaining a national economy on natural gas is to convert a major source of continuously renewable nonfossil carbon to substitute natural gas that is interchangeable with, or can be substituted for, natural gas. The most promising source of this carbon is land- and water-based biomass produced from solar energy by photosynthesis. An assessment of this concept is presented in this paper, and the major problems encountered in the development of the technology are reviewed. The technology for biomass production and conversion is sufficiently advanced so that break-throughs and discoveries of a fundamental nature are not required. Special emphasis is given to the importance of system design, biomass production, biomass conversion to SNG, economics, and energetics. A concept for the Net Energy Production Ratio of fully integrated systems is also presented. After suitable development, the commercialization of an SNG industry usin...

Conversion of coal to methane-rich gas - with methanisation distant from gasification but near consumers of reaction heat

Abstract: Conversion of coal to synthetic natural gas of high calorific value comprises gasification to synthesis gas of medium calorific value, and methanisation. The desulphurised synthesis gas is conveyed by pipeline over a distance of 30-490 km to >=1 methaniser situated near a user of the process heat. The synthesis gas is methanised at high temp. and separate streams of methan-rich gas and high-temp. heat distributed to consumers. The reaction heat can be used in industrial plants requiring process steam, for generation of electricity and/or in boiling water reactors. Full use can be made of the methanisation heat, which is only partially used when recycled to an adjacent coal gasification plant. Increase in energy available is 15-30% of the combustion energy of the natural gas. Fluctuations in demand can be balanced by using the storage capacity of the pipeline and by use of multiple methanisers.