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What is Gasification? |
| The Technology The gasification process converts any carbon-containing material into a synthesis gas composed primarily of carbon monoxide and hydrogen, which can be used as a fuel to generate electricity or steam or used as a basic chemical building block for a large number of uses in the petrochemical and refining industries. Gasification adds value to low- or negative-value feedstocks by converting them to marketable fuels and products. See graphic. Gasification technologies differ in many aspects but share certain general production characteristics. Typical raw materials used in gasification are coal, petroleum based materials (crude oil, high sulfur fuel oil, petroleum coke, and other refinery residuals), gases, or materials that would otherwise be disposed of as waste. The feedstock is prepared and fed to the gasifier in either dry or slurried form. The feedstock reacts in the gasifier with steam and oxygen at high temperature and pressure in a reducing (oxygen starved) atmosphere. This produces the synthesis gas, or syngas, made up primarily of carbon monoxide and hydrogen (more than 85% by volume) and smaller quantities of carbon dioxide and methane. The high temperature in the gasifier converts the inorganic materials in the feedstock (such as ash and metals) into a vitrified material resembling coarse sand. With some feedstocks, valuable metals are concentrated and recovered for reuse. The vitrified material, generally referred to as slag, is inert and has a variety of uses in the construction and building industries. Gas treatment facilities refine the raw gas using proven commercial technologies that are an integral part of the gasification plant. Trace elements or other impurities are removed from the syngas and are either recirculated to the gasifier or recovered. Sulfur is recovered either in its elemental form or as sulfuric acid, both marketable commodities. If the syngas is to be used to produce electricity, it is typically used as a fuel in an integrated gasification combined cycle (IGCC) power generation configuration. IGCC is the cleanest, most efficient means of producing electricity from coal, petroleum residues and other low- or negative-value feedstocks. The combined cycle system has two basic components. A high efficiency gas turbine, widely used in power generation today, burns the clean syngas to produce electricity. Exhaust heat from the gas turbine is recovered to produce steam to power traditional high efficiency steam turbines. The syngas can also be processed using commercially available technologies to produce a wide range of products, fuels, chemicals, fertilizer or industrial gases. Some facilities have the capability to produce both power and products from the syngas, depending on the plant’s configuration as well as site specific technical and market conditions. Top of the page |
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The Technology The gasification process converts any carbon-containing material into a synthesis gas composed primarily of carbon monoxide and hydrogen, which can be used as a fuel to generate electricity or steam or used as a basic chemical building block for a large number of uses in the petrochemical and refining industries. The Environment When linked with modern combined cycle turbines, gasification is one of the most efficient, environmentally effective means of producing electricity from solid or liquid feedstocks. The Industry Gasification has been in commercial use for more than fifty years as a process technology for the refining, chemical, and power industries. In 1999 the first World Gasification Survey was conducted by the firm of SFA Pacific, Inc. with support from the U.S. Department of Energy, and in cooperation with the member companies of the Gasification Technologies Council. |
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Gasification Technologies Council 4301 N. Fairfax Drive Suite 300 Arlington, VA 22203 Ph: 1-703-276-0110 Fx: 1-703-276-0141 |
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