The most basic definition of gasification is that it is any chemical or heat transaction used to convert a substance to a gas. Coal has been gasified ever since the industrial revolution to produce "town gas". This was once done in the community gas works, and every town had one. Heating the coal under controlled conditions with insufficient air to provide complete combustion produces a gaseous fuel known as syngas, which is also what is known as town gas when cooled cleaned and compressed. As we all know using gas as a fuel for so many jobs is vastly more controllable and vastly preferable to using coal. Gasification technology is at the forefront in the efforts to develop alternatives for conventional furnaces. It is of particular interest by reason of it offers an opportunity to utilize the product fuel gas in integrated gasification combined-cycle electric energy generation (IGCC). Great hopes are pinned on IGCC as a highly efficient and low polluting emissions technolo
gy. Gasification can also be fueled by materials that are not otherwise useful fuels, such as biomass or organic waste. In addition, it also solves many worries about reducing air quality. This is since the high temperature conversion reaction essential to the method also refines outside corrosive ash elements such as chloride and potassium, allowing clean gas production. Furthermore, many have reported that using their technology product gas heating (calorific) value can be made stable regardless of changes in feedstock type, ash content, or moisture content. In some types of gasification plant, gasification takes place on the three by-products of pyrolosis and uses them to fuel a second reaction by concentrating the heat onto a bed of charcoal. These coals normally reach 1800+ degrees F, in the gasifier, which is hot enough to break the aqua vapor into hydrogen, and the CO2 into carbon monoxide. Gasification is extremely environmentally friendly in that if proper
ly designed, gasification systems produce very minimal pollution yet when processing dirty feedstocks, such as high sulfur coals. In addition, gasification can effect large volume reductions in solid wastes while producing an environmentally friendly inert slag-type byproduct. Jan Becker, Technical Director, of a US energy society growing brisk on its gasification skills, added that; "the gasifier is becoming an primary factor in the race toward the 'greening of America' as there is more and more awareness that many of the substances that America throws away can be gasified and then made into useful products like electricity, ethanol, methanol, and bio-diesel." The gas produced by gasifiers (mainly comprising of 15-25% carbon monoxide, 10-20% hydrogen and 1-5% methane), is combusted in special burners for maximum efficiency. The best high quality gasifier systems can be fed on what are otherwise just low-grade waste oils or tar oils and slurries. Some s
lurry fed, O2 blown, entrained gasifiers operate at between 2400 degrees F and 2700 degrees F. Full text: http://computerandtechnologies.com/technology/news_2008-09-11-21-30-03-363.html
Thursday, September 11, 2008
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