Gasification
About Gasification
Gasification is a process that, through heat and pressure, can convert coal, biomass, and petroleum coke (or virtually any carbon-containing material) into a gaseous product stream called “syngas.” Syngas consists of hydrogen and carbon monoxide, which can be chemically manipulated to produce a broad variety of fuels and chemicals such as: Fischer-Tropsch diesel, jet fuel and naphtha; ammonia; methanol and dimethyl ether; syngas-derived ethanol; hydrogen, natural gas substitutes, and CO2 for enhanced oil & gas recovery and the accelerated growth of food and fuel crops.
In a traditional entrained flow system the carbon feedstock (coal, biomass, etc.) enters the gasifier where it encounters steam and oxygen or air in conditions of high temperature and pressure. This causes the feedstock to be broken down into syngas (with impurities) and a solid ash waste product. Purification systems remove the impurities from the syngas including sulfur, particulates, mercury, nitrogen oxides (NOx), and carbon dioxide (CO2), the majority of which are saleable byproducts.
The HyMelt® system is a revolutionary gasification approach, using molten iron and not steam as the heat exchange medium (see HyMelt® Technology). The HyMelt® system offers substantial cost and operating advantages over traditional entrained flow steam systems.
Gasification technologies are believed to represent a next generation of carbon based energy production systems. Gasification breaks down virtually any carbon-based feedstock into its basic constituents. This permits the economic separation of pollutants and CO2 and offers significant environmental benefits. Gasification also provides flexibility in the production of a wide range of products, as the following diagram shows.
Many Products From Gasification
Gasification: a Proven Technology
The Department of Energy’s National Energy Technologies Laboratory (NETL) maintains a world database of gasification plants. According to this list, as of 2007 there were more than 140 sizable gasification plants operating around the world, and about 30 more in development.