Plasma Assisted Gasification
Plasma gasification is a relativity new technology that can break waste down to 1/300th of its original size by using ionized gases to produce temperatures greater than 3 times the surface temperature of the sun.
This process can safely deal with almost all forms of hazardous and non-hazardous wastes by breaking down the matter into component molecules and producing a synthesis gas (syngas) which can be used as an industrial feedstock to produce biofuels, synthetic fuels or to produce hydrogen, or simply as a fuel (replacing fossil fuels) to generate steam or electricity.
What is plasma?
First discovered in 1879 by Sir William Crookes while conducting experiments with his Crooks tube, his discovery was initially called ‘cathode rays’ (electrons). The actual name for plasma however didn’t come about until 1928 when Irving Langmuir compared the ionized gas to blood plasma.
Plasma is an ionized gas, which is a gas where electrons are flowing freely and giving positive or negative charges to atoms, thus making it a highly efficient conductor of electricity and generator of heat. Plasma is extremely common in the universe. Some of the many examples of plasma include lightning, St Elmo’s fire nebula and the Sun. Man-made applications include plasma televisions and neon lights.
During the plasma gasification process, the Gasifier produces a gaseous product and an inert solid by-product; the individual amounts of which will depend on the type of waste being feed into the gasifier.
Synthesis gas (syngas), the main output of the plasma gasifier, can be used as a fuel source in power plants, or treated further to generate hydrogen. It can also be used in the rural and industrial sector in the production of a wide range of polymers, chemicals, biofuels (including ethanol), fertilizers, pressure agents and more.
Slag is the name given to the solid product produced from a plasma gasifier, and depending upon how it is cooled; the slag can create several types of commodities. These include an obsidian-like silicate material which can be used in concrete or asphalt, even shaped into bricks or pavement stones for use in the construction industry or even be used in the abrasives industry. Metals can also be extracted and on sold to various industries.
Rock wool can also be produced from the slag; this commodity is a highly efficient insulator with higher energy efficiencies than fibre glass, it is highly absorbent and lighter than water, with many potential methods of use in both the industrial and environmental segments.