- With this entry, I wanted to put together in one place some information on gasification technology for the reference of all those interested in renewable fuels and as an introduction to those who are new to this technology.
- Gasification is the process of converting carbon containing materials in the presence of steam, air or oxygen to a gaseous fuel called syngas (short for synthetic gas), which is a mixture of hydrogen and carbon monoxide (and methane in some cases). Syngas can be burned as a fuel as is, used to produce hydrogen or converted into liquid fuels such as synthetic gasoline and diesel using the Fischer-Tropsch process. Gasification is an old and established technology that could offer our societies an unlimited supply of clean fuel, from such materials as coal, petroleum, oil sands, biomass , industrial, household and farm waste. Almost any type of organic material can be turned into clean fuel with this process. Electricity can be produced using fuel cells running on syngas or hydrogen or by burning syngas in a gas turbine/IC engine-generator system.
- High temperature pyrolysis of carbonaceous material: In this method, the material, such as wood, charcoal, coal, etc. are heated to a high temperature (700 to 1000 degree C) to pyrolyze (thermal decomposition) the material into solid, liquid and gaseous products which undergo further processing. The Wikipedia article explains the processes involved in this method. This is the low cost option and is widely in use today. In fact, this method was used during the WW2 era, in parts of Europe and the US, to produce fuel for automobiles to overcome fuel shortages. Presently, biomass gasification and waste gasification processes are being carried out with this technique. There is a growing community of DIY biomass gasification enthusiasts and plenty of resources are being made avaiable, websites and books for educational purposes and hardware for making fuel from cellulosic or wood waste. Biomass gasifier-generator kits can produce a few 10s of kiloWatts of electric power, enough to power an average sized household or two. The burnt wastes produced by this method are usable as fertilizer, making it an extremely clean, green energy producing technology.
- Plasma gasification: In this method, a high temperature (>10,000 degree C) arc or microwave induced plasma is created which cracks the compounds into the constituent elements. The process produces gaseous fuels, molten metal run off and a glassy-slag that can be used as aggregate material in construction and building industries. The syngas is used to run a turbine-generator system that can provide energy for the plasma arc as well as surplus energy that can be fed into the power grid. Read the Plasma Arc Waste Disposal on Wikipedia for more information on this process.
But syngas contains CO, so why is it clean? This CO will eventually be turned to carbon dioxide through combustion. However, the CO comes from carbonaceous matter that would be wasted as landfill, matter which already has had a high price paid out during the production, processing, transportation and storage of the original material. Thus, by recycling this carbon to produce energy, fresh fossil fuels are not required to be burned to produce that energy. Moreover, the residue from the gasification process, known as biochar, is an excellent plant food. The syngas can be turned into other useful organic compounds, plastics, polymers, etc.
There are two methods of gasification.
Plasma gasification requires larger investment (several million dollars) and about 1 to 2 years of construction time, but the standard plasma gasifier plant can provide 100s of MegaWatts of electric power as well as gaseous and liquid fuels for transportation and industry, while at the same time reducing land fill. This is a very useful technology that should be more widely adopted. Plasma gasification offers a real and imminent potential for an endless source of renewable fuel supply.
Here are a list of websites that are useful.
- http://www.gasification.org/default.asp Maintained by the Gasification Technologies Council, with educational material describing the various gasification techniques and information on workshops and conferences.
- http://www.alternrg.com/ This company builds plasma gasification plants using the technologies developed by Westinghouse Plasma Corp. which AlterNRG now owns. They convert waste (garbage) into energy and raw materials for industry. The website has good educational material and video clips.
- http://www.plasma2energy.com/ Plasma 2 Energy uses microwave generated plasma for gasification.
- http://www.wood-gasification.com/ Maintained by Victory Gasworks, as the name suggests, this is one of the best resources for wood gasification, with lots of educational material and videos. They also have a store that sells gasifiers and other associated hardware.
- http://www.woodgas.com/index.htm This is a website developed by Dr. Tom Reed, a former professor at MIT. This website has lots of educational material and books and mini-gasifier stoves for sale. There is also a short PDF file describing how to make bio-diesel. http://www.woodgas.com/BiodieselinKitchen2.pdf
- http://www.gekgasifier.com/ This website is maintained by All Power Labs, “an incubator for open source energy experiments”. They also operate a Wiki and many other useful resources for biomass gasification. They also have free plans on how to build and run a wood gasifier. http://gekgasifier.pbworks.com/How-to-Build-and-Run-the-GEK-Gasifier
- http://www.netl.doe.gov/technologies/coalpower/gasification/index.html This is the link to the gasification page on the website of the National Energy Technology Lab, a division of the US Department of Energy. Plenty of educational material and links available here.