Wood Gasification
Wood gasification is the process by which wood is burned at very high temperatures, to create a cleaner, more efficient fuel than traditional wood burning can produce. (Many naturally-occurring fuel sources can be gasified, including coal, petroleum and biomass, most commonly wood.) Wood gasification can provide fuel to power vehicles, greenhouses, homes and farms. It produces less greenhouse gases than traditional wood burning, and its by products (char and ash) can be used for fertilizer. Since wood is a renewable resource, and gasification produces more energy from smaller amounts of wood, wise use of wood gasification can result in a sustainable global alternate energy source.
History
Interest in gasification dates back to the seventeenth century, when the first experiments were conducted in pyrolysis, the process of superheating biomass.[1] The first patent for gasification was obtained in 1788 by Robert Gardner, and the first documented use of coal gasification occurred in just four years later, with the use of coal for heating and cooking continuing for many years afterward.[2] However, it was not until 1839 that the first historically-credited wood/coal gasifier was created by Bischof, resulting in the powering of gas lamps using coal in large parts of London by 1850.[3]
In 1861, Siemens created the first successful commercial wood gasifier. In the decades to follow, manufacturing plants throughout the U.S. and Europe produced manufactured gas for widespread use as a gaseous fuel.[4]
In 1901, Thomas Hugh Parker built the first motor vehicle powered by wood gas.[5] By then, wood gas produced from coal was being used in many cities to power and heat residences.[6] The Fishcer-Tropsch process, of sorting and reassembling manufactured gas into liquid fuel, was used by Germany during World War II and by South Africa during the apartheid years.[7]
After 1945 gasoline and diesel became more readily accessible and usable as a cheap, plentiful fuel source for powering engines and machines.[8] As a result, gasification became a "forgotten" technology. [9] It took nearly 30 years before renewed interest in gasification brought about ongoing development in the technology for small-scale power generation.[10]
The Basics of Pyrolysis and Gasification
"Pyrolysis" refers to any "chemical change brought about by the action of heat."[11] Pyrolysis is the process at the heart of gasification. Gasification occurs when wood, coal, or any other source containing both carbon and hydrogen is treated at high temperatures and pressure (i.e., pyrolysis), causing changes in the original substance at the molecular level.[12] The processed fuel source is broken down into different gases, including hydrogen and carbon monoxide.[13] The gases are separated and cleaned of impurities by scrubbers and distillers; the purified gases can then be used to create various kinds of fuel, including "ethanol, methanol, butanol and other alcohols as well as methane gas, synthetic petroleum, dimethyl ether, kerosene, diesel and other gases and liquids. Even the “waste” gases can be used to form marketable products such as fertilizers and chemical feedstocks."[14]
The wood gasification boiler is the primary tool used for gasification.
- ↑ Turare, Chandrakant. "History and Development." Biomass Gasification: Technology and Utilisation. ARTES Institute, University of Flensburg, Germany , n. d. Web. 1 Feb. 2013. <http://cturare.tripod.com/his.htm>.
- ↑ (Turare)
- ↑ (Turare); Miller, Scott. "Gasification Technology - Page 2, Gasification Technology." Energy Independence. American Energy Independence, 01 Feb 2011. Web. 1 Feb 2013. <http://www.americanenergyindependence.com/gasification-2.asp&xgt;.
- ↑ (Turare); (Miller p.2)
- ↑ (Turare)
- ↑ (Miller p.2)
- ↑ (Miller p. 2)
- ↑ (Turtare)
- ↑ Turtare
- ↑ (Turtare)
- ↑ http://www.merriam-webster.com/dictionary/pyrolysis?show=0&t=1359757126
- ↑ Miller, Scott. "Gasification Technology - Page 1, Introduction." Energy Independence. American Energy Independence, 01 Feb 2011. Web. 1 Feb 2013. <http://www.americanenergyindependence.com/gasification.asp&xgt;.
- ↑ (Miller p.1)
- ↑ (Miller p. 2)
