Editing Gasification (section)

{{Short description|Form of energy conversion}}
{{About|the process|the water carbonator|Gasogene|the automobile device|Wood gas generator}}
{{Sustainable energy}}

'''Gasification''' is a process that converts [[biomass]]- or [[fossil fuel]]-based [[carbonaceous]] materials into gases, including as the largest fractions: [[nitrogen]] (N<sub>2</sub>), [[carbon monoxide]] (CO), [[hydrogen]] (H<sub>2</sub>), and [[carbon dioxide]] ({{CO2}}). This is achieved by reacting the feedstock material at high temperatures (typically >700&nbsp;°C), without combustion, via controlling the amount of [[oxygen]] and/or [[steam]] present in the reaction. The resulting gas mixture is called [[syngas]] (from synthesis gas) or [[producer gas]] and is itself a fuel due to the flammability of the H<sub>2</sub> and CO of which the gas is largely composed. Power can be derived from the subsequent combustion of the resultant gas, and is considered to be a source of [[renewable energy]] if the gasified compounds were obtained from biomass feedstock.<ref name="nnfcc">{{cite web| author =[[National Non-Food Crops Centre]]| url =http://wiki.gekgasifier.com/f/Review+of+Biomass+Gasification+Technologies.NNFCC.Jun09.pdf| title =Review of Technologies for Gasification of Biomass and Wastes, NNFCC project 09/008| access-date =2011-06-24| archive-url =https://web.archive.org/web/20170810171136/http://wiki.gekgasifier.com/f/Review+of+Biomass+Gasification+Technologies.NNFCC.Jun09.pdf| archive-date =2017-08-10| url-status =live}}</ref><ref>[http://www.biomass.uk.com/gasification.php The Clean and Renewable Energy Source], biomass.uk.com, accessed 16.05.11 {{webarchive|url=https://web.archive.org/web/20110910155717/http://www.biomass.uk.com/gasification.php |date=2011-09-10 }}</ref><ref>[http://www.gastechnology.org/webroot/app/xn/xd.aspx?it=enweb&xd=iea/homepage.xml Thermal Gasification of Biomass, International Energy Agency Task 33] {{Webarchive|url=https://web.archive.org/web/20110509002845/http://www.gastechnology.org/webroot/app/xn/xd.aspx?it=enweb&xd=iea%2Fhomepage.xml |date=2011-05-09 }}, http://www.gastechnology.org, accessed 16.05.11</ref><ref>{{cite web|url =https://waste-management-world.com/a/plasma-gasification-clean-renewable-fuel-through-vaporization-of-waste|title =Plasma gasification: Clean renewable fuel through vaporization of waste|website =www.waste-management-world.com|access-date =May 16, 2011|date =January 7, 2009|archive-url =https://web.archive.org/web/20151029155136/http://waste-management-world.com/a/plasma-gasification-clean-renewable-fuel-through-vaporization-of-waste|archive-date =2015-10-29|url-status =live}}</ref>

An advantage of gasification is that [[syngas]] can be more efficient than direct combustion of the original feedstock material because it can be combusted at higher temperatures so that the thermodynamic upper limit to the efficiency defined by [[Carnot's theorem (thermodynamics)|Carnot's rule]] is higher. Syngas may also be used as the hydrogen source in fuel cells, however the syngas produced by most gasification systems requires additional processing and reforming to remove the contaminants and other gases such as CO and {{CO2}} to be suitable for low-temperature fuel cell use, but high-temperature [[solid oxide fuel cell]]s are capable of directly accepting mixtures of H<sub>2</sub>, CO, CO<sub>2</sub>, steam, and methane.<ref>{{cite journal|last1=Giddey|first1=S.|last2=Badwal|first2=S.P.S.|last3=Kulkarni|first3=A.|last4=Munnings|first4=C.|title=A comprehensive review of direct carbon fuel cell technology|journal=Progress in Energy and Combustion Science|date=June 2012|volume=38|issue=3|pages=360–399|doi=10.1016/j.pecs.2012.01.003|bibcode=2012PECS...38..360G }}</ref>

Syngas is most commonly burned directly in [[internal combustion engines|gas engines]], used to produce [[methanol]] and hydrogen, or converted via the [[Fischer–Tropsch process]] into [[synthetic fuel]]. For some materials gasification can be an alternative to [[landfill]]ing and [[incineration]], resulting in lowered emissions of atmospheric pollutants such as [[methane]] and [[particulates]]. Some gasification processes aim at refining out corrosive ash elements such as [[chloride]] and [[potassium]], allowing clean gas production from otherwise problematic feedstock material. Gasification of [[fossil fuels]] is currently widely used on industrial scales to generate electricity. Gasification can generate lower amounts of some pollutants as SO<sub>x</sub> and {{NOx}} than combustion.<ref>Chris Higman and Maarten van der Burgt. ''Gasification'', Second Edition, Elsevier (2008).</ref>