[[File:Cardiff THP.png|thumb|Thermal Hydrolysis Plant in Cardiff, Wales, UK]] '''Thermal hydrolysis''' is a process used for treating [[industrial waste]], [[municipal solid waste]] and [[sewage sludge]] by applying heat and rapid lowering of pressure. It is used to sterilize the waste stream and produce fertilizer, [[biogas]], and other useful products. It was first deployed in 1996.
==Description== Thermal hydrolysis is a two-stage process combining high-pressure boiling of [[waste]] or [[sludge]] followed by a rapid decompression. This combined action sterilizes the sludge and makes it more [[biodegradable]], which improves digestion performance. Sterilization destroys pathogens in the sludge resulting in it exceeding the stringent requirements for land application (agriculture).<ref name=WaterWorld>{{cite journal |last1=Barber |first1=Bill |last2=Lancaster |first2=Rick |last3=Kleiven |first3=Harald |title=Thermal Hydrolysis: The Missing Ingredient for Better Biosolids? |url=http://www.waterworld.com/articles/wwi/print/volume-27/issue-4/editorial-focus/slidge-processing-biosolids/thermal-hydrolysis-the-missing-ingredient.html |journal=Water World |volume=27 |issue=4 |date=2012-09-01 |access-date=2014-05-24 |archive-date=2016-10-14 |archive-url=https://web.archive.org/web/20161014020522/http://www.waterworld.com/articles/wwi/print/volume-27/issue-4/editorial-focus/slidge-processing-biosolids/thermal-hydrolysis-the-missing-ingredient.html |url-status=live }}</ref>
In addition, the treatment adjusts the [[rheology]] to such an extent that loading rates to sludge [[anaerobic digesters]] can be doubled, and also dewaterability of the sludge is significantly improved.<ref name=JHazMat>{{cite journal |last1=Neyens |first1=Elisabeth |last2=Baeyens |first2=Jan |title=A review of thermal sludge pre-treatment processes to improve dewaterability |journal=Journal of Hazardous Materials |volume=B98|issue=1–3 |pages=51–57 |date=2003 |doi=10.1016/S0304-3894(02)00320-5|pmid=12628777 |bibcode=2003JHzM...98...51N }}</ref><ref name=WaterResearch>{{cite journal |last1=Skinner |first1=Samuel |last2=Studer |first2=Lindsay |last3=Dixon |first3=David |last4=Hillis |first4=Peter |last5=Rees |first5=Catherine |last6=Wall |first6=Rachael |last7=Cavalida |first7=Raul |last8=Usher |first8=Shane |last9=Stickland |first9=Anthony |last10=Scales |first10=Peter |title=Quantification of wastewater sludge dewatering |url=https://www.researchgate.net/publication/277133349 |journal=Water Research |volume=82 |pages=2–13 |date=2015 |access-date=2017-02-23 |doi=10.1016/j.watres.2015.04.045 |pmid=26003332 |archive-date=2021-10-09 |archive-url=https://web.archive.org/web/20211009203511/https://www.researchgate.net/publication/277133349_Quantification_of_wastewater_sludge_dewatering |url-status=live |doi-access=free |bibcode=2015WatRe..82....2S }}</ref> The first full-scale application of this process for sewage sludge was installed in [[Hamar]], Norway in 1996. Since then, there have been over 30 additional installations globally.<ref name=WaterWorld/>
[[File:Blue Plains - Thermal hydrolysis sludge treatment 2016a.jpg|thumb|Thermal hydrolysis reactors at Blue Plains in 2016.]]
== Commercial application at a sewage treatment plant == [[Sewage treatment plant]]s, such as [[Blue Plains Advanced Wastewater Treatment Plant|Blue Plains]] in [[Washington, D.C.]], USA, have adopted thermal hydrolysis of sewage sludge in order to produce commercially valuable products (such as electricity and high quality biosolid fertilizers) out of the [[wastewater]].<ref name="DC Water">{{cite news |last=Halsey |first=Ashley |date=2014-04-05 |title=DC Water adopts Norway's Cambi system for making power and fine fertilizer from sewage |url=https://www.washingtonpost.com/local/trafficandcommuting/dc-water-adopts-norways-cambi-system-for-turning-sewage-into-electricity-and-fertilizer/2014/04/05/3d456d7e-a642-11e3-9cff-b1406de784f0_story.html |newspaper=The Washington Post |access-date=2014-05-24 |archive-date=2014-04-12 |archive-url=https://web.archive.org/web/20140412231537/http://www.washingtonpost.com/local/trafficandcommuting/dc-water-adopts-norways-cambi-system-for-turning-sewage-into-electricity-and-fertilizer/2014/04/05/3d456d7e-a642-11e3-9cff-b1406de784f0_story.html |url-status=live }}</ref> The full-scale commercial application of thermal hydrolysis enables the plant to utilize the solids portion of the wastewater to make power and fine fertilizer directly from sewage waste.<ref name="From toilet to turbine">{{cite news |last1=Berkowitz |first1=Bonnie |last2=Lindeman |first2=Todd |date=2014-04-05 |title=From Toilet to Turbine |url=https://www.washingtonpost.com/local/trafficandcommuting/from-toilet-to-turbine/2014/04/05/9dc0e49e-bd26-11e3-bcec-b71ee10e9bc3_graphic.html |newspaper=The Washington Post |access-date=2014-05-24 |archive-date=2016-03-13 |archive-url=https://web.archive.org/web/20160313071007/https://www.washingtonpost.com/local/trafficandcommuting/from-toilet-to-turbine/2014/04/05/9dc0e49e-bd26-11e3-bcec-b71ee10e9bc3_graphic.html |url-status=live }}</ref>
==Municipal waste-to-fuel application== The city of [[Oslo]], Norway installed a system for converting domestic [[food waste]] to fuel in 2012. A thermal hydrolysis system produces [[biogas]] from the food waste, which provides fuel for the city bus system and is also used for agricultural fertilizer.<ref name="Oslo Biogas">{{cite press release |url=http://ens-newswire.com/2012/03/23/food-waste-to-fuel-oslos-city-buses/ |title=Food Waste to Fuel Oslo's City Buses |author=<!--Staff writer(s); no by-line.--> |date=2012-03-23 |website=Environment News Service |publisher= |location=Lincoln City, OR |access-date=2014-05-24 |archive-date=2014-07-09 |archive-url=https://web.archive.org/web/20140709002913/http://ens-newswire.com/2012/03/23/food-waste-to-fuel-oslos-city-buses/ |url-status=live }}</ref>
== 30 largest thermal hydrolysis plants == {| class="wikitable" ! scope="col" | Plant ! scope="col" | Capacity<br />{{Small|(TDS/A)<nowiki>*</nowiki>}} ! scope="col" | Commission<br />Year ! scope="col" | Thermal Hydrolysis<br />Supplier |- | [[Blue Plains Advanced Wastewater Treatment Plant|Blue Plains]], Washington DC, USA || 135,000 || 2014 || Cambi |- |[[Gaoantun]], Beijing, China || 134,000 || 2017 || Cambi |- | Gaobeidian, Beijing, China || 99,100 || 2016 || Cambi |- | [[Minworth]], Birmingham, UK || 91,250 || 2018 || Cambi |- | Davyhulme, Manchester, UK || 91,000 || 2013 || Cambi |- | Huaifang, Beijing, China || 89,100 || 2017 || Cambi |- | Xiaohongmen, Beijing, China || 65,700 || 2016 || Cambi |- | Qinghe II, Beijing, China || 59,500 || 2017 || Cambi |- | Crossness, London, UK || 58,500 || 2018 || Cambi |- | Ringsend, Dublin, Ireland || 56,000 || 2002 || Cambi |- | Howdon, Newcastle Upon Tyne, UK || 40,000 || 2010 || Cambi |- | Riverside, London, UK || 40,000 || 2009 || Cambi |- | Tees Valley, UK || 37,000 || 2008 || Cambi |- | Seafield, Edinburgh UK || 36,500 || 2015 || Cambi<ref>https://www.cambi.com/references/plants/europe/united-kingdom/edinburgh-seafield/ {{Dead link|date=February 2022}}</ref> |- | Beckton, London, UK || 36,500 || 2013 || Cambi |- | Cardiff, UK || 30,000 || 2009 || Cambi |- | Tilburg, Netherlands || 29,000 || 2014 || Cambi |- | Esholt, Yorkshire, UK || 26,400 || 2013 || [[Veolia]] |- | Santiago, Chile || 25,000 || 2010 || Cambi |- | Oxford, UK || 24,400 || 2010 || Veolia |- | Vilnius, Lithuania || 23,000 || 2010 || Cambi |- | Whitlingham, Norwich, UK || 23,000 || 2008 || Cambi |- | Vigo, Spain || 22,000 || 2014 || Cambi |- | Afan, UK || 20,000 || 2009 || Cambi |- | Bruxelles Nord, Belgium || 20,000 || 2007 || Cambi |- | Cotton Valley, Milton Keynes, UK || 20,000 || 2007 || Cambi |- | NOSES, Aberdeen, UK || 16,500 || 2001 || Cambi |- | Lille, France || 16,400 || 2013 || Veolia |- | EGE Waste Treatment, Oslo, Norway || 15,000 || 2012 || Cambi |- | Turku, Finland || 14,000 || 2009 || Cambi |- |Apeldoorn, Netherlands |13,000 |2015 |[https://www.sustec.com Sustec] |- | Oxley Creek, Brisbane, Australia || 12,900 || 2006 || Cambi |} {{Small|<nowiki>*</nowiki> Tons of Dry Solids/Year}}
==See also== * [[List of waste-water treatment technologies]]
== References == {{Reflist}}
==Further reading== {{Refbegin}} * {{cite web |last1=Kline |first1=Michele |last2=Gurieff |first2=Nicholas |last3=Bruus |first3=Jacob |date=2011-04-01 |title=Thermal Hydrolysis System Helps Increase Biogas Production |url=http://www.waterworld.com/articles/2011/04/thermal-hydrolysis-system-helps-increase-biogas-production.html |website=Water World |publisher=PennWell Publishing |access-date=24 May 2014}} {{Refend}}
==External links== *{{Commons category-inline}}
[[Category:Biodegradable waste management]] [[Category:Biofuels technology]] [[Category:Chemical reactions]] [[Category:Equilibrium chemistry]] [[Category:Sewerage]]