Anaerobic Digestion: Difference between revisions

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==Overview==

'''Anaerobic Digestion''' (AD) is a process where biodegradable material is broken down by micro-organisms in the absence of oxygen in an enclosed vessel. [[Biogas]] is produced that can be used for the generation of power (electic and heat), or refined and used as a 'biomethane', and [[Digestate]] is produced which can be used as a 'biofertiliser'.

AD plants can be categorised in a number of different ways with different commentators using slightly different approaches and slightly different datasets. This combined with the ongoing development of plants over time (with plants moving from development into operation each year) means that it is difficult to build a definitive list of the number and types of plants in operation. As a result this page summarises data from different sources without attempting to correlate them to one another where the links are unclear. The broad classification by feedstock is as follows:

reports commentators numbers without trying to cross-reference

The process of AD occurs in several stages and requires a community of micro-organisms:

# Hydrolysis - large, complex polymers like carbohydrates, cellulose, proteins and fats are broken down by hydrolytic enzymes into simple sugars, amino acids and fatty acids.

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|}

# noted as 427 by the [[Ofgem]] reported figures above (these figures appear to be reporting December 2016 figures despite saying December 2018 in the table)

[[ADBA]] maintain the national database of AD plants in the UK as an online tool<ref>[http://adbioresources.org/map ADBA AD Map]</ref>. The online tool captures those plants which are based on four different feedstock configurations and three different power output configurations. A summary of the total plants listed is set out below, with an extract in the map to the right of MSW/Commercial [[Food Waste]] AD facilities generating electricity:

[[File:ADBA AD MAp Extract.png|600px|right|Extract of ADBA Biogas Map showing Food Waste AD projects generating electricity]]

{| class="wikitable"

|-

! !! Electricity !! Heat !! Biomethane !! Column Total !! Matching Total

|-

| Agricultural || 314||30 || 67 || 411 || 374

|-

| MSW/Commercial (Food Waste) || 95 ||8 ||27 || 130 || 113

|-

| Industrial || 40 ||6 ||11 ||57 ||48

|-

| Sewage Sludge || 163 ||0 ||9 ||172 ||163

|-

| Row Total || 612 ||44 ||114 || ||

|-

| Matching Total|| 503 || 42 ||102 || ||

|}

The table below is reproduced from table 4.3 in the Renewable Obligation Annual Report 2017-18 by [[Ofgem]] and shows the consignments reported by AD against the sustainability criteria required by the [[Biomass Sustainability]] reporting, although those with <1MW are not formally linked to a [[ROC]] issue<ref>[https://www.ofgem.gov.uk/system/files/docs/2019/03/ro_annual_report_2017-18_final.pdf Renewable Obligation Annual Report 2017-18]</ref> :

@@ Line 7: / Line 7: @@
 ==Overview==
 '''Anaerobic Digestion''' (AD) is a process where biodegradable material is broken down by micro-organisms in the absence of oxygen in an enclosed vessel. [[Biogas]] is produced that can be used for the generation of power (electic and heat), or refined and used as a 'biomethane', and [[Digestate]] is produced which can be used as a 'biofertiliser'.
+AD plants can be categorised in a number of different ways with different commentators using slightly different approaches and slightly different datasets. This combined with the ongoing development of plants over time (with plants moving from development into operation each year) means that it is difficult to build a definitive list of the number and types of plants in operation. As a result this page summarises data from different sources without attempting to correlate them to one another where the links are unclear. The broad classification by feedstock is as follows:
+reports commentators numbers without trying to cross-reference
 The process of AD occurs in several stages and requires a community of micro-organisms:
 # Hydrolysis - large, complex polymers like carbohydrates, cellulose, proteins and fats are broken down by hydrolytic enzymes into simple sugars, amino acids and fatty acids.
@@ Line 93: / Line 100: @@
 |}
 # noted as 427 by the [[Ofgem]] reported figures above (these figures appear to be reporting December 2016 figures despite saying December 2018 in the table)
+[[ADBA]] maintain the national database of AD plants in the UK as an online tool<ref>[http://adbioresources.org/map ADBA AD Map]</ref>. The online tool captures those plants which are based on four different feedstock configurations and three different power output configurations. A summary of the total plants listed is set out below, with an extract in the map to the right of MSW/Commercial [[Food Waste]] AD facilities generating electricity:
+[[File:ADBA AD MAp Extract.png|600px|right|Extract of ADBA Biogas Map showing Food Waste AD projects generating electricity]]
+{| class="wikitable"
+|-
+!  !!  Electricity !! Heat !! Biomethane !! Column Total !! Matching Total
+|-
+| Agricultural || 314||30  || 67 || 411 || 374
+|-
+| MSW/Commercial (Food Waste) || 95 ||8 ||27 || 130 || 113
+|-
+| Industrial || 40 ||6 ||11 ||57 ||48
+|-
+| Sewage Sludge || 163 ||0 ||9 ||172 ||163
+|-
+| Row Total || 612 ||44 ||114 ||  ||
+|-
+| Matching Total|| 503 || 42 ||102 || ||
+|}
 The table below is reproduced from table 4.3 in the Renewable Obligation Annual Report 2017-18 by [[Ofgem]] and shows the consignments reported by AD against the sustainability criteria required by the [[Biomass Sustainability]] reporting, although those with <1MW are not formally linked to a [[ROC]] issue<ref>[https://www.ofgem.gov.uk/system/files/docs/2019/03/ro_annual_report_2017-18_final.pdf Renewable Obligation Annual Report 2017-18]</ref> :