Pyrolysis: Difference between revisions

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[[Category:Technologies & Solutions]]

[[Pyrolysis]] is the thermal degradation of waste in the absence of ~~air~~ to produce gas ([[Syngas]]), liquid and solid char fractions. The [[Syngas]] is then generally burnt to raise steam and create electricity, but many plants are exploring the option of cleaning the [[Syngas]] for use in a gas engine or separating the gas into usable fractions such as hydrogen for use, as an example, of liquid fuels which in turn may be eligible under the [[RTFO]]. The solid residue (sometimes described as a char) is a combination of non-combustible materials and carbon.

[[Pyrolysis]] is the thermal degradation of waste in the absence of oxygen to produce gas ([[Syngas|syngas]]), liquid and solid char fractions. The [[Syngas|syngas]] is then generally burnt to raise steam and create electricity, but many plants are exploring the option of cleaning the [[Syngas|syngas]] for use in a gas engine or separating the gas into usable fractions such as hydrogen for use, as an example, of liquid fuels which in turn may be eligible under the [[RTFO]]. The solid residue (sometimes described as a char) is a combination of non-combustible materials and carbon.

The process generally requires an external heat source to maintain the temperature required and to avoid the introduction of air. There are a range of different types of approach, often aligned to the waste being processed, and include fixed bed reactors, batch or semi-batch reactors, rotary kilns, fluidized bed reactors, microwave assisted reactors and some innovative solutions like plasma or solar reactors <ref> Czajczyńska et al, 2017. Potential of pyrolysis processes in the waste management sector. Thermal Science and Engineering Progress, [online] 3, pp.171-197. </ref>.

Typically, lower temperatures of between 300C to 850C are used during Pyrolysis of materials such as [[MSW]]. Pyrolysis processes tend to prefer consistent feedstocks and there is a limited track record of commercial scale Pyrolysis plant accepting [[MSW]] but a better track record of, for example, Pyrolysis of [[Biomass]] <ref> Defra, 2013. [https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/221035/pb13888-thermal-treatment-waste.pdf Advanced Thermal Treatment of Municipal Solid Waste.] London. </ref>.

Typically, lower temperatures of between 300C to 850C are used during Pyrolysis of materials such as [[MSW]]. Pyrolysis processes tend to prefer consistent feedstocks and there is a limited track record of commercial scale Pyrolysis plant accepting [[MSW]] but a better track record of, for example, Pyrolysis of [[Biomass|biomass]] <ref> Defra, 2013. [https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/221035/pb13888-thermal-treatment-waste.pdf Advanced Thermal Treatment of Municipal Solid Waste.] London. </ref>.

==References==