12 July 2021
Partnership uses HTC technology to turn food waste by-product into low-carbon, low-polluting renewable fuels
Unwanted by-product converted into renewable fuels
CPL Industries, the UK’s leading manufacturer and distributer of smokeless fuels, has partnered with Severn Trent Green Power to transform food waste into low-carbon solid fuels that are used for heating.
Utilising hydrothermal carbonisation (HTC) processing, CPL Industries converts the by-product from Severn Trent Green Power’s own processing of food waste to produce the low-carbon fuels. Across its waste sites, Severn Trent Green Power processes over 400 thousand tonnes of food waste each year. The majority of this is converted into green gas and electricity through the anaerobic digestion process. The remaining material is recycled to provide a natural fertiliser that is used across the agriculture sector. Before this fertilizer is spread it is screened to ensure the best possible quality. The screenings material is a by-product that is hard to break down and is sent to energy from waste plants.
Processing the by-product at its Immingham plant, CPL Industries is able to convert this material to produce renewable fuels. Severn Trent Green Power is currently trialling its technology further to determine if it can reach 10,000 tonnes of the by-product, which would lead to the production of 3,000 tonnes of renewable fuels by CPL Industries.
The HTC manufacturing process for the fuels is low carbon, emitting only 15kg of CO2 per tonne of product produced. The use of waste products supports the development of a circular economy. The fuels also have low NOx emissions and meet smokeless fuel regulations for Pm2.5 emissions, representing an c 80% reduction when compared to coal or untreated wood.
HTC provides a potential solution for digestate remaining from the anaerobic digestion process, a significant issue with the Government setting out ambitions for a major upscaling of anaerobic digestion technology to meet the net- zero challenge. HTC fuels can be used in homes to provide heating such as wood burners, as well as with district heating schemes and hard to heat sectors such as off-grid businesses in the leisure and hospitality industries.
As a secondary project Severn Trent Green Power and CPL have partnered with the Uni of Nottingham to establish whether the bio-coal produced from the HTC plant that would be burnt as a fuel can be into a biochar via pyrolysis fit for sequestration into soil. This would effectively lock a greater proportion of highly stable carbon into the biochar which is able to stay stable in the ground for centuries. This project has been awarded BEIS backes funding:
The aim of the study is to optimise process design and operation to turn up to 30 tonnes of Severn Trent Green Power food waste AD product into biochar for fit for sequestration. This would provide the data that would enable design options to be considered for producing over 600 tonnes of biochar p.a. (2000 tonnes CO2 capture equivalent) in the next development phase to achieve deployment by 2030.