Green Fingered Solutions

Cambridge City Council’s recent climate strategy update pointed out the need to reduce emissions from waste, which are currently 9% of Cambridge’s total emissions. This is particularly urgent, because biodegradable waste disposal in landfill could be banned from 2028 because it is a major source of methane emissions.

Some of the alternatives are rightly unpopular.  For example, Amey’s plans to build a massive incinerator near Waterbeach were refused permission back in July 2020. As the campaign group Cambridge Without Incineration, said at the time.  “We fully understand the need to move away from landfill but incineration is classified as the worst option.”

It’s becoming apparent that this was the right decision, because innovators are coming up with much better solutions than burning stuff. For example, Birmingham City Council and Aston University are exploring an exciting solution developed by the innovative company ‘Combind’, together with Aston University.  Their process is based on high tech version of the process that makes charcoal. The contents of green bins, hedge trimmings, agricultural waste and other sources of biomass are electrically heated in an inert atmosphere and ‘upcycled’ into a series of high value products, in a process called Pyrolysis.

Reassuringly, as nothing is burnt, the plant is totally clean and the only gas it emits is Oxygen (This was removed from air to create the inert atmosphere used in the process)

One of the products it produces is a form of biochar. When this is mixed with compost, for example from the composting facilities at Waterbeach Recycling centre, it dramatically improves performance, allowing the combined product to be used as peat replacement. This could be really useful for green fingered gardeners who’re avoiding using peat because of the damage this does to the environment.  

Astonishingly around half Cambridgeshire’s carbon emissions are considered due to Land Use, Landuse change and Forestry (LULUCF) mostly due to peat degradation in the fens. 

The process also produces other commercially valuable products. For example, one product can be used as a “natural” biodegradable herbicide to replace toxic chemicals like Glyphosate.  

Another part of the output can be used as fuel: either as an oil, or it can be designed to produce Syngas, which can in turn potentially be used for a variety of other products, ranging from aviation fuel to fertiliser.  Overall the process is carbon negative, which is very exciting.

Although the process plant isn’t cheap, the resulting products are commercially valuable, and so it is claimed it can offer a return on investment of up to 20% a year.

Cambridge is an innovative place, with lots of clever researchers and smart investors, surrounded by one of the UK’s leading agricultural regions. Wouldn’t it be great if our Local Authorities could explore using this process to simultaneously upcycle waste, make money, and cut carbon?