Many see anaerobic digestion as a vital tool in achieving a low carbon future. and

Feasibility studies confirm the market demand and acceptance of anaerobic digestion (AD) technology. The potential of this technology has only been within reach of large, profitable organisations, but a new project aimed at bringing cutting-edge anaerobic digestion technologies to rural and smaller scale businesses is being launched to combat this.

The Small Scale Anaerobic Digestion Technology (SSAD-TECH) platform provides underpinning process technology for the development of a series of commercial products for the local treatment of organic waste to produce energy (either as biogas, heat or electricity) and digestate, which can be considered as a non-fossil fuel derived fertiliser.

A five-strong consortium behind the project is led by The Centre for Process Innovation (CPI) and comprises CNG Services Ltd, Lyvennet Renewable Energy, Wardell Armstrong LLP and Field Science Limited. With grant funding from the Government-backed Technology Strategy Board, the project works with a total budget of £880,000 and will run over two years.

A part of the Government’s High Value Manufacturing Catapult, CPI is home to existing anaerobic digestion development facilities and is ideally placed to co-ordinate, direct and deliver another successful project.

The small scale anaerobic digestion system will be designed to generate income and power for farms and food manufacturers, and also resolve the issue of biomass waste disposal. The project’s aim is to reduce capital costs of a small anaerobic digestion plant, while delivering a process capable of accepting biomass feed streams, saving significant land fill tariffs and generating power, and/or revenue from the sale of power, for the end user.

Studies have highlighted that there is an unmet market need for commercially viable anaerobic digestion plants at the 250 kWe scale and below. The SSAD-TECH project will address these needs by looking at how various feedstocks behave in anaerobic digestion reactors. The aim is to accelerate the development of new technologies.

CPI Director of Sustainable Processing and Advanced Manufacturing, Dr Chris Dowle, says: “CPI is delighted to be leading in this project, which represents an excellent opportunity to drive the evolution of this key technology. Anaerobic digestion will play an important role in achieving a low carbon future, and the SSAD-TECH project makes the technology an achievable goal for smaller scale or rural businesses.”

In simple terms, anaerobic digestion works by:

• Digesting a feedstock (eg sewage and food waste) in the absence of oxygen;
• Harnessing the resulting biogas;
• Using the energy-rich component of the gas for heating, electricity or transport fuel;
• Preserving the by-products of this process (digestate) for use in other areas, such as bio-fertilizers etc.

The innovative aspects of the SSAD-TECH system include:

• The relatively small size (throughputs between 2500 and 5000 tonnes per annum);
• Small footprint, enabling stand alone integration into existing sites and facilities;
• Modular build configuration, designed to meet the needs of the agricultural and food manufacturing sectors;
• Low capital cost (£350-500,000);
• Short payback period (3-6 years);
• Commercially viable plant at a small scale, 60-150kWe;
• Next generation digester technology, optimized for digester stability and performance efficiency.

About CPI

The Centre for Process Innovation (CPI) is a UK based technology innovation centre and part of the government’s High Value Manufacturing Catapult. CPI offers market and technology expertise along with cutting-edge development assets to help its public and private sector clients build and prototype the next generation of products, processes and services quickly and efficiently, and with minimal risk.