A new software tool for anaerobic digestion aims to develop investor confidence and help developers and operators when a plant is operational. Dr Robert Gregory, Principal and Head of Energy Services UK at Golder Associates explains how
As the recent report from the Green Investment Bank made clear, the difficulties in obtaining investment is one of the biggest barriers to the roll out of more anaerobic digestion (AD) plants across the UK. One of the issues concerning investors is the lack of realistic and robust forecasts of the likely performance of the proposed plants.
Golder Associates has worked together with Cranfield University over the past two years to develop the new AD-Sim software tool. AD-Sim has been designed to help build investor confidence and aid the developer and operator throughout the life cycle of an AD plant. This new model is a robust software tool as it brings together practical knowledge and innovation, with experience and academic research. The exciting result is a simulation model which can be used to feed into and inform financial decision making and can be used as well to assess impacts of feedstock mixing in the operational phase.
AD-Sim forecasts the time dependency of biogas, energy, heat and digestate production from an AD plant. AD-Sim works equally well with either a simple single feedstock, as might be the case for a distillery or other manufacturing plant feedstocks, or a range of different feedstock types that may be encountered by merchant AD facilities.
At the project scoping and design stage, AD-Sim can give an objective view of plant sizing and a quantified, auditable assessment of potential plant operational performance. This approach is ideal for financiers requiring a robust and objective assessment of feedstock utilisation and process product generation rates.
At the operational stage, scenario modelling can be used to understand which feedstocks will generate better net energy revenues, without upsetting the biological system established in the digester. Such a feature is attractive to merchant plant operators as they are required to make decisions on the value of a particular feedstock being offered to them and hence gate fee that can be charged. This needs to be done ahead of feedstock acceptance, but the timeframe for this decision process to take place may be quite short; AD-Sim can help this rapid decision making process.
The engineered environment of a digester is not particularly forgiving regarding the inhibition effects of mixed feedstocks, unlike landfill. This is due to the smaller digester size and the dynamic mixing which takes place in the digester. AD-Sim delivers practical simulation, to deliver a robust AD optimisation and management decision tool.
- Golder launched AD-Sim at the ADBA conference held 3-4 July at the NEC, Birmingham.
Dr Bob Gregory has 30 years of waste management, biogas and landfill gas experience. He was responsible for developing the GasSim landfill gas model, and now the AD-Sim model.