GENERAL DESCRIPTION

There are number of phases in which gas production goes through, depending on the age of the landfill and the length of time that the waste has been covered for. Generally methanogenesis will commence shortly after the acetogenesis phase, with the microbial population growing and converting acetic acids into methane. Methane is a gas with a high greenhouse gas [GHG] effect, but is also high in energy value; as a result ‘biogas’ (gases produced from landfills, mostly methane and carbon dioxide) need to be carefully managed. Models of biogas production can enable operators to understand how much biogas is expected to be generated from the waste within the landfill, however due to the variable nature of landfills; these models need to be validated against actual data. 

In a select number of landfills the biogas production is much lower than expected, and so core samples from landfills managed by Viridor are being extracted in order to understand the reasons behind this. Biochemical methane potential [BMP] is a well-established selection of test methods, which can determine the biodegradability (and thus the methane potential) of the waste material (specifically the organic fraction). These tests take around 100 days. A novel enzymatic hydrolysis test [EHT] was developed at Cranfield University previously, which is completed within 24 hours and correlates strongly with the UK accepted version of the BMP protocol (the BMc).

PROJECT GOALS

The aim of this research project is to apply the EHT to extracted landfill samples and develop a protocol for estimating the biochemical methane potential from future samples. Specific objectives are:

• Critical literature review of landfill processes, monitoring methods and sample analysis.

• Develop a suitable sampling strategy and assist in the design of the necessary laboratory analysis, including any modifications to the existing methodologies.

• Set-up BMc and EHT tests in the lab, and monitor the results achieved.

• Recommend methods for estimating biogas potential in future sampling regimes, and suggest further development work.

FUNDING TYPE: DTA co-funded by EPSRC and Viridor

BUDGET: £120.000