Energy From Waste Plant Audits


Background

There are 40 fully operational Energy from Waste plants across the UK processing over 12 million tonnes of waste a year as of December 2017, with more being commissioned for construction in 2018.  An analysis of the composition of feedstock used for fuel in an EfW is vital in determining software derived calorific values of the incoming material, and which materials are most useful in providing energy efficiency to inform best processes and uses of technology in future EfW proposals. A thorough analysis of feedstock also helps identify materials that could be diverted for recycling, re-use, and composting before being processed by an EfW in the national drive for diverting waste from Landfill.

Methodology

M·E·L Waste Insights performs audits for multiple EfW plants across the UK every year. The vast majority of these concentrate on analysis of the waste entering an EfW via refuse collection vehicles with an appropriate focus on a majority percentage of kerbside collected household residual waste, and a smaller representation of commercial waste and material placed in the general waste skips at household waste recycling centres.

Samples are typically taken from several vehicles delivering waste to an EfW tipping floor, with each individual samples creating an overall combined plant sample for analysis. Each vehicle’s registrations, area of collection, waste origin and time of delivery are all recorded on a pre-prepared logging sheet to present a breakdown of the source of the combined sample. A team of M·E·L Research's dedicated analysts sort the waste sample into over 40 distinct categories and record their weights on pre-prepared sheets to present an in-depth breakdown of the composition of the sample.
The sample is also taken to an accredited laboratory for detailed analysis of its chemical composition when requested by the EfW operator.

The composition results are then used to calculate a calorific value for individual plants using an Ofgem approved method. This includes using specific calorific values for individual materials against the compositional makeup of a plant's sample.

Outcomes

M·E·L Waste Insight’s audits have been successful in providing a clear and detailed picture of the composition and calorific values of EfW feedstock. This information has proved vital in both formulating strategies for current EfW operation, and for planning and commissioning new EfW plants with the correct technology and plant design.