Appley Bridge Biomass to Energy Ltd

The Organisation

Appley Bridge Biomass to Energy Ltd is the owner-operator of two former municipal waste landfill sites located in Lancashire, both being capped-off in the late 1990s. The company aims to generate 5MWe from bio-liquids for export to the National Grid, showcasing the project as a flagship example combing renewable energy and technological innovation in the Northwest of England. The sites operated by Appley Bridge Biomass to Energy Ltd have several individual physical 

www.appleybridgebiomasstoenergy.co.uk

The Challenge

Leachate is the liquid that drains (or ‘leaches’) from a landfill site and amongst other pollutants, contains a variety of heavy metals, ammonia and other pollutants in either a dissolved or suspended state. The company discharges this as trade effluent, which has both environmental and economic impacts. Based on current data, doing nothing and paying for the trade effluent will have an estimated cost to the company of almost £339,000 taking account of leachate depletion forecasts in the future.  Appley Bridge Biomass to Energy Ltd required a chemical engineering investigation of the available options to them that could treat the leachate from the sites in Lancashire and Yorkshire whilst being cost effective, with a payback time of around five years or less.

Skills Sought

  • A strong understanding of chemical engineering processes
  • Enthusiasm, teamwork and commercial awareness
  • Conceiving engineering solutions to environmental challenges

The Solution

A team of four 3rd-year MEng Engineering students (constituted by three Chemical and one Mechanical) carried-out the project. Firstly, an on-site visit was conducted allowing the team to understand the individual system and site features including pipelines, pumps, sampling mechanisms, extraction wells, tanks, vegetation and security. The team then carried-out a series of investigations that included ‘SWOT’ analyses for on-site treatment solutions. This included an assessment of the options and methods of leachate treatment on landfill sites, pertinent to Appley Bridge Biomass to Energy Ltd. This included anaerobic/aerobic biological treatment processes; activated sludge; membrane bio-reactors; constructed wetlands; activated carbon and configurable stand-alone industrial systems. The team drew on case study material and best practice used elsewhere in the sector when evaluating potential solutions, alongside presenting findings on costs.

Cost & Impact

There was no cost to the company for this work, which was completed in two-weeks. The team made a series of recommendations based on their findings, allowing the company to progress with the favoured options Appley Bridge Biomass to Energy Ltd will shortly be investing in a reed bed system at their sites. 

Future Plans

Appley Bridge Biomass to Energy Ltd are now evaluating and testing a number of options with a view to making a selection most appropriate to their requirements. This will assist to mitigate both the environmental and economic impacts of landfill leachate.