The REnescience Northwich Project is a proposed new bio-resource facility to be constructed at the Lostock Works industrial site, near Lostock Gralam and Northwich, in Cheshire, UK. It will be the first commercial plant integrating Dong Energy’s proprietary REnescience technology, which handles unsorted household waste without prior treatment.
It will be fully financed, built and operated by Dong Energy, who announced the project in July 2015 and received the planning consent from Cheshire West and Chester Council in February 2016.
The construction of the facility is expected to start in early 2016 and commissioning is scheduled for early 2017. The project is expected to generate approximately 150 jobs during the peak construction phase and 24 full-time jobs during its 25 years of estimated operational life.
The plant will handle 120,000t of waste a year, equivalent to the waste generated from approximately 110,000 households, and generate between 5MW and 6MW of renewable electricity a year.
Dong Energy’s REnescience technology
The REnescience technology has been tested since 2009 at Dong Energy’s demonstration facility on the Island of Amager, near Copenhagen, Denmark, and was announced as reliable for commercial launch in January 2014.
The process starts with the preparation of the waste for enzymatic hydrolysis by mixing it with warm water. The prepared waste is then conveyed to a circulating REnescience bioreactor where the waste is mixed with enzymes at appropriate temperatures.
The enzymes extract the organic or bio-degradable material from the waste and concentrate it into a bioliquid, which accounts for approximately 90% of the output. The bioliquid is separated from the other 10% waste including cleaned recyclable materials and other waste, which are converted into a refuse-derived fuel (RDF) or a solid residue fuel (SRF) for energy generation elsewhere.
The recovered bioliquid undergoes anaerobic digestion (AD), where bacteria is used to digest the bioliquid in a sealed atmosphere without oxygen to produce a biogas, which is further used to generate renewable electricity using gas engines.
REnescience Northwich plant make-up and construction details
The integrated waste handling and power production project will involve the construction of a main building, incorporating offices, control room, waste bunker with crane, mechanical sorting stage facility, materials feeding facility and storage or loading area for recovered materials. The building will be adjoined by two REnescience bioreactors, each measuring approximately 45m in length and 4.5m in diameter.
Located on the western portion of the complex, the AD facility will incorporate two external bioliquid storage tanks, one additional back-up storage tank, four digestion tanks, two post-digester tanks and ancillary pipework, biogas treatment and pumping equipment.
The project will further involve the installation of five reciprocating gas engines, flue stacks measuring approximately 33m in height, a water treatment plant and site clearing activities, as well as the construction of drainage facilities and upgrade of the access road.
Waste supply and grid connection details
The waste for the facility will be supplied by FCC Environment, a UK-based waste management company involved in the collection of household waste in the Northwich region. The household waste will be conveyed to the project site by trucks in fully enclosed containers.
Approximately 5MW of the electrical output from the project will either be conveyed to the national grid, facilitated by a new transformer and an existing 132kV substation located adjacent to the project site, or supplied to local industrial customers via private transmission lines.
The remaining electrical output will be used within the site for plant operations, while the waste heat produced by the generators will be reused to pre-heat water in the AD facility.
Key technology partners
The research and development partners for the technology include Aarhus University, Amager Resource Center (arc), University of Copenhagen, Technical University of Denmark (DTU), and the Energy Technology Development and Demonstration Programme (EUDP).