Weltec UK, a subsidiary of Germany-headed biogas technology provider Weltec Biopower GmbH has begun construction of a biomethane plant near Pontefract, West Yorkshire, United Kingdom (UK). The client is Lanes Farm Energy, a gas-to-grid project being developed by Aqua Consultants Ltd. The plant is scheduled to go live in late 2019 and is expected to deliver approximately 7.3 million Nm³ of biomethane per annum to the UK gas distribution network.
Lanes Farm Energy is a gas-to-grid project being developed by Aqua Consultants near Pontefract, West Yorkshire, UK. Weltec UK was selected as the biogas technology supplier and it has begun construction on the biomethane plant.
After in-depth discussions with over ten technology providers, Weltec was selected to be our partner to deliver the technology, said Tel Sultan, director of Lanes Farm Energy.
Food waste and grass silage
Scheduled to go live in late 2019 the facility is expected to deliver approximately 7.3 million Nm³ of biomethane per annum to the UK gas distribution network. Food leftovers will account for more than half of the 80 000 tonnes per annum of substrate required by the plant
The locally sourced feedstocks contribute greatly to the project’s sustainability. Additionally, there is cattle and chicken manure as well as grass silage and hybrid rye said Dr Kevin Monson, Sales Manager at Weltec UK.
The solids are fed through two walking-floor feed hoppers with 110 and 220 m³ capacity respectively, and two MULTIMix units, which removes foreign objects, liquefies, shreds and macerates incoming solids to make them into an easily pumpable, easily mixed, easily digested liquid.
The mashing and shredding process will make sure that the bacteria can access the substances in the digester faster and will reduce the energy required for mixing, explained Carsten Hesselfeld, Sales Engineer at Weltec UK.
The liquids will be fed in controllable volumes directly to digesters from five pre-storage tanks, of which two are equipped with a stainless steel bottom. The gas production will take place in four stainless-steel digesters with a height of 8.8 m and an above-average capacity of 6 848 m³ each.
Weltec has also decided to implement membrane upgrading to transform the biogas into high-quality biomethane. In a separation process comprising several stages, the raw biogas will be refined efficiently without methane slippage. In this way, approximately 850 Nm³ per hour of biomethane suitable for gas grid injection will be produced from December 2019 onwards.
Additionally, the biomethane production will yield digestate, which can be used as high-quality fertiliser, returning organic material and nutrients to the land. For this purpose, it will first be pasteurised and separated. The focus on sustainability is also reflected in these process steps.
For example, the pasteurisation unit will be equipped with a state-of-the-art energy-efficient heat recovery system. For on-site electricity supply, a 500 kW cogeneration unit will be integrated with the operator able to earn additional income by exporting excess electricity to the grid.
Biomethane crucial to UK energy mix
The effective utilisation of leftovers is a key reason why Charlotte Morton, Chief Executive of the Anaerobic Digestion & Bioresources Association (ADBA), considers biomethane projects such as the one in Pontefract to be ecologically and economically trend-setting. According to ADBA, the anaerobic digestion (AD) of food leftovers could cover a third of the gas or power demand in the UK and create 35 000 new jobs.
Biomethane plants such as Lanes Farm Energy will play an increasingly important role in the UK national energy mix. Compared to coal or oil, the biomethane production from food waste enables carbon savings of about 90 percent.
With the UK needing to boost energy security post-Brexit and to re-balance its energy mix to reduce carbon emissions in accordance with the Paris Agreement, recovering clean, reliable biomethane from organic wastes and injecting it into the gas grid is a crucial piece of the energy jigsaw. The provision of sustainable renewable heat and transport fuel from wastes means that biomethane will surely be further promoted by forward-thinking Governments. Biomethane plants are the epitome of the sustainable circular economy. The technology is proven and the gas grid is a ready-made distribution network, ended Dr Kevin Monson.