McCulla Transport upgrades to RNG to be one of Ireland's greenest companies
The biogas plant belonging to the Northern Irish food logistics company McCulla Transport will go live producing biomethane in July 2021 following a plant expansion by Germany-headed biogas technology provider Weltec Biopower GmbH and partner companies. At the site in Lisburn, 10 km south of Belfast, 450 Nm3 of biogas will be upgraded into biomethane (aka renewable natural gas – RNG) every hour. This will fuel ten new CNG-powered trucks operated by the company.
With this amount, the logistics company can operate ten new CNG trucks, which are refueled directly at the company’s new biomethane filling point. The substrates for the production of the green fuel come from the 41 Lidl supermarkets in Northern Ireland.
Ashley McCulla, Chairman of the transport company was able to commission the first stage of his biogas plant from Weltec Biopower back in January 2017.
The intention at the time was to utilize the residual materials from his own agricultural business and to create synergies through the use of renewable electricity and heat in the refrigerated warehouse at its main logistics depot.
By digesting slurry, agricultural residues, and grass silage from our farm, we were able to produce green energy ourselves with a 500 kW CHP plant and use it on our company premises. Ultimately, this has significantly improved our carbon footprint, said Ashley McCulla.
The expansion to biogas upgrading, heavy goods vehicle (HGV) fuel, and becoming Irelands greenest fleet was the logical next step of this good experience with the anaerobic digestion (AD) plant and the company’s network in the food industry.
As one of Northern Ireland’s largest food transport companies with 235 employees and a cold storage facility of almost 8 500 m2, McCulla has been supplying Lidl Northern Ireland’s supermarkets for years.
With the conversion of the biogas plant, 17 500 tonnes per annum of food leftovers from Lidl stores will substitute the agricultural residues as a substrate for the HGV fuel production. Under the motto, Goodbye Diesel – Hello Biofuel, the ten new bio-CNG trucks will transport Lidl food deliveries with RNG.
Every lorry that runs on this green fuel emits 93 percent less carbon emissions than a diesel truck, said Ashley McCulla.
Due to the excellent eco-balance, the reduced emissions, and the lower dependency on fossil fuels, the deal between Lidl and McCulla is creating a positive response from all parties involved.
To ensure successful performance long-term, Weltec Biopower relied on its established components and technologies. Four pits are available for the pre-storage of the substrates. The subsequent anaerobic digestion takes place in two digesters made of stainless steel with a diameter of 23.03 m, a height of 6.30 m, and a capacity of 2 625 m³ each.
The digestate is stored in a 3 432m³ stainless steel gas-tight storage tank. In order to fully exploit the energy potential of the food waste, Weltec equipped the 80 m3 dosing feeder in combination with the MULTIMix pre-feed system. In it, food leftovers are shredded and homogenized.
In addition, the Lidl food waste is automatically unpacked and pasteurized at the biomethane plant. In the course of the extension, Weltec also upgraded the in-house developed LoMOS PLC-based control system.
By switching substrate to food waste, the biogas output has over doubled enabling the original 500 kW CHP unit to continue to run, as McCulla can use the electricity and heat for the headquarters and the cold store.
We also retrofitted the extra gas lines, installed a second emergency flare, and ensured that all components were connected smoothly with no downstream consequences on the original plant, which since commissioning has shown some of the top performance figures in the industry. Last but not least, our Biology Department guaranteed a trouble-free substrate changeover, more than doubling output from the original 500 kWe plant without further investment in digestion space, by switching from grass silage and slurry to food wastes, said Dr Kevin Monson, Sales Manager at Weltec Biopower.
The biogas upgrading system comes from Pentair Haffmans. The tried and tested module separates carbon dioxide (CO2) and other components of the biogas from methane using membrane technology to produce biomethane that is similar in its properties to natural gas.
With the newly upgraded plant, McCulla is able to lay claim to being one of the greenest transport companies in Ireland, and Ashley McCulla has already announced that the sustainable transport model in Lisburn will be applied to the entire truck fleet over the next five years.