Biogas boilers from Shaw Renewables save BioteCH4 £150k

A 10-week project by Shaw Renewables to replace legacy diesel boilers with carbon-friendly biogas alternatives is delivering cost and carbon savings for a leading AD operator, BioteCH4.
Since the two 1.5 MW Viessmann dual fuel boilers and associated equipment were installed at the R100 Energy plant in Goole, Yorkshire, the financial benefit to BioteCH4 is £150,000 (€176,500) per year. In addition to the cost savings, the company is now generating 3,000 MW/h of heat from renewable sources as opposed to fossil fuels, and has reported zero faults and downtime.
Seeking increased efficiencies
Commissioned in 2020, the R100 Energy AD plant generates 11 MWth of renewable biogas each year from 90,000 tonnes of organic waste from supermarkets, local authorities and manufacturing facilities. In order to pasteurise this and heat the digesters to the required temperature, BioteCH4 has a requirement for heat on-site. The team employed diesel boilers as an interim measure, but a need for cheaper, more reliable and more environmentally friendly CHP back-ups led the company to contact Shaw Renewables for support.
“We had worked with Shaw Renewables at some of our other sites and were impressed with their level of service and knowledge of biogas boilers,” states Adam Carter, group project lead for BioteCH4. “When we sought an alternative on-site heat solution for our R100 Energy plant, they were the obvious choice.”
Twice as nice
Although BioteCH4’s heat requirement was for 3 MW, Shaw Renewables recommended a solution which incorporated two separate 1.5 MW boilers. Andrew Shaw, managing director, explains why: “The use of two boilers brings a number of benefits. The first is modulation; our fully modulating burners provide excellent turndown ratios. But there’s a limit to how low you can go – with a 3 MW boiler, the maximum turndown would be around 1.2 MW, meaning that at off-peak or low-demand times we’re generating more than is required.
“The second benefit is backup. If one boiler goes down or needs servicing, a spare is available. And finally, there’s duty sharing. Alternating between two boilers means they share the wear and tear, prolonging their lifespan and that of the pumps and associated equipment.”
Containerised solution
Shaw Renewables created a two-boiler cascade solution for the R100 site, incorporating a modulating gas booster to deliver the required pressure. In just 10 weeks, Andrew Shaw and his team built a 40ft-long plant room with lighting, combustion air ventilation, small power for service equipment and a gas safety system with gas interlock.
The plant room houses two 1.5 MW Viessmann low-temperature hot water boilers with a steel shell, with fully modulating dual fuel (biogas and LNG) Riello gas burners. It also includes a variable-speed Utile gas booster with pressure transducers to provide fully modulating gas pressure, as well as Grundfos TPE pumps. Gas safety has been addressed with a multi-sensor alarm which monitors lower explosive limits, carbon monoxide, hydrogen sulphide, smoke and fire.
Superior project management
The team hired a crane to position the plant room in place, then oversaw the fabrication, installation and insulation of the heating pipework, biogas pipework and gas booster pipework. Testing and commissioning checks followed before the containerised biogas boiler solution was handed over to BioteCH4’s in-house engineers and operators.
“Being able to leave the installation and pre-commissioning to Andrew was a real bonus,” says Adam Carter. “Everything ran entirely to plan – it was one of the smoothest projects I’ve ever been involved with.”
Reaping the benefits
According to Adam, the benefits were clear from day one. “We’re coming up to our first service, and we’ve had no downtime at all. The new boilers are super-efficient, work exactly as we intended them to, and have given us no issues whatsoever.”
They’ve also delivered considerable cost savings. “Before, we had to pay for the fuel we used,” confirms Adam. “But now, we can use the biogas that we’re generating on site, meaning the fuel is effectively ‘free’ (barring nominal parasitic load and feedstock costs).”
The carbon savings are impressive, too. “We are now generating approximately 3,000 MW/h of heat from renewable sources, as opposed to fossil fuels,” adds Adam. “That’s the equivalent of around 240,000kg of kerosene.”
Remote monitoring
The new boilers come with remote monitoring as standard. The solution is interfaced with the plant-wide SCADA system, issuing alerts for any immediate problems and early warning fault messages for performance deterioration. Remote access enables the boilers to be monitored 24/7, stopped and started in seconds, and even the fuel type to be changed. This has been backed up by free 60-day aftercare from Shaw Renewables, followed by options including a service package to deliver six-monthly boiler servicing, retained labour, discounts for parts and a 24-hour dedicated helpline.
“I wouldn’t hesitate to recommend Shaw Renewables to other AD operators; we’ve already used them for a further two boiler projects at our other plants,” concludes Adam Carter. “They’re reliable and knowledgeable and delivered exactly what they promised us, resulting in real carbon and cost savings for our plant.”