The world’s first trial to replace natural gas with green hydrogen in brick-making is laying the foundations for a 60% reduction in embodied carbon
The world’s first feasibility study into the use of green hydrogen as a replacement for natural gas in clay brick manufacturing is under way in Sussex, with the results expected at the end of the summer.
Brick maker Michelmersh is leading the Deep Decarbonisation of Brick Manufacturing project as part of a consortium including Limpsfield Combustion, Net Zero Associates, the University of Brighton, Greater South East Net Zero Hub, FT Pipelines, Geopura, and Safety Monitors.
It is backed by £292,624 of UK government funding awarded through the Industrial Fuel Switching competition run by the Department for Business, Energy & Industrial Strategy.
The first phase of the project will demonstrate the viability of fuel switching. A test kiln at Michelmersh’s Freshfield Lane facility in Sussex has been retrofitted with a burner using 100% green hydrogen (hydrogen made using renewable energy). Parallel research, by Limpsfield Combustion, will develop and conduct laboratory tests of burners to investigate their energy efficiency.
Michelmersh has calculated that swapping natural gas for green hydrogen across the group's infrastructure would reduce the embodied carbon of clay bricks by over 60%. The remaining 40% would encompass factors such as process emissions, transport/delivery and the use of grid electricity elsewhere in operations.
As the future for green hydrogen in brick making is not guaranteed, Michelmersh is investigating other technologies that may prove more sustainable for certain production processes, such as ground source and electrification.
Sarah Le Gresley, innovation director and sustainability group chair at Michelmersh, said: ‘If green hydrogen did prove to be viable, both commercially and sustainably, it would still require a vast investment in infrastructure by the whole industry….Buying in green hydrogen is not currently commercially viable and there's not enough production in the country, but if we could produce our own hydrogen on site [that could change].’
This, she adds, would probably mean transferring typical operational expenditure on natural gas into capital expenditure for hydrogen production facilities.
The study will determine the impact of hydrogen firing on overall brick quality, integrity and aesthetics, and analyse any effect on process temperatures or stability. Bricks will be compared against control bricks made using 100% natural gas to ensure they meet all technical, aesthetic and characteristic requirements.
‘One potential hurdle is ensuring the same atmosphere inside the kiln, because hydrogen produces water as a byproduct, increasing moisture content,’ said Le Gresley.
Michelmersh is promoting the learning from the project through the dedicated brand HyBrick, bricks produced through the various testing phases will be sent to architects and luxury housing developers with a view to incorporating them into projects, provided they meet the necessary technical performance requirements.