Blocks made from sewage cut CO2
Published: 23 September, 2011
LEEDS: Yorkshire Water has teamed with Leeds University to trial house blocks made from incinerated sewage ash.
The blocks combine ash from incinerated sewage with vegetable oil to make blocks that are classified as carbon-negative because the oil comes from plants that have sucked out C02 from the atmosphere.
The university spinout company Encos has been specialising in alternatives to traditional building methods and the new blocks are being developed for commercial use.
During a patented process standard oils undergo a number of complex chemical reactions that transform it from a viscous liquid into a solid binding matrix.
Masonry units incorporating the binders and manufactured at the Encos laboratories have successfully passed crucial industry tests including fire, freeze-thaw and compressive strength.
The firm has also produced bricks and slips using the process. The products were also successfully used in the construction of several 'test walls' including one at Poundbury - the urban development project built on land owned by the Duchy of Cornwall.
A scale production plant is in design and is planned for operation in 2012.
Encos masonry blocks and bricks have been calculated to achieve a reduction of 160% and 120% respectively in greenhouse gas emissions, compared to traditional clay bricks and concrete blocks.