Pre-treating black bag municipal waste in an autoclave before sending it to anaerobic digestion (AD) could increase methane generation by more than 300% and substantially reduce the amount of material requiring disposal, it is claimed.
Poole-based AeroThermal Group said it compared samples of MSW with one part of each autoclaved and the other not.
The autoclave was injected with steam to reach the required pressure and temperature and left to ‘cook’ for 45 minutes.
Test results revealed that autoclaving gave a gas yield of about 150cu m per tonne, more than double the target of 65cu m per tonne of waste.
The company said autoclaving also greatly increased both the fraction of the waste that could be digested and the gas yield from waste sent to the digesters, which substantially reduced the amount of material requiring disposal.
Chief executive Christian Toll said: “We’re very excited that our research has proved autoclaving can make black bag MSW disposal more efficient, cost-effective and less damaging to the environment.”
AeroThermal said in March that the throughput of AD plants could be doubled with a combination of steam and pressure in an autoclave.