12 March 2018
Researchers at the University of Waterloo, Canada, have developed an innovative method for capturing renewable natural gas from cow and pig manure for use as a fuel for heating homes, powering industry, and even as a replacement for diesel fuel in trucks.
It is based on a process called methanation. Biogas from manure is mixed with hydrogen, then run through a catalytic converter, producing methane from carbon dioxide in the biogas through a chemical reaction.
The researchers claim that power could be taken from the grid at times of low demand or generated on-site via wind or solar power to produce the hydrogen. The renewable natural gas produced would yield a large percentage of the manure's energy potential and efficiently store electricity, while emitting a fraction of the gases produced when the manure is used as a fertiliser.
'The potential is huge,' said David Simakov, Professor of Chemical Engineering at Waterloo. 'There are multiple ways we can benefit from this single approach.'
Using a computer model of a 2,000-head dairy farm in Ontario, which already collects manure and converts it into biogas in anaerobic digesters before burning it in generators, the researchers tested the concept. They estimated that a $5-million investment in a methanation system would have a five-year payback period, taking government subsidies for renewable natural gas into account.
'This is how we can make the transition from fossil-based energy to renewable energy using existing infrastructure, which is a tremendous advantage,' Simakov said.