Manure
could heat your home
University
of Waterloo
Farm
manure could be a viable source of renewable energy to help reduce greenhouse
gas emissions that cause global warming.
Researchers
at the University of Waterloo are developing technology to produce renewable
natural gas from manure so it can be added to the existing energy supply system
for heating homes and powering industries.
That would eliminate particularly harmful gases released by naturally decomposing manure when it is spread on farm fields as fertilizer and partially replace fossil natural gas, a significant contributor to global warming.
That would eliminate particularly harmful gases released by naturally decomposing manure when it is spread on farm fields as fertilizer and partially replace fossil natural gas, a significant contributor to global warming.
"There are multiple ways we can benefit from this single approach," said David Simakov, a professor of chemical engineering at Waterloo. "The potential is huge."
Simakov
said the technology could be viable with several kinds of manure, particularly
cow and pig manure, as well as at landfill sites.
In
addition to being used by industries and in homes, renewable natural gas could
replace diesel fuel for trucks in the transportation sector, a major source of
greenhouse gas emissions.
To
test the concept, researchers built a computer model of an actual 2,000-head
dairy farm in Ontario that collects manure and converts it into biogas in
anaerobic digesters.
Some of that biogas is already used to produce electricity by burning it in generators, reducing the environmental impact of manure while also yielding about 30 to 40 percent of its energy potential.
Some of that biogas is already used to produce electricity by burning it in generators, reducing the environmental impact of manure while also yielding about 30 to 40 percent of its energy potential.
Researchers
want to take those benefits a significant step further by upgrading, or
converting, biogas from manure into renewable natural gas.
That would involve mixing it with hydrogen, then running it through a catalytic converter. A chemical reaction in the converter would produce methane from carbon dioxide in the biogas.
That would involve mixing it with hydrogen, then running it through a catalytic converter. A chemical reaction in the converter would produce methane from carbon dioxide in the biogas.
Known
as methanation, the process would require electricity to produce hydrogen, but
that power could be generated on-site by renewable wind or solar systems, or
taken from the electrical grid at times of low demand.
The net result would be renewable natural gas that yields almost all of manure's energy potential and also efficiently stores electricity, but has only a fraction of the greenhouse gas impact of manure used as fertilizer.
The net result would be renewable natural gas that yields almost all of manure's energy potential and also efficiently stores electricity, but has only a fraction of the greenhouse gas impact of manure used as fertilizer.
"This
is how we can make the transition from fossil-based energy to renewable energy
using existing infrastructure, which is a tremendous advantage," said
Simakov, who collaborates with fellow chemical engineering professor Michael
Fowler.
The
modelling study showed that a $5-million investment in a methanation system at
the Ontario farm would, with government price subsidies for renewable natural
gas, have about a five-year payback period.
A
paper on modelling of a renewable natural gas generation facility at the
Ontario farm, which also involved a post-doctoral researcher and several
Waterloo students, was recently published in the International Journal
of Energy Research.
