Methane, a powerful greenhouse gas, is generated via the anaerobic decomposition of solid waste in landfills. Collecting the methane for use as a gaseous fuel rather than allowing it to be released to the atmosphere provides an alternative to natural gas as an energy source and has a beneficial effect on the environment.

If a batch of waste with mass M(tonnes) [1 tonne or 1 metric ton = 1000 kg] is deposited in a landfill at t=0, the rate of generation of methane at a later time t is given by the following equation

V CH4 (t) = kL o M waste e –kt

Where:

V CH4 (SCM CH 4 /y) = methane generation rate [SCM = m 3 (STP)]

K = rate constant (y -1 ), a measure of how fast the waste decomposes

L o = landfill gas yield potential [SCM CH 4 /tonne waste]

M waste = tonnes of waste deposited at t= 0

a. Explain in your own words the benefits of reducing the release of methane from landfills and using the methane as a fuel instead of natural gas.