Can we collect the waste gas generated from pyrolysis plant?

The extra waste gas could not be emitted directly in the air, as it would get accumulated in the surroundings, and even a single spark can lead to blast.The waste gas is transferred back to the heating chamber to heat the pyrolysis reactor as fuel. During this period, it only cost little coal. It is hard to store this waste gas, because this gas is coming together with the tyre oil gas. The cost for storing this waste gas is more than the profit this waste gas can give. So usually this waste gas is burnt for heating the reactor.