a zero - discharge landfill process is disclosed herein . the process described in the present invention recycles the exhaust gases from a combustion engine which reheats the landfill and provides moisture . additionally , the co 2 from the exhaust gases releases additional methane . methane production in landfills can thus be enhanced by the method of the present invention . furthermore , a portion of the exhaust gas can be used to cultivate algae in a cultivation tank . the cultivation of the algal species is enhanced in the presence of water , co 2 , co , and the elevated temperatures . optionally , a first portion of the cultivated algae can be passed through the landfill to increase methane production in the landfill and a second portion of the cultivated algae can be transferred to a biodiesel production tank , for the conversion of the one or more algal oils and lipids to a biodiesel or a biofuel by a transesterification reaction