Wood from a dead palm tree was studied for its suitability to methane production. Ground wood samples of 3 kg were processed in fermentation tanks (plain sample in tank A). The gas was accumulated and measured over 30 days. Similar ground wood sample was put in another tank, also inoculating this with methanogen microbes (tank B), and the fermentation was compared to similar with cow dung as the substrate (tank C). The dependence of methane production on environmental conditions was also examined. The varied fermentation parameters were temperature, pretreatment of the substrate, and C/N ratio. It was found that tank C produced the largest amount of gas (4,125 cm3 ) followed by tank B (3,345 cm3 ), and finally tank A (2,010 cm3 ). Varying the fermentation temperature from high (outdoors) to medium (room temperature) and low (air conditioned room) gave about similar accumulated gas amounts in the range 1,865-2,010 cm3 . Pre-treatment of the substrate with alkaline (NaOH) produced more methane, about 2,412 cm3 , while pre-treatment with acid (1% HCl) gave about 1,936 cm3 produced gas, which was equal to fermentation without pretreatment. The gas production further increased to about 2,702 cm3 when nitrogen (ammonium phosphate) was added to the system, and was only about 1,314 cm3 when the C/N ratio was raised by adding molasses. The use of palm wood waste as substrate for biogas production is thus possible, but it should be fermented with inoculated methanogens, pre-treated with alkali, and the C/N ratio should be adjusted by adding nitrogen.
