Effect of Total Solid, Substrate to Inoculum Ratio, and Cellulase Addition on Methane Production in Dry Anaerobic Digestion of Wheat Straw Using Psychrophilic and Thermophilic inoculants

NIKEN INDRATI, Dr. Ria Millati, ST, MT.

2015 | Tesis | S2 Teknologi Hasil Perkebunan

The objective of this work was to investigate effect of total solid (TS) content, substrate to inoculum (S/I) ratio and addition of cellulase on methane production in dry anaerobic digestion of wheat straw. TS content of 21 and 30% with variation of S/I ratio of 1 and 2 was used. Each TS content with varied S/I ratio was added with cellulase and without cellulase. Samples were incubated at psychrophilic and thermophilic condition. Biogas production and gas composition were analyzed on 5th day and every 7 days for psychrophilic and 3rd, 5thday, and every 7 days for thermophilic. At psychrophilic condition, higher TS content leads to a high methane yield. So, TS content gives a positive effect to methane production on dry anaerobic digestion. While S/I ratio and the addition of cellulase give a negative effect, because methane yield decreases with higher S/I ratio and with addition of cellulase. And at thermophilic condition, TS content has a negative effect to methane production. Lower TS content leads to escalation of methane production. On treated straw, S/I ratio has negative effect, which mean methane production decreases with the increasing of S/I ratio. Whereas in untreated straw, S/I ratio gives positive effect to methane production. Cellulase addition gives a higher methane yield in batch with S/I ratio 1, but a lower methane yield in batch with S/I ratio 2.

The objective of this work was to investigate effect of total solid (TS) content, substrate to inoculum (S/I) ratio and addition of cellulase on methane production in dry anaerobic digestion of wheat straw. TS content of 21 and 30% with variation of S/I ratio of 1 and 2 was used. Each TS content with varied S/I ratio was added with cellulase and without cellulase. Samples were incubated at psychrophilic and thermophilic condition. Biogas production and gas composition were analyzed on 5th day and every 7 days for psychrophilic and 3rd, 5thday, and every 7 days for thermophilic. At psychrophilic condition, higher TS content leads to a high methane yield. So, TS content gives a positive effect to methane production on dry anaerobic digestion. While S/I ratio and the addition of cellulase give a negative effect, because methane yield decreases with higher S/I ratio and with addition of cellulase. And at thermophilic condition, TS content has a negative effect to methane production. Lower TS content leads to escalation of methane production. On treated straw, S/I ratio has negative effect, which mean methane production decreases with the increasing of S/I ratio. Whereas in untreated straw, S/I ratio gives positive effect to methane production. Cellulase addition gives a higher methane yield in batch with S/I ratio 1, but a lower methane yield in batch with S/I ratio 2.

Kata Kunci : wheat straw, dry anaerobic digestion, psychrophilic condition, thermophilic condition, TS content, substrate to inoculum ratio, cellulase addition