Effect of reactor configuration on biogas production from wheat straw hydrolysate.
The potential of wheat straw hydrolysate for biogas production was investigated in continuous stirred tank reactor (CSTR) and up-flow anaerobic sludge bed (UASB) reactors. The hydrolysate originated as a side stream from a pilot plant pretreating wheat straw hydrothermally (195 degrees C for 10-12 min) for producing 2nd generation bioethanol [Kaparaju, P., Serrano, M., Thomsen, A.B., Kongjan, P., Angelidaki, I., 2009. Bioethanol, biohydrogen and biogas production from wheat straw in a biorefinery concept. Bioresource Technology 100 (9), 2562-2568]. Results from batch assays showed that hydrolysate had a methane potential of 384 ml/g-volatile solids (VS)(added). Process performance in CTSR and UASB reactors was investigated by varying hydrolysate concentration and/or organic loading rate (OLR). In CSTR, methane yields increased with increase in hydrolysate concentration and maximum yield of 297 ml/g-COD was obtained at an OLR of 1.9 g-COD/l d and 100% (v/v) hydrolysate. On the other hand, process performance and methane yields in UASB were affected by OLR and/or substrate concentration. Maximum methane yields of 267 ml/g-COD (COD removal of 72%) was obtained in UASB reactor when operated at an OLR of 2.8 g-COD/l d but with only 10% (v/v) hydrolysate. However, co-digestion of hydrolysate with pig manure (1:3 v/v ratio) improved the process performance and resulted in methane yield of 219 ml/g-COD (COD removal of 72%). Thus, anaerobic digestion of hydrolysate for biogas production was feasible in both CSTR and UASB reactor types. However, biogas process was affected by the reactor type and operating conditions.
Kaparaju
Prasad
P
Department of Environmental Engineering, Technical University of Denmark, Building 115, DK-2800, Kgs. Lyngby, Denmark.
Serrano
María
M
Angelidaki
Irini
I
D000693:Anaerobiosis; D001674:Bioelectric Energy Sources; D019149:Bioreactors; D006868:Hydrolysis; D008372:Manure; D008697:Methane / Q000378:metabolism; D012722:Sewage / Q000382:microbiology; D013379:Substrate Specificity; D013696:Temperature; D014908:Triticum / Q000378:metabolism*
D008372:Manure; D012722:Sewage; D008697:Methane