Sun, Chihe; Xia, Ao; Liao, Qiang; Fu, Qian; Huang, Yun; Zhu, Xun; Wei, Pengfei; Lin, Richen; Murphy, Jerry D.

2018

November

Applied Energy

Improving production of volatile fatty acids and hydrogen from microalgae and rice residue: Effects of physiochemical characteristics and mix ratios

Published

Altmetric: 5 ()

Microalgae Rice residue Pretreatment Physicochemical characteristics Mix ratios Co-fermentation

230

1082

1092

Dark fermentation may be hindered by insufficient bioavailable carbon and nitrogen sources as well as recalcitrant cell wall structures of substrates. Protein-rich microalgae and carbohydrate-rich rice residue with various mix ratios can optimise biohydrogen and volatile fatty acids production. Optimal pretreatment of the microalgae with 1% H2SO4 and the rice residue with 0.5% H2SO4 under hydrothermal heating (140 °C, 10 min) achieved reducing sugar yields of 187.3 mg/g volatile solids (VS) (hydrolysis efficiency: 54%) and 924.9 mg/g VS (hydrolysis efficiency: 100%), respectively. Multiscale physiochemical characterisations of solid hydrolytic residues confirmed considerable damage to both substrates. Co-fermentation of pretreated rice residue and microalgae at a mix ratio of 5:1 exhibited the maximum hydrogen yield of 201.8 mL/g VS, a 10.7-fold increase compared to mono-fermentation of pretreated microalgae. The mix ratio of 25:1 resulted in the highest carbon to volatile fatty acids conversion (96.8%), corresponding to a maximum energy conversion efficiency of 90.8%.

0306-2619

http://www.sciencedirect.com/science/article/pii/S0306261918313709

10.1016/j.apenergy.2018.09.066

Other: Not Listed