A comparative study on biochemical methane potential of algal substrates: Implications of biomass pre-treatment and product extraction.
Dried powdered algae (SDPA), heat treated algae (MHTA), lipid extracted algae (LEA) and protein extracted algae (PEA) were digested to determine biomethane potential. The average CH4production rate was ∼2.5-times higher for protein and lipid extracted algae than for whole algae (SDPA and MHTA) whilst the cumulative CH4production was higher for pre-treated algae. Highest cumulative CH4production (318.7mlCH4g-1VS) was observed for MHTA followed by SDPA (307.4mlCH4g-1VS). CH4/CO2ratios of 1.5 and 0.7 were observed for MHTA and LEA respectively. Pre-treatment processes disrupted the algal cell wall, exposing intracellular material which remained intact as opposed to product extraction processes which broke down the intracellular compounds resulting in changes in elemental composition and decreases the cumulative gas yield and CH4/CO2ratio. Comparative analysis determined that the most profitable route of biomass utilisation was protein extraction followed by biogas production giving ∼2.5-times higher return on investment.
Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban 4000, South Africa.
Faiz Ahmad
FA
Ansari
Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban 4000, South Africa.
Shantanu
S
Wahal
Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban 4000, South Africa.
Sanjay Kumar
SK
Gupta
Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban 4000, South Africa.
Ismail
I
Rawat
Institute for Water and Wastewater Technology, Durban University of Technology, PO Box 1334, Durban 4000, South Africa. Electronic address: faizalb@dut.ac.za.
Faizal
F
Bux
D000693:Anaerobiosis; D056804:Biofuels; D018533:Biomass; D008055:Lipids; D008697:Methane / Q000096:biosynthesis*
D056804:Biofuels; D008055:Lipids; D008697:Methane
Algae; Biomethane; Lipid extracted algae; Proteins extracted algae; Sludge