Anaerobic digestion of the inedible oil biodiesel residues for value addition. (August 2017)

• Record Type: Journal Article
• Authors: Khuntia, Himanshu Kumar; Chanakya, H.N.; Siddiqha, Asma; Thomas, Christine; Mukherjee, Niranjan; Janardhana, Naveen
• Is Part Of: Sustainable energy technologies and assessments. Volume 22(2017)
• Page Start: 9
• Page End: 17
• Publication Date: 2017-08
• Subjects: JC Jatropha curcas -- JDC Jatropha deoiled cake -- JP Jatropha pods -- JDCW Jatropha deoiled cake without oil -- IJG Impure Jatropha glycerol -- MJG Methanol free IJG -- SMJG Water extracts of MJG by saponification -- Gm Modified Gompertz model -- Ap Experimental gas yield (ml) -- Ag Gas yield estimated from Gm -- λ Initial lag phase in days -- µm Specific gas production rate (d−1) -- PP Pongamia pinnata -- PDC Pongamia deoiled cake -- PP Pongamia pods -- PDCW Pongamia deoiled cake without oil -- IPG Impure Pongamia glycerol -- MPG Methanol free IPG -- SMPG Water extracts of MPG by saponification -- BMP Biological methane potential -- S/I Sludge/Inoculum ratio -- DC Deoiled cake -- AD Anaerobic digestion -- ₹ Indian National Currency, Indian Rupee; Biodiesel -- Jatropha curcas -- Pongamia pinnata -- Anaerobic digestion -- Biomethane potential; Renewable energy sources -- Periodicals; Energy development -- Technological innovations -- Periodicals; Electric power production -- Periodicals; Energy storage -- Periodicals; 333.79
• DOI: 10.1016/j.seta.2017.05.006
• Languages: English
• ISSNs: 2213-1388

Abstract

Graphical abstract: Highlights: Biodiesel production form non-edible oil seeds generate a lot of residues. The residues all together hold more energy than biodiesel. Anaerobic digestion of these residues generates biogas that can be reused or traded. The residues contain compounds that inhibit the anaerobic digestion. The inhibition can be reduced by subjecting anaerobic digestion at lower S/I ratio. Abstract: Biodiesel from inedible oil seeds is a sought after renewable energy resource, however, per kg of biodiesel production from Pongamia pinnata ( PP ) and Jatropha curcas ( JC ) generates 7.88 and 5.83 kg residues, respectively in the form of pods, deoiled cakes (DC) and impure glycerol (IG). The pods and DC are lignocellulosic whereas IG contained 18–30% glycerol along with methanol, water, oil, soap, etc. The presence of inhibitory compounds in the residues such as lipids in DC; acid insoluble lignin in pods; methanol, lipids and soap in IG reduces the overall volume and rates of biogas production. The removal of methanol from IG enhanced the biogas volume by 10–20% and simultaneously reduced the lag phase by 50% at (S/I) ratio of 0.25. The co-digestion of IG with lignocellulosic residues at 1:1 ratio also increased the biogas yield and reduced the lag phase by over 50% without any need for supplementary nutrients. The total biogas yields from PP residues was 2–3 times higher than JC residues, offering relatively faster returns on investments. The biogas generation from the residues and its reuse as an energy source was estimated to reduce the biodiesel manufacturing costs by 40–80% and 19–40% in PP and JC, respectively.