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Title: Biogas production from anaerobic digestion of Spirulina maxima algal biomass

Abstract

The photosynthetic spectrum of solar energy could be exploited for the production of chemical energy of methane through the combined algal-bacterial process. In this process, the algae are mass produced from light and from carbon in the first step. The algal biomass is then used as a nutrient for feeding the anaerobic digester, in the second step, for the production of methane by anaerobic bacteria. The carbon source for the production of algal biomass could be either organic carbon from wastewaters (for eucaryotic algae), or carbon dioxide from the atmosphere or from the combustion exhaust gases (for both prokaryotic and eukaryotic algae). The technical feasibility data on the anaerobic digestion of algal biomass have been reported for many species of algae including macroscopic algae and microscopic algae. Research being conducted in the authors' laboratory consists of using the semimicroscopic blue-green alga Spirulina maxima as the sole substrate for this combined algal-bacterial process. This species of alga is very attractive for the process because of its capability of using the atmospheric carbon dioxide as carbon source and its simple harvesting methods. Furthermore, it appeared that the fermentability of S. maxima is significantly higher than other microscopic algae. This communication presents themore » results on the anaerobic inoculum development by the adaptation technique. This inoculum was then used for the semicontinuous anaerobic digestion of S. maxima algal biomass. The evolutions of biogas production and composition, biogas yield, total volatile fatty acids, alkalinity, ammonia nitrogen, pH, and electrode potential were followed.« less

Authors:
;
Publication Date:
Research Org.:
Dept of Chemical Engineering, Laval Univ, Sainte-Foy, Quebec, Canada G1K 7P4
OSTI Identifier:
6408556
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biotechnol. Bioeng.; (United States); Journal Volume: 24:8
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 59 BASIC BIOLOGICAL SCIENCES; ALGAE; ANAEROBIC DIGESTION; CYANOBACTERIA; METHANE; PRODUCTION; BIOMASS PLANTATIONS; CARBON; CARBON DIOXIDE; CARBOXYLIC ACIDS; METHANOGENIC BACTERIA; PH VALUE; PRODUCTIVITY; ALKANES; BACTERIA; BIOCONVERSION; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; DIGESTION; ELEMENTS; HYDROCARBONS; MANAGEMENT; MICROORGANISMS; NONMETALS; ORGANIC ACIDS; ORGANIC COMPOUNDS; OXIDES; OXYGEN COMPOUNDS; PLANTS; PROCESSING; WASTE MANAGEMENT; WASTE PROCESSING; 090122* - Hydrocarbon Fuels- Preparation from Wastes or Biomass- (1976-1989); 550700 - Microbiology; 140504 - Solar Energy Conversion- Biomass Production & Conversion- (-1989)

Citation Formats

Samson, R., and LeDuy, A. Biogas production from anaerobic digestion of Spirulina maxima algal biomass. United States: N. p., 1982. Web. doi:10.1002/bit.260240822.
Samson, R., & LeDuy, A. Biogas production from anaerobic digestion of Spirulina maxima algal biomass. United States. doi:10.1002/bit.260240822.
Samson, R., and LeDuy, A. 1982. "Biogas production from anaerobic digestion of Spirulina maxima algal biomass". United States. doi:10.1002/bit.260240822.
@article{osti_6408556,
title = {Biogas production from anaerobic digestion of Spirulina maxima algal biomass},
author = {Samson, R. and LeDuy, A.},
abstractNote = {The photosynthetic spectrum of solar energy could be exploited for the production of chemical energy of methane through the combined algal-bacterial process. In this process, the algae are mass produced from light and from carbon in the first step. The algal biomass is then used as a nutrient for feeding the anaerobic digester, in the second step, for the production of methane by anaerobic bacteria. The carbon source for the production of algal biomass could be either organic carbon from wastewaters (for eucaryotic algae), or carbon dioxide from the atmosphere or from the combustion exhaust gases (for both prokaryotic and eukaryotic algae). The technical feasibility data on the anaerobic digestion of algal biomass have been reported for many species of algae including macroscopic algae and microscopic algae. Research being conducted in the authors' laboratory consists of using the semimicroscopic blue-green alga Spirulina maxima as the sole substrate for this combined algal-bacterial process. This species of alga is very attractive for the process because of its capability of using the atmospheric carbon dioxide as carbon source and its simple harvesting methods. Furthermore, it appeared that the fermentability of S. maxima is significantly higher than other microscopic algae. This communication presents the results on the anaerobic inoculum development by the adaptation technique. This inoculum was then used for the semicontinuous anaerobic digestion of S. maxima algal biomass. The evolutions of biogas production and composition, biogas yield, total volatile fatty acids, alkalinity, ammonia nitrogen, pH, and electrode potential were followed.},
doi = {10.1002/bit.260240822},
journal = {Biotechnol. Bioeng.; (United States)},
number = ,
volume = 24:8,
place = {United States},
year = 1982,
month = 8
}
  • The semimicroscopic blue-green alga Spirulina maxima makes an ideal substrate for anaerobic digestion because it is easy to harvest, it can use carbon dioxide from the atmosphere as its carbon source, and its fermentability is higher than that of other small algae. Digestion experiments demonstrated that S. maxima can serve as the sole nutrient for biogas production and that municipal sewage sludge, when adapted to this new substrate, is very stable. During semicontinuous daily-fed trials under non-optimal conditions at an 0.06 lb volatile solids (VS)/ft/sup 3/ (0.97 kg VS/m/sup 3/) loading rate, 33-day retention time, and 86/sup 0/F (30/sup 0/C)more » digestion temperature, the daily methane yield was 4.2 CF/lb (0.26 m/sup 3//kg) VS added, which represents 47% of the maximum theoretical yield. Studies on optimizing the process are underway.« less
  • Spirulina maxima algal biomass could be used as the sole nutrient for the production of biogas by anaerobic digestion process. It is relatively simple to adapt the municipal sewage sludge to this new substrate. The adapted sludge is very stable. Under nonoptimal conditions, the methane yield and productivity obtained were 0.26 m/sup 3//(kg VS added day) and 0.26 m/sup 3//(kg VS added day), respectively, with the semicontinuous, daily fed, anaerobic digestion having loading rate of 0.97 kg VS/(m/sup 3/ day), retention time of 33 days and temperature of 30/sup 0/C.
  • Biomass of the blue-green alga Spirulina maxima was converted to methane using continuous stirred tank digesters with an energy conversion efficiency of 59%. Digesters were operated using once-a-day feeding with a retention time (theta) between 5 and 40 days, volatile solid concentrations (Sto) between 20 and 100 kg VS/cubic m, and temperatures between 15 and 52/sup 0/C. The results indicated a maximum methane yield of 0.35 cubic m (STP)/kg VS added at theta = 30 days and Sto = 20 kg VS/cubic m. Under such conditions, the energy conversion of the algal biomass to methane was 59%. The maximum methanemore » production rate of 0.80 cubic m (STP)/cubic m day was obtained with theta = 20 days and Sto = 100 kg VS/cubic m. The mesophilic condition at 35/sup 0/C produced the maximum methane yield and production rate. The process was stable and characterized by a high production of volatile acids (up to 23,200 mg/l), alkalinity (up to 20,000 mg/l), and ammonia (up to 7000 mg/l), and the high protein content of the biomass produced a well-buffered environment which reduced inhibitory effects. At higher loading rates, the inhibition of methanogenic bacteria was observed, but there was no clear-cut evidence that such a phenomenon was due to nonionized volatile acids or gaseous ammonia. The kinetic analysis using the model proposed by Chen and Hashimoto indicated that the minimum retention time was seven days. The optimum retention time increased gradually from 11 to 16 days with an increase in the initial volatile solid concentration. The kinetic constant K decreased with the improvement in the digester performance and increased in parallel with the ammonia concentration in the culture media. 32 references.« less
  • Oleaginous microalgae contain a high level of lipids, which can be extracted and converted to biofuel. The lipid-extracted residue can then be further utilized through anaerobic digestion to produce biogas. However, long-chain fatty acids (LCFAs) have been identified as the main inhibitory factor on microbial activity of anaerobic consortium. In this study, the mechanism of LCFA inhibition on anaerobic digestion of whole and lipid-extracted algal biomass was investigated with a range of calcium concentrations against various inoculum to substrate ratios as a means to alleviate the LCFA inhibition.
  • Anaerobic digestion is applied widely to treat the source collected organic fraction of municipal solid wastes (SC-OFMSW). Lipid-rich wastes are a valuable substrate for anaerobic digestion due to their high theoretical methane potential. Nevertheless, although fat, oil and grease waste from sewage treatment plants (STP-FOGW) are commonly disposed of in landfill, European legislation is aimed at encouraging more effective forms of treatment. Co-digestion of the above wastes may enhance valorisation of STP-FOGW and lead to a higher biogas yield throughout the anaerobic digestion process. In the present study, STP-FOGW was evaluated as a co-substrate in wet anaerobic digestion of SC-OFMSWmore » under mesophilic conditions (37 {sup o}C). Batch experiments carried out at different co-digestion ratios showed an improvement in methane production related to STP-FOGW addition. A 1:7 (VS/VS) STP-FOGW:SC-OFMSW feed ratio was selected for use in performing further lab-scale studies in a 5 L continuous reactor. Biogas yield increased from 0.38 {+-} 0.02 L g VS{sub feed}{sup -1} to 0.55 {+-} 0.05 L g VS{sub feed}{sup -1} as a result of adding STP-FOGW to reactor feed. Both VS reduction values and biogas methane content were maintained and inhibition produced by long chain fatty acid (LCFA) accumulation was not observed. Recovery of a currently wasted methane potential from STP-FOGW was achieved in a co-digestion process with SC-OFMSW.« less