mohsen saghouri; Reza Abdi; Mohammadali Ebrahimi-Nik; Abbas Rohani; Mohammadali Maysami
Abstract
Increasing in consumption of fossil fuels and their price and environmental impacts, have led to a growing need and interest in replacement of these fuels with new and renewable energy sources. Anaerobic digestion is one of the attractive methods to produce biogas from organic matter.Wet state and solid ...
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Increasing in consumption of fossil fuels and their price and environmental impacts, have led to a growing need and interest in replacement of these fuels with new and renewable energy sources. Anaerobic digestion is one of the attractive methods to produce biogas from organic matter.Wet state and solid state arethe categories of anaerobic digestion. Some benefits of solid-state anaerobic digestion (SS-AD) include the need for smaller reactor capacity requirements, less energy used for heating, and easier handling.In this study, SS-AD of organic fraction of municipal solid waste (OFMSW) was examined. The study was done in the laboratory scale of (1-liter volume), mesophiliccondition (37°C), and 20% solid content. Characterization of OFMSW indicated good potential of these materials to produce biogas through SS-AD (69.37% of total solids, 76.2% of volatile solids, and a C/N ratio of 38.28%). According to the results of SS-AD, a total of 372 ml biogas/g of volatile solids was obtained under normal laboratory conditions, of which 230 ml (61.82%) was methane. Also, a reduction of 64.7% was obtained for volatile solids, which is one of the parameters of the experiment productivity.
Zeynab Ramedani; Reza Abdi; Mahmoud Omid; Mohammadali Maysami
Abstract
It is essential to have integrated information on the energy exchange of forage crops in order to allow comparisons of their energy consumption patterns. Thus the aims of this study are examination of the energy consumption pattern, estimation of the amount of produced CO2eq. and modeling between the ...
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It is essential to have integrated information on the energy exchange of forage crops in order to allow comparisons of their energy consumption patterns. Thus the aims of this study are examination of the energy consumption pattern, estimation of the amount of produced CO2eq. and modeling between the yield and energy inputs in three forage crops. These forage crops that are fed to dairy cows were wheat straw, maize silage and alfalfa. The total amount of energy inputs in fields of wheat (and its straw), silage corn and alfalfa were calculated as: 32077.85, 93049.87 and 30208.04 MJ ha-1 respectively. The amount of produced CO2eq. in these three crops were estimated to be 2704.67, 5861.79 and 5538 respectively. The value of energy ratio in two crops of wheat and alfalfa were computed as 2.69 and 2.18 while in the silage crop due to higher amount of output energy rather than input energy was calculated less than one. Also, the adaptive neuro-fuzzy inference system was used for modeling the relation of the yield of these forage crops and the amount of energy inputs. For estimation of the model for wheat straw, the model with three 'gaussmf' memberships function for each input variables was the best among the other models. Also, the best model for maize silage and alfalfa were 'pimf' for tow memberships function and 'trapmf' for three memberships function, respectively.
Abstract
One way to recycle crop residue and animal manure is the production of biogas by anaerobic digestion. The present study evaluated and compared the extraction of biogas from residual canola straw,cattle manure and rumen contents. Reactors, mixers, and a hot water bath were designed and manufactured to ...
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One way to recycle crop residue and animal manure is the production of biogas by anaerobic digestion. The present study evaluated and compared the extraction of biogas from residual canola straw,cattle manure and rumen contents. Reactors, mixers, and a hot water bath were designed and manufactured to compare the extraction of biogas from these resources. Substrates were cast into the reactors after mechanical and thermal pretreatment to determine the percentage of carbon to nitrogen and the total and volatile solids. The treatments included: (1) residue of canola straw + manure + rumen contents, (2) manure, and (3) rumen contents. The treatments were compared in a completely randomized design with three replications in one-liter reactors. The results showed that the experimental treatment factors of biogas production, percentage of methane, accumulated methane, and decrease in total solids showed significant differences. Treatment (1) fell into group A with 504.1 l/kg VS of biogas produced and accumulated methane of 277.9 l/kg VS. Treatment (2) fell into group B with 178.6 l/kg VS of biogas produced and accumulated methane of 116.5 l/kg VS. Treatment 3 fell into group C with 14.8 l/kg VS of biogas produced and accumulated methane of 4 l/kg VS. The percentage of methane in groups A and B was 55% and 60%, respectively. The percentage of decrease in total solids in treatments (1) and (2) was 59% and 46%, respectively. There were no significant differences between groups B and C for ratio of carbon to nitrogen. The results indicate that fresh cattle manure + rumen contents in combination with canola residue produced the highest accumulated methane and use of this combination is recommended.
