Title: An optimum process for anaerobic digestion of wild tree wastes under alkaline pretreatments in biogas plants
Abstract: In the present study, a new strategy was developed by integrating mathematical modeling, restrictive goals, and desirability analysis to improve anaerobic digestion of wild tree wastes and clean biogas production. For this purpose, different mixtures (inoculum : terebinth waste : cow manure) and pretreatments (NaOH and urea) were tested based on a combined D-optimal experimental design. The results indicated that biogas production of mixtures with higher cow manure amounts was more purified, with higher terebinth waste had more CO and CO2, and with higher inoculum had more H2S. Further, the addition of NaOH and urea below 1.5% improved the quality of biogas. By overlaying the biogas parameters according to the restriction goals, the best ranges of the inoculum : terebinth waste : cow manure were equaled to 0−10% : 4−22% : 71−97%, and the best concentration ranges of NaOH and urea were 0.19−1.83% and 0−1.2%, respectively. Using these optimum ranges of the input factors, CH4, H2S, CO2, CO, corrected CH4, T90, cumulative biogas production and cumulative methane production were >50.3%, <0.0003%, <9.85%, =0%, >66.21%, >4.89 day, >799.02 mL and >8.49 mL/gVS, respectively. It can be concluded that to improve the biogas plant efficiency in the areas with high tree wastes, a lot of cow manure is needed (> 3 times of tree wastes), and the substrates should be chemically pretreated with NaOH amount less than 1.83% and urea amount less than 1.2%.
Publication Year: 2021
Publication Date: 2021-08-26
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 13
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