Optimization of biogas production through anaerobic digestion of fruit and vegetable waste : a review
- Authors: Maile, Ireen , Muzenda, Edison , Mbohwa, Charles
- Date: 2016
- Subjects: Biomethane , Fruit and vegetable waste , Methane
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/216550 , uj:21520 , Citation: Maile, I., Muzenda, E & Mbohwa, C. 2016. Optimization of biogas production through anaerobic digestion of fruit and vegetable waste : a review.
- Description: Abstract: Anaerobic digestion is the biodegradation of the waste material with the aid of microbes which thrive in the absence of oxygen. Fruits and vegetable wastes (FVW) are a good substrate with potential to produce biomethane and are abundantly available. The optimization of biogas production from FVW was reviewed. A careful consideration when selecting the operating process parameters such as temperature, pH, hydraulic retention time (HRT), organic loading rate (OLR), inoculum to substrate ration (ISR) , particle size and nutrients. The following factors can improve the methane yield from FVW: co-digestion, pre-treatment and digester configuration.
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Biogas production from anaerobic digestion of fruit and vegetable waste from Johannesburg market
- Authors: Maile, Ireen , Muzenda, Edison , Mbohwa, Charles
- Date: 2016
- Subjects: Biogas , Fruits and vegetables , Microbes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217553 , uj:21654 , Citation: Maile, I., Muzenda, E. & Mbohwa, C. 2016. Biogas production from anaerobic digestion of fruit and vegetable waste from Johannesburg market.
- Description: Abstract: Biogas production from anaerobic digestion is a promising technology for sustainable energy development. Biochemical methane potential (BMP) tests are normally run to determine the possible methane that can be obtained from each biomass. The aim of this study is to determine the biochemical potential of fruits and vegetable wastes from the Johannesburg market. The biochemical methane potential tests were carried out using the bioprocess control Automatic Methane Potential Test System (AMPTS) II machine. The initial pH of the feedstock was low during the preparation of the feed since fruits and vegetable waste (FVW) are acidic and thus buffer solutions were used to increase the pH to 6.5-7.5. The BMP for the FVW was determined to be on average 300 ml CH4 /g VS added with methane content between 50-60 % volume.
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Biochemical methane potential of OFMSW for City of Johannesburg
- Authors: Maile, Ireen , Muzenda, Edison , Mbohwa, Charles
- Date: 2016
- Subjects: Anaerobic digestion , Landfill , Methane potential
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/216566 , uj:21522 , Citation: Maile, I., Muzenda, E. & Mbohwa, C. 2016. Biochemical methane potential of OFMSW for City of Johannesburg.
- Description: Abstract: The accumulation of Organic Fraction of Municipal Solid Waste (OFMSW) in landfills not only pose threat to the environment, it may also lead to potential health hazards. Anaerobic digestion stands a very good chance to mitigate this waste accumulation in landfills and has potential to create green jobs. BMP has been widely studied in anaerobic digestion for the production of sustainable energy. Bioprocess control Automatic Methane Potential Test System (AMPTS) II machine was used to set up the assays and run the tests. OFMSW was observed to have a low pH which affects the production process and biogas yield. Buffer solutions that were used in this study were calcium carbonate (CaCO3) and sodium hydroxide (NaOH). It was observed that CaCO3 not only stabilizes the pH but it also gives nutrients to the microbes and thus results in higher biogas yields. Inoculation also helped in stabilizing the process and improved the yield. The digester with CaCO3 resulted in a higher methane yield than the others. Though CaCO3 gave good results its use was discontinued as it has a negative impact on the environment. The BMP of OFMSW was found to be 200 ml CH4 / g VS. The methane content was found to be on average 58%.
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A review of biogas purification through chemical absorption
- Authors: Muzenda, Edison , Maile, Ireen
- Date: 2014
- Subjects: Anaerobic digestion , Biogas purification , Chemical absorption
- Type: Article
- Identifier: uj:5041 , http://hdl.handle.net/10210/13561
- Description: Biogas is an alternative source of energy which is produced by anaerobic digestion (AD) of waste materials. Biogas contains 50 -70% methane and 30-50% carbon dioxide as well as small a amounts of other gases with a calorific value of about 21-24 MJ/m3 . These trace components limit the usage of the biogas as they lower the calorific value of the gas and limit its commercialization. Hence, there is a need for purification and upgrading to meet specified application standards. The purification and upgrading processes can be classified into four major techniques which are absorption, adsorption, membrane separation and cryogenic separation. This review is focused on biogas enrichment through chemical absorption. This process involves amine washing with mono-,di- or tri-ethanolamine solutions, alkali washing with calcium oxide, calcium, potassium and sodium hydroxides, and synthesised ionic solutions of halide imidazolium ionic liquids. The regeneration of the spent chemicals for re-use will also be studied.
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