Authors: Pascal Blaise GNIMPIEBA DONGMO, Anne Pulcherie Ayo
Published in: CSBE-SCGAB Technical Conferences » 5th CIGR and AGM Quebec City 2021 » Special Session on Biogas
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Description: Faced with the depletion of fossil energy resources and the challenges of global warming, biomass appears as a credible renewable carbon resource that can be mobilized and promoted as an alternative to fossil fuels for the production of solid fuels, but also for the synthesis of fossil fuels. fuels (liquid or gaseous). The world is generating more and more waste, with agriculture being the second most emitting sector of activity after transportation is no exception. Tons of waste from harvesting different crops are produced continuously in our country. However, they are considered either worthless waste and are therefore burned or used as livestock feed. Also, the droppings of different animals from the breeding are simply dumped in nature. The uncontrolled process of the degradation of this waste largely contributes to the emission of the greenhouse gases responsible for the destruction of the ozone layer, thereby promoting climate change. To this end, the production of methane by anaerobic biomass digestion of biomass is considered as one of the sectors of the future to help reduce our dependence on fossil fuels.
Ecologically viable solutions such as anaerobic digestion can contribute positively to this global challenge. IRAD started a few years ago, but its studies are still at the laboratory level. The controlled and valorized methanisation is a depollution activity because it brings an energetic and ecological answer to the problem of the organic waste treatment. It contributes to sustainable development. Moreover, when biogas from anaerobic digestion is not burned, it has a 25-fold impact on the greenhouse effect than CO2 (Mayer, 2018). This technology is booming for the production of methane, a source of renewable energy. It has been used for several years. However, it is less interesting when the digestate resulting from this process is not valued and when it is done in a traditional way. The thorny problem arises of finding strategies to optimize the process of anaerobic digestion and to show the interest of digestate in agricultural production.
This project aims to valorize biomass energy at IRAD while highlighting its products. To do this, the waste generated on IRAD experimental farms was first selected (corn spathe and cow dung), collected and analyzed. We then proceeded to design, build and commission a small-scale biodigester. Finally, we valorized the products resulting from this process of methanation as agricultural amendment in comparison with the chemical fertilizer and for the drying of the agricultural products. Our work has focused on the valorization of digestate. Optimization methods for yield improvement have also been found. The quantification of waste has revealed a loss of organic resources estimated at around 15.58 tonnes per year, potentially convertible into 3091.2 m3 of biogas. Laboratory test results reveal that cow dung is alkaline while corn spathe is acidic. On the other hand, the mixture of the two wastes in a 1/9 ratio gave a near neutral pH. Also, cow dung and corn spathe have a C / N ratio of 15.36 and 27.68, respectively. Mixing the two in the same ratio as before gave a C / N value of 21.22. These results also reveal that corn spathe degrades more rapidly than cow dung. After analyzing the BOD5, we found that the composition of the substrate in the same ratio is easily biodegradable. The biodigester designed has a total volume of 250l with a useful volume of 192l, with a production capacity of 17.75 m3. The digestate obtained has been promoted as an amendment on the maize crop. At the end of this exercise, we observed that the yield in t / ha is higher in the plots where the digestate was applied in half dose or recommended dose.
A hybrid (biogas / solar) and ecological dryer has been set up where biogas is converted into heat for its operation in order to reduce or eradicate post-harvest losses. For this fact, the literature reviews were conducted on drying, solar driers and biogas. They led to the characterization of the activity of drying and the determination of structuring criteria determining the choice of ideas for a dryer. The use of tools such as functional analysis, sizing methodology and computer-aided drawing (CATIAV5) have made it possible to develop a standard implementation methodology for our dryer.
Keywords: biomass, biodigester, methanisation, digestate, hybrid dryer and ecological
Conference name: 5th CIGR International Conference and CSBE-SCGAB AGM 2021, Quebec City,QC, 11-14 May 2021.
Session name: Special Session Biogas
Publication type: Presentation
Language 1: en
Rights: Canadian Society for Bioengineering