Agricultural waste management
E. Alboativi; A. Asakereh; H. Zaki Dizaji; Y. Mansoori
Abstract
Introduction: Bagasse is the dry pulpy fibrous residue that remains after sugarcane stalks are crushed for juice extraction. Bagasse is widely used in conversional and by-product industries. Bagasse is commonly used as a substitute for wood in many tropical and subtropical countries for the production ...
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Introduction: Bagasse is the dry pulpy fibrous residue that remains after sugarcane stalks are crushed for juice extraction. Bagasse is widely used in conversional and by-product industries. Bagasse is commonly used as a substitute for wood in many tropical and subtropical countries for the production of pulp, paper, and board. One of the most important conversional industries in the sugarcane agro-industry is chipboard production. In recent years, two chipboard factories from bagasse were exploited in Khuzestan province. In the production of chipboard from bagasse, a lot of waste is produced, most of which include pith. The waste is transferred to the outside of the factory at a great cost and energy level. Also, annually, a large amount of surplus bagasse of conversional Industries is obtained in Khuzestan agro-industries. These wastes cause many environmental and health problems, while these wastes can be used to generate energy. On the other hand, chipboard industries consume a lot of energy which is mostly fossil energy. Nowadays, in many sugarcane agro-industries in different countries, wastes are used to generate energy for sugar plants and conversional industries. Bagasse is often used as a primary fuel source for sugar mills.Materials and Methods: Current research is focused on the direct energy consumed in chipboard production from sugarcane bagasse and whether it can be provided by using residues and wastes of Debal Khozaie Agro-Industry Company. Data were collected from agro-industry companies as well as by sampling and measuring waste, input and energy consumption at the chipboard factory of Debal Khozaie. Direct energy consumed in the chipboard production from bagasse includes diesel fuel, electricity, natural gas, and labor. Input and output values of materials (bagasse, pith, etc.), and energy consumption (electricity, diesel, natural gas, etc.) were collected using both laboratory tests and data available in agro-industry. Potential of energy generation from bagasse, pith, wood chips, and straw in Debal Khozaie agro-industry, were considered by the direct burning method. Also, the potential of biogas production from vinasse in agro-industry for energy production was calculated. The moisture of bagasse (fresh bagasse, 24 hours, five days, 30 days, and 45 days after gathering), outdoor dried pith, outdoor dried straw and wood chip were measured based on the ASTM D2974 standard method in the laboratory. Ash percentage of bagasse, peat, straw, and Wood chips were measured using a furnace, desiccator and a scale. Also, the lower heating value of bagasse, straw, pith, and wood chips were measured using a calorimeter bomb.Results and Discussion: The direct energy consumption in the chipboard factory was determined to be 5.829 GJ m-3 of produced chipboard. Natural gas and electricity were the major sources of direct energy with 78.52% and 18.87% share, respectively. To replace these sources, pith and woodchips form chipboard factory, sugarcane leaves, remainder sugarcane bagasse, and vinasse from molasses-based Razi alcohol factory were considered. Properties of the substituted resources were determined including ash, moisture content, heating value (using bomb calorimeter), and amount of woodchips along with the biogas potential from anaerobic fermentation of vinasse. Results showed that woody residues from chipboard factory and Debal Khozaie Agro-Industry Company had the potential to provide 4.33 fold the energy provided by gas in the chipboard factory, considering the efficiency equal to 60%. Using the residues of the chipboard factory individually, it is possible to replace all the consumed natural gas and electricity energy needed in the chipboard factory as well. According to the volume of available vinasse, the potential biogas production from this resource estimated to be 8.82 Gm3.Conclusion: Electricity, natural gas, and diesel fuel constitute the direct energy consumed in the production of chipboard, and natural gas with 78.52% has the highest share. Electricity accounts for 18.87% of direct energy consumption. The specific energy of chipboard production at the chipboard factory was 5.829 GJ m-3. Only using the pith of chipboard factory can produce 2.85 times the total energy of natural gas consumed in chipboard factory. Investigation of the potential of biogas production from vinasse in Debal Khozaie agro-industry showed that it is possible to generate energy equivalent to 8824.3 thousand cubic meters of natural gas. Overall, the study showed that using the wastes of chipboard factory and sugarcane agro-industry has the potential to replace the entire natural gas and electricity consumption in chipboard factory.
