مطالعه امکان تامین انرژی تولید تخته نئوپان از باگاس با استفاده از ضایعات نیشکر (مطالعه موردی: کشت و صنعت دعبل خزاعی)

در این مطالعه مصرف انرژی مستقیم در تولید تخته نئوپان از باگاس نیشکر و امکان جایگزینی آن با ضایعات کشت و صنعت نیشکر دعبل خزاعی و صنایع جانبی آن بررسی گردید. انرژی مستقیم مصرفی به ازای هر مترمکعب نئوپان تولیدی 829/5 گیگاژول محاسبه شد که گاز طبیعی، برق و سوخت دیزل به‌ترتیب 52/78، 87/18 و 61/2 درصد آن را تشکیل می‌دهند. پیت و خرده چوب‌های حاصل از ضایعات کارخانه نئوپان‌سازی، برگ و پوشال نیشکر، باگاس مازاد و ویناس حاصل از تولید الکل از ملاس نیشکر به‌عنوان ضایعات جهت تولید انرژی در نظر گرفته شدند. خاکستر، رطوبت، ارزش حرارتی خالص (با استفاده از بمب کالری‌متر) و مقدار ضایعات خشبی و همچنین پتانسیل تولید زیست‌گاز از تخمیر بی‌هوازی ویناس اندازه‌گیری و محاسبه شد. نتایج نشان داد با استفاده از پسماند خشبی کارخانه نئوپان‌سازی و کشت و صنعت دعبل خزاعی می‌توان 33/4 برابر کل انرژی گاز مصرفی در کارخانه نئوپان‌سازی انرژی حرارتی با بازده 60 درصد تولید کرد. همچنین با استفاده از ضایعات کارخانه نئوپان‌سازی و باگاس، می‌توان کل گاز و برق مصرفی کارخانه نئوپان‌سازی را جایگزین کرد. بررسی حجم ویناس و پتانسیل تولید زیست‌گاز از آن نشان داد پتانسیل تولید انرژی معادل ‌8824319 مترمکعب گاز طبیعی در سال وجود دارد.

Potential Assessment of Energy Providing for Bagasse-Based Chipboard Industry Using Sugarcane Waste (A case study: Debal Khozaie Agro-Industry)

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 byproduct 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 agroindustry 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 agroindustries. 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 agroindustries 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 AgroIndustry Company. Data were collected from agroindustry 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 agroindustry. Potential of energy generation from bagasse, pith, wood chips, and straw in Debal Khozaie agroindustry, were considered by the direct burning method. Also, the potential of biogas production from vinasse in agroindustry 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 m3 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 molassesbased 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 AgroIndustry 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 m3. 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 agroindustry 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 agroindustry has the potential to replace the entire natural gas and electricity consumption in chipboard factory.