بررسي پتانسيل توليد بيوگاز از ضايعات نخل خرما با پيش‌فرآوري‌هاي مختلف قليايي

Global energy deman‎d has been growing at an increasing rate since the Industrial Revolution in the 18th century. At the same time, fossil fuel resources are rapidly decreasing, which has led to an increase in the price of energy from fossil fuels. Therefore, one of the most important concerns of industrialized countries is to provide the energy needed for the future. Also, in recent years, the excessive use of fossil fuels has caused climate change, water an‎d soil pollution, an‎d the emission of greenhouse gases such as carbon dioxide an‎d methane into the atmosphere. These problems have caused countries to seek alternative fuels. One of these alternative fuels is biogas, which is obtained from biomass sources. In order to achieve the best biogas production potential an‎d break the regular an‎d dense lignocellulosic structure of palm oil waste, preprocessing should be used. Alkaline preprocessing is one of the most effective methods for preprocessing lignocellulosic materials. This method modifies the structure of lignocellulosic materials by increasing the contact surface, reducing the crystallinity of cellulose, an‎d removing hemicellulose an‎d delignification. The effect of the efficiency of this pretreatment is highly dependent on the conditions of its implementation, such as temperature, concentration, an‎d pretreatment time, as well as the structure of the lignocellulosic material. In this project, the effect of alkaline pretreatment on date palm waste (leaf an‎d trunk mixture) was investigated to improve methane production in the anaerobic digestion process. . Anaerobic digestion was performed using a microbial mixture prepared from the North Isfahan Treatment Plant an‎d the rumen of a cattle from Shahreza Veterinary Hospital. All experiments were performed in 118 ml reactors an‎d in the laboratory phase. Alkaline pretreatment was performed with sodium hydroxide, potassium hydroxide, an‎d calcium hydroxide solutions of 8% an‎d 1% by weight at temperatures of 0, 60, an‎d 120 degrees Celsius for one hour, an‎d hot water pretreatment was performed at 100 degrees Celsius for one hour. The best efficiencies in biogas production were obtained from alkaline pretreatment with sodium hydroxide an‎d potassium hydroxide with similar conditions of 8% at 60 °C, respectively, increasing methane production by 70% (208 mL CH4/gr VS) an‎d 66% (203 mL CH4/gr VS), an‎d pretreatment with hot water by 32% (162mL CH4/gr VS). Based on environmental issues an‎d solids recovery rate, pretreatment with potassium hydroxide (8% an‎d 60 °C) was selec‎ted as the optimal an‎d best pretreatment, an‎d most of the applied pretreatments yielded acceptable results. Pretreatment with 8% by weight sodium hydroxide solution at 120 °C produced less methane than the unpretreated state, indicating excessive lignocellulose removal, with a recovery rate of 52%.

علي اكبر دادخواه

حميد زيلوئي

محمد هادي جزيني , اسماعيل مهريار