توليد بيوهيدروژن و بيوگاز از كاه برنج با استفاده از پيش‌فرآوري قليايي و فتوكاتاليست نانودي‌اكسيد تيتانيوم

چكيده انگليسي :

Biohydrogen and Biogas Production from Rice Straw using Alkaline Pretreatment and Nano Titanium Dioxide Photocatalysis Ramin Shafieepoor r shafieepoor@ce iut ac ir June 19 2017 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Hamid Zilouei hzilouei@cc iut ac irAbstractNowadays ever increasing consumption of fossil fuels due to populate as well as industrialgrowth has led to serious ecological threats due to excessive emission of greenhouse gasesand pollutants Therefore using renewable recources as alternative for fossil fuels has beenchosen as an important and interesting strategy in recent years Biomass is among the cleanestand least expensive choice of renewable recources which has been the subject of manyresearches during last years Rice straw is one of the most frequent lingocellulosic cropresidues which is plentiful in Asian countries especially Iran and case a lot of environmentalproblems after harvesting the rice for the farm The problem with using rice straw like otherlingocellulosic feed stocks is its structural solidity due to lateral bonds between cellulose hemi cellulose and lignin To further expedite anaerobic digestion and dark fermentation bymicroorganisms it is necessary to destruct the crystalline structure through variouspretreatment methods In this study the effect of alkaline pretreatment via sodium hydroxidefollowed by nano titanium dioxide photocatalysis on rice straw was performed in order toincrease biohydrogen and biogas yield through dark fermentation and anaerobic digestion Anaerobic sludge was used as inoculum for anaerobic digestion while heat shocked 15 minat 95 C pretreated sludge was used for dark fermentation Rice straw was first pretreatedusing 3 concentrations of NaOH 0 2 4 w v at three temperatures 30 60 90 C Thepretreated rice straw was further hydrolyzed using three concentrations of TiO2 0 0 01 0 1 w v under UV irradiation for two time durations 30 60 min Dark fermentation wasperformed for 4 days and hydrogen in gas phase and volatile fatty acids VFAs in liquidphase were analyzed Consecutive production of biogas was studied by addition of anaerobicmicrobial inoculum to remain of the hydrogen fermentation All experiments were carried outin 118 ml dark bottles at 37 C for duplicates Quantitative investigations were done usingparameters of total and volatile solids analysis of biohydrogen and biogas concentration ofthe produced volatile fatty acids and combination percentage of carbohydrate and lignin insolid samples Qualitative comparison of samples was performed using scanning electronmicroscopy SEM pictures Total and cellulosic crystallinity were investigated using fouriertransform infrared spectroscopy FTIR and X ray diffraction XRD tests A significanteffect was observed in alkaline pretreatment followed by TiO 2 on rice straw as increasing thesurface availability and decreasing crystallinity as well as lignin removal The highestbiohydrogen production 86 ml g VS was occured in the sample pretreated with 4 NaOH at90 C followed by hydrolysis at 0 1 TiO2 for 60 min UV irradiation shows five foldenhancement compared to the non pretreated sample and two fold enhancement compared toabsence of TiO2 The highest amount of biomethane production 577 ml g VS was achievedin pretreatment with 0 NaOH at 30 C followed by hydrolysis at 0 1 TiO2 for 60 min UVirradiation which shows two fold enhancement compared to the non pretreated sample Keywords Biohydrogen Biogas Rice Straw Alkaline Pretreatment Nano Titanium Dioxide

شفيعي پور، رامين

توليد بيوهيدروژن و بيوگاز از كاه برنج با استفاده از پيش‌فرآوري قليايي و فتوكاتاليست نانودي‌اكسيد تيتانيوم

بيوهيدروژن , بيوگاز , كاه برنج , پيش‌فرآوري قليايي , نانودي‌اكسيد تيتانيوم