بررسي پتانسيل توليد بيوگاز و بيو هيدروژن از ضايعات گياه پنبه با پيش فراوري قليايي

چكيده انگليسي :

94 Investigation of Biogas and Biohydrogen Production Potential from Cotton Waste with Alkali Pretreatment Mohsen Ghasemian mohsen ghasemian@ce iut ac ir Date of submission June 21 2014 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language PersianSupervisor Hamid Zilouei hzilouei@cc iut ac irAbstractFossil fuels are source of non renewable energy and also have seriously negative impacts on the environment e g soil water air and climates These problems are caused to serious attention in use of renewable energyresources by many countries Regarding this matter using the energy from biomass sources such as biogas andbiohydrogen is one of the best options Annual production of 33 million tones cotton in the world in 2012 isassociated with production of huge amounts of cotton plant wastes In current study potential of biogas andbiohydrogen production from cotton plant wastes cotton stalk and boll was investigated In order to improveyield of biogas and biohydrogen production alkaline pretreatment was performed with 8 sodium hydroxidesolution by weight at 0 C and 100 C for 10 30 and 60 minutes and with 4 and 8 ammonia solution byweight at 40 C and 80 C for 6 and 12 hours Anaerobic digestion process was performed with mixed cultureobtained from Isfahan North Wastewater Treatment sludge at mesophilic conditions at 37 C Prior tobiohydrogen production experiments mixed culture was thermally pretreated at 85 C for 45 minutes to removehydrogen consuming bacteria According to the results 80 8 and 88 5 mL CH4 g VS was produced fromuntreated cotton stalk and boll respectively More biogas was produced from pretreated samples except for theboll pretreated by 8 wt sodium hydroxide at 0 C for 60 min and the boll pretreated by 8 wt ammonia at 40 Cfor 6 h compared to untreated ones The maximal biogas production of 246 4 mL CH 4 g VS 78 3 of thetheoretical value of methane production was achieved from the boll pretreated by 8 wt sodium hydroxidesolution at 100 C for 10 min Furthermore this pretreatment method led to the highest reduction in lignin content 31 and the highest increase in glucan content 21 7 Prolongation of sodium hydroxide at both temperatures 0 and 100 C resulted in reduction of methane production while more increment in methane production wasachieved by performing the pretreatment at higher temperature compared to lower temperature In addition thebest result by ammonia pretreatment of boll was obtained at the pretreatment condition of 4 wt ammoniaconcentration and 80 C for 12 h Increasing the temperature of ammonia pretreatment of boll at both ammoniaconcentrations 4 and 8 wt resulted in more methane production The highest methane production of 219 mLCH4 g VS 76 6 of the theoretical value of methane production was obtained from cotton stalk by 4 wtammonia solution treatment at 80 C for 12 hours whereas performing the pretreatment at lower temperatureproduced methane with lower yield In addition the best result by sodium hydroxide pretreatment of cotton stalk 205 4 mL CH4 g VS was obtained at the pretreatment condition of 8 wt sodium hydroxide concentration and0 C for 60 min while lower methane was produced from sodium hydroxide pretreated cotton stalk at highertemperature Amount of methane in produced biogas from pretreated materials was 54 61 in term of volume Samples accompanied with the highest methane production were used to hydrogen production Once again sodium hydroxide pretreated boll at the same conditions which led to maximum methane production caused themaximal hydrogen production of 17 mL per gram of volatile solids The highest hydrogen production of 15 2 mLper gram of volatile solids was achieved by 4 wt ammonia solution treatment The results of the hydrogenproduction in this study showed satisfactory agreement with Gompertz equation which is a kinetic model fordescribing substrate decomposition and biohydrogen production by batch method relative to the time Cryst

قاسميان، محسن

بررسي پتانسيل توليد بيوگاز و بيو هيدروژن از ضايعات گياه پنبه با پيش فراوري قليايي

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