توليد اتانول زيستي از ماكروجلبك قهوه اي سارگاسوم آنگوستيفوليوم

چكيده انگليسي :

27 Bioethanol production from Sargassum angustifolium brown macroalgae Yasaman Ardalan y ardalan@ce iut ac ir 21 Jun 2017 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Dr Keikhosro Karimi karimi@cc iut ac ir Dr Mohammadhadi Jazini m h jazini@cc iut ac irAbstractDue to the reduction and concerns about the future of fossil fuels extensive research has been carried out todevelop renewable alternatives with less greenhouse gas emissions One of the renewable sources is bioethanol which can be produced from cellulosic biomass cultivated in water and soil Bioethanol production from algae isreferred to the third generation biofuels The benefits of this generation include the use of non edible sourceswith high production efficiency and no need for freshwater and fertile soil for their growth In this study Sargassum angustifolium macroalga was used as the raw material for bioethanol production This brown alga washarvested from Persian Gulf in summer and winter It contained appreciable amounts of alginate as a valuableingredient with many applications in various industries Also it composed of cellulose with different propertiesthan lignocellulosic plants that do not required complex pretreatment for efficient biological conversions Accordingly at first alginate was extracted from the alga which is a valuable byproduct of ethanol production This extraction process acted as a type of pretreatment for subsequent ethanol production Alginate extractionwas conducted with acid treatment 0 2 N hydrochloric acid followed by an alkaline extraction 2 w w sodiumcarbonate The amounts of sodium alginate obtained were 24 40 and 22 40 for the samples harvested insummer and winter respectively The corresponding rates of solid residue recovery in the extraction process were31 and 16 5 for the summery and wintery alga samples In order to evaluation the effect of alginate extractionfrom alga the solid residue from extraction and raw algal samples were subjected to enzymatic hydrolysis bycommercial cellulase cocktail Cellic CTec2 Extraction of alginates from alga increased the hydrolysis efficiencyfrom 32 3 to 53 2 percent and from 32 8 to 61 9 percent in summery and wintery alga respectively In order toproduce ethanol the raw algal samples and wastes from alginate extraction were subjected to non isothermalsimultaneous saccharification and fermentation using the Saccharomyces cerevisiae for ethanol fermentation Theresults showed that the summery algal samples produced 124 8 and 172 2 g kg ethanol where the winterysamples produced 148 4 and 187 2 g kg ethanol from raw algal and solid residue of alginate extraction process respectively The final step was replacement algal extract with yeast extract in the ethanol production process Algal extract was obtained in alginate extraction from the alga in two stages i e before and after alkalineextraction The two types of algal extracts were replaced with yeast extract and the ethanol production wasdetermined The use of wintery algal waste using the algal extract after alkaline extraction instead of yeastextract improved ethanol yield by 3 48 and the ethanol production increased to 197 20 g kg wintery algalwaste Key words Bioethanol Brown macroalgae Sargassum angustifolium Sodium alginate

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توليد اتانول زيستي از ماكروجلبك قهوه اي سارگاسوم آنگوستيفوليوم

اتانول زيستي , ماكروجلبك قهوه‌اي , سارگاسوم آنگوستيفوليوم , سديم آلژينات