Fed-Batch Fermentation for Acetone-Butanol-Ethanol Production and Recovery by Pervaporation

Title
Fed-Batch Fermentation for Acetone-Butanol-Ethanol Production and Recovery by Pervaporation
Authors
러셀
Keywords
fedbatchfermentationforacetonebutanolethanolproductionandrecoverybypervaporation
Issue Date
2011
Publisher
인하대학교
Abstract
Butanol has been considered as a potential substitute for gasoline. The search for renewable sources of energy has led to renewed interests in the biochemical route for production of butanol (biobutanol) which alongside produces acetone and ethanol. Batch-wise production of bio-butanol suffers from several drawbacks such as low product concentration and productivity due to product inhibition to the butanol producing microorganism. Process engineering of the ABE fermentation process along with in-situ recovery of ABE could deal with these challenges. Among the in-situ recovery option membrane processes such as pervaporation have great potential. In this work, fed-batch fermentation is utilized along with cell (Clostridium acetobutylicum ATCC 824) immobilization by calcium alginate. Fed-batch fermentation using free cells did not improve product concentration. The use of immobilized cell coupled with fed-batch fermentation improved product concentration by 50% and productivity by at least 100%. As for the recovery of ABE, pervaporation experiments were conducted using model solutions. The effects of temperature, feed concentration, and ultrasound irradiation on permeate concentration and flux of pervaporation for recovery of n-butanol/ABE from aqueous solutions using a silicone rubber tubing were investigated. Temperature (50 ˚C, 60 ˚C and 70 ˚C) and n-butanol feed concentration (5, 10, 20 g/L) were varied for the investigation while ABE concentration was fixed at 10 g/L butanol in an ABE mixture with ratio of 3:6:1. In the n-butanol-water system, permeate n-butanol concentration as well as flux increase with increase in temperature and n-butanol feed concentration. As for the effect of ultrasound irradiation, the permeate n-butanol concentration and n-butanol flux was enhanced by as much as 18% and 35% respectively. Pervaporation studies with ABE-water mixture were carried out at 50, 60, and 70 ˚C for 2, 4, 6, and 8 hours. Butanol and ABE mass flux increased with
Description
1. INTRODUCTION. 1 1.1. Development of ABE Fermentation 2 1.1.1 History 2 1.1.2 Revival of ABE Fermentation Plants. 2 1.2 Butanol Producing Microorganisms. 2 1.3 ABE Fermentation by C. acetobuylicum. 3 1.4 Problems in ABE fermentation. 4 1.5 Modes of ABE Fermentation. 4 1.5.1 Batch4 1.5.1 Fed-Batch. 4 1.5.2 Continuous. 4 1.5.3 1.5.1 Contiuous Stirred Tank Reactor 4 1.5.4 1.5.2 Plug Flow Reactor 5 1.6 Cell Immobilization 5 1.6.1 Entrapment. 5 1.6.2 1.6.1.1 Entrapment by Calcium Alginate 6 1.7 Butanol/ABE Recovery. 6 1.7.1 Pervaporation.7 1.7.1.1 Mechanism 7 1.7.2 Membrane Selection . 7 1.8 Ultrasound Irradiation/Sonication. 7 1.8.1 Classification. 8 1.8.2 Mechanism of Action. 8 1.8.2.1 Mechanical Effect 8 1.8.2.1 Vibration Effect 8 1.8.2.2 accoustic Streaming Effect. 8 1.8.2.2 Thermal Effect. 9 1.8.2.3 Chemical Effect/Cavitation 9 1.9 Applications of Ultrasound Irradiation. 9 2. OBJECTIVES. 10 3. METHODOLOGY. 11 3.1. Pervaporation Studies. 11 3.1.1. Butanol-Water Mixture. 11 3.1.2. ABE-Water Mixture 11 3.2. Fermentation Studies. 11 3.2.1. Batch 12 3.2.2. Fed-batch 12 3.2.2.1 Suspended Cells 12 3.2.2.2 Calcium Alginate Immobilized Cells 12 3.2.3. Fermentation media 12 3.2.4. Immobilization by Calcium Alginate 13 3.2.4.1 Alginate Solution 13 3.2.4.2 Crosslinking Solution 13 3.3 Analysis. 13 3.3.1 GC Analysis. 13 4. RESULTS AND DISCUSSIONS 14 4.1 Pervaporation Studies. 14 4.1.1 Butanol-Water Mixture 14 4.1.2 ABE-Water Mixture. 16 4.2 Fermentation Studies. 23 4.1.1 Free C. acetobutylicum Cells 23 4.1.1.1 Batch. 23 4.1.1.2 Fed-batch 25 4.1.2 Calcium Alginate Immobilized Cells 26 4. CONCLUSIONS 31 5. REFERENCES 32 Figure 1 Plot of Permeate concentration of butanol vs. temperature 17 Figure 2 Plot of amount of butanol vs. temperature. 18 Figure 3 Total mass concentration Profile 20 Figure 4 Flux Profile 21 Figure 5 Percent Recovery Profile 22 Figure 6 Batch Fermentation 24
URI
http://dspace.inha.ac.kr/handle/10505/22852
Appears in Collections:
College of Natural Science(자연과학대학) > Ocean Sciences (해양과학) > Theses(해양과학 석박사 학위논문)
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