| Summary: | 碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程所 === 90 === The Effects of pH and mixing level in a Completely Stirred Reactor on Anaerobic Hydrogen Production for Wheat Dregs
Student：Cheng-Wei-Wang Advisors：Jiunn-Jyi-Lay
Department of Safety Health and Environmental Engineering
National Kaohsiung First University of Science and Technology
ABSTRACT
Biomass energy is a widely available and can be regenerated in nature. Hydrogen is a clean form of alternative energy because it cause less pollution and emits less green house gases. Hydrogen can be produced by many ways. Among those, the microbial hydrogen production receives greatest attention. The microbial process is to use microorganisms to convert organic substrate into hydrogen gas and can reduce organic fractions in the waste. Biohydrogen can be produced through anaerobic digestion and photosynthesis. Among many anaerobic hydrogen producing microorganisms, clostridium sp. has the greastest potential. Because clostridium sp. havs spores.
In the anaerobic digestion process, hydrogen is an intermediate product during the metabolish of bacteria. Many environmental factors such as pH, rotational speed, temperature affects the direstions of the metabolic pathways toward the production of hydrogen, acids or alcohols.
The purpose of this study is to investigate the effects of pH and rotational speed on biohydrogen production. The experiment is composed of pre-test and batch test which is to investigate the effects of pH and mixing level on anaerobic hydrogen production for wheat dregs.
The system is operated in 4 consequent sets. Each set is controlled at 4 different pH, 5, 5.5, 6 and 6.5 respectively. There are 6 runs of rotational speed at 20, 45, 75, 100, 125, 150 rpm for each pH and the Reynolds number are 1996、4319、7360、8807、10529、12375. There are 24 runs in this study.
The quadratic mpdels are developed for specific hydrogen producing potential (Ps), specific hydrogen producing rate (Rs), and lag-phase time (λ). By using the methods of response surface method, the optimal pH value and rotational speed are found to be pH=6,rotational speed 100 rpm respectively. The corresponding Ps, Rs and λ are 20.4 (mL H2/g TVS)、214 (mL H2/g TVS/day) and 9.4 hours.
Keyword：mixing level、 pH、anaerobic digestion、hydrogen
|
|---|
