Study On Optimization Of Hydrogen Production Conditions And Immobilization

With the development of economy,people in the whole world pay more and more attention to energy scarcity and environmental pollution.Developing new energy system is being arranged by most of main countries.Hydrogen has been considered as one of the most ideal future energy,because it is clean,pollution-free, high heat value and can be stored and transported very easily."Hydrogen economy" is becoming an important part of economic development for many countries.In this research,we figured out some common rules influence the activity of the hydrogen production(e.g.nitrogen source,carbon sources,glucose concentration, initial pH,temperature).The results of single-factor test of Klebsiella oxytoca HP1 suggests that:(1) carbon source is more important than nitrogen source in hydrogen production;(2)(NH₄)₂SO₄(2g/L) and peptone(1g/L) is chosen as the nitrogen source; (3) glucose is the best carbon source among different carbon sources in hydrogen production;(4) rotate rate 100r/min is choosen in the study.Using orthogonal test optimizes the conditions above,and finally it indicates that the ideal hydrogen production condition should be:glucose concentration 10 g/L,pH 8.0 and the temperature 37℃.Klebsiella oxytoca HP1 can be immobilized by agar,alginate,PVA and glutin. Alginate is the best immobilization material for Klebsiella oxytoca HP1 cells and it keeps the activity of hydrogen production and has good biological compatibility. Na₂HP0₄-KH₂P0₄ and citric acid can break down the Ca-alginate gel beads,but Tris don't,so Tris is the best buffer and we figure out that the best concentration is 5 g/L in the study.The best immobilization temperature for hydrogen production of Klebsiella oxytoca HP1 is the same to mobilization temperature,however,the best immobilization pH for hydrogen production of Klebsiella oxytoca HP1 is not the same. The main reason is that we use the Tris instead of the K₂HP0₄-NaH₂P0₄ in the study. The result of immobilization test of hydrogen production suggests that:initial immobilization pH 9.0,immobilization temperature 37℃,rotate rate 150r/min is the best ideal hydrogen production condition.When the Ca-alginate gel beads are applied for continuous hydrogen production, under the conditions:initial sugar concentration 10 g/L,initial pH 9.0,HRT 2h, temperature 37℃,the average rate of hydrogen production is achieved as 33.8 mmol/L·h,during a 7-day continuous hydrogen production.