| ABSTRACT This paper is a series research of "Research on Small and Medium System of Photobiological Hydrogen Production from Solar Energy and Production Run" supported by national "863"(No.2004AA515010)and the fund of doctor subject for scientific research projects(No.20060466001).Photobiological hydrogen productionPhotobiological hydrogen production is the biological method for hydrogen production.By this way,hydrogen is produced in mild conditions of metabolization of photosynthetic bacteria under normal temperature,normal pressure and illumination. It can combine with waste utilization,solar energy translation and pollution treatment. Photobiological hydrogen production was thought being the best way to solve lack of energy resources and pollution of environment,being most potential for development and application.It is important to realize industry biological hydrogen production that providing stable and applicable production equipment.Photobioreactor is the key part in system of photobiological hydrogen production.It is the key equipment in biological hydrogen production.Considering there are only labware and small equipment for experiment before,this paper studied larger scale photobioreactor for continuous photobiological hydrogen production,in which the experiments of batch culture hydrogen production and continuous culture hydrogen production were carried out. This paper studied the transmission process of the main energy types--heat energy and light energy in photobioreactor during photobiological hydrogen production.The best way of heat energy transmission and control was found.The approach of saving energy was obtained.Calculation of heat balance of this kind of bioreactor was determined.The way of calculation of light transfer was advanced,meanwhile the data of light illumination were measured,and main approaches of improving light conversion efficiency were indicated.Results of studies show that the energy use can reduce and light conversion efficiency sees outstanding improvement when reasonable energy arrangement and utilization were made in the circumfluence cylindrical photobioreactor designed in this paper. Main research results of this paper as following:1.A novel circumfluence cylindrical 31.07L photobioreactor for photobiological hydrogen production is made successfully,by design,calculation and research on structure,style,operation pattern,substrate medium transmission and mix,light energy collection and transmission,heat exchanger and temperature control and so on.The bioreactor is made as cylindrical standing can with conic bottom,in which four transparent sleeves are installed to settle optical divider.Circumfluence circulation mode is employed for avoiding leak of gas caused by inside stirrer, which sharply reduce the damage for cell caused by mechanical stir or airlift loop. Instead of double walls or coil,heat exchanger of the bioreactor is settled on the way of circulation pipe,which combines circulation mix and heat exchange of reaction liquid.The temperature of reaction liquid is controlled while it is mixed, by this way,the manufacture price is lower and the volume of bioreactor is smaller. The use of artificial intelligence technique-fuzzy logic theory in temperature adjustment of heat exchanger solved the problems that building mathematics model is difficult and temperature adjustment is slow,as reaction mechanism complex, multi influential factors,time-varying factors in biological reaction process, utilized the energy that can use,reduced the energy expenditure and running cost. In order to increase solar light energy conversion efficiency,efficient solar energy focused and transmission equipment is employed,which is made of solar energy focusing and collecting implements,light filter,optical fiber,optical divider and so on.The use of them transmits the light that is in the same co-operating spectrum band whit photosynthetic bacteria absorption spectrum into the deep place of bioreactor,which efficiently increased the light density in deep layer and improved the solar energy utilization ratio.All that can afford reliable experimental data, technical parameters and scientific reference value to the design of medium-scale bioreactor of photobiological hydrogen production from solar energy of the photobiological hydrogen production.2.Batch and continuous hydrogen production experiments were carried out in the 31.07L photobioreactor with the immobilized photosynthetic bacteria group, pre-treatment swine manure as reaction liquid.Following results were reached:in batch process,with initial 5130 mg·L-1COD reaction liquid,pH value of reaction liquid kept between 5.6 and 6.8 without adjustment,illumination measured range:1840.2 lx～3012 lx continuously,reaction liquid temperature kept between 29℃and 33℃,hydrogen production lasted 96h in higher rate.The average and highest of hydrogen production rate were 484.7ml/L·d and 877.4ml/L·d respectively,as well as hydrogen production rate of COD was 171.4mlH2/gCOD·d, hydrogen conversion efficiency of substrate medium was 68.4%.In continuous process,with initial 5216 mg·L-1COD reaction liquid,supplied substrate medium COD range:5000 mg·L-1～5500 mg·L-1.PH value of reaction liquid rose to keep between 6.3 and 6.5 from 5.6 without adjustment,illumination measured range: 1557.8 lx～3079.9 lx continuously,reaction liquid temperature kept between 29℃and 33℃.The experiment lasted 69d,while stable hydrogen production lasted 63d, the highest of hydrogen production rate was 722.6ml/L·d,the average hydrogen production rate was 633.1ml/L·d during stable hydrogen production.Meanwhile hydrogen production rate of COD was 172.9ml/gCOD·d,hydrogen conversion efficiency of substrate medium was 61.7%.The experiment results show that the novel circumfluence cylindrical photobioreactor is reasonable and practical for photobiological hydrogen production,which can afford high scientific reference value to the larger scale experiment and application in circumfluence cylindrical photobioreactor,and Technology optimization of the photobiological hydrogen production.3.The transmission process of the heat energy in photobioreactor during photobiological hydrogen production was studied basing on the experimental data. Calculation formula of heat balance of this kind of bioreactor was determined.The main influential factors in calculation formula were studied and analyzed by experiment and calculation.In addition,the best way of heat energy transmission was found.4.In order to increase light energy conversion efficiency,the transmission process of the light energy in photobioreactor during photobiological hydrogen production was studied.The approach of light energy calculation was presented,the higher light energy conversion efficiency in the course of batch and continuous hydrogen production experiments was reached as 10.85%and 14.55%respectively basing on the experimental data,which showed that by using the technique of solar light collection,light filter,light transmission,light division,light supplement and so on, the light on the surface can be efficiently used,and light energy conversion efficiency can increase sharply.
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