Hydrogen production by aqueous phase catalytic reforming of glycerine

Biodiesel is one of the alternative and renewable fuels used to meet the increasing energy demand. Considering the natural cycle, CO2 emission of biodiesel is much lower than the petro diesel. Glycerine is a by-product which is obtained during biodiesel process. 10 wt % of the oil converts to glycerine during biodiesel process employing vegetable oils and fats. If biodiesel is produced in large quantities, also glycerine will be produced in large amounts, therefore it is important to find useful application area at the word market for glycerine.Glycerine is a potential feedstock to produce hydrogen. Hydrogen can be obtained from glycerine via steam reforming (SR) or aqueous-phase reforming (APR) methods. External energy supply at APR becomes much lower than SR because APR is carried out at lower temperatures. Since the temperature employed is also suitable for water gas shift reaction, it is possible to have lower CO concentrations in one reactor. According to APR, seven moles of hydrogen can be produced from one mole of glycerol.The main objective of this research is to convert glycerol to hydrogen in the medium of Pt/Al2O3 catalyst via APR. The effect of temperature on APR was carried out in an autoclave reactor and the effects of feed flow rate and feedconcentration were carried out in a continous system. The effects of reaction temperature (160-280oC), feed flow rate (0.05- 0.5 mL/dak) and feed concentration (5-85 % wt glycerine) on product distrubution were investigated. It was shown that when temperature was increased in the interval mentioned, hydrogen composition decreased from 71 % to 44 %, CO2 and other hydrocarbons? concentrations increased. Maximum gas production rate was found at feed flow rate around 0.1 mL/min. It was also found that when glycerol concentration decreased, hydrogen composition and gas production rate increased.