HYDROGEN PRODUCTION BY ETHANOL STEAM REFORMING: THERMODYNAMIC ANALYSIS AND REACTOR MODELING

Abstract

It has been estimated that fossil fuels will be fully exhausted by the end of this century. Hence alternatives for them have been searched which includes mainly renewable source of energy such as solar energy, geothermal energy etc. Among these alternatives hydrogen may prove to be the solution of world energy crisis as it is a non-polluting source of energy and can be produced from renewable sources. These renewable sources may be ethanol or methanol. In the present study ethanol is considered for hydrogen production due to advantages associated with it such as nontoxic, nonpolluting, easy to transport etc. In the present study ethanol steam reforming has been done with objective to maximize the hydrogen production. To determine the conditions at which maximum hydrogen production occurs, thermodynamic analysis has been done. Based on this following operating condition has been chosen to operate reactors. Temperature=903 K for Membrane and fixed bed reactor, Pressure= 1 bar for FBR and 2 bar for MR at reaction side and steam to ethanol ratio in feed has been taken equal to 13 because Raw bio ethanol which obtains from fermentation contains this much amount of water. One dimensional model has been simulated using Ni based catalyst. Catalyst is assumed to be packed in tube side in the Pd membrane. Mathematical model was a set of first order ordinary differential equation which was solved using solver tool in MATLAB along with above aforementioned operating conditions and following results have been obtained in isothermal membrane reactor. Conversion=>99%, yield=94%, selectivity=73.8%, Recovery of hydrogen=64% of total hydrogen produced.