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Acetone–butanol–ethanol–water mixture is obtained by fermentation of biomass namely, corncob, wheat straw, sugarbeets, sugarcane, etc. For using the individual components, one alternative is to separate the mixture by distillation, which is costly and energy intensive operation. This paper proposes its other use in available conditions to produce hydrogen fuel by oxidative steam reforming process. For the proposed process, thermodynamic equilibrium modeling has been performed by using non-stoichiometric approach of Gibbs free energy minimization. The compositions of acetone, butanol and ethanol in mixture are 0.33:0.52:0.15 on molar basis. The influence of pressure (1–10 atm), temperature (573–1473 K), steam to ABE mixture molar feed ratio (FABE = 5.5–8.5), and oxygen to ABE mixture molar feed ratio (FOABE = 0.25–1) have been tested by simulations on the yield of products (at equilibrium) namely, H2, CH4, CO2, CO, and carbon as solid. The optimum conditions for maximum production of desired H2, minimization of undesired CH4, and elimination of carbon (solid) formation are T = 973 K, P = 1 atm, FABE = 8.5, and FOABE = 0.25. Under same operating conditions, the maximum generation of H2 is 7.51 on molar basis with negligible carbon formation. The total energy requirement for the process (295.73 kJ/mol), the energy required/mol of hydrogen (39.37 kJ), and thermal efficiency (68.09%) of the reformer have been obtained at same operating conditions. The exergy analysis has also been investigated to measure the work potential of the energy implied in the reforming process. [ABSTRACT FROM AUTHOR]

Recently, hydrogen is utilized by numerous chemical industries as an alternate over non-renewable fuels, and surely it will be considered as an important fuel in the near future. This paper reports a review of various reforming technologies for hydrogen production from butanol produced by fermentation of feedstocks like wheat, sugar beets, sugar cane, etc. with a number of aspects involving selection of an appropriate catalyst to suppress undesirable products as many reforming reactions are dependent on the catalyst properties to enhance the formation of significant fuels which may fulfill the future energy needs. An overview of butanol reforming processes with experimental and theoretical studies in order to grasp possibilities and restrictions of these processes is not comprehensively presented yet. In this paper, an assessment of published articles in brief related to essential parameters to carry out a pertinent research in the future is presented for the advancement of fuel processing technologies. [ABSTRACT FROM AUTHOR]

Exact analytical solutions for the temperature profile and the efficiency of a nonlinear rectangular fin model have been obtained in the forms of well-known algebraic/non-algebraic functions. In the considered nonlinear fin model, the thermal conductivity and the heat transfer coefficient have been assumed to vary as distinct power-law functions of temperature thereby yielding a nonlinear BVP in a 2nd order ODE (ordinary differential equation). These exact solutions have been obtained by employing the derivative substitution method which not only include the solutions of previously studied simplified cases of the same problem but also the solutions of a similar problem of reaction-diffusion process occurring in a porous catalyst slab. These exact solutions have been successfully validated against their numerical counterparts. Besides, effects of various parameters on the obtained solutions have been studied, and the conditions for their existence, uniqueness/multiplicity and stability/instability are analyzed and discussed in detail. [ABSTRACT FROM AUTHOR]

Hydrogen production by oxidative steam reforming of methanol in a fixed bed catalytic reactor was modeled and simulated. The addition of O2 to feed reduced the temperature in the reformer. 99.86% conversion was obtained at 550 K and S/C molar ratio of unity in steam reforming while it is at 540 K in oxidative steam reforming. Although H2 and CO yields were decreased in oxidative steam reforming in comparison to steam reforming, the reductoin H2 yield was note significant whereas reduction in CO was appreciably high. The thermal and exergy efficiencies were favored by reforming temperature and S/C molar ratios. However, variation in S/C molar ratio showed negligibly small effect on efficiencies. The reforming temperature had a notable influence on the efficiencies. The exergy destruction was found to be lower at higher temperature and S/C molar ratio. Thus, oxidative steam reforming of methanol at 540 K and S/C molar ratio of unity utilizes sufficient amount of input energy in the form of useful work and thermodynamic irreversibilities in the reactor are quantitatively small. [ABSTRACT FROM AUTHOR]