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A thermodynamic equilibrium analysis on steam reforming process to utilize acetone-butanol-ethanol-water mixture obtained from biomass fermentation as biorenewable fuel has been performed to produce clean energy carrier H 2 via non-stoichiometric approach namely Gibbs free energy minimization method. The effect of process variables such as temperature (573–1473 K), pressure (1–10 atm), and steam/fuel molar feed ratio ( F ABE  = 5.5–12) have been investigated on equilibrium compositions of products, H 2 , CO, CO 2 , CH 4 and solid carbon. The best suitable conditions for maximization of desired product H 2 , suppression of CH 4 , and inhibition of solid carbon are 973 K, 1 atm, steam/fuel molar feed ratio = 12. Under these conditions, the maximum molar production of hydrogen is 8.35 with negligible formation of carbon and methane. Furthermore, the energy requirement per mol of H 2 (48.96 kJ), thermal efficiency (69.13%), exergy efficiency (55.09%), exergy destruction (85.36 kJ/mol), and generated entropy (0.29 kJ/mol.K) have been achieved at same operating conditions. [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]

The butanol-ethanol (B–E) mixture with water, obtained from ABE (Acetone-Butanol-ethanol) fermentation, is utilized as a renewable biofuel for the production of clean energy carrier hydrogen by steam reforming process (SRB–E). The thermodynamic analysis of steam reforming process for B–E mixture is carried out by Gibbs free energy minimization method. The thermal and exergy efficiencies for the process are investigated to exploit the potential of B–E mixture for hydrogen production. For performance evaluation, the variational trends of moles of products (H 2 , CO, CO 2 , CH 4 , and carbon) are studied at equilibrium as a function of temperature (573–1473 K), pressure (1–10 atm), steam/fuel molar feed ratio (0–12) for composition of B–E mixture (50 to 90% B). For mixture (90% B), the maximum production of H 2 (9.555 mol per mol of fuel) is achieved at 973 K temperature, 1 atm pressure, molar feed ratio of 12. Methane and carbon formation are negligible at high temperature (>873 K) and molar feed ratio (>5) for all B–E compositions. Energy required per mol of H 2 is 50.77 kJ/mol for mixture (90% B) and is lower than that for steam reforming of butanol. The thermal efficiency is 70.071%, close to maximum for mixture (90% B), which is higher than butanol (69.885%), and ethanol (68.491%). For 90% B mixture, exergy efficiency (48.582%) is also comparable with that of butanol (48.693%) and ethanol (46.145%). This study proposes an economic process for hydrogen production via steam reforming of B–E mixture directly. [ABSTRACT FROM AUTHOR]

Abstract: Analysis of a fuel processor based on methanol steam reforming has been carried out to produce fuel cell grade H2. Six reactor configurations namely FBR1 (fixed bed reactor), MR1 (H2 selective membrane reactor with one reaction tube), MR2 (H2 selective membrane reactor with two reaction tubes), FBR2 (FBR1+preferential CO oxidation (PROX) reactor), MR3 (MR1+PROX), and MR4 (MR2+PROX) are evaluated by simulation to identify the suitable processing scheme. The yield of H2 is significantly affected by H2 selective membrane, residence time, temperature, and pressure conditions at complete methanol conversion. The enhancement in residence time in MR2 by using two identical reaction tubes provides H2 yield of 2.96 with 91.25mol% recovery at steam/methanol ratio of 1.5, pressure of 2bar and 560K temperature. The exit retentate gases from MR2 are further treated in PROX reactor of MR4 to reduce CO concentration to 4.1ppm to ensure the safe discharge to the environment. The risk of carbon deposition on reforming catalyst is highly reduced in MR4, and MR4 reactor configuration generates 7.4NLmin−1 of CO free H2 from 0.12molmin−1 of methanol which can provide 470W PEMFC feedstock requirement. Hence, process scheme in MR4 provides a compact and innovative fuel cell grade H2 generating unit. [Copyright &y& Elsevier]

The paper aims to investigate the steam reforming of biogas in an industrial-scale reformer for hydrogen production. A non-isothermal one dimensional reactor model has been constituted by using mass, momentum and energy balances. The model equations have been solved using MATLAB software. The developed model has been validated with the available modeling studies on industrial steam reforming of methane as well as with the those on lab-scale steam reforming of biogas. It demonstrates excellent agreement with them. Effect of change in biogas compositions on the performance of industrial steam reformer has been investigated in terms of methane conversion, yields of hydrogen and carbon monoxide, product gas compositions, reactor temperature and total pressure. For this, compositions of biogas (CH 4 /CO 2 = 40/60 to 80/20), S/C ratio, reformer feed temperature and heat flux have been varied. Preferable feed conditions to the reformer are total molar feed rate of 21 kmol/h, steam to methane ratio of 4.0, temperature of 973 K and pressure of 25 bar. Under these conditions, industrial reformer fed with biogas, provides methane conversion (93.08–85.65%) and hydrogen yield (1.02–2.28), that are close to thermodynamic equilibrium condition. • A model for an industrial reformer for steam reforming of biogas (SRB) developed. • Preferable process feed conditions are P = 25 bar, T = 973 K, S/C = 4 and heat flux = 65 kW/m2. • An existing industrial reformer for steam reforming of methane can be used for SRB. • Performance of industrial reformer is close to that achieved at equilibrium. • The study provides the guidelines for industrial steam reforming of biogas (SRB). [ABSTRACT FROM AUTHOR]