Supercritical water gasification of biomass: thermodynamic analysis with direct Gibbs free energy minimization

Abstract A thermodynamic model is developed to estimate equilibrium composition for supercritical water gasification (SCWG) of biomass. With a local optima solver and a global optima solver of LINGO, the algorithm based on Peng–Robinson EoS formulations and direct Gibbs free energy minimization can guarantee the convergence to the correct solution. Results are given for the supercritical water processes including supercritical water reforming of methanol, supercritical water gasification of glucose, catalyzed supercritical water gasification of cellulose and supercritical water gasification of real biomass. Model predictions are compared with various experimental measurements and the agreement is generally satisfying and therefore the correctness of the proposed model is demonstrated. Significant improvements of the comparison are obtained by analyzing reaction network and controlling steps of these processes and accounting them into calculation.

[1]  R. J. Divilio,et al.  Biomass gasification in supercritical water , 2000 .

[2]  P. B. Butler,et al.  Methanol and hydrogen oxidation kinetics in water at supercritical states , 1996 .

[3]  R. Smith,et al.  Water gas shift reaction kinetics under noncatalytic conditions in supercritical water , 2004 .

[4]  Hedzer J. van der Kooi,et al.  Phase equilibria for biomass conversion processes in subcritical and supercritical water , 2004 .

[5]  L. I. Stiel,et al.  A Combined Algorithm for Stability and Phase Equilibrium by Gibbs Free Energy Minimization , 2002 .

[6]  T. Minowa,et al.  Hydrogen production from biomass by catalytic gasification in hot compressed water , 1999 .

[7]  R. Reid,et al.  The Properties of Gases and Liquids , 1977 .

[8]  David Mautner Himmelblau,et al.  Applied Nonlinear Programming , 1972 .

[9]  Takuya Yoshida,et al.  Gasification of biomass model compounds and real biomass in supercritical water , 2004 .

[10]  C. Floudas,et al.  Global optimization for the phase and chemical equilibrium problem: Application to the NRTL equation , 1995 .

[11]  S. F. Rice,et al.  Hydrogen production in a compact supercritical water reformer , 2003 .

[12]  Naoko Akiya,et al.  Roles of water for chemical reactions in high-temperature water. , 2002, Chemical reviews.

[13]  A global MINLP approach for phase equilibrium calculations , 1996 .

[14]  Fang Zhen,et al.  Cellulose decomposition in hot-compressed water with alkali or nickel catalyst , 1998 .

[15]  Masaru Watanabe,et al.  Catalytic hydrogen generation from biomass (glucose and cellulose) with ZrO2 in supercritical water , 2002 .

[16]  S. Gómez,et al.  Multiphase equilibria calculation by direct minimization of Gibbs free energy with a global optimization method , 2002 .

[17]  H. L. Julien,et al.  Thermodynamic equations of state for hydrazine and monomethylhydrazine , 2002 .

[18]  M. Sasaki,et al.  Kinetics of cellulose conversion at 25 MPa in sub‐ and supercritical water , 2004 .

[19]  K. Gasem,et al.  Multiphase Equilibrium Calculations Using Gibbs Minimization Techniques , 2003 .

[20]  In-Gu Lee,et al.  Gasification of Glucose in Supercritical Water , 2002 .

[21]  Kunio Arai,et al.  Glucose and fructose decomposition in subcritical and supercritical water: Detailed reaction pathway, mechanisms, and kinetics , 1999 .

[22]  E. Dinjus,et al.  Methanol Reforming in Supercritical Water , 2003 .

[23]  J. Prausnitz,et al.  Computer calculations for high-pressure vapor-liquid equilibria , 1968 .