a b s t r a c tProduction of hydrogen rich gas from gasification of biomass was studied at bench-scale using oxygen as the gasifying agent. A series of experiments were performed to investigate the effects of different operating parameters on the performance of the gasification process. These included the oxygen to fuel equivalence ratio (0.12e0.4), reaction temperature (700e850 C), reaction residence time (45e120 min), and catalyst type. The catalysts selected are marly clay, calcium hydroxide, dolomite, and cement kiln dust. Within the range of the experimental conditions tested, the results suggest that the best operating conditions for the gasification process are; temperature, 800 C, an oxygen to fuel ratio of 0.25, a reaction time of 90 min, and calcined cement kiln dust as a catalyst. The results have also demonstrated that the product gas from gasification of cotton stalks with calcium hydroxide has higher H 2 and CO concentration (45 and 33%). In addition gasification of cotton stalks with calcined cement kiln dust resulted in higher hydrogen and CO enrichment as well as higher overall gas yield (39vol%, 33vol%, and 1.5 m 3 /kg) compared to other agriculture residues of corn stalks and rice straw.

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The photo-Fenton process is intensified for degradation of carbofuran by using a tubular microreactor coiled around a florescent light. The microreactor attained 7.5 times faster degradation rate compared to a batch reactor operated under a LED light. At the initial Fe 2+ concentration of 0.25 mM, the degradation rates in the batch reactor were fast at first, subsequently became slow, and afterward gradually increased with time regardless of light intensity. In the microreactor, the degradation rates appeared to decrease similarly to the firstorder reaction despite the same initial Fe 2+ concentration. A proposed kinetic model well fitted the results of both batch and microreactors by modeling that Fe 3+ is photoreduced in a complex in equilibrium with Fe 3+ and intermediates with carboxyl group decomposed from carbofuran.

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To predict PEFC performance without complicated simulation or a lot of experimental data is required for the optimum design of the cell, especially the cathode catalyst layer (CCL). In our previous study, the effectiveness factor of CCL was reported to be a function solely of 4 dimensionless moduli which were derived from the isothermal one-dimensional model of the cathode consisting of oxygen balance, oxygen transport, proton transport, reaction stoichiometry, and rate. In this study, the dependency of the oxygen reduction reaction (ORR) rate on CCL thickness is analyzed and a method to determine dimensionless moduli is proposed.