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Nowadays the importance of nano-particles and their uses in different industries have attracted many researches. The materials in nano-scale show different characteristics in comparison with their bulk state. Nano-materials have potential applications in optoelectronics, catalysis, and membranes. In this paper Nano-size porous γ-alumina was successfully synthesized by precipitation method under ultrasonic vibration mixing. Sonochemistry help the nano particles to synthesis regular form. The synthesized catalyst was characterized by SEM, XRD, BET, and TPD techniques. The effect of two most important operating conditions (i.e. Temperature and WHSV) on performance of this catalyst was investigated for dehydration of methanol to dimethyl ether (DME). The optimum operating condition was at temperature of 320 º C and WHSV of 15 h -1 . . Currently his main efforts are taken to synthesis of γ-Al2O3/CNTs catalyst for dehydration of methanol and other acidic catalysts.

In this paper, a hybrid turboexpander-fuel cell (TE-FC) is investigated for extraction of electrical energy from high pressure gas in which the fuel cells are used for preheating the gas. Combination of expanders and fuel cells will reduce the fuel consumption and greenhouse gas emission. This study reveals that there are some circumstances in which the use of fuel cells in conjunction with a turboexpander is not recommended from an economic point of view. This paper seeks the region in which utilization of fuel cells along with a turboexpander presents maximum economic profit. Using the strategy provided in this paper one can decide whether to invest in the hybrid fuel cells-turboexpander or individually planned turboexpander with a conventional gas fired preheating system. Almost all effective parameters are taken into account and this can be considered a superiority of the present paper.

The reduction stage of chemical looping steam methane reforming was investigated to determine the kinetics of the reduction reaction for CeO2‐Fe2O3 mixed oxides. CeO2, Fe2O3, and CeO2‐Fe2O3 mixed oxides with different molar ratios were prepared by chemical precipitation. Characterization tests indicated the lowest Brunauer‐Emmett‐Teller surface area for samples with higher Fe content. The largest area under reduction peaks during hydrogen temperature‐programmed reduction measurements was also related to the samples with highest Fe content. Reduction of the oxygen carriers with lower Fe content was well represented by a phase boundary‐controlled model.

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