Various H-ZSM-5 catalysts were assessed for ethanol conversion into lower olefins. Ethanol was converted to lower olefins over H-ZSM-5 catalyst without modification. The selectivities for ethylene and propylene were much lower than those for aromatics such as benzene, toluene, and xylene (BTX), and C1-C4 saturated hydrocarbons. Addition of W and La was found to reduce aromatization and olefin hydrogenation, and, under ethanol conversion of almost 100％ , the selectivity for propylene and ethylene was improved, whereas the selectivity for BTX was decreased. The amount of carbon deposit was almost the same as that without modification. The selectivity for propylene formation may be associated with the percentage of Brønsted acid sites on the catalyst surface.

Cu/Ce1-xZrxO2 (x 0-1) was prepared by a coprecipitation-decomposition method using NH3 ・H2O as precipitant (to avoid residues of alkali metals), followed by a boiling process to eliminate NH3 and decompose [Cu(NH3)4] 2 complex. Then Cs was introduced to Cu/Ce1-xZrxO2 by the impregnation method. The prepared CsCu/Ce1-xZrxO2 catalysts (Cs: 1.0 wt%; Cu: 20 wt%) were used to catalyze the synthesis of mixed alcohols in a high-pressure fixed-bed flow reactor under reaction conditions of T 573 K, P 3 MPa, H2/CO 2/1, and GHSV 2400 h -1 . CsCu/CeO2 showed higher CO conversion than the industrial catalyst CsCu/ZnO due to the reducibility of the CeO2 support. Moreover, the STY of higher alcohols over CsCu/CeO2 was much higher than that over CsCu/ZnO due to the oxygen storage capacity of the CeO2-based compounds. Introduction of Zr 4 ions into CeO2 lattices increased the reducibility and the oxygen storage capacity of the CeO2-based compounds, so the STY of higher alcohols over CsCu/Ce0.8Zr0.2O2 was larger than that over CsCu/CeO2. CO conversion increased but selectivity for methanol decreased with higher reaction temperature over CsCu/Ce0.8Zr0.2O2. The selectivity for higher alcohols was maximum at 573 K over CsCu/Ce0.8Zr0.2O2. Both CO conversion and selectivity for higher alcohols increased with higher reaction pressure over CsCu/Ce0.8Zr0.2O2 for the synthesis of mixed alcohols from syngas.

Ru _ SiO2 catalysts with uniform structure were prepared by the alkoxide method using various Ru precursors, and used to catalyze the Fischer-Tropsch (F-T) synthesis in the slurry phase under the reaction conditions of T 503 K, P 1 MPa, H2/CO 2/1, and W/ W/ W F /F / 5 g-catal.h/mol. All catalysts showed stable activity during the F-T reaction for 40 h. The CO conversion was relatively low over the catalyst prepared from ruthenium chloride, because of the trace amounts of residual Cl on the surface. The catalysts prepared from ruthenium nitrosyl nitrate and ruthenium acetylacetonate showed high activity, with suppression of CH4 and CO2 formation. The CO conversion linearly increased with the loading amounts of Ru, indicating identical dispersion of Ru regardless of the amount. The olefi n/paraffi n ratio of the products could be explained in terms of the electronic state of Ru on the catalysts.

Uniform pore sizes of 10 wt Ru _ SiO2 catalysts prepared by the alkoxide method were varied in the range of 4-8 nm, by adding formamide (FA) at the sol-gel preparation stage. The prepared catalysts were used to catalyze the Fischer-Tropsch (F-T) reaction in the slurry phase under the reaction conditions of T 503 K, P 1 MPa, H2/CO 2/1, and W/ W/ W F 5 g-catal.h/mol. The Ru particle sizes estimated by H2 adsorption increased with increasing pore size, although the Ru crystallite sizes evaluated by XRD line broadening were only slightly changed. The selectivity for CH4 decreased and the selectivity for higher hydrocarbons increased with increasing pore size of the catalysts, caused by diffusivity of the slurry solvent and/or the products in the uniform meso-pores, or uniform Ru particle size effects.

Fast pyrolysis with three typical modified zeolite catalysts was evaluated to produce bio-oil from Jatropha waste. Jatropha waste was pyrolyzed in a stainless-steel reactor at 600 under N2 gas flow. The aromatic hydrocarbon selectivity in the bio-oil was in the order: PtPd/ZSM(30) (73.7 %) PtPd/Beta(22.5) (68.6 %) PtPd/USY(20) (48.7 %), where the weight ratio of Jatropha/catalyst was 1. In addition, catalyst regeneration was carried out to study the catalyst efficiency. The analysis of fresh and regenerated catalysts by XRD, NH3-TPD, and TG/DTG, as well as product selectivity and surface properties showed that coke deposition and removal were associated with the zeolite structure and surface acid property. Due to pore size regulation, H-ZSM-5 with 10-membered ring (10 MR) could promote the pyrolysis reaction on the outside surface rather than in the inside channels. In USY zeolite with 12 MR, the reaction could occur inside the channels, but the moderate acid nature resulted in only slightly developed coke formation, which could be removed, at least partly, after regeneration. In beta zeolite with 12 MR, the total amount of surface acidity was more than twice that of USY, which undergoes more condensed coke formation, and was more difficult to remove by regeneration than the coke over USY. Thus, under these pyrolysis conditions, PtPd/ZSM(30) seems to be a better candidate for pyrolysis of Jatropha waste compared to PtPd/Beta(22.5) and PtPd/USY(20).