Jinsheng Gao

Catalytic cracking of tar component from high-temperature fuel gas

The cracking removal of tar component in high-temperature fuel gas cleanup is one of the most crucial problems in developing cleanest advanced power technology. Five catalysts were evaluated to tar component removal from high-temperature fuel gas in a fixed-bed reactor. 1-Methylnaphthalene was chosen as a model of tar component. The Y-zeolite and NiMo catalysts were found to be the most effective catalysts. Two catalysts almost removed 100% tar component at 550 °C. The process variables, temperature and space velocity, have very significant effects on tar component removal with catalysts. The long-term durability shows that two catalysts maintain more than 95% removal conversion at 550 °C in 168 h. The combustion study of coke deposited on catalysts by thermal gravimetric analysis technology shows that very small amount buildup of coke appears on two catalysts surface. Using a first-order kinetic model, the apparent energies of activation and pre-exponential factors for tar component removal reaction and coke combustion on catalysts were obtained for the most active catalysts.

Adsorption of alkali metal vapor from high-temperature coal-derived gas by solid sorbents

Abstract Seven sorbents for alkali metal removal from high-temperature coal-derived gas were tested in a fixed-bed reactor at 840 °C. NaCl was used as an alkali metal model compound. It was found that five sorbents, including the second grade alumina, bauxite, kaoline, acidic white clay and activated Al 2 O 3 , present higher adsorption efficiency, and activated Al 2 O 3 shows the highest capture capacity. In capturing time of 3 h, the adsorption efficiency and sodium content absorbed by activated Al 2 O 3 are, respectively, up to 98.20% and 6.20 mg/g. The tests indicate the removal of alkali metal vapor with activated Al 2 O 3 is a physical adsorption process in the absence of moisture. The adsorption kinetics of activated Al 2 O 3 with NaCl indicates that there are critical times at which adsorption constants begin to change. The critical time is at about 4–5 h.

A study on the reaction kinetics of HCl removal from high-temperature coal gas

Abstract A study on chloride removal from high-temperature coal gas shows that all the tested sorbents can rapidly react with HCl vapor and reduce the HCl vapor concentration to less than 1×10−6 in a fixed-bed reactor. The ECl1 sorbent lab-made has the highest chloride capacity. The experimental data obtained were analyzed by a model based on fixed-bed reactor and shrinking core models, It is found that reaction between sorbent and HCl vapor is of first-order with respect to initial HCl concentration. The reaction is governed by combination of the chemical reaction and product layer diffusion.

Study on the direct liquefaction reactivity of Shenhua coal catalyzed by SO42–/ZrO2 solid acid

Abstract Effects of liquefaction conditions, including temperature, time, initial hydrogen pressure, and catalyst dosage on direct liquefaction were investigated by batch hydro-liquefaction of Shenhua coal catalyzed by SO 4 2– /ZrO 2 solid acid. The mechanism and catalysis of Shenhua coal liquefaction catalyzed by SO 4 2– /ZrO 2 solid acid were also discussed by distribution and IR analysis of the products. The results indicate that increase in temperature is favorable for catalytic hydrocracking of coal, an increase in liquefaction conversion, and yields of oil plus gas. Raising the initial hydrogen pressure facilitates coal conversion into asphaltene and preasphaltene, but depresses the formation of oil and gas. The increase of liquefaction time is beneficial to the hydrocracking of preasphaltene with an increase in yields of oil plus gas. SO 4 2– /ZrO 2 solid acid mainly catalyzes the hydrocracking of coal macromolecular structure so that the conversion and yields of oil plus gas increase with increasing catalyst dosage. In addition, the conversion of the oxygen-containing structures such as hydroxyl needs high liquefaction temperature and initial hydrogen pressure.

Hydrothermal liquefaction of corn straw under CO atmosphere: Effect of catalysts

The effects of different catalysts (homogeneous catalysts: NaOH, Na<inf>2</inf>CO<inf>3</inf>, KOH and K<inf>2</inf>CO<inf>3</inf>; heterogeneous catalysts: JB-1, JT-201 and JT-203) on the hydrothermal liquefaction of biomass under CO atmosphere were investigated mainly using a high-pressure autoclave reactor at 380°C. The results indicated that the conversion of biomass and the yield of liquid products increased obviously with the adding of the catalysts. Compared with the raw material, the conversion of corn stalk increased from 82.3% to 93.3–99.9%, the H/C molar ratio and the higher heating value (HHV) increased, the contents of both hydrogen and carbon increased significantly, and the contents of oxygen, nitrogen and sulfur reduced in liquid products. The activity order of the catalysts was as follows: CO<inf>3</inf>^2™>OH^™; Na⁺> K⁺. JT-203 was the most effective of the three commercial catalysts. For the biomass deoxidization, heterogeneous catalysts were more effective than homogeneous catalysts.