Recently, Fischer-Tropsch synthesis （FTS） has become an interesting technology because of its potential role in producing biofuels via Biomass- to-Liquids （BTL） processes. In Fischer-Tropsch （FT） section, biomas...Recently, Fischer-Tropsch synthesis （FTS） has become an interesting technology because of its potential role in producing biofuels via Biomass- to-Liquids （BTL） processes. In Fischer-Tropsch （FT） section, biomass-derived syngas, mainly composed of a mixture of carbon monoxide （CO） and hydrogen （H2）, is converted into various forms of hydrocarbon products over a catalyst at specified temperature and pressure. Fixed-bed reactors are typically used for these processes as conventional FT reactors. The fixed-bed or packed-bed type reactor has its drawbacks, which are heat transfer limitation, i.e. a hot spot problem involved highly exothermic characteristics of FT reaction, and mass transfer limitation due to the condensation of liquid hydrocarbon products occurred on catalyst surface. This work is initiated to develop a new chemical reactor design in which a better distribution of gaseous reactants and hydrocarbon products could be achieved, and led to higher throughput and conversion. The main goal of the research is the enhancement of a fixed-bed reactor, focusing on the application of KenicsTM static mixer insertion in the tubular packed-bed reactor. Two FTS experiments were carried out using two reactors i.e., with and without static mixer insertion within catalytic beds. The modeled syngas used was a mixed gas composed of H2/CO in 2 ： 1 molar ratio that was fed at the rate of 30 mL（STP）·min^- 1 （GHSV ≈ 136 mL·gcat^-1 ·h^-1） into the fixed Ru supported aluminum catalyst bed of weight 13.3 g. The reaction was carried out at 180 ℃ and atmospheric pressure continuously for 36 h for both experiments. Both transient and steady-state conversions （in terms of time on stream） were reported. The results revealed that the steady-state CO conversion for the case using the static mixer was approximately 3.5 times higher than that of the case without static mixer. In both cases, the values of chain growth probability of hydrocarbon products （α） for Fischer-Tropsch synthesis were 0.92 and 0.89 for the case with and without static mixer, respectively.展开更多
The coolant thermal mixing performance in the hot gas plenum (HGP) in the core bottom reflector of the 10MW high temperature gas-cooled reactor test module (HTR-10) was experimentally investigated on a 1:1.5 scale tes...The coolant thermal mixing performance in the hot gas plenum (HGP) in the core bottom reflector of the 10MW high temperature gas-cooled reactor test module (HTR-10) was experimentally investigated on a 1:1.5 scale test model. The experimental results show that the HGP installed with a radial partition static mixer results in excellent thermal mixing of the coolant with a nondimensional temperature mixing degree (ε) value of 94%. Within the Re range from 1. 4 ×105～5. 8×105, the ε value reaches 94% at the outlet of the HGP and 99% at the outlet of the hot gas duct (HGD). There is little influence of the inlet flow rate ratio. Gh/Ge. on the thermal mixing performance in the Gh/Ge range from 0.5～2.0.展开更多
基金supported by the project of the National Science and Technology Development Agency (NSTDA),Thailand
文摘Recently, Fischer-Tropsch synthesis （FTS） has become an interesting technology because of its potential role in producing biofuels via Biomass- to-Liquids （BTL） processes. In Fischer-Tropsch （FT） section, biomass-derived syngas, mainly composed of a mixture of carbon monoxide （CO） and hydrogen （H2）, is converted into various forms of hydrocarbon products over a catalyst at specified temperature and pressure. Fixed-bed reactors are typically used for these processes as conventional FT reactors. The fixed-bed or packed-bed type reactor has its drawbacks, which are heat transfer limitation, i.e. a hot spot problem involved highly exothermic characteristics of FT reaction, and mass transfer limitation due to the condensation of liquid hydrocarbon products occurred on catalyst surface. This work is initiated to develop a new chemical reactor design in which a better distribution of gaseous reactants and hydrocarbon products could be achieved, and led to higher throughput and conversion. The main goal of the research is the enhancement of a fixed-bed reactor, focusing on the application of KenicsTM static mixer insertion in the tubular packed-bed reactor. Two FTS experiments were carried out using two reactors i.e., with and without static mixer insertion within catalytic beds. The modeled syngas used was a mixed gas composed of H2/CO in 2 ： 1 molar ratio that was fed at the rate of 30 mL（STP）·min^- 1 （GHSV ≈ 136 mL·gcat^-1 ·h^-1） into the fixed Ru supported aluminum catalyst bed of weight 13.3 g. The reaction was carried out at 180 ℃ and atmospheric pressure continuously for 36 h for both experiments. Both transient and steady-state conversions （in terms of time on stream） were reported. The results revealed that the steady-state CO conversion for the case using the static mixer was approximately 3.5 times higher than that of the case without static mixer. In both cases, the values of chain growth probability of hydrocarbon products （α） for Fischer-Tropsch synthesis were 0.92 and 0.89 for the case with and without static mixer, respectively.
文摘The coolant thermal mixing performance in the hot gas plenum (HGP) in the core bottom reflector of the 10MW high temperature gas-cooled reactor test module (HTR-10) was experimentally investigated on a 1:1.5 scale test model. The experimental results show that the HGP installed with a radial partition static mixer results in excellent thermal mixing of the coolant with a nondimensional temperature mixing degree (ε) value of 94%. Within the Re range from 1. 4 ×105～5. 8×105, the ε value reaches 94% at the outlet of the HGP and 99% at the outlet of the hot gas duct (HGD). There is little influence of the inlet flow rate ratio. Gh/Ge. on the thermal mixing performance in the Gh/Ge range from 0.5～2.0.
