Biomass derived tar decomposition over coal char bed

ABSTRACT: The effect of coal char on the decomposition of rice straw derived tar was investigated in a two-stage fixed bed reactor. The reactor was divided into a pyrolysis zone (upper part) and a volatile-char contacting zone (lower part). Rice straw was pyrolysed at different temperatures in the upper part. Coal char, prepared by the pyrolysis of Indonesian coal at either 600 °C (char600) or 800 °C (char800), was located in the lower part. Volatiles from the rice straw (upper part) were produced and then came in contact with the coal char at the lower part under the N2 (pyrolysis) or steam/N2 (steam reforming) gas flow. Under pyrolysis, both char600 and char800 exhibited a catalytic effect on the thermal tar decomposition. The coal chars also played a significant catalytic activity on the decomposition of the heavy aromatic hydrocarbons that were generated at a high pyrolysis temperature. In the presence of steam, char600 also exhibited a catalytic role in tar steam reforming, while char800 did not reveal any such significant catalytic activity because of the predominant coke/carbon formation

Investigation of agglomerates growth mechanism for thermal seawater desalination

Desalination technology has been paid large attention because water demand has been increasing due to the industrial development and high growth rate of population. To develop a novel desalination process with high energy efficiency and with high recovery ratio, a self-heat recuperative seawater desalination process using a fluidized-bed evaporator has been proposed (1). The fluidized-bed evaporator was employed to prevent scale deposition on the heat transfer surface during seawater evaporation. The seawater evaporation experiment using a lab-scale fluidized bed showed that the proposed evaporator prevents scale deposition on the heat transfer surface (2). However, it was also found that the seawater feed into the bed causes agglomeration of fluidized particles, which has the possibility to cause defluidization. In this research, seawater evaporation experiments using the lab-scale fluidized-bed evaporator were conducted and the influence of operating conditions such as fluidizing gas velocity, seawater feed rate and bed temperature on the agglomeration behavior of fluidized particles was examined. Furthermore, the mechanism of agglomerates growth was investigated and the optimal operating conditions of the fluidized bed for thermal desalination were examined. REFERENCES H. Mizuno, Y. Kansha, M. Ishizuka and A. Tsutsumi. A Novel Thermal Desalination Process Using Fluidized Bed. Chem. Eng. Trans., 39: 181-186, 2014 H. Mizuno, Y. Kansha, M. Ishizuka and A. Tsutsumi. Agglomeration behavior in fluidized-bed evaporator for thermal seawater desalination. Appl. Therm. Eng., 89: 1096-1103, 2015

Control of particle circulation rate in circulating fluidized bed by a pulsed gas flow

As a coal-fired power generation technology for further improvement of power generation efficiency of coal-fired power generation, exergy regeneration type coal gasification power generation technology (1), a triple-bed circulating fluidized bed (2), has been proposed. The authors analyzed the flow characteristics of the triple-bed circulating fluidized bed, it has the flow characteristics of the riser and downer perform the proposed approach to representation by the equivalent circuit model. The equivalent circuit model of the riser and downer are shown in Figure 1. This equivalent circuit has the nature of the low-pass filter. A combination of the low-pass filter and the pulse voltage is used as a switching power supply. Then, we applied that the pulsed gas supply to the riser combined with a low-pass filter characteristics to control the particle circulation rate of the triple-bed circulating fluidized bed. Figure 2 shows the input output characteristics of the equivalent circuit of the riser/downer inputting a pulse voltage. We used an electric circuit simulator SPICE to calculation of circuit behavior. Circuit constant is to use the value of the reference 3, the input pulse height is set to 80V. When the input pulse width is changed, the output current is changed depending on the pulse width. Moreover, when changing the density of the pulse, the output current is changing depending on the pulse density. This result by giving a pulsed gas supply to the riser, it shows the possibility controlling the particle circulation rate of the triple-bed circulating fluidized bed. Please click Additional Files below to see the full abstract

A Concise Asymmetric Total Synthesis of (+)-Epilupinine

Asymmetric total synthesis of (+)-epilupinine was achieved in just 3 steps using only commercially available common reagents. The total synthesis involved alkylations of N-nosylamide, ozone oxidation, and sequential reactions of the removal of the nosyl group, intramolecular dehydrative condensation, intramolecular Mannich reaction catalyzed by L-proline, and a reduction