DEVELOPMENT OF ANEW FLUID-BED CATALYTIC REACTOR TO PRODUCE LIQUID FUELS FOR THE NEXT GENERATION

气相流化床已用于由氢气和一氧化碳合成轻质烃燃料。这是因为可以容易地除去反应热，且可以在反应器中将反应温度保持在恒定温度。然而，对于涉及流化床中气体体积减少的反应，流化质量急剧下降。当气体体积减少的程度大时，来自气泡的气体供应不能补偿乳液相中的体积减少。因此，乳液相的空隙率降低，并且乳液相流动性的降低干扰气泡上升。最后，在床中发生反流化。在这种情况下，反应堆无法安全运行。在本研究中，反应条件，以保持良好的流化质量进行了研究。在实验中，以氢气和二氧化碳合成甲烷为模型反应，在镍催化剂上进行。根据气体体积减少率和气体体积比，得到了稳定运行的判据。结果表明，当减容速率大于0.01 l/s，最大容积比小于0.9时，不能建立稳定的操作。此外，还研究了内构件对流化床流化质量的影响。筛的开口面积分数为0.70。当使用一个网板时，通过破坏所产生的去流化部分而不是通过破坏所产生的去流化部分来防止去流化部分的产生是有效的。因此，当金属网安装在分布器上方10-20 cm处，网间距为10-20 cm时，可以建立良好的流化。

Gas phase fluidized beds have been used for the synthesis of light hydrocarbon fuels from hydrogen and carbon monoxide. This is because that reaction heat can be easily removed and reaction temperature can be kept at a constant temperature in the reactor. However, the fluidization quality drastically decreased for the reaction involving a decrease in gas volume in the fluid bed. When the degree of the gas volume decrease is large, the gas supply from bubbles cannot compensate the volume decrease in the emulsion phase. Consequently, the voidage of the emulsion phase reduces and the decrease in the fluidity of the emulsion phase disturbs bubbles to rise. Finally, defluidization in the bed occurs. The reactor cannot be operated safely at these conditions. In the present study, the reaction conditions to keep the good fluidization quality were investigated. In the experiments, methane synthesis from hydrogen and carbon dioxide as a model reaction was carried out over Ni catalysts. The criterion for the stable operation was obtained based on the gas volume reduction rate and the ratio of gas volume. It was shown that the stable operation could not be established when the volume reduction rate was over 0.01 l/s and maximum volume ratio was below 0.9. In addition, the effects of internals were studied to improve the fluidization quality. The fractional open area of the sieve was 0.70. When one mesh plate was used, it is effective to prevent the generation of the defluidized part by breaking the generating defluidized part rather than by breaking the generated defluidized part. Therefore, the good fluidization could be established when the metal meshes were installed at 10-20 cm above the distributor and the intervals between the meshes were 10-20 cm.