Phuakpunk Kiattikhoon, Chalermsinsuwan Benjapon, Putivisutisak Sompong, Assabumrungrat Suttichai
Center of Excellence in Catalysis and Catalytic Reaction Engineering, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University Bangkok Thailand 10330.
Fuels Research Center, Department of Chemical Technology, Faculty of Science, Chulalongkorn University Bangkok Thailand 10330
RSC Adv. 2018 Jul 5;8(43):24209-24230. doi: 10.1039/c8ra03901a. eCollection 2018 Jul 2.
The sorption-enhanced steam reforming of ethanol (SESRE) has recently been reported as a novel process for hydrogen (H) production. SESRE can operate well on a Ni-based catalyst with dolomite as a sorbent in packed-bed reactors. In this study, the circulating fluidized bed (CFB) concept was proposed to obtain higher productivity and continuous operation of SESRE. Particular focus was directed to the design and selection of suitable operating conditions of the CFB riser. Two-dimensional transient models using the Euler-Euler approach and the kinetic theory of granular flows were applied to investigate the H production performance from a pilot-scale riser. The 2 full factorial design method was utilized to examine the significances of five specific parameters, namely, the riser diameter, inlet temperature, catalyst-to-sorbent ratio, solid flux, and inlet gas velocity on two response variables, namely, H purity and H flux. From the ANOVA results, either the main effect or the interactions of each parameter were shown to be significant on both the H purity and the H flux, particularly the riser diameter and the solid flux. For optimizing the operation and reaction parameters, the best case was the system with riser diameter of 0.2 m, inlet temperature of 600 °C, catalyst-to-sorbent ratio of 2.54 kg kg, solid flux of 200 kg m s, and gas velocity of 3 m s, obtaining H purity of 91.30% on a dry basis with a significantly high H flux of 0.147 kg m s. The hydrodynamics showed that SESRE reached breakthrough within the bottom dense zone. However, incomplete conversion occurred in the core of the riser because of the very dilute bed.
乙醇吸附增强蒸汽重整（SESRE）最近被报道为一种新型制氢工艺。SESRE在填充床反应器中以白云石为吸附剂的镍基催化剂上能良好运行。在本研究中，提出了循环流化床（CFB）概念以实现SESRE更高的生产率和连续运行。特别关注CFB提升管合适操作条件的设计与选择。采用欧拉 - 欧拉方法和颗粒流动力学理论的二维瞬态模型来研究中试规模提升管的制氢性能。利用二水平全因子设计方法来考察五个特定参数，即提升管直径、入口温度、催化剂与吸附剂的比例、固体通量和入口气体速度对两个响应变量，即氢气纯度和氢通量的影响。从方差分析结果来看，每个参数的主效应或相互作用对氢气纯度和氢通量均显示出显著影响，尤其是提升管直径和固体通量。为了优化操作和反应参数，最佳情况是提升管直径为0.2 m、入口温度为600℃、催化剂与吸附剂比例为2.54 kg/kg、固体通量为200 kg/(m²·s)、气体速度为3 m/s的系统，在干基上获得91.30%的氢气纯度以及0.147 kg/(m²·s)的显著高氢通量。流体动力学表明，SESRE在底部密相区内达到穿透。然而，由于床层非常稀薄，提升管核心区域发生了不完全转化。
