2.2 Catalytic Reaction System for Lower Alcohols Synthesis from Syngas
The CO hydrogenation was carried out in a stainless steel fixed-bed reactor (8 mm × 200 mm). The flowchart of reaction apparatus is shown in Figure 1. For convenience, the Cu25Fe22Co3K3 catalyst bed was denoted as CFCK and the Cu4.5Zn4.5Al1 catalyst bed was denoted as CZA. For single loading mode and mixed loading mode, single Cu4.5Zn4.5Al1 or Cu25Fe22Co3K3 catalyst and the mechanical mixture of these catalysts (diluted with 3.0 mL of 40–60 mesh size quartz sand) was loaded in a reactor as shown in Figure 2a. For layered loading mode, different volume of Cu4.5Zn4.5Al1 and Cu25Fe22Co3K3 catalysts were separated with a multihole thin metal plate between the two layers to construct a two-stage bed reactor as shown in Figure 2b. In the catalyst combination systems, if the feed gas was fed in downstream through CFCK catalyst bed layer first and then through the CZA catalyst bed layer, it was denoted as CFCK(x)//CZA(y) (x, y, the loading volume of CFCK catalyst bed and CZA catalyst bed, respectively, 1.0 ≤ x ≤4.0 mL; 1.0 ≤ y ≤ 4.0 mL); whereas, it was denoted as CZA(y)//CFCK(x). If the feed gas was fed in through the two catalyst bed layers simultaneously, it was denoted as CFCK(x)–CZA(y).