Turning glycerol surplus into renewable syngas through glycerol steam reforming over a sol-gel Ni–Mo2C-Al2O3 catalyst

In this work, a sol-gel Ni–Mo₂C–Al₂O₃ catalyst is employed for the first time in the glycerol steam reforming for syngas production. Catalyst stability and activity are investigated in the temperature range of 550 °C–700 °C and time on stream up to 30 h. As reaction temperature increases, from 550 °C to 700 °C, H₂ yield boosts from 22% to 60%. The stability test, carried out at milder conditions (600 °C and Gas-Hourly Space-Velocity (GHSV) of 50,000 mL h⁻¹.g_cat⁻¹), shows high catalyst stability, up to 30 h, with final conversion, H₂ yield, and H₂/CO ratio of 95%, 53% and 1.95, respectively. Both virgin and spent catalysts have been characterized by a multitude of techniques, e.g., Atomic-Absorption spectroscopy, Raman spectroscopy, N₂-adsorption-desorption, and Transmission Electron Microscopy (TEM), among others. Regarding the spent catalysts, carbon deposits’ morphology becomes more graphitic as the reaction temperature increases, and the total coke formation is mitigated by increasing reaction temperature and lowering GHSV.     

Simulation analysis of instantaneous impact on the radiant syngas cooler by rapping vibrators

Slag or ash removal from water wall tubes in a radiant syngas cooler (RSC) is a routine task in operation, which can effectively increase the overall thermal efficiency. Rapping ash removal is one of the valid methods for shedding off the ash deposits in the high-pressure surroundings of the RSC. In this study, the model of a real RSC was established by a numerical simulation based on the finite element software ABAQUS, and modal analysis and instantaneous response analysis (IRA) were researched to reveal the natural vibration characteristics of the RSC and aid the design of rapping ash removal. On the basis of the results of natural vibration characteristics and a subsequent harmony response, 16 Hz was set as the impact frequency, balancing off the vibrator number and the water-tube displacement effect. It was indicated that ash deposit in the area around 1/2 longitudinal position was easy to remove due to great response to rapping action. Moreover, rapping at ½ position generally obtained greater displacement response in the whole RSC. A rapping design was proposed with six vibrators at the ½ longitudinal position and 16 Hz frequency, and then two rapping intervals were investigated comparatively. The case with a half-cycle interval had a slightly larger response than the one-cycle case, with a larger displacement in more circumferential tubes as well as with a greater sound pressure response in the RSC.     

An overview of mono-ethylene glycol synthesis via CO coupling reaction: Catalysts,kinetics, and reaction pathways

Monoethylene glycol (MEG) is a promising chemical and a useful feedstock for the synthesis of several industrial products. The current commercial process of MEG production utilizes petroleum feedstock (ethylene) and an expensive catalyst, and the yield is low. Syngas is an attractive alternate feedstock for MEG. Syngas to MEG proceeds in two steps: the self-closing, green step of carbonylation of alkyl nitrile to produce dialkyl oxalate, and further hydrogenation of oxalate to MEG. Many reviews which focused on catalyst development, reaction mechanisms, and process variables were published earlier. The present work covers the developments in the syngas-to-MEG synthesis process after 2014. It overviews the performance of novel catalyst systems reported in literature. A discussion on reaction pathways and kinetic models is also presented. This work will provide useful insight into syngas-to-MEG conversion.     

用于合成气制高值产物的InZrOx 氧化物制备及性能

以四水合硝酸铟和五水合硝酸锆为原料，通过共沉淀法和水热法制备InZrOx氧化物，并在最佳制备条件下探究煅烧温度对合成氧化物的影响，与SAPO-34分子筛结合为双功能催化剂用于用于合成气催化转化制高值产物。采用XRD、SEM-EDS、HRTEM、XPS和BET对氧化物的织构性质、晶体结构、形貌特征及表面电荷进行表征与测试，并在固定床反应器中系统研究了空速、原料气氢碳比（物质的量）、氧化物与分子筛质量比、反应温度及反应压力对催化效果的影响规律。结果表明，共沉淀法得到的氧化物在各方面表现均优于水热法，最佳煅烧温度为550 ℃。在空速为2000 mL/(gcat·h)、原料气氢碳比（物质的量）为3：1、m(InZrOx)：m(SAPO-34)=1：1、400 ℃、3 MPa的反应条件下，CO转化率为67.58%，高值产物选择性为70.81%[C2-4=选择性为37.74%、液体燃料（C5+）烃类选择性为33.07%]，C2-4=收率可达23.98%，副产物CO2选择性仅为5.99%。