The coal to ethylene glycol (CTEG) process has drawn much attention due to the serious conflict between supply and demand of ethylene glycol in China. However, it is inevitably accompanied by the problem of high CO2 emissions. Carbon capture is one of the most promising potential effective ways to address this issue. However, the CTEG process, integrated with carbon capture technology, will lead to energy and economic penalties. Thus, a comprehensive evaluation of CTEG process with different CO2 capture technologies is urgently needed. This study analyzed the technoeconomic performance of four CO2 capture alternatives for the CTEG process: Rectisol, mono-ethanol amine (MEA), chilled ammonia process (CAP) and dimethyl carbonate (DMC) technologies. Results show the energy consumption of CO2 capture of the Rectisol process is the lowest, 1.88 GJ/tCO2, followed by the DMC process, 2.10 GJ/tCO2, the CAP process, 3.64 GJ/tCO2, and the MEA process, 5.20 GJ/tCO2. The CO2 capture cost of the Rectisol process is lowest, CNY 169.5/tCO2, followed by the DMC process, CNY 193.2/tCO2, the CAP process CNY 232.6/tCO2, and the MEA process CNY 250.5/tCO2. As the Rectisol technology has the best comprehensive performance, it is the best option for CTEG industry in comparison with the MEA, CAP, and DMC technologies.
Two different methods of simulating iron contamination in a laboratory were studied. The catalysts were characterized using X-ray diffraction, N2 adsorption–desorption, and SEM-EDS. The catalyst performance was evaluated using an advanced cracking evaluation device. It was found that iron was evenly distributed in the catalyst prepared using the Mitchell impregnation method and no obvious iron nodules were found on the surface of the catalyst. Iron on the impregnated catalyst led to a strong dehydrogenation capacity and a slight decrease in the conversion and bottoms selectivity. The studies also showed that iron was mainly in the range of 1–5 μm from the edge of the catalyst prepared using the cycle deactivation method. Iron nodules could be easily observed on the surface of the catalyst. The retention of the surface structure in the alumina-rich areas and the collapse of the surface structure in the silica-rich areas resulted in a continuous nodule morphology, which was similar to the highly iron-contaminated equilibrium catalyst. Iron nodules on the cyclic-deactivated catalyst led to a significant decrease in conversion, an extremely high bottoms yield, and a small increase in the dehydrogenation capacity. The nodules and distribution of iron on the equilibrium catalyst could be better simulated by using the cyclic deactivation method.
The issues of feedstocks, product markets, and environmental emissions have continuously proposed a number of challenges for industrial evaluation of fresh fluid catalytic cracking (FCC) catalyst before its application in commercial units. In this work, a convenient method was proposed by comparing with the existing commercial equilibrium catalyst. A series of laboratory experiments for steam treatments and microactivity tests were established to collect reliable data, and the standalone catalyst or co-catalysts were assessed to show the evaluation process and the predicted unit performance. The results had deviation, but a consistent yield distribution than that of a commercial equilibrium catalyst. These evaluations and predictions would provide us with not only the view of hydrothermal stability and yield distribution at the unit level, but also the economic potential for fresh catalyst based on the existing industrial catalyst, which will provide refiners with industrial basis for further decisions.