Regarding the catalyst for the dehydrogenation unit of CO2 compressors

1. For fertilizer production plants, the main factor that causes poisoning of dehydrogenation catalysts is sulfur; therefore, it is essential to strengthen sulfur control, especially in plants that use coal as a raw material. 2. During operation, the main reason for the pulverization of the catalyst is as follows: First, when starting up, the CO2 compressor should supply gas to the dehydrogenation unit slowly, in order to avoid the gas flow from impacting the catalyst. If there is a dehydrogenation bypass line, it is best to use that line first; once the pressures before and after are stable, gas can be slowly introduced into the dehydrogenation process. Second, during startup and shutdown, it is necessary to prevent excessive water vapor from entering the dehydrogenation reactor. 3. The main reason for the large temperature difference between the hydrogen inlet and outlet is that the hydrogen content in CO2 is too high; it is possible that there is a problem with the decarburization process in ammonia synthesis. Under normal conditions, the temperature at the dehydrogenation outlet rises rapidly; in principle, an emergency shutdown should be initiated once it exceeds 250°C, to prevent more hydrogen from entering the urea plant, as this could lead to overpressure in the high-pressure sections of the plant and even an explosion. 4. If the pressure difference between the inlet and outlet of the dehydrogenation reactor is high, there are several possible explanations: First, it may indicate that the catalyst has become pulverized, resulting in increased resistance. Second, it is possible that the CO2 gas contains a high amount of oil; oil contamination may adhere to the upper layer of the catalyst or carbon may have formed as a result of this oil, thereby increasing resistance. Third, some manufacturers use a thermal potassium-alkali process to produce ammonia-functionalized carbon; as a result, the alkali present in the liquid is carried into the dehydrogenation reactor by the CO2 compressor, where it accumulates. There are examples of this among domestic manufacturers. This post was last edited by lxq700918 on 2009-2-4 22:15.]

I would like to ask: when driving the equipment, the synthesis pressure is low during material feeding; when stopping the operation, CO2 is removed too quickly, resulting in low outlet pressure. In general, could all of these situations – low pressures at the four outlet stages – lead to an increase in pressure differences? This post was last edited by lxq700918 on 2009-2-4 23:52

What is it that you mainly want to convey? Is your dehydrogenation at the four outlets of the CO2 compressor? Is it centrifugal or reciprocating? In short, efforts should be made to minimize the impact of air currents on the catalyst in order to avoid pulverization.