Process Section – Daily Hydrogenation Process Knowledge Question No. 011
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What causes an excessive temperature rise in the reactor? The diene value of the material is too high. The catalyst has high activity; blockages in the tubes of the circulating oil cooler or malfunctions of the bypass control valves can lead to high inlet temperatures. Malfunctions in the flow meters for the fresh feed rate (too high) or the circulating oil volume (too low) can also contribute to this issue
Quench hydrogen is used to control temperature rise; it allows the temperature of the catalyst bed to be adjusted, thereby preventing the catalyst at the lower levels from deactivating prematurely.
1) The bromine value, sulfur content, and nitrogen content of the raw materials increase； (2) Increase in hydrogen purity ； (3) Decrease in hydrogen-to-oil ratio ； (4) Voltage control failure, resulting in an increase in the system’s total pressure. Handling method: When the temperature rises, close attention should be paid to the temperature changes at various points in the reaction bed, and appropriate measures should be taken to maintain normal operation. If overheating becomes severe, emergency cooling and pressure reduction procedures must be carried out.
(1) Increase in the bromine value, sulfur content, and nitrogen content of the raw materials； (2) Increase in hydrogen purity ； (3) Decrease in hydrogen-to-oil ratio ； (4) Voltage control failure, resulting in an increase in the system’s total pressure.
1. Changes in the olefin content as well as the sulfur and nitrogen contents of the raw materials lead to a significant increase in temperature； 2) Changes in hydrogen purity or flow rates of recycled hydrogen and cold hydrogen ； 3) Unstable operation, fluctuations in reaction temperature and pressure ； 4) Air velocity variation ；
The diene value of the raw material is too high; the catalyst is highly active; the tube bundle of the circulating oil cooler is blocked, or the bypass control valve fails, resulting in a high inlet temperature. The flow meters for the amount of fresh feed (too high) or the amount of circulating oil (too low) are malfunctioning
The diene value of the material is too high. The catalyst has high activity; blockages in the tubes of the circulating oil cooler or malfunctions of the bypass control valves leading to internal leakage result in high inlet temperatures. There are also issues with the flow meters for measuring the fresh feed volume (which may be too high) or the circulating oil volume (which may be too low)
The diene value of the material is too high. The catalyst has high activity; blockages in the tubes of the circulating oil cooler or malfunctions of the bypass control valves can lead to high inlet temperatures. Malfunctions in the flow meters for the fresh feed rate (too high) or the circulating oil volume (too low) may also occur
The diene value of the material is too high. The catalyst has high activity; blockages in the tubes of the circulating oil cooler or malfunctions of the bypass control valves can lead to high inlet temperatures. Malfunctions in the flow meters for the fresh feed rate (too high) or the circulating oil volume (too low) can also contribute to this issue