Practical Exercise on Purification Technology Version [007]

1) Use a low-temperature, high-activity catalyst to reduce the gas-to-wet semi-water gas ratio in the shift converter.        Experiments have shown that, to achieve the same conversion rate, the higher the reaction temperature, the higher the steam ratio required. Therefore, using a low-temperature, high-activity catalyst can reduce the steam-to-gas ratio fed into the furnace, thereby saving steam.  (2) Increase the temperature and saturation of the semi-coke gas at the outlet of the saturated tower.       Typically, depending on the temperature of the semi-water gas at the outlet of the saturation tower, 1.0 to 1.5 tons of steam can be recovered per ton of NH3; the higher the outlet temperature, the more steam can be recovered, so it is advisable to increase the temperature of the semi-water gas at the outlet of the saturation tower as much as possible. To this end, there must be a tower diameter, height, and packing area that meet the production requirements, efficient packing, and an appropriate amount of hot water circulation.   (3) Improve temperature regulation and heat recovery between converter sections to make rational use of heat.       The transformation reaction is an exothermic reaction, and heat must be continuously removed during the reaction process. High-variation reactors use water spraying for cooling in order to remove this heat; the condensed water or deionized water sprayed into the reactor vaporizes there, which not only helps to regulate the temperature of the catalyst bed and remove heat but also increases the water vapor content in the gas entering the lower catalyst bed, thereby saving external steam supply. The full low-temperature variation process involves gradually heating the circulating hot water in the saturated hot water tower according to the varying reaction temperatures at each stage; this not only removes the heat generated by the reactions but also raises the temperature of the semi-coke gas at the outlet of the saturated tower through the circulating hot water, thereby recovering steam.   (4) Improve the insulation of equipment and pipelines to reduce heat loss.  

Insulation, for heat and cold exchange of materials

1. The full low-variability process with a saturated hot water tower results in lower steam consumption. 2. Cobalt-molybdenum-based sulfur-resistant shift catalysts with good activity at low temperatures result in lower steam consumption. 3. During operation, strive to adjust the hot water circulation rate to an appropriate level so as to maintain a higher temperature of the gas exiting the saturation tower; this way, more saturated steam is generated by the saturation tower itself, resulting in less steam consumption. 4. During operation, it is crucial to control the CO level in the conversion process and prevent large fluctuations; this is also one of the key factors in reducing steam consumption. 5. Proper protection of the catalyst is one of the key factors in reducing steam consumption; maintaining its good activity at all times helps to lower steam usage.

1) Use a low-temperature, high-activity catalyst to reduce the steam-to-gas ratio. 2) Increase the temperature and saturation of the gas exiting the saturated tower. 3) Ensure proper temperature regulation and heat recovery between the transition sections. 4) Strengthen the insulation of equipment pipelines to reduce heat loss.

It can increase the temperature of the gas at the outlet of the saturated tower. Increase the water content in the gas to reduce steam usage. Insulation can be improved, and it’s best not to use saturated steam; instead, a steam with a slightly higher temperature is preferable

1) Use a low-temperature, high-activity catalyst to reduce the steam-to-gas ratio. 2) Increase the temperature and saturation of the gas exiting the saturated tower. 3) Ensure proper temperature regulation and heat recovery between the transition sections. 4) Strengthen the insulation of equipment pipelines to reduce heat loss.

1 Optimize operations 2 Improve heat exchange efficiency 3 Enhance low-temperature heat recovery in the system

1) Use a low-temperature, high-activity catalyst to reduce the gas-to-wet semi-water gas ratio in the shift converter. (2) Increase the temperature and saturation of the semi-coke gas at the outlet of the saturated tower. 3) Ensure proper temperature regulation and heat recovery between the sections of the converter, and make rational use of heat. (4) Improve the insulation of equipment and pipelines to reduce heat losses

Heat preservation, condensate recovery, installation of steam traps, prohibition of direct discharge....

Heat preservation, condensate recovery, installation of steam traps, prohibition of direct discharge....