What is the reasonable steam consumption for a medium-low low-change process without alcohol coupling?
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What is the reasonable steam consumption for a medium-low low-change process without alcohol coupling? If the process is suitable, can it be achieved without adding additional steam? What is the maximum temperature at the gas outlet of a saturated hot water tower?
There is no coupling alcohol in the medium-low low-shift process, the steam consumption is generally 300-350kg/t ammonia, and the temperature of the semi-water gas at the outlet of the saturated hot water tower is 120-128°C.
The two key factors to achieve zero steam consumption are to reduce heat loss and strengthen thermal insulation. The second is to strengthen heat recovery. It is generally difficult to achieve the second point. The key equipment is the saturated hot water tower. The gas temperature at the outlet of the hot water tower cannot be controlled too high. The most important thing to achieve this is that the amount of circulating water must be appropriate. The amount of circulating water is large. The water temperature at the outlet of the saturated tower is high and the gas at the outlet of the hot water tower cannot be reduced. Therefore, the type of the saturated tower and its nozzles must be improved to increase the saturation of semi-water gas as much as possible.
In fact, the steam consumption of low-to-medium-low steam should reach 250Kg/tNH3. The main energy-saving factor here is that the operating temperature of low-to-medium-low furnaces is relatively low, so the operating temperatures of equipment such as low-variable furnaces, saturated hot water towers, first water heaters, and second water heaters will be lowered, and heat losses will be relatively reduced.； At the same time, because the low-conversion catalyst requires less steam during normal operation, and the hot water circulation volume of the saturated hot water tower has also been reduced from 20m3/tNH3 at full medium-conversion catalyst to 8~10m3/tNH3, therefore, the use of medium-low conversion catalysts is still very energy-saving.