The amount of oxygen converted is unstable
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We use 100,000 units of methanol and 6,000 units of air separation equipment. The oxygen produced by the air separation system is sent to the conversion unit via oxygen compressors (piston type, two in operation with one as a backup). The oxygen level obtained from the distillation tower is well controlled, and the exhaust pressure of the oxygen compressors is also stable. The air separation system adjusts the oxygen pressure according to the requirements of our conversion process, while we control the flow rate. The problem we’re facing with the conversion process here is frequent large fluctuations in the oxygen flow rate. Yet there are no obvious abnormalities in operations or pressure on our end or at the air separation plant – why is this? (We have been in production for a short time yet and are not operating at full capacity.)
Is the temperature of the converter stable? If the furnace temperature is unstable, it may be due to fluctuations in oxygen temperature, which in turn cause fluctuations in pressure and temperature.
Are the raw gas fluctuations large? Also, what is the range of fluctuations in oxygen flow rate?/This is generally caused by the pressure relief of the molecular sieve in air separation units. If there is no change in the bed temperature, check the flow meter
An oxygen tank is added at the compressor outlet to achieve pressure balance and buffering; furthermore, the pressure in the conversion system must be kept stable. Check again whether the control valve is working properly
An oxygen tank is added at the compressor outlet to achieve pressure balance and buffering; furthermore, the pressure in the conversion system must be kept stable. Check again whether the control valve is working properly
My company simply added a buffer tank, and the result was good.
This phenomenon is quite common; first, it is necessary to determine whether it is caused by fluctuations in oxygen pressure, as conversion systems are mostly static equipment. Oxygen pressure, steam pressure, and coke oven gas are all directly related to the pressure in such systems, and instability in the system is often due to fluctuations in steam pressure.
First, it should be checked whether there is a problem with the gauge.
The fluctuations in the oxygen flow rate to the conversion unit are caused by variations in the pressure within that conversion system; the oxygen pressure from the air separation unit, on the other hand, does not fluctuate. Generally, there is a pressure control valve in place to regulate the pressure of the oxygen supplied from the air separation unit to the conversion unit, and as long as automatic mode is selected, no fluctuations will occur in the pressure from the air separation unit.