Question

1)

a) What kind of problem manifest at a choke if temperature gets too low? What can be done to remedy this problem?

b) Produced natural gas is usually saturated with water vapor. Why is the presence of water vapor not favorable? What can be done to remove the water content?

c) What is done to gas that flashes in lower pressure separators? Give example of two equipment commonly used for this process.

Answer 1

a) When the temperature becomes less, the gas especillay CO2 and H2O gets solidifed ( under cryogenic conditions) and choke the aluminium exchanger used in cryogenic air separation plants. This increases the pressure drop acroos the exchangers.

b) since natrual gas has to be used as fuel, the water vapor needs to be removed and this can be done by adsorption.

c) the gas (except for hydrogen and helium), cools during flashing the gas can be returned and can be used for instrument as well as fuel gas heater. The two devices are orficemeter and diaphragmmotor

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