A Different Purpose for a Flare Knockout Drum: Producing Clean Energy

In a previous article, we talked about how the natural gas that is found in the oil field (the so-called associated gas) often cannot be transported from the refining plants and has to be burnt.

Such practice is called gas flaring, and is somewhat controversial. While on the one hand burning gas is a better solution than simply releasing it in the environment, on the other it remains a waste of resources, and contributes to Co2 emissions.

The solution to this issue is GTL (Gas To Liquid) technology, which transforms gas into fuel, so that it can be transported through the existing infrastructure of the refinery. In recent years, the use of GTL technology contributed to a reduction of gas flaring.

The importance of a flare knockout drum for the safety of an oil refinery

Whenever gas is flared, it is very important that it contains no liquids, whether water or any type of fuel. If a mix of gas and liquids reached the top of the flaring tower, the burning gas would fall downwards with very dangerous consequences.

To purify gas from liquids, a particular type of pressure vessel is used, called flare knockout drum, which can be either horizontal or vertical. While the first are preferred for high quantities of liquids and gas, the latter are used for lower amounts, or if there is little space available.

An example of flare knockout drum we produced is the one for ISAB energy. In this case however, the destination was not a gas flaring tower, but a plant for the gasification of heavy fuel oils for the production of clean energy, in particular for the deasphaltisation of oil.

This particular use of a flare knockout drum shows how existing technology can be used to produce cleaner energy.