Gas sweetening as an environment-friendly process
This natural resource without being treated contains great amounts of toxic components so that is must pass through a series of chemical treatment to eliminate said components
Gas sweetening is a process which consists of eliminating toxic elements from the gas extracted from the ground, so that it could be used as an energy source, lowering ecosystem damage
It is said that it is relatively friendly with the environment because it produces less amount of waste in its combustion comparing it to other energy sources such as coal, oil, and derivatives.
From this point of view, no wonder it’s the leading energy source in the global market, sadly, no all nations count on huge reserves of this precious hydrocarbon.
For the gas to access those less-favored countries and be used a source of energy, it must pass through different process, given that once it is extracted from the ground, it cannot be transported immediately.
This natural resource, without being treated, contains huge amounts of contaminants such as hydrogen sulfide (H2S) and carbon dioxide (CO2) that for any of its later uses results damaging, that is why it must go for a series of chemical treatment to eliminate toxic components.
The process whereby said components are eliminated, which make the gas sour, is called “Gas Sweetening”
As there are different types of contaminants in different concentrations of grades and the desired result isn’t always the same either is the removal-process selection.
Gas Sweetening process with chemical solvents
In this process, gas’ sour components are eliminated with a chemical solution which contains an active component, it could be an amine or potassium carbonate, with its respective ups and downs of temperature and pressure.
In general, chemical solvents present high efficient in eliminating toxic components.
Gas Sweetening process with physical solvents
This process is characterized by its capacity for absorbing different sour components from the hydrocarbon stream. In this type of process, high pressures and low temperature allow successful removal. This method is normally used in gas treatment with high concentrations of CO2 and H2S
Gas Sweetening process with hybrid solvents
Hybrid process work with combinations of physical and chemical solvents and, naturally present characteristic of both.
Depending on the solvent composition, it can remove CO2, H2S, COS, CS2, and mercaptans. The selectivity to the H2S is achieved by adjusting the solvent composition and contact time.
Gas Sweetening process with molecular sieves
Molecular sieves can be used to absorb physically sour solvents, such as hydrogen sulfide and carbon dioxide, and they are regenerated using high temperatures or low pressured gas.
It possesses an affinity for polar molecules such as the CO2 and H2S, but because of the sieves-pores’ size, it has selectivity with the molecules it removes.
Once this phase is successfully done, the resulting gas is considered “Sweet”, in this form it can flow around the plant without being harmful to equipment and it could be afterward treated for commercialization.
Finally, sweet gas is taken to a dehydration process.