Absorption Performance Study of STONVENT for C02-Natural Gas System

As sweet gas in Malaysia has gradually decreased and most of the remaining natural gas
is acidic gas where C02 is found highly contained (approximately 80% volumetric), C02
separation technique has become essential in which to remove as many C02 as possible.
Numerous of separation techniques are available such as absorption into a liquid solvent,
adsorption onto a solid, cryogenic separation, permeation through membranes, and
chemical conversion but however, each of these techniques has limitations which cannot
cater the problem mentioned above. In order to achieve natural gas sweetening,
absorption is the most promising technique to remove the C02 gas. There are several
liquid used as the solvent such as alkanolamines, potassium carbonate and sodium
hydroxide. Alkanolamines however are the most commonly used solvent in the current
industry but it still has the drawbacks which brings to the introduction of an enhanced
amine-based solvent called STONVENT. Experimental work was done to evaluate the
absorption performance of the solvent under atmospheric pressure, different temperature
ranging from 30 to 50 °C and different liquid flowrates (0.5 and 1.0 Llmin). 50 °C is
found to be the best temperature while 1.0 Llmin gives higher absorption efficiency. The
recycle capacity of the solvent also has been studied where it is found that STONVENT
has high recycle capacity as it can absorb as much even until six cycles.