Replacing Gas-Assisted Glycol Pumps with Electric Pumps

Gas-assisted pumps are the most common circulation pumps in remote areas that do not have an electrical power supply. They are basically pneumatic gas driven pumps, specially designed to take advantage of the energy of high-pressure natural gas entrained in the rich (wet) TEG leaving the gas contactor. Additional high-pressure wet production gas is necessary for mechanical advantage, and therefore more methane rich gas is carried to the TEG regenerator, where it is vented with water boiled off of the rich TEG. The mechanical design of these pumps places wet, high-pressure TEG opposed to dry, low pressure TEG, separated only by rubber seals. Worn seals result in contamination of the lean (dry) TEG making it less efficient in dehydrating the gas, requiring higher glycol circulation rates. Typical methane emissions are about 1,000 cubic feet (Mcf) for each million cubic feet(MMcf) of gas treated.