Storage of natural gas in liquid solvents and methods to absorb and segregate natural gas into and out of liquid solvents

Abstract

Bulk storage of natural gas or methane is facilitated by absorbing and storing the gas in a liquefied medium through the interaction of moderate pressure, low temperature and a solvent medium. Systems and processes are provided that facilitate the absorption of natural gas or methane into a liquid or liquid vapor medium for storage and transport, and back into a gas for delivery to market. In a preferred embodiment, the absorptive properties of ethane, propane and butane under moderate conditions of temperature and pressure (associated with a novel mixing process) are utilized to store natural gas or methane at more efficient levels of compressed volume ratio than are attainable with natural gas alone under similar holding conditions. The preferred mixing process efficiently combines natural gas or methane with a solvent medium such as liquid ethane, propane, butane, or other suitable fluid, to form a concentrated liquid or liquid vapor mixture suited for storage and transport. The solvent medium is preferably recycled in the conveyance vessel on unloading of the natural gas.