Hydrocarbon adsorbers, method of making and use therefor

摘要

A method for improving the adsorption properties of a hydrocarbon adsorber involves contacting a molecular sieve hydrocarbon adsorber at ambient temperature with an agent for modifying the acid sites of the molecular sieve to impregnate the molecular sieve with the agent. The average pore diameter of the intracrystalline porosity of the molecular sieve is about 3 to 20 angstroms. The agent has an anionic portion which is retained within the structure of the molecular sieve. The modified molecular sieve has the ability to retain adsorbed hydrocarbons at higher temperatures than the unmodified molecular sieve. The acid-modified molecular sieve can be used to remove hydrocarbons from a hydrocarbon-containing stream. The hydrocarbon-containing stream is passed through the modified adsorber at atmospheric pressure at a temperature ranging from room temperature to about 150 DEG C. to cause adsorption and retention of the hydrocarbons. The adsorbed hydrocarbons can then be desorbed at a higher temperature than would otherwise occur with an unmodified adsorber.