A MEMBRANE-BASED PROCESS FOR THE REMOVAL OF BTEX FROM GLYCOL DEHYDRATION VENTS

A major source of volatile organic compound emissions into the environment is thevent stream from the glycol-based dehydration units used to remove water fromnatural gas. A glycol dehydration unit operating on a 50-million SCFD naturalgas stream will typically discharge more than 40 tons per year of varioushazardous volatile organic air pollutants - about half of which is "BTEX"(benzene, toluene, ethylbenzene, and xylenes).Bend Research, Inc., proposes to develop a simple and efficient membrane-basedsystem that can be retrofited to the conventional vent condensers currently usedto reduce emissions from glycol dehydrators. This process will be based on ahollow-fiber pervaporation module that enables the use of a unique system designthat eliminates the problematic wastewater stream produced by conventionalcondenser systems, while also recovering the BTEX. In Phase I, they willfabricate small modules and operate them in a bench-scale apparatus. A designbased on the results of these tests, as well as an economic assessment of thistechnology will provide the basis for a decision to proceed into the Phase IIprogram. By the end of Phase II, they will have field-tested this process incombination with a conventional condenser system.