Amoco Chemical Company
The Texas City marine docks xylene emission abatement project was started in 1992 and completed in May of 1995. Prior to this effort, the marine docks loaded vessels utilizing a simple open system with little instrumentation. Hydrocarbon vapors were simply displaced into the atmosphere.
The new vapor abatement design is complex and utilizes closed loading where vapors are piped back to an absorption tower. Amoco designed and installed a programmable logic control system to monitor and control the loading process, to minimize operator error and to increase the overall safety and reliability of the system. The technology used in the absorber towers is lean oil absorption. The technology has been around for quite some time, and was selected because it is simple, safe, frugal on energy and materials. By using lean oil absorption the xylene can be recovered, and is not sent to a flare for incineration. The lean oil enters the top of an absorption tower and, as it falls through the packing, strips the xylene from the nitrogen being displaced from the cargo tank. The oil leaving the absorber is "rich" with xylenes and is trucked to Amoco Chemical Texas City Plat "A" for further processing.
The dock vapor recovery system will reduce 95% of the emissions generated from loading activities. Amoco expects to recover 140,000 pounds of xylene in a typical year.
Details of Reductions
Additional Information :
The project cost approximately $10 million. Recovery of vapors makes this option preferable to flaring the vapors, and the lean oil recovery system has lower operating costs than cryogenic and flare systems. And by not using a flare, Amoco eliminates a major source of concern of the community around the plant.