(436h) Development of a Novel Emission Control Technology for Onshore-Offshore Applications

Condensate storage tank emissions have been identified as potential sources of emission release into the atmosphere. They are usually accounted for as working, breathing and flash losses. With the rapid expansion in unconventional crude oil and natural gas production in the United States and with propose regulations by USEPA underway, emission control technology would proffer a sustainable research path to effectively maximized production in the oil & gas and petrochemical industry. While the most widely used technology is the vapor recovery units or adsorption, this may not be economical in some cases or may lead to creation of another waste stream.

This study focuses on the design, modeling and testing of a field scale emission monitoring, control technology (EMCT) to capture, and recovers vapors from point source. Volatile organic compounds and natural gas are the focus of this study.

The field test design involved the use of novel carbon adsorbent. The operation of the field scale EMCT unit occurs in continuous cyclic steps including. Online-mode: The unit operations presented received the feed streams of a mixture of gases emitted from the point source, which then comes into the EMCT vessel. The EMCT vessels are connected in parallel and operated in a continuous cyclic manner independent of either each other (online or offline mode). The mixture of gases is exposed to layers of a chemically impregnated novel adsorbent of various forms used to enhance molecular attraction of the gases emitted for it to be accumulated on the adsorbent surface area to capture the VOCs, hydrogen sulfide and other inert gases separated from natural during treatment. The capturing phase by adsorption is monitored until a specified breakthrough point is observed, by which the automated control system switched from adsorption to bed regeneration, which occurred in about 15 minutes. As the online EMCT vessel is undergoing selective adsorption, the other vessel is offline. When breakthrough is evident in the online vessel, the system proceeds to regeneration, while the second vessel is open for adsorption.

Regeneration of the bed is automatically initiated as a result of the state of the art control systems design implemented, which in turn controls the in-vessel heat source to enhance the desorption of the VOCs and other gases, subsequently followed by liquid recovery via condensation.

The combinations of approach involved for the developed methodologies and apparatus in this inventions to efficiently controls the emitted vapor through adsorption, desorption and condensation provide a pathway for a reduce system cycle time, which consequently leads to less power requirement.

The study is supported by a built in mathematical model based on derived governing equations, embedded in the control systems to allow comparisons between the field scale treatment efficiency and the model prediction in real time.

The competitive edge of this invention over the existing technologies includes, but not limited to its ability to make new product in liquid form (Liquid VOCs), recovery of natural gas, shorter cycle times , 100% automation during operations, reduce footprint, 50-75% reduction in adsorbent requirement due to bed regeneration, treatment efficiency stands at 99.8% compared to 95% required by regulations. Preliminary mathematical results from this study at temperature of 1 atm at well production rate of 1000 bbl/day indicate adsorption, desorption and recovery of the VOC emissions of 97%, and 98% respectively.

This project proffers an ability to make new viable petro-chemical product in liquid form by ultimately eliminating flares or vent during well completions.