Process Engineering and Design for a Wastewater Treatment Plant

A client was having issues with volatile organic compound (VOCs) air emissions coming from the wastewater treatment plant (WWTP) within their refinery. 

Jōb Industrial Services (Jōb) was contracted to evaluate the existing configuration of the facility and to design a solution to reduce air emissions to an amount significantly below their permitted limit. Jōb found that the facility layout and mode of operation did not promote full utilization of the API Separator (oil/water separation equipment). The first phase of the project was to redesign piping to move the API Separator to the front of the process train, where it would be most effective. 

The second phase was to install a new column and flash drum. The packed column uses natural gas to strip the VOCs from the wastewater. The natural gas and stripped VOCs are sent to the fuel gas system where they can be utilized in the process heaters. The flash drum provides a means to sequester gases that may be entrained in the water during the stripping process. The now clean and de-gassed wastewater is then pumped to the existing atmospheric tanks, ready to be processed by the biological portion of the WWTP. 

The project was executed using simulation software and computer aided design software in conjunction with a 3D laser scan of the existing facility. A computer simulation of the refinery’s WWTP process was developed in ProMax. This model was used to evaluate different solutions and scenarios that could achieve the aggressive VOC reduction. When the two phased solution was agreed upon, a virtual model was created and overlaid on top of the 3D laser scan. This approach allowed for quick design reviews and virtual walk throughs of the new facilities. Key personnel in the Salt Lake City and Houston Jōb Industrial Services offices and onsite at the Texas refinery were able to collaborate on, assess, and modify the design via teleconferencing.  The technologic capabilities of Jōb greatly reduced the travel and on-site personnel throughout the duration of the project. The project was not delayed during the COVID-19 international pandemic, while adhering to CDC social distancing practices.