Oct-2024

Specifying waste water treatment unit biomass separation pilot test equipment (TiA)

Problem: A Texas Gulf Coast refinery performed a pilot trial testing biomass solids separation.

Will Strauss
Stratus Engineering

Article Summary

A trailer unit for biomass separation technology was utilised for the trial. The effluent from the pilot is not pumped; it flows out of the unit by gravity. This posed a problem as the effluent from the pilot trailer needed to be routed to the existing solids separation unit a few hundred feet away at a higher elevation than the pilot trailer.

The proprietary Process Engineering ToolS (PETS) was utilised to:
· Size all the process lines to and from the trailer.  
· Size the effluent holding tank and determine the working volume.
· Determine the pump’s net positive suction head available.
· Determine the pump’s required discharge pressure.
· Size a restricting orifice to provide continuous minimum flow spillback.

The speed and ease of PETS enabled the project team to find the equipment needed, get it installed, and perform a successful trial.

PETS was used to determine the fittings equivalent lengths (see Figure 1). After the equivalent length was determined, the pipe pressure drop (see Figure 2) was calculated for all the pipes required for the trial.

The tank sizing tool enabled the engineer to determine that an 8ft (2.4m) diameter and 7ft (2.1m) high tank provided sufficient residence time (see Figure 3). A minimum of five minutes residence time at maximum flow rate was the tank sizing criteria.

The net positive suction head (NPSH) tool was used to determine the NPSH available for the effluent pump (see Figure 4).

Conclusion
Having equipment sizing tools can improve the efficiency and productivity of the project design team. In this case study, the project team was able to locate all the equipment needed for the trial in a short period of time. The waste water treatment unit (WWTU) solids separation pilot trial successfully led the project to the next design phase. 

This short case study originally appeared in PTQ's Technology In Action Feature - Q4 2024 Issue

For more information: willstrauss76@googlemail.com