Project Synopsis
Perform a dispersion analysis for various relief and venting scenarios at a chemical manufacturing facility in the Northeast US.
Project Summary
The client, a chemical manufacturer, contracted Process Engineering Associates, LLC (PROCESS) to perform a dispersion analysis for various relief and venting scenarios at their chemical facility in the Northeast US. The primary objective of the analysis was to determine the required vent stack height and diameter needed to prevent flammable and Immediately Dangerous to Life or Health (IDLH) conditions at key locations within the facility’s battery limits. Additionally, the evaluation included vent stack diameter sizing based on pressure safety valve (PSV) outlet backpressure limitations, assessing the impact of backpressure on existing relief devices.
Using DNV’s PHAST dispersion software, PROCESS generated estimated boundaries of hazardous concentrations (IDLH) for more than a dozen (12+) predefined scenarios. These scenarios included reactor relief cases involving both abnormal heat input and the loss of cooling water. They also included pool fire scenarios affecting pressure vessels as well as those associated with the plant’s vacuum system. A variety of chemical species were modeled, including acetone, methanol, hexane, toluene, methyl methacrylate, and others. Multiple weather conditions were also incorporated to ensure a robust analysis.
This scope of work resulted in the following project deliverables:
- A comprehensive Project Presentation Report detailing the design basis, modeling methodology, and key dispersion modeling outputs generated using DNV’s PHAST software.
- A suite of dispersion modeling output graphs across all scenarios, including hazardous concentration contour plots.
- A summary table identifying controlling scenarios, relevant chemical components, recommended vent stack heights to prevent IDLH conditions, and an evaluation of stack backpressure effects on relief devices.
To support the client’s goal of minimizing the likelihood of IDLH conditions at critical locations within their facility, PROCESS’ modeling results provided the detailed technical data necessary to guide data-driven decision-making regarding vent stack height, diameter, and placement. These recommendations facilitate safe vapor dispersion and assist in achieving the facility’s safety objectives.
Industry Type
Chemical Manufacuring
Utilized Skills
- Dispersion analysis
- Pressure relief scenarios evaluation
- Vent stack height determination.