Project Synopsis
Analyze and determine the root cause of issues that damaged a Urea Reactor at a plant site that produces agricultural, industrial, and animal feed chemicals.
Project Summary
The client, a producer of agricultural, industrial, and animal feed chemicals located in the US, contracted Process Engineering Associates, LLC (PROCESS) to provide full-time process engineering support for their production facility. More specifically, PROCESS analyzed the mechanisms that damaged the facility’s Urea Reactor. Structures, piping, and baffles were damaged and caused significant downtime for the unit.
The main challenge with this analysis was the lack of pressure instrumentation on the reactor since it has thick walls and instrument placing can lead to the possibility of unwanted reactor leaks. This reactor is designed to operate at high temperatures and pressures, but the reactor was damaged at low temperature and pressure. The reactor experienced unusual rapid cooling as well.
It was determined that under low pressure conditions two-phase critical flow occurred through the nozzles that separated flow through each of the sections within the reactor. The two-phase critical flow created large pressure drops through the nozzles. This resulted in impeding flow and allowing the ammonia in each zone to greatly expand.
During this project, PROCESS performed phase equilibrium and hydraulic studies using Aspen Plus 14 with the Thermodynamic package ELECNTRL and OLI Spreadsheet 11.5. Aspen was primarily used to study the two-phase flow through the reactor nozzles.
This study provided the client with the range of temperatures, pressures, and ammonia compositions that could result in ammonia phase changes creating large pressures within the reactor. PROCESS’ report is being considered by upper management for possible process design changes.
Industry Type
Fertilizer and Animal Feed Manufacturing
Utilized Skills
- Process event investigation
- Process simulation
- Process troubleshooting.