Background:

A major petrochemical corporation commissioned a grassroots processing unit to fulfill full-plant masterplan requirements. The new unit relied entirely on the existing site-wide flare network for pressure relief off-gas handling. Concurrently, the multi-unit expansion project had a total crude processing capacity in the 10-million-tonne scale, generating substantial relief loads. As detailed design progressed and unit counts and capacities were adjusted, the originally planned flare system reached 100% design capacity. Constrained by piping right-of-way (ROW) limitations and physical plot space for flare infrastructure, expanding the existing flare network was rendered technically infeasible, leaving no relief margin for future processing units.

Solution:

In strict compliance with industry standard API 521, SimTech deployed a multi-tier engineering methodology—combining steady-state relief analysis, dynamic simulation, and flare load mitigation strategies—to systematically re-evaluate and optimize flare relief rates at the source.

Benefits:

SimTech developed high-fidelity steady-state and dynamic models for all process units, conducting comprehensive relief load evaluations under credible contingency scenarios and formulating targeted mitigation measures:

1) Existing Flare System Integration:

Following the integration of the new processing unit into the operating flare network, backpressures across all flare main headers remained well within original design limits. Factoring in thermal radiation limits, the optimized flare relief rate was drastically reduced compared to original design estimates, successfully resolving the relief tie-in bottleneck for the grassroots unit.

2) Grassroots Flare System Optimization:

The overall optimized flare relief load for the expansion project was significantly scaled down relative to baseline design figures. This substantial reduction overcame plot plan and piping ROW constraints, safeguarding project execution and schedule certainty.