Process Hazard Analysis for Risk Assessment In New Projects

This paper shows how the use of a powerful Risk Assessment Tool can help preventing future process safety problems.

A capital project was approved to change the existing installation to adequate it for a new formulation production.

In-house dilution of anhydrous ammonia was considered as part of the project scope.

HAZOP methodology was used in the detailing phase of this project, in order to proper design the In-house dilution.

A multi-disciplinary team worked together for 2 consecutive weeks to identify vulnerabilities of the proposed design as well as to define the adequate barriers for them.

To define the most appropriate safeguards, benchmarking was done with other chemical industries which also handled anhydrous ammonia.  Other Company affiliates, as well as the plant aqueous ammonia supplier were also part of this benchmarking

External experienced experts from the Company Headquarter were also engaged on this review and could contribute with their experience in other similar installations.

After the whole analysis, main outcomes were:

• 43 recommendations were pointed to be addressed by the design;
• A new equipment was included in order to assure anhydrous ammonia was kept as liquid;
• Failure position (in lack of air and power) was defined for all automatic valves;
• 14 new safety interlocks were defined and 11 existing safety interlocks were modified;

In general, decisions faced by engineers of facilities in the chemical industries are difficult and complex.  Some of the most challenging decisions involve Process Safety risks which often require experience and knowledge to be addressed.  The use of proper methodology, combined with Teamwork, can drastically improve the design of new installations handling High Hazardous Materials.

The goal is to create a process that is intrinsically safe and error proof.  This paper provides a very successful application of this concept.