Abstract
The purpose of a Reactive Chemicals Program is to prevent uncontrolled chemical reactions that have the potential to result in injury, property damage, or environmental harm. Key to realizing this prevention is the management of the inherent energy contained in the chemicals used to produce useful products in the chemical industry. Since most chemical processes proceed “downhill” thermodynamically, it is critical to the success of a chemical process to manage that energy release in a controlled manner to prevent, for example, problematic runaway reactions. These undesired events can have extremely negative consequences in terms of injury to workers, release to the environment, and severe economic impact on the company. The Reactive Chemicals Program at The Dow Chemical Company has been in place for nearly 50 years and has evolved into a recognized industry model. This paper will discuss the various aspects or elements of this successful program and how it is implemented at scales starting in the small R&D environment and eventually to the large full scale chemical plant. Important elements include: the design of inherently safe systems, personal ownership of the reactive chemicals issues, and commitment to fully understanding of the energy release hazards of the process, including how to mitigate them.
Also discussed is the experimental testing program employed to help define the so-called “safe operating envelope” of the process. These tests include several calorimetric methods such as Differential Scanning Calorimetry (DSC) and Accelerating Rate Calorimetry (ARC). In conjunction with the calorimetric testing, the flammability and dust explosion potential of the processes are also studied. In addition various estimation and calculational strategies are employed as needed.
Finally the Reactive Chemicals Program culminates with mandatory Process Hazard Reviews where experts in many areas (Process Engineers, Chemists, Testing experts, Environmental experts, Operators, etc.) meet to go over all aspects of the process, ensuring every unit operation is covered and in sufficient detail to assure that the process will operate within safe boundaries. These reviews are held long before the process is started, and also periodically after the process is in operation. If changes to the process are needed, the facility must get that change evaluated for its reactive chemical implications. This is done through a formal “Management of Change” (MOC) process where experts are required to “sign off” before the change is allowed to be implemented.
