What to be alarmed about in your chemical plants and refineries?

posted Mar 31, 2016, 10:21 AM by Niels Jensen   [ updated Feb 13, 2017, 10:29 AM ]
Alarm systems are integral to the safe operation of chemical plants and refineries. They alerts the operations personel when a plant condition is about to escalate to an undesired situation, such as the fire shown in the picture to the right (Source of picture: www.csb.gov). The fire at Morton International was the result of a so-called run away reaction. A run away reaction in chemical plant or refinery happens, when the energy and / or material balance are significantly off balance.

What to be alarmed about in chemical plants and refineries is usually decided by senior process engineers in collaboration with senior operators. Sometimes equipment vendors provide long lists of things to be alarmed about around the operation of a particular piece of equipment. We call such list c.y.a.-lists, and recommend, that you either ignore them completely - after all the plant and its operation is your responsibility - or at least reduce them from alarm events to just logging events in the secondary control room or the maintenance shop. Otherwise your operators become accustomed to just acknowledging these nuisance alarms. However, the big question is how do senior engineers and senior process operators decide what to be alarmed about in your particular plant or refinery? Most likely the answer will be based on experience! So what happens when your plant involve new technology?

We think a more fundamental approach is needed to decide what to be alarmed about in chemical plants and refineries. If a chemical plant or refinery runs smoothly, then energy and material balances are in balance. That means there is no accumulation of neither energy nor material in your facility. Accumulation of energy and material in a chemical plant or refinery usually occur, then something is not working or functioning as designed. We believe, that this is where functional models such as Multilevel Flow Models - MFM - can help you decide what to be alarmed about and when to be alarmed. A properly designed MFM model of your plant or refinery will allow you to reason about how a deviation moves through your facility until it eventually disturb the ability of the facility to achieve its goal, e.g. producing certain chemicals in certain amounts and purety. The result of reasoning with the MFM model and plant status information will allow your operators to intervene in the process before the deviation has escalated beyond recovery. The MFM model may even be used to arrive at possible actions for counteracting the initial deviation. 

Currently we are working closely with researchers and others at leading universities and companies to make these ideas move from research to operations. For more information about this project write to niels.jensen@safepark.dk.