Safety is consistently among the highest priorities for manufacturers and producers. Critical goals are to avoid safety incidents, keep site personnel safe, protect the community around you, protect the environment as a whole, and improve your corporate financial health. A robust safety culture has many facets, including occupational safety, containment safety, process safety, and functional safety.
I caught up with Emerson’s Martin McDonough on how chemical industry manufacturers are addressing their safety programs. He noted that all industries, including chemical producers, are regulated by global standards set by the IEC. The standard for safety is IEC 61508, and more specific to the process industry, the standard is guided by IEC 61511. It is this standard that is often associated with functional safety. Across the world, many world-area and industry-specific standards organizations build their regulations from this standard.
Layers of protection are used in process safety risk mitigation. The analysis considers basic process chemistry & components, process design, staff training & procedures, equipment maintenance & monitoring practices, basic process control system alarm management, safety shutdown systems, and relief systems. Each level is reviewed for potential safety issues that must be addressed to mitigate risks.
Martin shared that Emerson can help address the layers: staff training & procedures, equipment maintenance & monitoring practices, basic process control system alarm management, safety shutdown systems, and relief systems to help mitigate risks to personnel, assets, and the environment.
Here are 12 focus areas and solutions targeting known safety problems in a chemical plant.
From an occupational safety perspective, Martin shared three solutions—personnel location awareness, safety shower & eyewash station monitoring, and automated sampling & rounds. Manual sampling can be automated in many cases, and the industry has recognized that fact. One example from a McKinsey report identified that 40-60% of operator time can be saved in a typical chemical plant with automation.
Emerson has various measurement and analytical technologies to help automate sampling processes. These technologies can be direct or inferred process fluid measurements, including viscosity, density, API gravity, hydrogen purity, acid strength, concentration, BTU or heating value, pH, and conductivity. Many wireless sensors are available to automate manual rounds.
From a containment safety perspective, monitoring solutions are available for real-time piping corrosion, tank over- & under-pressure, level & leaks, heat exchangers, pumps, fired heaters, and fire & leak monitoring.
From a process safety perspective, additional measurements help gain better insight into what is happening within the process. There are many ways to do this. One is taking advantage of easily adding extra measurement points using wireless devices. Another example is to leverage some of the diagnostics that are in some of the devices to use them to detect abnormal situations or process upsets.
You can detect entrained air or gas, for example, using a Micro Motion Coriolis meter from the density measurement and dive gain, which could indicate a seal failure. There are process intelligence diagnostics in Rosemount pressure transmitters that monitor the standard deviation, mean, and coefficient of variation to detect changes in process noise, which can detect abnormal process conditions like entrained air, pump cavitation, distillation column flooding agitation loss, impulse line coating and flame instability. Pressure relief valves can also be monitored with acoustic wireless sensors for leaks and pressure releases.
Finally, from a functional safety perspective, safety instrumented systems provide the last layer of preventing safety incidents. This is where many plants use the SIL-rated devices and add additional devices to increase redundancy and may use a 1oo2 (one-out-of-two) or 2oo3 voting scheme for the emergency shutdown function. On a tank, you may have multiple level gauges combined with a switch going into an automatic overfill prevention system. For a flow measurement, you may have multiple transmitters across an orifice plate to meet your desired SIL rating.
Visit the Solutions to Optimize Your Chemical Plant Performance page on Emerson.com and view the Chemical Applications Guide: Safety & SIS Systems document for more on the automation technologies and solutions to drive improved safety performance. You can also speak with Martin directly by arranging a time here.