While ‘thermal oxidizers’ are a solution to the industry’s needs, they carry inherent operational risks that in turn require tight control.
As the world begins to place greater emphasis on eco-friendliness and sustainability to avert long-term disaster, the need to reduce the emission of harmful chemicals into the environment has become paramount.
As the demand for chemicals is tied to industrial production—which has grown by 7.2% in production output—the demand for chemical products have also risen: overall global chemicals output has risen by 5.8%.
This is leading to challenges in the installation of combustion systems and in ensuring ESG compliance in the chemicals industry to stop the release of air pollutants such as volatile organic compounds (VOC).
In many industrial chemical processes, gaseous by-products are produced in addition to the desired main product. These streams of gaseous by-products are often explosive mixtures consisting of hydrogen and nitrogen in addition to traces of organic compounds. As the global production of chemicals increases, industrial workers are now more at risk from hazardous chemical exposure, while environmental pollution is also increased.
Pitfalls of using thermal oxidizers
Besides worker safety issues, pollution control regulations are increasing global pressures on chemical production plants. These regulations revolve around the management of material waste and air pollutants.
One of the most effective ways to eliminate hazardous emissions is the deployment of ‘thermal oxidizers’ in process industries. With a thermal oxidiser installed, gaseous by-products from the upstream production plant are burned completely using high temperatures. This is an important aspect to the reduction of pollutant emissions.
However, while industrial facilities are adopting thermal oxidizers to reduce emissions and increase sustainability, the method is not without its risks. The oxidizers can present significant safety risks and inherent hazards when the processes are mismanaged.
Potential malfunctions such as the interruption to the power supply, control systems problems, and process deviations can result in fire and explosion hazards in the thermal oxidizers, leading to potentially lethal damages.
Managing the risks
To ensure that thermal oxidizer risks are controlled, chemicals industries can employ devices such as ‘Safety Integrity Level controllers’ and boiler protection systems and burner management system (BCS/BMS) to ensure that all residues are combusted.
Additionally, the ratio control and monitoring of the gaseous by-product and combustion air has to be stringent. The BCS/BMS application ensures that the process values are kept stable. The control system intervenes and corrects deviating process values immediately. If safety limits are exceeded, the control system will shut down the plant accordingly to prevent incident escalation and the consequent increase of downtime.
Finally, the process values need to be kept stable in a Heat Recovery Steam Generator before the safety control system has to shut down the plant. According to the SIL2/3 requirements in the Hazard and Operability Analysis processes, a gaseous by-product/combustion ‘air ratio control structure’ and an ‘independent shutdown interlock’ should be installed.
Such smart monitoring and control systems can help to optimize and stabilize process values while maintaining compliance with the current safety standards: plant availability can be boosted while gaseous by-product throughput is optimized.
