Mitigating hazards and risks in alkylation units through inherently safer design principles and effective assessment

For many years now, chemical process industries have become very large world-class plants. As a result of this increase in the size of these chemical plants, the likelihood of the occurrence of catastrophic accidents has increased also. Due to the awareness of the possible consequences of such accidents, lots of safety measures are normally put in place for the hazards associated with such plants to be managed and controlled. Although these measures that are normally put in place are effective, the fact that there is a possibility of the systems failing is not changed and such system failures could result in very serious accidents. Recently, the need for the application of inherently safer designs has been recognised and efforts are being made to the development of inherently safer processes. Alkylation is a crucial process in the production of high-octane gasoline, but it poses significant safety hazards due to the presence of highly reactive and flammable materials, including hydrogen fluoride (HF), Tetraoxosulphate (IX) acid (H₂SO₄), and olefins. Inherently safer design (ISD) suggests that the hazards and risks associated with alkylation can be reduced by adopting measures that minimize the use of hazardous materials, reduce the chances of their release, or minimize the impact of accidents. This article discusses measures for reducing hazards and risks in alkylation units, along with a method for assessing the effectiveness of these measures by comparing the hazards and risks posed before and after implementation. Applying ISD principles to alkylation can help reduce the hazards and risks associated with the process. Measures like catalyst substitution, process simplification, multiple barriers, and safer material selection can effectively improve the safety of alkylation units. The effectiveness of these measures was also assessed by comparing hazard and risk levels before and after their adoption. This work is aimed at evaluating the methods of reducing or eliminating the hazards and risks involved in alkylation units by applying mitigation systems and the principles of inherently safer design.