ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Inherently safer process design for chemical reactors at the preliminary design stage

Muhammad Athar, Azmi Mohd Shariff, Azizul Buang, Muhammad Imran Rashid, and Asim Umer

Department of Chemical Engineering, Muhammad Nawaz Sharif University of Engineering and Technology, Multan, Pakistan

E-mail: m.athar@mnsuet.edu.pk

Received: 4 November 2025  Accepted: 3 April 2026

Abstract:

There are two approaches to inherent safety namely overall and equipment. The first one is typically preferred via the first-order concept i.e., without making modifications in the design. The equipment approach has been least focused and typically applied for a few equipment via second-order concept, i.e., modifications in design. However, specific method for inherently safer process design of chemical reactors with design modifications for reactors is not available in the literature. A new method, inherently safer chemical reactor design technique (ISCRDT), is consolidated in this paper to modify the process design using inherent safety principles for chemical reactors operating with chemical mixtures at the preliminary design stage. A relative ranking index has been developed, as the first part of the method, to compare the potential of reaction runaway relatively. Next, risk assessment and analysis are carried out to check the fire damage in case of any leak. In case, the risk is beyond acceptability, inherent safety principles are engaged to modify the design until the risk is acceptable. The proposed technique is validated using the MMA-TBA chemical process. This technique is expected to equip design engineers to make preliminary stage decisions regarding reaction runaway potential for chemical reactors.

Keywords: Chemical reactors; Inherent safety; Preliminary design; Indexing; Runaway potential

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-04883-6

Chemical Papers 80 (7) 8213–8231 (2026)