Chemical process manufacturing is associated with risks, which cannot be eliminated. Anyhow, controlling or minimizing of risks is possible up to a certain extent through various process safety strategies. Among these strategies, the inherent approach offers a sustainable process design. This review aims to offer an extensive survey regarding the bibliometrics and the features of the state-of-the-art inherent assessment methods. For the bibliometric part, numerous trends like publication trend, authors and geographical cooperation and prominent keywords are presented using the VOSviewer software. For the second intention, the scope and features of inherent assessments methods for sustainable process design are discussed in addition to the historical development of these methods. The techniques are categorized among seven groups based on the method adopted for inherent assessment along with the benefits and detriments of each group. It is revealed that initially, the inherent assessment has focused on the comparison of various process routes, whereas, the modern methods intend to minimize the risk. Furthermore, it is recognized that the process equipment approach is not much explored yet, which may improve the sustainable process designing via the equipment characteristics. Finally, the limitations of present schemes and future research directions for inherent assessment implications in the sustainable process design are also highlighted, such that the objectives of economic, healthier, safer and environmental-friendly process plants can be materialized.

Graphical Abstract

"The scope of the review covers the comprehensive bibliometric analysis and the classification of groups for inherent assessment methods followed by the detailed investigation of each technique in the group to identify the features and the gaps. The bibliometric analysis involves the mathematical and statistical concepts based on the publication trend, authors and their cooperation, active countries and prominent keywords related to inherent assessment. The literatures for the review study which related to the inherent safety assessment for chemical process design were retrieved from Web of Science (WoS) and Scopus databases. These literatures were manually refined based on their relevance to Chemical Engineering and English as the language. The identified literatures were analyzed using VOSviewer and MS Excel for the bibliometric analysis and the evaluation of the inherent assessment techniques."

Framework for the literature investigation

Process Safety: Inadequate implementation of process safety element in the design and development of the chemical plant amplifies the exposure to risks, hazards, and accidents.

Process Safety Assessment Methods: The lack of comprehensive bibliometric analysis and features within inherent assessment methods hinders effective risk management strategies aimed at minimizing hazards and mitigating the associated consequences in chemical processes.

Sustainability: By incorporating sustainable process design principles through inherent assessment, industries can minimize their environmental footprint, promote resource efficiency, and contribute to long-term environmental sustainability.

Decision Making: The comprehensive review on the inherent assessment methods provides useful insights for decision makers to implement suitable approach in chemical process design and development that prioritizes safety, health and environment.

Classification layers of the inherent assessment

Orders of Inherent Assessment: Two orders of inherent assessment methods were identified to achieve sustainability; first-order methods focuses on hazard avoidance whereas second order methods concentrates on hazard minimization. Thus, by adopting the second order inherent assessment methods, the guide words can be utilized to practically implement a sustainable process design.

Classification of Inherent Assessment Approach: The inherent assessment in process design were classified into two approaches: overall process and individual unit operation.

Inherent Assessment Technique: Seven techniques were recognized to perform the inherent assessment, in which indexing was preferred among other methods due to its simplicity in the preliminary process design.

Adressing Gaps In Existing Inherent Assessment: Few gaps were identified in the established inherent assessment methodologies that includes the limited focus on health and environmental aspects, as well as lack of cost considerations, necessitating the future development of new tools that integrate these aspects through systematic research efforts.

Risk Mitigation: By identifying and addressing potential risks early in the design phase through inherent assessment, organizations can mitigate operational, financial, and reputational risks. These risk mitigation strategies can enhance market stability and resilience, attracting investors and stakeholders.

Regulatory Compliance: Adhering to regulatory requirements related to safety, environmental protection, and sustainability are essential for market access and credibility. Inherent assessment ensures compliance with regulations, reducing the risk of fines, penalties, and legal issues that could impact market potential.

Cost Savings and Efficiency: Sustainable process design driven by inherent assessment can lead to cost savings through optimized resource utilization, reduced waste generation, and improved operational efficiency. Lower operating costs can improve competitiveness and profitability in the market.

Innovation and Product Development: The identified gaps in the established inherent assessment techniques creates potential for future research and exploration of new methodologies.

Frequent case study for the demonstration of inherent assessment methods