Jaedeuk Park

Integration of qualitative and quantitative risk assessment methods for gas refinery plants

This paper focuses on the development of an integrated risk assessment system to increase the safety of gas refinery plants. This integration is important in managing the design and the operation of chemical plants and it requires significant time, effort and specialized expertise. We propose a systematic procedure to apply quantitative and qualitative hazard identification methods before constructing the refinery plants. Advantages of this assessment procedure are 1) systematic method in identifying most of the important hazards, 2) complete and rigorous analysis, and 3) reducing budget and time. The qualitative and quantitative assessment method consists of two and three steps, respectively. After these five steps, the risk of the same plant was calculated and analyzed. This method can identify risk and potential hazards from local gas refinery plants effectively and systematically. We applied the integrated qualitative and quantitative risk assessment method to remove the risk of a local gas refinery plant with 160 P&ID sheets. The result of this work confirmed that no residential population existed within the bounds of the 1×10−6 per annum risk contour. Therefore, the risk to the public from the gas refinery plants should be considered acceptable.

Development of COI classification algorithm for chemical terrorism

This study focused on a novel approach for classifying hazardous chemicals to be used for chemical terrorism. We developed a novel algorithm to classify nationally customized chemicals of interest (COI) out of 325 COI in USA. The proposed COI classification algorithm aims to identify a key set of factors that reflect nation-wide uniqueness: intentional use, objectives, toxicity, related laws (CWC, ITF-25, CAA, etc.) and responsive counter-actions to terrorism. Although the U.S. has managed 325 COI to prevent terrorism, there are some nations in which the management and control of all the hazardous chemicals are beyond their capability. Based upon the outcome of this study the Ministry of the Environment of Korea has made appropriate revisions on relevant law. As a result, the Korean government has officially added a new set of 13 chemical species to the list of existing hazardous chemicals. This work is worthwhile to contribute to protecting the people’s lives and property from possible chemical accidents including terror by chemicals.

A multistream heat exchanger model with enthalpy feasibility

Abstract A temperature feasibility constraint is an important part of multistream heat exchanger (MSHE) modeling. However, temperature feasibility of an MSHE model makes a numerical issue when a physical property package is used to obtain highly accurate temperature-enthalpy relationships in equation-oriented modeling environment. To resolve the issue, this study proposes a new MSHE model with enthalpy feasibility using the fact that enthalpy is a monotonically increasing function of temperature. A natural gas liquefaction process, called a single mixed refrigeration process, is optimized using the proposed MSHE model under an equation-oriented modeling environment with a physical property package as a case study.