Kyusang Han

Optimal Layout of a Chemical Process Plant to Minimize the Risk to Humans

Abstract The process layout of chemical plants is usually designed in a compact configuration for economic efficiency. However, most of the chemical process units are vulnerable to accidents such as fires and explosions, and these accidents can cause severe damage to humans. In this study, direct risks to humans from such hazards were quantitatively assessed as individual risk and converted into safety distances for each piece of process equipment. Then, a process layout optimization problem was formulated with risk zones constructed using those safety distances. Boundary factors accounting for land uses around the process site and protection factors from additional protective devices were also considered. A case study for an ethylene oxide plant was conducted. With the proposed methodology, a cost-efficient and inherently safe layout can be provided in the early stage of the design of a process plant.

Analysis of Integrated Gasification Combined Cycle (IGCC) Power Plant Based on Climate Change Scenarios with Respect to CO2 Capture Ratio

Abstract This paper presents the analysis result of integrated gasification combined cycle (IGCC) power plant based on climate change scenarios suggested by International Energy Agency (IEA). IGCC power plant and IGCC with carbon capture and sequestration (CCS) power plant has been simulated and modeled using Aspen Plus, and verified using various materials such as the report which is named as “Cost and Performance Baseline for Fossil Energy Plants”, and published by NETL/DOE, several recent papers of Computers and Chemical Engineering, Energy Conversion and Management etc., and the related guideline prepared by Aspen plus. In order to compare the economy of IGCC and IGCC with CCS power plants with respect to CO 2 capture ratio, the concept of levelized cost of energy (LOCE) is adopted as a comparison tool, and three different climate change scenarios suggested by IEA are adopted as possible events. Analysis results indicate that CO 2 capture ratio of IGCC power plant has a great sensitivity with respect to coal and CO 2 prices.

Optimal layout of chemical process using risk index approach to minimize risk to human

Abstract Many chemical processes are constructed within very compact areas due to the limitation of resources including land and cost although many of their units are dangerous and vulnerable to accidents such as fire or explosion. There have been many researches to make chemical processes safer by modifying the layout of process to ensure the safety distance among hazardous equipment. Even the safety among units is secured, however, this situation can get worse if the process site is near residential areas or the workspace of employees is located in the site because of the risk to human, which is usually not concerned for process layout. In this study, quantitative risk to human as well as the risk of equipment itself is considered to give more reliable layout of chemical processes. Among various quantitative risk approaches, modified individual risk index has been adopted. Individual risk counts for the risk that a person near the dangerous environment can take. With this index, optimal process layout is designed by minimization of cost and land area to consider the limitation of resources, also. The proposed methodology can provide the guideline to designing safe layout of chemical process concerning the various safety distance measures including equipment- equipment distance, equipment-employees distance and equipment-the public distance.

A Study on the Monitoring Criteria of Disaster Signs for Early-warning System based on Multiple Hazardous Gas Sensor

Abstract - The number of large and complex buildings is growing and they are usually concentrated in met-ropolitan cities. There is a possibility in such buildings that a small accident can expand to a massive disaster since their scale and complexity. To deal with this issue, a research on gas sensors which can detect multiple gases and early-warning systems has been conducted. Proper criteria or standards are necessary for effective application and operation of such sensor-based disaster monitoring system. In this study, we have proposed the alarm criteria of concentration of hazardous gases for the detection and the alarm release. For each alarm level, systematic disaster response plans consist of responsive actions and information delivery have been prepared. These disaster monitoring criteria can help the detection of hazardous gas-related disaster in the early stage of accident and the provision of appropriate emergency responses.Key words : disaster management, early-warning system, alarm criteria, response plan