Process safety data management program based on HAZOP analysis and its application to an ethylene oxide/ethylene glycol plant

HAZOP analysis is a process hazard analysis method that has been widely applied both within and outside the chemical processing industries. This paper presents a design method for a process safety data management program for petrochemical plants based on HAZOP analysis and demonstrates the steps of application involved in building a process safety data management system for an ethylene oxide/ethylene glycol production plant. Firstly, the production data files and relevant documents of the plants should be classified and stored in the program database as reference documents and treatment schemes for coping with abnormal situations should be collected and summarized as guidance documents. Secondly, the HAZOP analysis method is employed to identify all the dangerous deviations possibly existing in the production process of the ethylene oxide/ethylene glycol plant. Then, the relationships among the deviations, the reference documents and the guidance documents should be considered and evaluated. Finally, each dangerous deviation will be given a corresponding reference document and guidance document. The reference documents and guidance documents stored in the expert system can be utilized to help operators solve the corresponding technical problems and cope with abnormal situations. The process safety data management program will contribute to the identification, analysis and resolution of operation problems. When an abnormal situation occurs, according to the deviations exhibited in the system, the necessary reference documents and guidance documents will be quickly consulted by the operators, and an appropriate decision will be made to address the abnormal situation. Therefore, by using the process safety data management program, plant security and human safety in the petrochemical industries will be improved.     

Evaluation of process safety indicators collected in conformance with ANSI/API Recommended Practice 754

At the request of the U.S. Chemical Safety and Hazard Investigation Board (CSB), we examined some of the possible uses of the process safety event metrics proposed by the American Petroleum Institute and published as ANSI/API Recommended Practice 754. We examined many sources to try to estimate what the likely number of Tier 1 and Tier 2 process safety events would be at refineries. Then we calculated the statistical power that would be available to compare rates, both over time and across facilities and firms. As Tier 1 and Tier 2 are defined, it appears that the event frequencies estimated for U.S. refineries (i.e., 0.12 per 100 employees for Tier 1 and 0.26 for Tier 2) would make it unlikely that even two-fold differences in the rates would be statistically significant, except at large refineries with several thousand workers.     

Managing process chemicals,technology and equipment information for pilot plant based on Process Safety Management standard

Injuries, accidents or even fatalities while working in pilot plant are reported worldwide. The OSHA Laboratory Standard and Hazard Communication Standard have been used as a guideline to manage safety of laboratories and pilot plant. In spite of the implementation of these standards, incidents which result in injuries and property loss are continuously occurring. The implementation of OSHA Process Safety Management (PSM) Standard in pilot plant is expected to further reduce the risks of accidents. This paper presents a new system for managing process chemicals, technology and equipment information in pilot plant and the concept is developed based on Process Safety Information (PSI) element of PSM 29 CFR 1910.119(d). It provides organized strategies to manage documentations, communicate information, and written program for maintaining, revising and updating related information. Process and Instrumentation Diagram (P&ID) is used as a foundation for data management. Implementation of this system at the CO₂ Hydrocarbon Absorption System pilot plant as a case study is examined and discussed.     

Flixborough: A final footnote

The Flixborough explosion was the largest-ever peacetime explosion in the UK. There were 28 fatalities as well as near-complete destruction on the 24 ha plant. An official Court of Inquiry was immediately established and charged with the responsibility of determining the cause(s) of the disaster and the lessons to be learnt. Reviews are made here of the evidence and arguments behind an alleged 8 in initiation to the event and briefly that of the Court's determination of failure—the simultaneous failure of two 28 in bellows attached to a temporary 20 in dog-leg pipe bridge. Both cases are seen as flawed. The only credible hypothesis appears to be one that involved the failure, most probably by fatigue, of only one of the two bellows attached to the dog-leg—this then buckled, sealing the lower reactor. The dog-leg later collapsed by the blast. This process resulted in a much smaller explosive release than either alternate hypothesis and thus may have consequences for reportable inventories and process safety. The investigation employs NIST FDS CFD analyses of the potential releases, fires and their influence.     

Assessment of chemical process hazards in early design stages

A new method called SREST-layer-assessment method with automated software tool is presented that in a hierarchical approach reveals the degree of non-ideality of chemical processes with regard to SHE (safety, health and environment) aspects at different layers: the properties of the chemical substances involved (substance assessment layer (SAL)), possible interactions between the substances (reactivity assessment layer (RAL)), possible hazard scenarios resulting from the combination of substances and operating conditions in the various equipments involved (equipment assessment layer (EAL)), and the safety technologies that are required to run a process safely and in accordance with legal regulations (safety-technology assessment layer (STAL)). In RAL, EAL and STAL the main focus is put on process safety. A case study is used to show the principles of the method. It is demonstrated how the method can be used as a systematic tool to support chemical engineers and chemists in evaluating chemical process safety in early process development stages.     

A review of the past,present and future of the European loss prevention and safety promotion in the process industries

In 2013, the European Federation of Chemical Engineering (EFCE) celebrates its 60th anniversary. EFCE has continually promoted scientific collaboration and supported the work of engineers and scientists in thirty European countries. As for its mission statement, EFCE helps European Society to meet its needs through highlighting the role of Chemical Engineering in delivering sustainable processes and products. Within this organizational framework the Loss Prevention Symposium series, organized throughout Europe on behalf of the Loss Prevention Working Party of the EFCE, represents a fruitful tradition covering a time span of forty years. The tri-annual symposium gathers experts and scientists to seek technical improvements and scientific support for a growingly safer industry and quality of life. Following the loss prevention history in this paper, a time perspective on loss prevention and its future is presented.     

应用遗传算法优化氢气/空气燃烧反应系数

研究目的是优化氢气/空气简化反应机理的系数,使得简化机理在一定的误差范围内,能代替详细机理.通过计算氢气/空气详细反应机理得到的组分浓度作为遗传算法的适应度目标,对简化机理进行优化.结果显示,优化后的简化机理不仅在在计算组分浓度,而且在层流预混火焰速度和组分时空分布方面,更加接近详细机理所能达到的计算结果,比优化之前的简化反应机理计算结果更加准确.