Kamarizan Kidam

Technical Analysis of Accident in Chemical Process Industry and Lessons Learnt

A study of past accidents in the chemical process industry (CPI) has been carried out. It is found that the majority (73%) of the accidents were caused by technical and engineering failures. Based on the causes of accident and types of equipment failures, five common features of accident in the CPI were identified. The analysis reveals that the contribution of the design to accidents is significant and the advancement of knowledge/technology is not shared effectively by practitioners. Dependency on the add-on control strategy should be reduced and inherently safer or passive engineered must be considered as premier risk reduction strategy to lessen the safety load, for better design and to prevent accident effectively.

The Influence of 90 Degree Bends in Closed Pipe System on the Explosion Properties Using Hydrogen-Enriched Methane

This work sought to evaluate the explosion severity on hydrogen enrichment in methane-air mixture explosion. For this purpose, different hydrogen mixture compositions ranges between 4 to 8% v/v were considered. This work was performed using CFD tool FLACS that has been well validated for safety studies on both natural gas/methane and hydrogen system. FLACS is used to validate the maximum pressure and flame speed predicted by the CFD tool for combustion of premixed mixtures of methane and hydrogen against the experimental data. Experimental work was carried out in a closed pipe containing 90- degree bends with a volume of 0.41 m3, operating at ambient conditions. From the experiment observation, it shown that the coupling effect of bending and thermal diffusivity gave the dramatic influent on explosion severity in hydrogen-methane/air at very lean concentration. However, simulation results showed that FLACs is under-predicting the overpressure at very lean concentration of hydrogen in methane/air mixtures. It can be said that lower hydrogen content in methane/air mixture limits the hydrogen diffusivity, leading to the decrease of the burning rate and flame speeds. It is also demonstrated that the presence of 90-degree bend in closed pipe system increases the simulated flame speeds to the factor of 2-3, as compared to the experimental data. There are significant discrepancies between experimental and simulation, however, the results seem conservative in general.

Analysis of main accident contributor according to process safety management elements failure

Process safety management (PSM) covers the aspect of process hazard identification, understanding the level of risk and hazard reduction to prevent process-related failures. The need for understanding on how the process safety elements fail is essential in improving the quality of the accidents prevention effort. In this paper, the contributions of PSM element to chemical process accident are studied using major process failures in the chemical process industry (CPI). Around 770 major accident cases were collected and analysed from several accident data base such as Chemical Safety and Hazard Investigation Board (CSB-US), European Major Accident Reporting System (EMARS), Failure Knowledge Database (FKD-Japan) and Accident Reporting Information Analysis (ARIA). The PSM element failures were ranked in accordance to their frequency and importance in accident prevention. Based on the result, majority of the element failure is classified as design and technical reasons (53 % of total process failures) and the rest is related to management related causes (47 %). The most common accident contributors were identified to be the process hazards analysis (19 % of total process failures), operating procedures (17 %), employee participation (12 %), training (11 %), management of change (9 %), mechanical integrity (9 %), and permit to work (9 %). In depth, analysis on individual PSM elements were made for better understanding on their readiness and its implementation issues in the CPI. Appropriate suggestion for continuous improvement of PSM implementation will also be suggested.

Major Hazards of Process Equipment Failures in the Chemical Process Industry

Process equipment failures play significant roles in most accidents that occur and recur in the chemical process industry resulting in fire, explosion, and toxic release. In this study, 50 equipment-related accident investigation reports were used to analyze type and severity of incidents. The comprehensive accident report data were retrieved from U.S. Chemical Safety and Hazard Investigation Board (CSB) and U.S. National Transportation Safety Board (NTSB) accident databases with a mean year of 2005. Among the identified process equipment failures were piping systems (32%), storage tanks (20%), process vessels (16%), separation equipment (10%), reactors (8%), heat transfer equipment (8%), and others (6%). The analysis shows that 32% of the cases led to fire and explosion, followed by toxic release (26%), and explosion (22%) incidents. A total of 126 fatalities, 590 injuries, 260 exposures, four shelter-in-place, and 13 evacuations were reported. In most accident cases, fire, explosion, and/or toxic release incidents occur simultaneously. The synergy between major hazards results in catastrophic accidents with severe consequences in numbers of fatalities, injuries, exposures, shelter-in-place, and evacuations. To minimize the losses, plant and equipment should be designed and prepared for the worst-case scenario, not just adapting to any ‘applicable’ standards or guidance.

The application of first and second orders of inherent safety in the chemical process industry

The inherent safety (IS) concept has been introduced for more than 45 years, yet its adoption into process design is still very low. As a result, similar accidents keep on occurring worldwide since a majority of the risk reduction strategies used are based on the outer layers of protection such as active engineered and procedural. To enhance the uptake of inherent safety into chemical plant design, this paper aims to outline the common inherent safety strategies that have been used by the chemical process industry (CPI) to prevent accidents. 502 cases of inherently safer design (ISD) applications in the CPI have been collected and analysed. The process changes through plant modification are grouped based on the four main ISD strategies of minimisation, substitution, moderation, and simplification. The four main ISD keywords are then further classified into a hierarchy of inherent safety order. 58 cases (12 %) fall under first order IS which is from substitution keyword. For the 2nd order IS (magnitude), the keyword minimisation gives 242 cases (48 %) while moderation gives 151 (30 %). The simplification keyword which is under 2nd order IS (likelihood) gives 51 cases (10 %). The 2nd order IS (magnitude) seems to give the biggest numbers of design changes made by the CPI. Magnitude reduction strategy is the common choice by the CPI when designing safer equipment or process.

Contribution of permit to work to process safety accident in the chemical process industry

Permit to Work (PTW) is the Technical Measurement Document required to control work such as maintenance, inspection, modification and non-routine high risk activities to prevent a major accident. It is one of the elements of the Process Safety Management (PSM). The current issue of the chemical process industry (CPI) is that the accident rate has not decreased even though PSM has been widely implemented in the developed country. Statistics on the accident cases published by Chemical Safety and Hazard Investigation Board (US), European Major Accident Reporting System and Failure Knowledge Database (Japan) has revealed that PTW has significance contribution to the occurrence of accidents and is worthwhile to be studied in details. Failure in complying with PTW system has caused major accidents cases, such as Motiva Enterprise LLC (2001), Phillips Pasadena (1989) and Piper Alpha Platform (1988). Another reason for studying PTW, being that the trend of its percentage of contribution to process accident rate is not decreasing over the past two decades even though there are shared information and feedback available. In the chemical process industry, there are various types of PTW namely Hot Work, Confined Space Entry, Line breaking & vessel opening and others. Each has its own function and the percentage contribution of each PTW type is determined using data mining approach. This study is focusing on the identification of main factors of PTW- related accidents which are classified under organisation, human factors, communication, competency, procedure, supervision, tools and equipment and etc. The percentage contribution of each main factor is determined and the results are presented for sharing and learning purposes.

The contribution of management of change to process safety accident in the chemical process industry

Management of Change (MOC) is a process for evaluating and controlling modifications to facility design, operation, organisation, or activities. It is one of the most important elements of Process Safety Management (PSM). In chemical process industries (CPI), MOC is required to ensure that safety, health and environment are controlled. In recent years, the number of accidents related to MOC failure is significant and caused by the lacks of MOC management, organisation safety culture, design failure, incompetency, human factor and etc. From the accident statistics published by Chemical Safety and Hazard Investigation Board (CSB-US), European Major Accident Reporting System (EMARS-European), Failure Knowledge Database (FKD-Japan) and Accident Reporting Information Analysis (ARIA-France), MOC contributes significantly to the occurrence of accidents and its percentage contribution to accident rate is not decreasing over the past 20 years. In this paper, the contribution of MOC failure to accidents and their main failure factor are identified from the study of over thousands of accident cases and analysed with data mining method. Study revealed the major factor of MOC failure are the lack of organisation commitment, lack of experience, limitation of resources, inadequate of HAZOP study, human factor, safety culture and etc. Good practice of MOC has to be inculcated in CPI through learning from past accident and continuous improvement of MOC system.

Current status on hydrogen production technology by using oil palm empty fruit bunch as a feedstock in Malaysia

In Malaysia, the growth of economic is connected to the fossil energy resources which are continued to effect by the growing of energy demand. Hydrogen is an alternative for energy and electricity generation, especially for transportation application and can significantly reduce the carbon monoxide (CO) emission and air pollution. The research on renewable energy especially from biomass such as oil palm empty fruit bunch (OPEFB) can contributes to reduce the concern over the energy insecurity and will help Malaysia in creating a sustainable energy supply. Research on the hydrogen production process by using OPEFB was reported in several papers. However, the review criteria and the best technology for hydrogen production process application are still missing. This paper attempts to develop hydrogen technology database from various types of hydrogen production process of OPEFB. It can be used to determine the most feasible and promising route to be applied. This study is also significant in helping the industry to see the differences of various design alternatives and make process design decisions on them.

Dielectric properties for extraction of orthosiphon stamineus (Java Tea) leaves

A dielectric properties study was performed at ISM frequencies and a range of temperatures (25 – 45 °C) on the extraction of Orthosiphon Stamineus (Java Tea) leaves system in order to relate their dielectric properties to microwave heating mechanisms and design of microwave applicator quantitatively. The main results concluded that the heating mechanism of the extraction mixture in an electromagnetic field was controlled by the dielectric properties of solvent (water), where the solvent was the major component (> 90 % v/v) as well as the component with highest dissipation factor (tan d). The penetration depths of extraction mixture at ambient temperature (25 °C) are 3.8 cm, 3.2 cm and 1.4 cm at ISM frequencies of 0.433 GHz, 0.915 GHz and2.45 GHz. These tiny penetration depths limit the potential to achieve the successful scale up of a microwave- assisted extraction of Orthosiphon Stamineus leaves in batch mode at ISM frequencies. This will lead to inhomogeneous bulk temperature distribution within the extraction mixture and irreproducible extraction yield without sufficient stirring and stirrer compatible with microwave system. A fast heating rate based on a high value of tan d of the extraction mixture revealed that the microwave heating technique has a great potential in reducing the processing time especially at heating up stage compared to conventional thermal heating technique in extraction of Orthosiphon Stamineus leaves. The dielectric properties of extraction mixture are worth to be considered to certify the consistency and reproducibility of the microwave-assisted extraction at large scale production.

A simulation of claus process via aspen hysys for sulfur recovery

Abstract In refineries, due to the environmental pollutions, sulfur content in petroleum need be reduced. The incineration process is used for sulfur recovery system which is not friendly process to the environment and needs high temperature. This actual process exhaust high amount of SO2 from the incinerator stack to the environment. The Claus process is the best method to recover sulfur from acid gases that contain hydrogen sulfide. The particular reaction for sulfur removal from sour gas is hydrogen sulfide (H2S) sulfur dioxide (SO2) reformation (2H2S+O2=S2+2H2O). The aim of this study is to get a simulation that is suitable for the characterization of sulfur recovery units. The experimental design for this study was collected from a petroleum refinery located in Iran. This experimental relation supports us to gather with definite consistency that is normally not available online for such process. Aspen HYSYS v8.8 software was used to simulate the Claus process by reactors and component splitters. The result shows the complete conversion of sour gas to product. The simulation protects the environmental impact by SO2 emission. This behavior can be reproduced by this HYSYS design very well. It was found that the BURNAIR feed composition and molar flow is the only factors which can affect the hydrogen sulfide conversion. The sulfur mole fraction increased only in the range of 0.94 to 0.98 by increasing N2 from 0.7 to 0.9.