Process Control Safety Research Articles

High sensitivity gas detection based on Au waveguide

Hydrogen, as a representative of the new energy source, has great potential for development, and the detection of the low concentration of hydrogen plays a crucial role in process safety control. In this paper, a gas sensor based on a metal-insulator-metal (MIM) structure with high sensitivity and low response time is proposed. The sensor is bilaterally coupled with a ring resonant cavity and a metal nanopillar, and the outgoing field superposition is achieved by bilaterally coupling the resonant cavity to achieve a lower transmittance, which facilitates detection. The symmetry of the structure was broken by different methods, and the results showed that the complexity and response time of the structure increased significantly after breaking the symmetry, but the transmittance appeared to decrease and the transmission characteristic curve was independent of the coupling phase. The waveguide structure shows a highly linear relationship between resonance wavelength and refractive index with a maximum sensitivity of 2433.00 nm/RIU when used for refractive index sensing, and a maximum sensitivity of −2.61 nm/% when used for hydrogen gas sensing. For methane gas sensing, the maximum sensitivity is −9.22 nm/%.

Process safety assessment of thermal technologies for biomass valorization by numerical descriptive approach

Process-based safety assessment of biomass thermal valorization technologies including hydrothermal gasification (HTG), pyrolysis, and conventional gasification has been evaluated based on the Numerical Descriptive Logistics Equation (NuD). Process-related data such as temperature, pressure, heat of reaction, and process inventory were collected from the literature for this purpose. The data has been analyzed by using the NuD equations to obtain the process safety total score (PSTS), and then hierarchy of control (HOC) has been applied to propose the strategies for risk mitigation. According to the NuD results, the HTG process has a lower PSTS (210.2) compared with pyrolysis (226.4) and gasification (228.5), and it reveals that HTG is the safest among these three technologies. HTG has the highest score for pressure (60.48) because it has the high pressure (20–25 MPa) process requirement, but the lowest scores for temperature and heat of reaction due to lower temperature operations (374–400 °C) compared with pyrolysis and gasification. The results determined by the NuD have been compared with subjective safety evaluation methods (Process Safety Index Analysis and Inherent Safety Index), and the results of inherent safety index (ISI) are also consistent with that determined by the NuD. Hierarchy of control has been proposed to control and reduce the process risk. As per results, engineering and administrative measures could be drafted for more effective process safety control.

Pouzdanost i validnost mernog instrumenta za ocenu organizacionih faktora u modelu menadžmenta rizikom opreme pod pritiskom

In recent decades, process safety control and process safety risk assessment have become very attractive topics. The way control is carried out, using tools such as HAZOP, FMEA, FTA, and similar is not sufficient to adequately prevent or control accidents with serious consequences in the process industry. The need to analyze the causes of the causes themselves, with special emphasis on the impact of organizational factors has arisen. This research results in the development of an original, reliable, and valid measuring instrument for assessing organizational factors important for risk assessment methodologies in working with pressure equipment. The initial instrument was designed based on the previous research and then checked by statistical analysis, using the Kaiser-Meyerto-Olkin test, exploratory factor, and reliability analysis. The proposed instrument has reduced 71 to 48 dimensions, describing 10 organizational factors important for risk management of pressure equipment. Providing a valid and reliable measurement instrument is essential for a proactive approach, which enables managers employed in the organization to mitigate the risks of pressure equipment operation, and prevent accidents. The proposal of further research is the application of confirmatory factor analysis or/and structural equation modeling on data collected.

Economic and financial consequences of process accidents in Brazil: Multiple case studies

Along with the advancement of process industries, there has been an increase in process safety accidents (as defined in the 1970s), which often cause deaths and damages to properties, communities, the environment, and the local economy. Process safety management (PSM) and legislation that can minimize dangerous incidents due to the failure of process operations are still insufficient in Brazil. Thus, this work aims to quantify the economic and financial consequences of three different process safety accidents using a case study methodology. The two first cases reflect extreme situations of accidents involving ruptures in tailings dams, which were used to store wastewater generated during ore processing (Mariana and Brumadinho). The Mariana dam disaster caused about 40 × 106 m3 of mining waste to be released, covering ∼1500 ha. The accident had a significant impact on the environment and economy throughout the Doce River Basin, resulting in a loss of US$5.28 billion. The Brumadinho disaster resulted in 270 deaths and 11 missing people, as well as severe environmental damage and property loss. Thirteen million cubic meters of tailings were released, damaging a 270-hectare region, and contaminating the Atlantic Forest natural reserves and the Paraopeba River. The total estimated cost, including production losses, fines, and damages, is US$13.48 billion. The third case is the fire at the Santos port terminal (São Paulo) caused by Ultracargo, which highlights the need for PSM policies and legislation because fire accidents are common in Brazil. Only the Port of Santos experienced at least one major fire case per year from 2013 to 2020. The fire spread to six storage tanks, consuming ∼30,000 m3 of fuel, resulting in a US$91.91 million loss for the company. The fire burned for nine days, causing delays in shipments, and a 4.3% reduction in agricultural exports during that period. Industrial process accidents, regardless of the severity of the accident or the type of product handled, have consistent economic and financial impacts on companies and the surrounding regions where they operate. This study exposes Brazil’s vulnerability in terms of process safety control and product storage. Therefore, Brazil has the opportunity to explore this topic further.

Use of a Curtius Rearrangement as Part of the Multikilogram Manufacture of a Pyrazine Building Block

Commercial route definition for a glucokinase activator called for a reevaluation of the synthesis and processes used to access multikilogram quantities of 2-amino-5-methylpyrazine. After consideration of different options, a variation of the Curtius rearrangement used by the medicinal chemistry route was selected for further development. The formation of an acyl azide for the Curtius rearrangement required a process safety control strategy to be put in place. The process developed was used to successfully deliver multikilogram quantities of 2-amino-5-methylpyrazine in an overall yield of 68%, starting from 5-methylpyrazine-2-carboxylic acid.

Cyclic operation of trickle bed reactors: A review

Familiarized with the steady state behavior and advantages of the trickle bed reactors (TBR), for the past two decades, researchers and process engineers are continuously exploring the unsteady state hydrodynamics of periodically (or cyclic) operated trickle bed reactors to extract even more from its efficiency and performance. Despite its complicated nonlinear behavior that attributes to the process control safety at the commercial scale, cyclic operation of TBR is a promising process intensification technology that has immense potential for implementation on industrial TBR. In this paper, we have summarized and reviewed the research and progresses made in recent years on cyclic operation of TBR and potential applications of various mode of its operation. Several issues associated with its hydrodynamics scale-up and designs have been discussed with an emphasis on shock wave attenuation that arises during flow modulation.

Molecularly Imprinted Polymers—Potential and Challenges in Analytical Chemistry

AbstractFor Abstract see ChemInform Abstract in Full Text.

Molecularly imprinted polymers—potential and challenges in analytical chemistry

Among the variety of biomimetic recognition schemes utilizing supramolecular approaches molecularly imprinted polymers (MIPs) have proven their potential as synthetic receptors in numerous applications ranging from liquid chromatography to assays and sensor technology. Their inherent advantages compared to biochemical/biological recognition systems include robustness, storage endurance and lower costs. However, until recently only few contributions throughout the relevant literature describe quantitative analytical applications of MIPs for practically relevant analyte molecules and real-world samples. Increased motivation to thoroughly evaluate the true potential of MIP technology is clearly attributed to the demands of modern analytical chemistry, which include enhanced sensitivity, selectivity and applicability of molecular recognition building blocks at decreasing costs. In particular, the areas of environmental monitoring, food and beverage analysis and industrial process surveillance require analytical tools capable of discriminating chemicals with high molecular specificity considering increasing numbers of complex environmental contaminants, pollution of raw products and rigorous quality control requested by legislation and consumer protection. Furthermore, efficient product improvement and development of new products requires precise qualitative and quantitative analytical methods. Finally, environmental, food and process safety control issues favor the application of on-line in situ analytical methods with high molecular selectivity. While biorecognition schemes frequently suffer from degrading bioactivity and long-term stability when applied in real-world sample environments, MIPs serving as synthetic antibodies have successfully been applied as stationary phase separation matrix (e.g. HPLC and SPE), recognition component in bioassays (e.g. ELISA) or biomimetic recognition layer in chemical sensor systems. Examples such as MIP-based selective analysis of flavones/flavonoids in wine, the determination of mycotoxins in beverages and analysis of organic contaminants in environment samples will elucidate the perspectives of this technology and will be contrasted with the challenges of rational MIP design providing control on binding site density, receptor capacity and selectivity.

Team situation awareness for process control safety and performance

AbstractThis paper defines situation awareness (SA) and discusses its importance to operator‐machine system safety and functioning in the context of process control activities. Specifically, identified are relationships of human detection of critical process cues converying the status of automated control systems and operator interpretation of the meaning and relevance of such information to the potential for negative incidents in chemical processing. Beyond individual operator SA in interacting with control systems, intra‐ and inter‐ work team SA are discussed for supporting individual attainment of process control responsibilities. Factors critical to team SA are discussed. “Road blocks” to team SA are also analytically examined. Lastly, methods for assessing individual and team SA are reviewed and vehicles for relating outcomes of these methods to changes in process control operator and team behavior to improve human‐machine system safety and performance are relayed.

Safety in process-control: An operator-centred point of view

Safety efforts are traditionally determined by the results of accident and incident analysis. Such analyses point to certain human errors as the dominant source of accidents. Support systems are then developed specifically to decrease these human errors. Based on an external safety viewpoint, this applies to transportation safety as well as plant safety. What is suggested in this paper, on the basis of findings from aeronautical field studies, is a more operator-centred safety viewpoint (internal viewpoint) which could explain some current disappointments in aiding operators. Pilots take care of incidents, planning and organizing their work as a result of their metaknowledge. They know they have limited resources and try to manage these resources as well as possible in order to do a good job with minimum risk. Most pilot expertise lies in avoiding situations where they have no solution or no chance of applying known solutions. In brief, pilots know that they are rather weak in reacting to events and compensate for these weaknesses by anticipating. The key-words of such a performance model are schematics of mental representation, flexibility in planning, anticipation, and balance between risk and efficiency. Consequences for the design of assistance systems are three-fold. First is the case of assistance systems which aim at providing the pilot with more information and more intelligence. According to the human performance model, the results of such assistance are often paradoxical, improving performance but not safety. Pilots tend spontaneously to maintain the same level of (acceptable) risk to the detriment of safety improvement. Second are support systems which aim at reacting to events. Again, the result is often disappointing. The picture is that such systems are hard for humans to understand because of the different nature of reasoning. Third are assistance systems which force the pilot to follow procedures or to be passive (the case of automation). Due to the rigidity of these procedures or automations, pilots cannot apply the model of anticipation-accommodation which is the basis of their own safety strategies. Therefore, they tend to abandon their role in order to ensure safety. The conclusion suggests that a design of support systems exclusively based on an external safety viewpoint can interact with natural and ecological ways of ensuring safety. The design of future support systems must take this perspective into account better in order to respect and take benefit from natural human abilities in ensuring safety. Some possible solutions to improve the design of assistance systems are indicated in the final section.

Standards and Certification as a Tool towards Safety in Process Control

Standards and Certification as a Tool towards Safety in Process Control