Process Sites Research Articles

Analysis of physical and cyber security-related events in the chemical and process industry

Security threats are becoming an increasing concern for chemical sites and related infrastructures where relevant quantities of hazardous materials are processed, stored or transported. In the present study, security related events that affected chemical and process sites, and related infrastructures, were investigated. The aim of the study is to frame a clear picture of the threats affecting the chemical and process industry, and to issue lessons learnt from past events. A database of 300 security-related accidents was developed and populated, starting from European and American sources. Threat categories that caused such events were identified and analyzed. The attack modes were investigated. Important differences were found with respect to geographical areas and industrial sectors affected. The use of explosives (both military and improvised explosive devices) is by far the more frequent attack mode, although armed attacks and arson are also frequent events and may result in an in-depth penetration of the attackers. In recent years, cyber-attacks are also posing important threats. Lessons learnt call for the implementation of a specific security management system in the chemical and process industry, aiming at the physical and cyber protection of industrial sites.

Surface-Enhanced Raman Spectroscopy of Carbon Nanomembranes from Aromatic Self-Assembled Monolayers.

Surface-enhanced Raman scattering spectroscopy (SERS) was employed to investigate the formation of self-assembled monolayers (SAMs) of biphenylthiol, 4'-nitro-1,1'-biphenyl-4-thiol, and p-terphenylthiol on Au surfaces and their structural transformations into carbon nanomembranes (CNMs) induced by electron irradiation. The high sensitivity of SERS allows us to identify two types of Raman scattering in electron-irradiated SAMs: (1) Raman-active sites exhibit similar bands as those of pristine SAMs in the fingerprint spectral region, but with indications of an amorphization process and (2) Raman-inactive sites show almost no Raman-scattering signals, except a very weak and broad D band, indicating a lack of structural order but for the presence of graphitic domains. Statistical analysis showed that the ratio of the number of Raman-active sites to the total number of measurement sites decreases exponentially with increasing the electron irradiation dose. The maximum degree of cross-linking ranged from 97 to 99% for the three SAMs. Proof-of-concept experiments were conducted to demonstrate potential applications of Raman-inactive CNMs as a supporting membrane for Raman analysis.

Two-photon fluorescence probe for precisely detecting endogenous H2S in lysosome by employing a dual lock system

Hydrogen sulfide (H2S) is involved in various pathological and physiological processes as well as regulation of lysosomal functions. Thus, it is essential to develop precise method for the detection of H2S in lysosome. Although a large number of fluorescent probes for H2S have been developed, the probe for lysosomal H2S assay still remains rare. Herein, a two-photon fluorescent probe, named Lyso-Nap, is designed and synthesized for detecting H2S in lysosome by employing a dual lock system (dual PET process and dual reaction sites). The fluorescence of Lyso-Nap with dual lock system is opened by H2S only when the probe is localized within acidic lososomes, which can avoid the disturbance from neutral cytosol and other organelles. Moreover, two-photon fluorescent probes with weak auto-fluorescence, large penetration depth and reduced photodamage, are particularly favored for bioimaging. Accordingly, Lyso-Nap can be successfully used for precisely tracking and detecting endogenous H2S in lysosome of living cells and tissue.

Authority and access to the cassiterite and coltan trade in Bukama Territory (DRC)

This study analysed how local dynamics are influenced by artisanal mining sector reforms introduced in the Democratic Republic of the Congo (DRC) starting in 2009. These reforms, aiming to prevent the mineral trade from financing the country’s armed conflict, redefined local access provision to mineral trade. Examining the specific case of Bukama, a territory in south-eastern DRC, the study showed how the objective of establishing responsible supply chains resulted in a process of territorialisation. Through this process, traders and mine sites became listed, demarcated and classified, creating a new access order, giving rise to disputes and redirecting access towards large-scale traders. Against a background of the central state’s limited territorial reach and in the absence of a clear legal framework, the reforms allowed institutional voids to surface. This study found that the resulting emergence and acceptance of locally negotiated access arrangements redirected access-granting authority towards local state institutions. Although the reforms have resulted in increased oversight over mineral flows, they have had the opposite effect on the organisation of access, making the provision of access to the mineral trade less transparent. The article draws upon extensive intermittent qualitative fieldwork conducted in Bukama territory, Kalemie and Lubumbashi from 2014 to 2016.

Microbiological Profile of Three Commercial Poultry Processing Plants in Colombia

Poultry meat production in Colombia has significant growth potential to fulfill national demands and to become an important global exporter. Entering export markets requires compliance with international food safety standards and the support of a rigorous national inspection system. To support the development of national standards, information about the microbiological profiles of poultry operations is needed, and no official microbiological baseline is currently available. A total of 480 chicken carcass rinses and 64 fecal samples were collected at different process sites from three commercial poultry processing establishments located in different regions of Colombia. Samples were analyzed to determine the prevalence of Salmonella and the levels of Escherichia coli in chicken rinse. Six steps were selected for sampling in the slaughter, evisceration, and chilling processes. The overall Salmonella prevalence after water immersion chilling at the three establishments was 12.5% (73 of 584 samples). E. coli levels were 1.2 to 2.2 log CFU/mL (mean, 1.65 log CFU/mL) after the chilling process. Significant differences (P < 0.05) were found for E. coli levels among the processing sites at the three establishments; however, there were no significant differences in the distribution of Salmonella-positive samples through the sites at each plant. These results can be used as reference data for microorganisms in chicken meat facilities in Colombia and will help the poultry industry and regulators in the design of new prevention programs and food safety management systems.

Memories of past morphologies

Cell Biology When developing neurons round and divide during neuronal differentiation, daughter cells tend to take up the same morphology exhibited by their mother. Boubakar et al. set up a chick embryo slice model to image the polarization of dorsal root ganglion neurons. These neurons differentiate from neural crest cells (NCCs) generated by bipolar progenitors. The authors examined the young neurons directly after their migration or after additional division in situ. Bipolar NCCs lost their polarity and retracted their processes to round for division. The daughter neurons directly acquired bipolar morphology by emitting processes in the same location. The morphological polarity features appeared to be stored by a polarity-associated protein known as Septin-7. Septin-7 “tagged” the process sites during NCC remodeling, allowing the cells to recolonize the original footprints after division. Neuron 95 , 834 (2017).

Molecular Memory of Morphologies by Septins during Neuron Generation Allows Early Polarity Inheritance

Transmission of polarity established early during cell lineage history is emerging as a key process guiding cell differentiation. Highly polarized neurons provide a fascinating model to study inheritance of polarity over cell generations and across morphological transitions. Neural crest cells (NCCs) migrate to the dorsal root ganglia to generate neurons directly or after cell divisions in situ. Using live imaging of vertebrate embryo slices, we found that bipolar NCC progenitors lose their polarity, retracting their processes to round for division, but generate neurons with bipolar morphology by emitting processes from the same locations as the progenitor. Monitoring the dynamics of Septins, which play key roles in yeast polarity, indicates that Septin 7 tags process sites for re-initiation of process growth following mitosis. Interfering with Septins blocks this mechanism. Thus, Septins store polarity features during mitotic rounding so that daughters can reconstitute the initial progenitor polarity.

AgCu/SiC-powder: A highly stable and active catalyst for gas-phase selective oxidation of alcohols

Highly active and selective bimetallic AgCu/SiC-powder catalysts have been prepared by a facile method for the gas-phase selective oxidation of alcohols (such as 99.3% benzyl alcohol conversion and 99.6% benzyl aldehyde selectivity). The catalytic activity can maintain at least 200h compared with Cu/SiC (only within 10h). The formation of Ag-Cu2O ensembles brings about enhanced improvement both in conversion and stability. The XPS results reveal that large amounts of Ag0-Cu2O active sites formed after pre-activation process and Cu2O sites play a dominant role in benzyl alcohol oxidation reaction. Dehydrogenation reaction process has also been confirmed by O2-TPD.

A novel screening framework for waste heat utilization technologies

Waste heat exploitation improves the energy efficiency of process sites, ensuring lower costs and lower CO2 emissions. Technologies such as organic Rankine cycles, absorption chillers, mechanical heat pumps, absorption heat transformers and absorption heat pumps exist to utilize waste heat. Though these technologies make waste heat re-use technically feasible, selection of technologies based on different heat source temperatures still needs to be addressed. In this work, a novel screening approach is proposed to compare technologies considering the waste heat source quality. A methodology is also presented to select technologies for a process site based on the screening results. Since multiple energy form interactions occur, the screening criterion considers the deviation of the actual performance from the ideal performance of technology options, taking into account irreversibilities as a result of finite temperature heat transfer. The tool is applied to screen and select technologies for waste heat sources below 265 °C. Results identify the temperature ranges where technologies have minimum exergy degradation. The framework systematically matches heat source temperatures with technology options compared to a trial and error approach. The framework was applied to an industrial case study to recover 45,660 kW of useful energy from the available waste heat.

A study on the performance assessment of anti-terrorism physical protection systems in chemical plants

The threat originating from deliberate attacks against process and chemical sites where relevant quantities of hazardous substances are stored or processed is a credible one, as confirmed by the attacks carried out in France in the summer of 2015. Although such chemical sites implement multiple layers of protection to address safety-related accidents, they often get behind with providing adequate attention and resources to the protection of assets against external adversaries or, in other words, terrorist threats. The lack of a consolidated practice in the risk-informed implementation of security countermeasures goes hand in hand with the existence of very few rigorous approaches to the effectiveness assessment of security systems, and in particular of physical protection systems (PPSs). The present study addresses the issue of quantitatively assessing the effectiveness of physical security systems adopted to protect process and storage facilities, recognized as high-consequence loss physical assets. To this purpose, the security functions of PPSs were analyzed to guide the selection of performance parameters. Experts from the industry were involved to identify variables and influencing factors relevant to the successful accomplishment of security functions. Experience-based judgments on performance, to be expressed in terms of probabilistic estimates, were also obtained. An insight into the belief that experts hold on the probability of PPSs effectively preventing the success of an external attack and in the identification of critical elements was obtained. The application of the results to the quantitative assessment of the contribution of security controls in reducing vulnerability was also addressed.

GIS-based fuzzy MCDA approach for siting refugee camp: A case study for southeastern Turkey

After domestic turbulence in Syria on 2011, many Syrian refugees have migrated to Turkey in progressive amounts. Turkey provides temporary protection for these refugees both in and out of refugee camps. Approximately 10% of the refugees stay at the refugee camps according to statistics of Ministry of Interior Directorate General of Migration Management. These events reveal the need for additional refugee camps. In this shift from emergency to stable phase, scientific based selection and design methods are beneficial for the situation. Thus, a three-step solution approach is developed. Firstly, various geographic, social, infrastructural and risk related criteria are determined for 10 southeastern cities in Turkey which are very close to Syrian border. Secondly, these criteria are entered into geographic information system (GIS) software to assign a refugee camp siting availability score. Lastly, indicators are prioritized using fuzzy analytic hierarchy process (FAHP) and potential refugee camp sites are ranked using technique for order of preference by similarity to ideal solution (TOPSIS). As a result, 15 new refugee camp sites are offered considering the pre-determined indicators. The model definitely shows that suggested alternative camp locations are more suitable than the current camps.

A mixed integer linear programming model for integrating thermodynamic cycles for waste heat exploitation in process sites

Thermodynamic cycles such as organic Rankine cycles, absorption chillers, absorption heat pumps, absorption heat transformers, and mechanical heat pumps are able to utilize wasted thermal energy in process sites for the generation of electrical power, chilling and heat at a higher temperature. In this work, a novel systematic framework is presented for optimal integration of these technologies in process sites. The framework is also used to assess the best design approach for integrating waste heat recovery technologies in process sites, i.e. stand-alone integration or a systems-oriented integration. The developed framework allows for: (1) selection of one or more waste heat sources (taking into account the temperatures and thermal energy content), (2) selection of one or more technology options and working fluids, (3) selection of end-uses of recovered energy, (4) exploitation of interactions with the existing site utility system and (5) the potential for heat recovery via heat exchange is also explored. The methodology is applied to an industrial case study. Results indicate a systems-oriented design approach reduces waste heat by 24%; fuel consumption by 54% and CO2 emissions by 53% with a 2year payback, and stand-alone design approach reduces waste heat by 12%; fuel consumption by 29% and CO2 emissions by 20.5% with a 4year payback. Therefore, benefits from waste heat utilization increase when interactions between the existing site utility system and the waste heat recovery technologies are explored simultaneously.The case study also shows that the novel methodology can select and design optimal solutions for waste heat exploitation which are technically, economically and environmentally feasible from a range of technology options, heat sources and end-uses of recovered energy.

Distributions, profiles and formation mechanisms of polychlorinated naphthalenes in cement kilns co-processing municipal waste incinerator fly ash

Co-processing municipal solid waste incinerator (MSWI) fly ash in cement kilns is challenging because the unintentional production of persistent organic pollutants (POPs) during the process is not well understood. The distributions, profiles and formation mechanisms of polychlorinated naphthalenes (PCNs) as new POPs covered under Stockholm Convention in two cement kilns co-processing MSWI fly ash were studied. The average concentrations of PCNs in stack gas samples were 710 ng m−3. The PCN concentration in particle samples collected from different process stages in the cement kilns ranged from 1.1 to 84.7 ng g−1. Three process sites including suspension pre-heater boiler, humidifier tower, and the kiln back-end bag filter were identified to be the major formation sites of PCNs in cement kilns co-processing MSWI fly ash. The PCN distribution patterns were similar to that of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs), which indicates the possibility for simultaneous control of PCNs and PCDD/Fs in cement kilns co-processing fly ash. Chlorination was suggested to be an important formation mechanism of PCNs, and chlorination pathways of PCN congeners are proposed based on the congener profiles. Thermodynamic calculations, including relative thermal energies (ΔE) and standard free energy of formation (ΔG), and the charge densities of the carbon atoms in PCN supported the proposed chlorination mechanisms for PCN formation. The results presented in this study might provide helpful information for developing techniques and strategies to control PCN emissions during cement kilns co-processing MSWI fly ash.

Hydroformylation: Fundamentals, Processes, and Applications in Organic Synthesis

Highly active and selective bimetallic AgCu/SiC-powder catalysts have been prepared by a facile method for the gas-phase selective oxidation of alcohols (such as 99.3% benzyl alcohol conversion and 99.6% benzyl aldehyde selectivity). The catalytic activity can maintain at least 200 h compared with Cu/SiC (only within 10 h). The formation of Ag-Cu2O ensembles brings about enhanced improvement both in conversion and stability. The XPS results reveal that large amounts of Ag0-Cu2O active sites formed after pre-activation process and Cu2O sites play a dominant role in benzyl alcohol oxidation reaction. Dehydrogenation reaction process has also been confirmed by O2-TPD.

Modelling and screening heat pump options for the exploitation of low grade waste heat in process sites

The need for high efficiency energy systems is of vital importance, due to depleting reserves of fossil fuels and increasing environmental problems. Industrial operations commonly feature the problem of rejecting large quantities of low-grade waste heat to the environment. The aim of this work is to develop methods for the conceptual screening and incorporation of low-temperature heat upgrading technologies in process sites.The screening process involves determination of the best technology to upgrade waste heat in process sites, and the combination of waste heat source and sink temperatures for a technology. Novel simplified models of mechanical heat pumps, absorption heat pumps and absorption heat transformers are proposed to support this analysis. These models predict the ratio of the real performance to the ideal performance in a more accurate way, than previous simplified models, taking into account the effect of changing operating temperatures, working fluids non-ideal behaviour and the system component inefficiencies.A novel systems-oriented criterion is also proposed for conceptual screening and selection of heat pumps in process sites. The criterion (i.e. the primary fuel recovery ratio) measures the savings in primary fuel from heat upgraded, taking into account power required to drive mechanical heat pumps and missed opportunities for steam generation when absorption systems are used.A graphical based methodology is also developed for applying the PRR in process sites and applied to a medium scale petroleum refinery. Results show that applying the PRR yields 9.2% additional savings in primary fuel compared to using the coefficient of performance to screen and incorporate heat pumps.

Process integration of waste heat upgrading technologies

Technologies such as mechanical heat pumps, absorption heat pumps and absorption heat transformers allow low-temperature waste heat to be upgraded to higher temperatures. This work develops a comprehensive Mixed Integer Linear Program (MILP) to integrate such technologies into existing process sites. The framework considers interactions with the associated cogeneration system (in order to exploit end-uses of upgraded heat within the system and determine their true value), temperature and quantity of waste heat sources and of sinks for the heat upgraded as well as process economics and the potential to reduce carbon dioxide (CO2) emissions. The methodology is applied to an industrially relevant case study. Integration of heat upgrading technologies has potential to reduce total costs by 23%. Sensitivity analysis is also performed to illustrate the effect of changing capital costs and energy prices on the results, and demonstrate the model functionality.

Evaluating the potential of process sites for waste heat recovery

As a result of depleting reserves of fossil fuels, conventional energy sources are becoming less available. In spite of this, energy is still being wasted, especially in the form of heat. The energy efficiency of process sites (defined as useful energy output per unit of energy input) may be increased through waste heat utilisation, thereby resulting in primary energy savings.In this work, waste heat is defined and a methodology developed to identify the potential for waste heat recovery in process sites; considering the temperature and quantity of waste heat sources from the site processes and the site utility system (including fired heaters and, the cogeneration, cooling and refrigeration systems). The concept of the energy efficiency of a site is introduced – the fraction of the energy inputs that is converted into useful energy (heat or power or cooling) to support the methodology. Furthermore, simplified mathematical models of waste heat recovery technologies using heat as primary energy source, including organic Rankine cycles (using both pure and mixed organics as working fluids), absorption chillers and absorption heat pumps are developed to support the methodology. These models are applied to assess the potential for recovery of useful energy from waste heat.The methodology is illustrated for an existing process site using a case study of a petroleum refinery. The energy efficiency of the site increases by 10% as a result of waste heat recovery. If there is an infinite demand for recovered energy (i.e. all the recoverable waste heat sources are exploited), the site energy efficiency could increase by 33%. The methodology also shows that combining technologies into a system creates greater potential to exploit the available waste heat in process sites.

A hierarchical approach for evaluating and selecting waste heat utilization opportunities

This paper presents a ranking criterion for evaluating opportunities that utilize recovered energy from the available waste heat in process sites. The ranking criterion takes into account the energy performance of waste heat recovery technologies associated with each opportunity, their potential to reduce greenhouse gas emissions (namely CO2) and the economics (costs and benefits). Mathematical modelling of the opportunities using the ranking criterion is developed to allow for systematic evaluation of opportunities, for example within an optimization framework. A methodology using the ranking criterion to design site waste heat recovery systems is also proposed.The methodology is applied to a case study of a petroleum refinery. Hierarchy and performance of waste heat utilization opportunities depends on the temperature of the heat available, amongst other factors. The site operating cost and CO2 emissions reduce by 26% and 18% respectively when opportunities to use the recovered energy from waste heat within and outside the process site boundaries are explored. Sensitivity of the ranking to energy prices is studied, to explore the outlook for waste heat utilization in the future. The methodology can be applied to the process industries and other facilities producing waste heat.

Detonations and vapor cloud explosions: Why it matters

The methods used to evaluate the consequences of a vapor cloud explosion assume deflagrations within congested process pipework regions and consequently a significant effort has been invested in developing models to estimate the severity of these deflagrations. Models range from the simpler screening approaches to detailed Computational Fluid Dynamics. There is clear evidence from large scale experiments and incidents that transition from deflagration to detonation is credible and has occurred and it is the contention of this paper that deflagration is only the first stage in many major vapor cloud explosions and that detonation is readily foreseeable. Why does this matter? The methods currently used in the design and location of buildings on and around process sites are based on an incomplete picture of vapor cloud explosions. Whilst this might not have a significant effect in some cases, it is shown that there is the potential to significantly underestimate the explosion hazard. This will result in occupied buildings either being placed in the wrong location or under-designed for the explosion threat, increasing the risks to personnel on these sites.

Modelling and planning public cultural schedules for efficient use of resources

This paper addresses a decision making problem concerning the planning of cultural schedules. The model maximizes the overall welfare of the entire system by integrating the different parties involved in the process (artistic agents, sites and administration) in a unified setting. In order to solve the proposed model this paper also derives fast ad hoc heuristics and different Lagrangian relaxations that lead to good lower and upper bounds. These bounds are later used to obtain feasible solutions that improve the currently available lower bounds. All these elements are tested over a testbed of random instances to analyze their computational performance, showing promising results. In addition, we present one particular instance based upon actual data gathered in Andalusia (Spain). The results of this analysis draw interesting conclusions on how to improve the efficient use of public funds devoted to promote cultural activities.