Search

Polymeric membranes are at non-equilibrium nature and inherently undergo a spontaneous evolution towards equilibrium known as physical aging. It is required to incorporate physical aging phenomena in membrane permeation mechanism to quantify such effect to the separative performance under varying membrane thicknesses. In this work, the volume relaxation process over the course of aging has been modeled employing the dual mode mechanism, which is comprised of lattice contraction and diffusion of free volume. Later, the dual mode model has been integrated within a succession of states methodology that analytically addresses the separation mechanism in a cocurrent membrane based on the solution-diffusion theory. To the best of our knowledge, this paper is the first pioneering attempt that incorporates the effect of aging on separation performance of membrane. In this study, when membrane thickness is increased from 100 to 400 nm, the initial membrane requirement is also increased by 3.85 times. Nonetheless, the recovery performance after 1 year of aging also reduces from 21.35% to 12.39%. It is found that although the thinner polymeric membrane inherits higher permeance characteristic, making it a highly sought after structure as compared to its bulk counterpart by exhibiting higher driving force and hence smaller area requirement, the thinner membrane also demonstrates drawback of accelerated physical aging, which contributes to higher reduction in product recovery. The optimum membrane thickness has been determined to be 174 nm in present work.

In this study, the solubility of carbon dioxide (CO2) in the aqueous solution of piperazine (PZ) activated N-methyldiethanolamine (MDEA) was investigated. In the aqueous solution the concentrations of the N-methyldiethanolamine (MDEA) and piperazine (PZ) were kept constant at 30 wt. % and 3 wt. %, respectively. The solubility experiments were carried out between the temperatures ranges of 303.15 to 333.15 K. The pressure range was selected as 2-50 bar for solubility of carbon dioxide in the aqueous solution. The solubility of the CO2 is reported in terms of CO2 loading capacity of the solvent. The loading capacity of the solvent is the ratio between the numbers of moles of CO2 absorbed to the numbers of moles of solvent used. The experimental data showed that the CO2 loading increased with increase in CO2 partial pressure, while it decreased with increase in system’s temperature. It was also observed from the experimental data that the higher pressure favors the absorption process while the increased temperature hinders the absorption process of CO2 capture. The loading capacity of the investigated solvent was compared with the loading capacity of the solvents reported in the literature. The investigated solvent showed better solubility in terms of loading capacity.

The employment of different mathematical models to address specifically for the bubble nucleation rates of water vapour and dissolved air molecules is essential as the physics for them to form bubble nuclei is different. The available methods to calculate bubble nucleation rate in binary mixture such as density functional theory are complicated to be coupled along with computational fluid dynamics (CFD) approach. In addition, effect of dissolved gas concentration was neglected in most study for the prediction of bubble nucleation rates. The most probable bubble nucleation rate for the water vapour and dissolved air mixture in a 2D quasi-stable flow across a cavitating nozzle in current work was estimated via the statistical mean of all possible bubble nucleation rates of the mixture (different mole fractions of water vapour and dissolved air) and the corresponding number of molecules in critical cluster. Theoretically, the bubble nucleation rate is greatly dependent on components’ mole fraction in a critical cluster. Hence, the dissolved gas concentration effect was included in current work. Besides, the possible bubble nucleation rates were predicted based on the calculated number of molecules required to form a critical cluster. The estimation of components’ mole fraction in critical cluster for water vapour and dissolved air mixture was obtained by coupling the enhanced classical nucleation theory and CFD approach. In addition, the distribution of bubble nuclei of water vapour and dissolved air mixture could be predicted via the utilisation of population balance model.

Natural gas has attracted high attention in the last few decades because of the increasing demand for alternative energy sources owing to depleting conventional energy sources. Raw natural gas consists of several components (light, heavy and aromatic hydrocarbons) and contaminants (i.e. water, CO2, H2S, mercury, N2 and many others) that need to be processed and purified before it is introduced to the market. Water vapour is considered one of the most important contaminants in natural gas. Water vapour needs to be removed before further processing because it might be the main reason for blockage or corrosion of pipelines and facilities as its existence can lead to the creation of natural gas hydrates. Adsorption among other alternative techniques is one of the most efficient and cost-effective processes. Zeolites have shown high potential and sustainability among other solid desiccants in terms of high adsorption capacity, low regeneration costs and high selectivity. The results show that the adsor...

Intumescent coating is an insulating material designed to decrease heat transfer to a substrate structure. This research presents the results of different formulations developed to study the effects of kaolin clay on expansion of coating and heat shielding during the fire test. The intumescent coating formulations (ICFs) were tested at 950 °C for 1 h. The results showed that the coatings were stable and well bound with substrate. The coatings were characterized by using Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The morphology of char was studied by FESEM on the coating after fire test. XRD and FTIR showed the presence of carbon (graphite), boron phosphate, boron oxide, sassolite and kaolinite in the residual char. TGA showed that kaolin clay reinforced formulation; IF5-KC enhanced 49% residual weight than that of IF-Control formulation. XPS analysis showed that elemental composition of IF5-KC char residue gave 41.80% carbon content in the residual char. An accelerated weathering test ASTM D 6695-03 showed that IF5-KC coating sustained its integrity up to 90 days under accelerated weathering chamber.

Removal of CO2 from natural gas using a membrane-based process has been adopted on an industrial scale, and about 200 membrane separation plants have been installed all over the world. In industry, inorganic membranes are preferred over the polymeric and mixed matrix membranes in CO2 separation from natural gas because of their good chemical stability and high separation performance. Among all inorganic membranes, deca-dodecasil 3 rhombohedral zeolite (DDR) membrane exhibits the highest selectivity in CO2 separation from natural gas. However, synthesis of DDR membranes requires a long duration, with a minimum of 25 days. Therefore, reduction of duration in the synthesis of the DDR membrane remains a challenging issue. In this review, separation performance of polymeric, mixed matrix and inorganic membranes are compared. Synthesis methods of DDR membranes and their performance in CO2 separation reported by various researchers are discussed. The challenges and issues related to the formation of DDR membrane...

Melamine-formaldehyde (MF) resins of improved environmental compatibility were synthesized at different molar ratios, temperature and pH. Five molar ratios of melamine and formaldehyde: 35:65, 36.5:63.5, 38.3:61.7, 41.1:58.9 and 42.4:58.6 were used to synthesize the corresponding resins. The prepared samples were characterized by using molecular weight determination viscometery, field emission scanning electron microscopy and thermogravimetric analysis. It was noticed that the solid content in the resin increases with an increase in pH. The maximum percentage of the solid content (51 %) was obtained for pH of 8.5 and temperature range of 95–98 oC. The refractive index of the final product was found increasing with an increase of melamine concentration in the resin. A similar trend was noticed in molecular weight of the resins with an increase in monomer yield. The maximum molecular weight of 114218 was obtained from the sample synthesized with MF molar ratio of 42.4:58.6.

Membrane technology effectively separates CO 2 from CH 4 and has been practiced for many years but requires membranes with high selectivity and permeability. Different approaches are employed to improve membrane performance and it is soon possible to develop a blended polymeric membrane that separates high pressure gas streams at the point of processing pressure. However, glassy polymers suffer a lack of permeability causing their performance to drop as an upper bound trade-off but highly selective and rubbery polymers have high permeability with low selectivity. As an amine solution is capable of purifying naturally acidic gas, blending glassy, rubbery polymers with amines-specifically, polysulfone and polyvinyl acetate with diethanol amine in dimethyl acetamide as solvent-we developed flat sheet membranes with desirable properties. As it is now possible to acquire amine-polymer blends with more desirable properties by mixing with a miscible polymer, it is essential to observe factors that affect the polymer's miscibility with amines. Hence, we also analyzed the effects of blend ratios on different properties. Blended membranes of different ratios were synthesized and their functional groups were characterized by Fourier Transformed Infra-Red spectroscopy (FTIR). We then employed Thermal Gravimetric Analysis (TGA) to describe weight loss and Field Emission Scanning Electron Microscopy (FESEM) to determine respective morphologies.

Minimization of energy consumption was explored for countercurrent switched cryogenic packed beds in which separation of CO2 and other components of natural gas can be achieved based on differences in freezing or desublimation points. Highly pure CO2 and methane were obtained after separation. An experimental setup for CO2 removal from natural gas was constructed and a detailed experimental study was conducted by changing different operating parameters. Compared to other cocurrent or jacket-cooled constant-temperature configurations, countercurrent switched beds provided optimal separation and energy efficiencies. The effects of important process parameters like initial temperature profiles of the cryogenic bed, feed composition, and feed flow rate on energy requirement, bed saturation, bed pressure, and cycling times were investigated. The energy requirement for cryogenic packed beds was compared with the conventional cryogenic distillation process.

The precious demand not in the push away and broad off from receive forward developed technology approaches place the hand almost several lacks of warns and in-needed developed technique and techniques for greater than before contract and analysis for several issues, no complimentary and talk to studies within the literature describe the system comes in multi component and dual phase particularly for those that ought to be investigated at offshore conditions, the novel technique and setup has been created for such scope, the recently developed set up has the flexibility to analyses the sorption isotherms and kinetic for multi component and dual phase mixtures (gas and vapor) at offshore conditions in term of temperature up to 150 oC and pressure up to 150 bar. Additionally to the pretreatment that would be finished to the sorbents used at temperatures up to 400 oC and vacuumed pressure. The primer experiments are done using 13 X zeolites for the sorption of pure CO2 and binary mixtures (CO2 and CH4) at elevated conditions.

Work permit is something not to take lightly because it involved non-routine work such as hot work which failure to comply with the work permit procedures could resulted in large-scale loss of life and/or property. Investigations by Chemical Safety Board (CSB) have reported 60 fatal hot work accidents in about 20 years in the USA though hot work permits were issued for all operations. No matter how simple the procedure and work permit forms are, it is the strict application of the procedures and practices associated with the assessment of risk and application of permit to work conditions that ensures work can be done safely. A model for hot work permit that is incompliance with the Process Safety Management (PSM) regulations requirements is introduced that includes necessary fire preventive actions to be taken. In addition, a few existing hot work permits were studied to verify this model. It was found that the model required more information to safeguard an effective hot work permit system and better compliance with the PSM regulation. In addition, the model is also more precise, adaptable, user-friendly and easier to comprehend. As a conclusion, the model created could improve the conventional hot work permitting system. To ensure that the permit is more strict and effective hot work permitting system, a more sophisticated coding and software could be further expanded.

Development of novel mixed matrix membranes (MMMs) has become frontier candidates for improving the upper bound trade-off curve between permeability and selectivity of gases for industrial polymeric membranes. However, fabrication of ideal MMMs is practically challenging as the dispersion of inorganic phase into the polymer may produce polymeric-inorganic interfacial defects at the vicinity of the polymer matrix. For instance, the inorganic phase may cause interfacial void, polymer chain rigidification or partial pore blockage on the overall MMMs. Since there are only few studies that specifically focus on the issues of the interfacial morphology of MMMs, therefore, the present study provides brief description of the aforementioned interfacial (non-ideal) defects of MMMs and summarizes the techniques used to repair the interfacial defects for enhanced gas separation in MMMs.

Accident is one of the big issues that occur repeatedly in the process industries today though there is numerous application of the variety safeguarding measures that have been introduced. Equipment failure is identified as one of the root causes of these major accidents. One of the established standards that addressed the above issue is a Mechanical Integrity (MI) element of Process safety Management System (PSM) 29 CFR 1910.119(j). The main objective of this study is to introduce a systematic technique to implement PSM MI in process industries. This study covered analysis of requirements of the standard, development of framework and prototype tool as well as concept validation through a case study. Implementation of this technique will help employers to prevent major accidents and compliance to the PSM standard simultaneously.

The present study investigates the effects of intercalation process of protonated primary, secondary and tertiary amines on structural and surface characteristics of sodium form of bentonite clay. For this purpose, sodium form of bentonite clay was prepared and then exchanged with mono-, di-and triethanolammonium cations via intercalation mechanism into the interlayer space of the clay. The prepared samples were characterized by XRD and BET techniques. An increase in the d-spacing of bentonite clay with the molar mass of amines was observed in their x-ray diffractograms, following the order of: triethanolamine > diethanolamine > monoethanolamine. The BET results showed a gradual decrease in the BET surface area with the increase in the molar mass of amines used. Based on the results obtained, it can be concluded that the molar mass of amines has significant effects on structural and surface properties of bentonite clay.

The precious demand not in the push away and broad off from receive forward developed technology approaches place the hand almost several lacks of warns and in-needed developed technique and techniques for greater than before contract and analysis for several issues, no complimentary and talk to studies within the literature describe the system comes in multi component and dual phase particularly for those that ought to be investigated at offshore conditions, the novel technique and setup has been created for such scope, the recently developed discovered has the flexibility to analyses the sorption isotherms and kinetic for multi component and dual phase mixtures (gas and vapor) at offshore conditions in term of temperature up to 150 oC and pressure up to 150 bar. Additionally to the pretreatment that would be finished to the sorbents used at temperatures up to 400 oC and vacuumed pressure. The primer experiments are done using 13 X zeolites for the sorption of pure CO2 at numerous conditions and binary mixtures (CO2 and CH4) with the existence of water vapor.

The paper presents the concept of cryogenic growth kinetics during separation of CO2from natural gas using Avrami nucleation model. The interface frost layer on the glass packing of cryogenic bed is assumed asgerm nuclei. The bed porosity is considered time dependent. The expression for time varying bed porosity is derived based on Avrami model. The experimentation was conducted to validate the model and the resulting simulation studies show good resemblance with experimental results.

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 CO 2 Hydrocarbon Absorption System pilot plant as a case study is examined and discussed.

Mixed matrix membrane (MMM) has shown significant progress towards gas separation. Rigid polymers are suitable materials for MMM fabrication but adhesion problems with filler need to be addressed. A variety of inorganic fillers have been studied for CO2 separation but clay minerals were not considered much in this class. The layered silicate structure of nanoclay such as montmorillonite provides excellent opportunity to manipulate its properties, leading towards better dispersion and adhesion towards the polymer matrix. This paper reviews the potential of polymer-nanoclay MMM for CO2/CH4 separation.

Compliance audit for process safety management (PSM) is a technique to verify that the implementation of the PSM program is in compliance with OSHA standards and to identify potential deficiencies in the PSM program used. However, unavailability of an easy audit techniques hinders the compliances to PSM standards in industries. An audit model is introduced based on OSHA PSM standard to provide a standardize format that utilizes the Piping and Instrumentation Diagram (P&ID) as a basis. A case study based on the training element of OSHA PSM is performed to verify the effectiveness and to ensure the PSM standard compliances. The model is based on Microsoft Access which enables the user to input data, manage and track information. The model is useful to the employee as the weaknesses in the PSM program can be identified and rectified to prevent any major accidents.

The control of anthropogenic carbon dioxide release is one of the most challenging environmental problem faced by developing countries, as the interfering of atmospheric carbon dioxide level and climate revolutionize. An rising technology is the membrane gas separation, which is more dense, energy efficient and possibly more economical than past technologies, such as solvent absorption. Amine has a greater efficiency for removal of carbon dioxide. The blending technique not only provides improved chemical and thermal stability but is also efficient enough to improve the perm-selective properties with economical viability. In this study, research will be carried out to study the gas permeability behavior of glassy Polysulfone and Polyvinyl acetate rubbery polymeric blend membranes with diethanol amine. Polymeric amine blend membranes with different blending ratios were prepared in dimethyl acetamide solvent, flat sheet membrane were developed with enhance properties. We were studied PSU/PVAc blend with DEA amine using a gas permeability application for CO 2 and CH4 at different feed pressures.

Zeolitic imidazole frameworks-8 (ZIF-8) is a subclass of metal-organic frameworks (MOFs) with the transition metal cations (Zn2+) linked by imidazolate anions forming tetrahedral frameworks in zeolite-like topologies. This article reports on the synthesis of ZIF-8 nanoparticles by varying the synthesis parameters at room temperature. The crystallization duration, molar ratios, and pH of the mixture solution were varied in order to study the effects of these parameters on the formation of ZIF-8 nanoparticles. The structural and morphology transformation of the resultant particles were characterized using x-ray diffraction, field emission scanning electron microscopy, and Brunauer–Emmett–Teller (BET) surface analysis. The CO2 adsorption characteristics of ZIF-8 nanoparticles were tested using CO2 physisorption analysis. Mature structural evolution was observed for ZIF-8 synthesized at 60 and 1440 min, but insufficient crystallization was found for ZIF-8 synthesized at 5 min. Meanwhile, ZIF-8 nanoparticles s...

Carbon dioxide (CO2) is the major cause of accelerating global warming. It is important to employ efficient method to capture CO2. Absorption is the most established technique to separate CO2 and amines are most commonly used as solvent. In this study, density and viscosity of an amine based novel solvent named Stonvent were investigated at temperature ranging from 298.15 K to 338.15 K. CO2 solubility in Stonvent was measured at varying pressures, temperatures and concentrations. The experiments were conducted at temperatures (303.15, 318.15 and 333.15) K, and at pressures (0.5, 1, 1.5 and 3) MPa over a wide range of concentration (10, 20, 30 and 100) mass %. Solubility of CO2 was determined from pressure drop due to absorption of CO2 into solvent within equilibrium cell. Absorption capacity of Stonvent increases significantly with increasing pressure. Solubility of CO2 in Stonvent is higher compared to Monoethanolamine (MEA), 1-amino-2-propanol (MIPA) and 2-amino-2-methyl-1,3-propanediol (AMPD) at elevated pressure, hence posing Stonvent as an attractive alternative for acid gas absorption in high pressure conditions. Substantial increase in CO2 loading was observed when concentration of Stonvent is increased and when temperature is decreased.

Symmetric and asymmetric polysulfone membranes were fabricated using different of solvents; N-methyl-pyrrolidone (NMP), Tetrahydrofuran (THF) and Dimethylacetamide (DMAC) at different polymer concentration (15 and 20%) to study the influence of varying type of solvents and polymer concentration in membrane fabrication. The membranes were characterized using Field Emission Scanning Electron Microscopy (FESEM), Thermogravimetric Analyzer (TGA), Universal Testing Machine (UTM) and Fourier Transform Infra-Red (FTIR).The results disclosed that the symmetric, higher polymer concentration membrane contributed to better thermal and mechanical stabilities. PSF/THF membrane showed good mechanical strength while PSF/DMAC membrane illustrated great thermal stability. 20% of polymer concentration and PSF/THF membrane led to the thicker skin layer and dense structure formation.

The solubility of carbon dioxide (CO2) was measured in (0.2, 0.4, 0.6 & 1.2) molars of aqueous solutions of Piperazine (PZ) at three temperatures (30, 40 and 60) °C. The measurements were made over the pressure range of 5 to 60 bar. The results are presented as a function of pressure. It has been found that PZ gives significantly higher CO2 loadings at higher pressures. The influence of pressure on solubility is found to be positive. However, solubility decreases with the increase of temperature and PZ concentration.

Inherent safety concept has been introduced to overcome the shortcoming of traditional hazard assessments by allowing modification to be made at any stage of lifecycle of a process plant. However, most of the proposed inherent safety modifications were suitable to prevent fire, explosion and toxic hazards assessment but less attention on human and organizational factor. Therefore, this paper introduces the inherently safer analysis for human and organizational factor to be implemented during design stage or process operation. Analytic Hierarchy Process model integrated with fuzzy logic and known as FAHP was employed to rank identified inherently safer strategies. The model was applied to select inherently safer strategies to reduce collision risk of a floating production, storage and offload and the authorized vessel. The result shows that minimization of hazardous procedure when the procedure is unavoidable is the best strategy to increase human performance. It is proven that the proposed methodology is capable to select the inherently safer strategy without requiring a bunch of precise information to transfer expert judgment in human performances perspective.

Removal of CO2 had been one of the main issues facing in worldwide. Intensive researches are still going on to effectively reduce CO2 at low cost. Physical absorption is one of the well-established technologies used to removal CO2 from other gases. The physical absorption process is simple; whereby it contains only one gas liquid contactor and a series of flash tank to regenerate solvent. The CO2 will be absorbed in the physical solvent in the high pressure gas liquid contactor and flashed out in the medium and low pressure flash tank. The advantage of using physical solvent is that the CO2 is absorbed without any chemical reaction involved, thus it can be flashed out easily by reducing the pressure, passing inert gas through the solvent and mild thermal regeneration. The physical absorption is the best operated at high pressure and low temperature as the solubility of CO2 in the solvent is high at the particular condition. Researches carried out currently are focusing on solvent development, absorption and desorption process development and mathematical modeling.

Many publications have reported about 37% of major accidents in petroleum, chemical, nuclear, aviation, and in the other process industries that occurred worldwide were due to human error. One of the keys contributing factors that could prevent these accidents is to provide appropriate training to the plant personnel. However, accidents still can happen if training is poorly managed and improperly trained personnel handling the operation of the plant. One of the established industrial standards to manage the training is Training element of Process Safety Management (PSM) 29 CFR 1910.119(g). This paper presents a system to manage training for safe operation following 29 CFR 1910.119(g) namely Operational Training Management System (OPTRAMS). It provides strategies to manage information and documentation related to training. OPTRAMS was implemented at the CO2-Hydrocarbon Absorption System (CHAS) pilot plant at Universiti Teknologi PETRONAS as a case study. The study showed that all operational training can be managed efficiently with OPTRAMS and also assists end users to identify the gaps that hinder training of PSM compliance. The implementation of this technique could help end users to prevent and minimize catastrophic accidents and comply with training of PSM standard.

In gas separation, the trade off limitations of polymeric membranes and economical consideration of inorganic membranes motivated the researchers to search for alternative approaches. Membranes with high selectivity and high permeability are required. Different modifications are in practice to improve the performance of membranes like mixed matrix, cross linking, grafting, polymer blending, making composite or hybrid membrane. It will be possible to develop polymeric blend membrane for separating high pressure gas streams at their processing pressure. This advantage could offer cost savings that may provide a new incentive for polymeric blend membranes. This result opens a new tool for studying gas separation by polymeric blend membranes. In this context blending of glassy and rubbery polymer that is Polysulfone and Polyvinyl acetate in dimethyl acetamide solvent, flat sheet membranes were developed with desirable properties. Membranes were synthesized with different blending ratios and the developed membranes were characterized by Fourier Transformed Infra-Red Spectroscopy (FTIR), Thermal Gravimetric Analysis (TGA), Field Emission Scanning Electron Microscopy (FESEM) and Gas Permeability to study the effect of blend ratio on different properties.

One of the most pervasive problems affecting people throughout the world is inadequate access to clean water and sanitation. Problems with water are expected to grow worse in the coming decades, with water scarcity occurring globally. Many recent studies have been reported on the photodegradation of the organic compounds in industrial wastewater in the presence of TiO2 semiconductor as photocatalyst. Heterogeneous photocatalysts using iron as a dopant metal, so far, have been reported for various environmental applications. This paper highlights the recent advances and applications of Fe-TiO2 photocatalysis for the degradation/photodegradation of various pollutants, alkanolamines and other organic pollutants like phenols and dyes.

In this study, research will be carried out to identify the functional group behavior of glassy and rubbery polymeric blend membrane with amines. Polymeric blend membranes with different blending ratios were prepared and the developed membranes were characterized by FTIR to see the effect of blend ratio on different functional groups. The developed membranes are flat dense sheet membrane of 20% wt/wt. The pure and blend membrane polysulfone, polyethersulfone, polyvinyl acetate with different composition, with 10% methyl diethanol amine, mono ethanol amine, diethanol amine are developed with dimethyl acetamide solvent. Fourier Transform Infrared (FTIR) spectroscopy was utilized to study the interaction between two polymers and to analyze the type of bonding present. To observed frequencies were assigned to various mode of vibration in terms of fundamentals and combination. These spectral changes indicated the existence of molecular interaction among the enhanced polymeric blends; highlight the compatible nature among each other.

The physical properties such as densities, viscosities, and refractive indices of aqueous solutions of potassium carbonate (PC) blended with glycine (Gly) as solvent blends for CO2 capture were measured. The properties were measured at ten different temperatures from (298.15 to 343.15) K. The mass fractions (w1 + w2) % of the (PC + Gly) blends were (0.05 + 0.01, 0.10 + 0.02, 0.15 + 0.03, 0.20 + 0.04, 0.25 + 0.05, 0.30 + 0.06, 0.35 + 0.07, and 0.40 + 0.08), respectively. The analysis of experimental results shows that, the densities, viscosities, and refractive indices of the aqueous (PC + Gly) blend increase with increasing the concentration of the potassium carbonate and glycine, and decrease with decreasing the temperature. The experimental data of density, viscosity and refractive index were correlated by a least-squares method as a function of temperature. The predicted data were estimated from coefficients of correlation equations for all measured properties, and reported with standard deviation (SD). The experimental data are in consistent with the predicted data.

Bimetallic Cu-Ni/TiO2photocatalysts were synthesized using wet impregnation (WI) method with TiO2(Degussa-P25) as support and calcined at different temperatures (180, 200, and 300°C) for the photodegradation of DIPA under visible light. The photocatalysts were characterized using TGA, FESEM, UV-Vis diffuse reflectance spectroscopy, fourier transform infrared spectroscopy (FTIR) and temperature programmed reduction (TPR). The results from the photodegradation experiments revealed that the Cu-Ni/TiO2photocatalysts exhibited much higher photocatalytic activities compared to bare TiO2. It was found that photocatalyst calcined at 200°C had the highest photocatalyst activities with highest chemical oxygen demand (COD) removal (86.82%). According to the structural and surface analysis, the enhanced photocatalytic activity could be attributed to its strong absorption into the visible region and high metal dispersion.

The continuously increasing of sour natural gas reservoirs worldwide necessitate a highly efficient CO2 removal technology for offshore application. Therefore, the intensification technology for absorption attaches research interest to address this issue. This review covers the intensification factor, operating feasibility and perspective for each potential technology. Microchannel reactor offers the highest ideal intensification factor but suffers from offshore operation difficulties. Even-though high frequency ultrasonic reactor and rotating packed bed demonstrate high flexibility for long-term operation, yet both technologies require high energy consumption. Combination of hollow fibre membrane contactor and rotating packed bed is suggested to optimize the overall absorption process.

The physicochemical properties such as density, viscosity, and refractive index of aqueous solutions of sodium l-prolinate (SP) as a solvent for CO2 capture was measured. These properties were measured at different temperatures from (298.15 to 343.15) K. The mass fractions of SP were 0.05, 0.10, 0.20, 0.30, and 0.40. The coefficient of thermal expansion was calculated from the experimental density values in the same temperature range. The analysis of experimental results shows that the densities, viscosities, and refractive indices of the aqueous solutions of SP increase with an increase in the mass fraction in the solution, and decrease with increasing temperature. The thermal expansion coefficient slightly increases with increasing temperature and concentration. The experimental data of density, viscosity, and refractive index were correlated by the least-squares method as a function of temperature. The predicted data were estimated from correlation coefficients for all measured properties and reported ...

Simply attributing incidents to human error is not adequate; human factors aspects should be investigated such that lessons are learnt and the true root causes are established in order to prevent recurrence. Whilst many petroleum and allied industry businesses have investigated and analyzed incidents – whether with major hazards or occupational injuries potential – human factors aspects are rarely addressed sufficiently. Therefore, this paper presents a hybrid methodology that combines a conventional Swiss Cheese model with Bayesian inference to predict the failure probability of human factors. An inherent safety concept associated with human factor is proposed and utilized as preventive measures to overcome the identified root causes. This approach is then applied to offshore safety assessment study. As a result, the failure probability of human factor can be monitored with time and the best preventive measure can be prioritized once human performance is degraded. It is proven that the approach has the ability to act as predictive tool that provides early warnings toward human deficiency. A preventive measure can then be taken to enhance the overall human performance and ultimately to reduce the likelihood of major incidents.

At preliminary design stage, process designers normally lack of information on the risk level from process plant. An inherently safer process plant could be designed if the information of risk levels could be known earlier at the preliminary design stage. If the risk level could be determined, there is a possibility to eliminate or reduce the risk by applying the well-known concept: inherent safety principle. This paper presents a technique to determine the risk levels at preliminary process design stage using a 2-region risk matrix concept. A model to calculate the severity and likelihood of a toxic release accident was developed in Microsoft Excel spreadsheet. This model is integrated with process design simulator, iCON to allow for data transfer during preliminary design stage. 2-region risk matrix is proposed and used to evaluate the acceptability of the inherent risk based on the severity and likelihood rating. If the inherent risk level is unacceptable, modification for improvement can be done using the inherent safety principles. A case study has been carried out to illustrate the benefit of applying this newly developed technique. It was successfully shown that an inherently safer plant could easily be designed by applying this technique.

Fire hazard has contributed to about one-third of world major accidents in chemical plants. One of the approaches to avoid or minimize fire hazard is by using an inherent safety concept. This concept is best implemented at the preliminary design stage. However, practical application of inherent safety is still limited due to non-availability of easy to use tool for direct application in a process plant. This paper addresses the above issue by proposing a prototype tool known as Inherent Fire Consequence Estimation Tool (IFCET) that can be used during preliminary design stage to eliminate or minimize the consequence of fire accidents. The tool is developed in MS Excel for pool fire model and linked with process design simulator, iCON. The functionality of the IFCET is demonstrated using case studies of flammable liquid leaked from a process stream and spilled of LPG during unloading at filling station. The results from the case studies show that IFCET can be used to eliminate or minimize the consequence due to pool fire during preliminary design stage. IFCET has a potential to be extended to include other types of fire accidents such as Jet Fire, BLEVE, etc.

The application of Inherent Safety (IS) principles and Inherently Safer Design (ISD) concept has been proven to reduce the risk of accidents and economically attractive for process plants. However, there are always trade-offs and conflicts that arise from the suggested modifications. An inherently safer design from one perspective could possibly alter the hazards in other dimensions. Therefore, this limitation should be resolved before obtaining the best ISD alternatives. This paper presents a methodology for producing and evaluating Inherently Safer Design (ISD) alternatives using a risk-based approach at preliminary design stage. The proposed methodology is applied to nitration of toluene with the objective of preventing and minimizing runaway reaction. The results have shown that the new tool can capture the risk transferred due to the change of design proposed by the inherent safety principles at preliminary design stage in the form of new hazards and change of magnitude of existing hazards.

The physical properties including the density, viscosity, and refractive index of aqueous blends of sodium glycinate (SG) and piperazine (PZ) as a solvent for CO2 absorption were measured under the wide temperature range (298.15 to 343.15) K. Different concentrations (mole fraction) of sodium glycinate and piperazine (SG + PZ) blends were (0.0348/0.0089, 0.0263/0.0177, 0.0177/0.0263, and 0.0089/0.0348), respectively. From the observations, it was found that the densities of the aqueous blends decrease when the piperazine concentration in the blend increases. It was noticed that the viscosity of the blend decreases initially by increasing the concentration of piperazine from 0.0089 to 0.0177 mole fraction; however, on further increasing the piperazine and decreasing the sodium glycinate concentration in the blend, the viscosity tends to increase. The refractive indices of the aqueous blend of sodium glycinate and piperazine decrease with increasing the concentration of piperazine in the blend. The density,...

Toxic release is one of major accidents in process plant that caused many fatalities. Some examples of major disaster due to the toxic release are the tragedy of TCDD release in Seveso, Italy (1976) and MIC release in Bhopal, India (1984). Common and popular practices to prevent such accidents are by installation of add-on protective system and to follow safe operation procedure. Even though these techniques are proven effective to minimize the probability of accidental release of toxic materials; however, the hazard is still remained in the process plant. This study reports on an alternative design approach to avoid or minimize the toxic release accidents by utilizing an inherent safety concept. A process design tool was developed by the integration of process design simulator, iCON from PETRONAS with toxic release consequence model created in MS-Excel spreadsheet. The consequence model was based on the method recommended by Center for Chemical Process Safety. This unique prototype tool allows the consequence analysis of potential toxic release to be done early in preliminary design stage. If the design fails to meet the limitation of toxic release criteria, the improvement can be done using an inherent safety concept to avoid or minimize the toxic released consequence. A case study of ammonia release from a purification column was conducted, and the results show that the toxic release consequence can be avoided or minimized during the process simulation stage. More studies are currently carried out to explore the full capabilities of the developed prototype tool for inherently safer design options before commercial applications.

Three-dimensional computational fluid dynamics studies related to dynamics adsorption of CO2 from natural gas is found to be limited. 3D analyses for dynamics adsorption are substantially crucial to give a better prediction on the adsorption process by considering the actual fluid flow behavior within the packed-bed porous media. A kinetic adsorption model has been integrated in a commercial fluid dynamics simulator to simulate the 3D hydrodynamics and adsorption phenomenon in a zeolite-filled packed column for a CO2-methane separation system. The effects of various parameters such as Reynolds number, CO2 feed concentration, feed temperature, and column dimension on CO2 adsorption efficiency have been investigated. A correlation for adsorption efficiency based on the CO2 concentration profiles has been developed and validated.

The increase in global population and industrialization has led to an increase in global energy consumption exponentially. Over 85% of global energy is supplied by burning fossil fuel, which releases large volume of CO2 emissions in the atmosphere. Increasing of CO2 emissions is the major cause for the catastrophic climate change, which has led to increased demand for efficient and effective CO2 capture. CO2 absorption by chemical solvents is the most widely used technique commercially nowadays. Alkanolamine solvents such as monoethanolamine (MEA) and methyldiethanolamine (MDEA) are the most commonly used absorbents for CO2 removal from various gas streams. However, it is well known that these solvents suffer from variety of drawbacks such as limited CO2 loading capacity, equipment corrosion, toxic nature and highly volatile. Moreover, these absorbents are easily degradable, require high regeneration energy, and cause flooding problems in the operation. Therefore, better and efficient solvents should be searched for the removal of CO2 from exhaust gas streams. Aqueous amino acid salts and their blends are the promising solvents for CO2 capture as compared to alkanolamine. In this chapter, amino acid salts and their blends are introduced and their performance analysis as potential solvents for commercial possibilities are discussed. Based on the analysis, these absorbents show superior performance as an alternative to the conventional alkanolamines for CO2 capture. These solvents are environmental friendly with higher CO2 loading capacity, faster reaction kinetics and require less regeneration energy compares to the commercial amines. Besides, these solvents are non-volatile, less corrosive and oxidative stable. Moreover, aqueous amino acid salts are more effective by blending with additives such as piperazine.

Over recent years, incorporation of unit operation in industrial process simulators remains an intriguing area of research. This is especially applicable to natural gas plant aimed for CO 2 gas removal in offshore platform that is often accompanied with a number of unit operations, complicated configurations, non-standard operating conditions and high impurities content. In addition, it is highly desirable to link the natural gas purification unit with other pretreatment, dehydration and auxiliary equipments already implemented in the process simulators to constitute the entire process plant. Although research work has arisen in this area, the incorporation is particularly challenging for iCON® process simulator since it does not inherit the intrinsic capability to incorporate standalone models of additional unit operations. Nonetheless, the incorporation is of exceptional importance since the intrinsic physical property and thermodynamic databases of iCON® process simulator can be employed conveniently to determine heating value of the product streams. Therefore, in current research work, a mathematical model has been developed to describe the countercurrent hollow fiber membrane module, which has been integrated as an extension in iCON® through utilization of the export/import functions embedded within the Excel unit operation of the process simulator. Validity of the simulation model has been demonstrated through good accordance with published literature. It is found that by determining the separation mechanism via adaptation of the mathematical model, heating value of the purified product stream can be reflected directly in iCON® to evaluate feasibility of the entire process design in offshore natural gas purification platform.

Objectives: To investigate experimental data of surface tension of aqueous sodium salt of L-phenylalanine (Na-Phe) at temperatures ranging from 298.15 to 343.15 K and concentration ranging from 0.05 to 0.40 (w). Methodology: This work was carried out through an optical contact angle tensiometer (OCA 15 EC). It is a video based instrument which employs a pendant drop method for contact angle measurement. Findings: It was observed that surface tension values rise as aqueous Na-Phe concentration increases and decrease with the increase in system’s temperature. Experimental surface tension data were used to calculate the dervied surface thermodynamic properties such as surface enthalpy and entropy. Surface enthalpy was found to increase with concentration and tend to decrease with the rise in temperature. While, estimated surface entropy values were found to decrease with the increase in Na-Phe concentration. Temperature and concentration dependent empirical correlation was utilized to predict the surface tension data. A good agreement was found between the experimental and correlated data. Applications/Improvements: The findings reported in this study could be helpful significantly for the selection of appropriate solvent, and in the calculations for the efficient design of absorption column.

Sonochemical-assisted method has been identified as one of the potential pre-treatment methods which could reduce the formation duration of zeolite as well as other microporous and mesoporous materials. In the present work, zeolite T was synthesized via sonochemical-assisted pre-treatment prior to hydrothermal growth. The durations for sonochemical-assisted pre-treatment were varied from 30 min to 90 min. Meanwhile, the hydrothermal growth durations were ranged from 0.5 to 3 days. The physicochemical properties of the resulting samples were characterized using XRD, FESEM, FTIR and BET. As verified by XRD, the samples synthesized via hydrothermal growth durations of 1, 2 and 3 days and sonochemical-assisted pre-treatment durations of 60 min and 90 min demonstrated zeolite T structure. The samples which underwent sonochemical-assisted pre-treatment duration of 60 min yielded higher crystallinity with negligible change of zeolite T morphology. Overall, the lengthy synthesis duration of zeolite T has been successfully reduced from 7 days to 1 day by applying sonochemical-assisted pre-treatment of 60 min, while synthesis duration of 0.5 days via sonochemical-assisted pre-treatment of 60 min was not sufficient to produce zeolite T structure.