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Phosphorus (P) overloading in aquatic environments has long-been recognized as the leading cause of water quality deterioration, harmful algal bloom, and eutrophication. This study investigated P removal performance by five cost-effective carbonaceous materials (CMs) in flow-through packed column systems. These CMs include biochars pyrolyzed from feedstocks of Eucalyptus (E-biochar) and Douglas fir (D-biochar), commercial biochar (C-biochar), iron oxide-coated biochar (Fe-biochar), and commercial activated carbon (AC). The physicochemical properties of CMs, such as specific surface area (SSA), pore volume, pore diameter, elemental composition, and surface charge, were characterized. The packed column experimental results showed that P removal performance followed the order: E-biochar < D-biochar < C-biochar < Fe-biochar < AC. Specifically, the sorption capacity of 1 mg/L of P in packed columns was 0.0036 mg P/g E-biochar, 0.0111 mg P/g D-biochar, 0.0369 mg P/g D-biochar, 0.077 mg P/g Fe-biochar, and 0.088 mg P/g AC, respectively. The largest SSA (1012 m2/g) and pore volume (0.57 cm3/g) of AC accounted for the most outstanding P removal efficiency mainly by physical sorption, while electrostatic interaction explained the high P removal by Fe-biochar (SSA as low as 32.4 m2/g). Our findings provide direct practical implications for effectively removing P in water by cost-effective CMs. [ABSTRACT FROM AUTHOR]

Wetted wires are a unique column internal with several advantages compared to spray and packed columns. These include near-perfect liquid distribution, extremely low pressure drops, and better heat or mass transfer due to droplet circulation. Currently, wetted-wire columns remain within the laboratory prototyping stage. The primary goal of this review is to present the current research on wetted-wire columns and to highlight the gaps that impede scale-up and commercialization. Initially, wetted-wire columns were proposed as an alternative to spray towers. However, wetted-wire columns occupy a space in between spray towers and packed columns. Therefore, wetted-wire columns should also be analyzed more like packed columns to increase the speed of technological translation. Wetted-wire column literature is presented by defining features (wire diameter, nozzle diameter, pitch, and material) and by performance indicators (operating range, pressure drop, hold-up, and separation efficiency). In addition, adjacent literature on wire-like structures is discussed. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) capture is an important strategy to mitigate greenhouse gas emissions and reduce global warming effects. This study synthesizes two nanomaterials, Ce‐doped Ni–Al mixed metal oxide (CNAO) and Mn‐doped Ni–Al mixed metal oxide (MNAO), from Mn‐ and Ce‐doped Ni–Al‐layered double hydroxides using a co‐precipitation method followed by a calcination process. The materials are characterized using various techniques, such as High‐resolution transmission electron microscopy‐energy dispersive x‐ray spectroscopy/selected area electron dispersion (HRTEM‐EDS/SAED), X‐ray diffraction (XRD), x‐ray photoelectron spectroscopy (XPS), Brunauer‐Emmett‐Teller (BET), and attenuated total reflection Fourier transform infrared (ATR FT‐IR). The CO2 adsorption performance of the materials is evaluated using packed‐bed column experiments at the testing conditions of 13 vol% ± 1 vol% CO2 in N2 simulated flue gas, flow rate of 20 mL min−1, inlet pressure of 14.15 ± 0.1 psi, and temperature of 31 °C ± 2 °C. The results show that both CNAO and MNAO are promising nanomaterials for CO2 capture applications due to their high CO2 adsorption capacity and efficiency. CNAO has a higher saturation capacity of 11.4 mmol g−1 and a longer breakthrough time than MNAO, which has a saturation capacity of 10.0 mmol g−1. The doping of Ce and Mn enhances the CO2 adsorption capacity of the materials compared to the un‐doped Ni–Al mixed oxide. The mechanisms of CO2 adsorption are mainly linearly adsorbed CO2, bidentate, and monodentate or bulk carbonate formation, as revealed by ATR FT‐IR analysis. The regeneration performance results suggest that CNAO is more stable than MNAO under multiple regeneration cycles and more promising material for large‐scale CO2 capture applications. [ABSTRACT FROM AUTHOR]

It is imperative to minimize radioiodine release to the environment through gaseous emissions of spent fuel reprocessing facilities, thereby mitigating its potential impact on the general public. One effective and widely adopted strategy for achieving this objective is caustic scrubbing, a method that involves the absorption of molecular iodine from gaseous streams using caustic soda ( NaOH ) solution in a packed column. In-depth laboratory-scale experiments were conducted to ascertain the overall volumetric mass transfer coefficient K G a for the absorption of dilute iodine vapor from air into a caustic soda solution in a packed column and to establish optimum performance parameters for this process. The investigation yielded noteworthy findings: K G a increased proportionately to (Gas phase Reynolds number)1.0 at constant liquid flow rates across all types of packing tested. K G a displayed relative independence from liquid velocities for high and moderate NaOH concentrations. However, this coefficient varied proportionately to (Liquid phase velocity)0.26 to 0.42 at lower NaOH concentrations under conditions of high gas flow rates NaOH . As the height of the column increased, K G a was found to decrease slightly. The presence of NOx at an inlet concentration of 9000 ppm in the gaseous stream led to a reduction in the mass transfer coefficient of iodine, particularly at low NaOH concentrations. In summary, the study underscores the importance of caustic scrubbing as an effective means to minimize the release of radioiodine. The investigation's results provide valuable insights into optimizing performance parameters for this process, contributing to enhanced environmental protection. [ABSTRACT FROM AUTHOR]

The paper presents the estimate of hydrodynamic parameters of the gas phase motion at low-temperature fractionation of boron trifluoride in a packed column. The following parameters are detected: density and viscosity for reacting phases in the operational temperature range, gas velocity at the phase inversion point, Reynolds number, and retention capacity for the investigated types of packed beds. Using the Logos software, numerical simulation of gas velocity and pressure distribution in the packed bed is performed for fractionation of boron trifluoride. [ABSTRACT FROM AUTHOR]

Mass transfer performance of CO2 absorption is based on selecting an effective amine solvent, hence, an examination of the overall mass transfer coefficient (KGav) and CO2 removal efficiency, is significant for obtaining the most favorable CO2 capture performance. This study compared KGavand CO2 removal efficiency of the highly concentrated ternary amines solvent at various concentrations with the benchmark monoethanolamine (MEA) in a laboratory scale CO2 absorption packed-column. The six blends of 2-amino-2-methyl-1-propanol (AMP), piperazine (PZ), and MEA are formulated as ternary solvents at high PZ/AMP molar ratio (1.25–3.75) and total amine concentration (6M and 7M). Be noted that the solvent precipitation was not observed in this study. The absorption experiment was operated at 303 K temperature, 12% CO2 by volume, and CO2 loading of 0.25 mol CO2/mol amine. The experimental results showed that KGavand CO2 removal efficiency for AMP-PZ-MEA and MEA solvents increased as total amine concentration increased. Also, KGavand CO2 removal efficiency of the PZ-AMP-MEA solvent are greater than those of 5M MEA. An increase of PZ/AMP molar ratio had a positive influence on the absorption performance for ternary amines. In comparison with the benchmark 5M MEA, all the studied AMP-PZ-MEA solvents showed an outperformance. The two suggested formulae, which are 0.95:3.55:1.5 (6M) and 0.95:3.55:2.5 (7M), possessed approximately 1.5 and 2.5 times higher KGavand 17.34% and 17.63% greater CO2 removal efficiency compared with the benchmark 5M MEA.

In order to improve the mass transfer performance of packed column and investigate comparatively different absorbents, a monoethanolamine (MEA)-based lab pilot plant with CO2 absorption and desorption packed columns with CY-700 structured packings was built. The volumetric mass transfer coefficient (KGav) and CO2 capture rate of monoethanolamine (MEA) aqueous solution absorbing CO2 under different operating conditiions were investigated, and the regeneration energy consumption was also evaluated. The results show that KGav increases with the increasing liquid flow rate and decreases with the increase of lean CO2 loading and CO2 partial pressure. However, the increasing gas flow rate has negative effect on KGav. Liquid-to-gas ratios and reflux rate of condensate back to the desorber have significant effect on the working cyclic capacity and regeneration energy. Specifically, under the conditions with CO2 capture rate ≥90%, 5 L/h liquid flow rate and 0.48 m3/h gas flow rate, the regeneration energy and the cyclic capacity were about 85 MJ/kg CO2 and 0.67 mol/kg respectively. The findings verify the stability and repeatability of the CO2 capture pilot plant, and the good mass transfer performance of CY-700 packing, which also provide important comparative reference data of the baseline solvent for comparison with novel water-lean amine-based absorbents in the next step of work.

In this study, for the first time, we investigate cobalt-mediated radical block copolymerization of vinyl acetate (VAc) and methyl acrylate (MA) in a packed column system in the presence of cobalt(II) acetylacetonate (Co (acac)2) as a controlling agent. This copolymerization system has the capability to remove the residual catalyst and separate copolymers with different molecular weights, simultaneous to polymerization. Synthesis of high-purity poly (vinyl acetate)-b-poly(methyl acrylate-co-vinyl acctate) (PVAc-b-P(MA-co-VAc)) copolymers were successfully performed by initiating the radical copolymerization of MA and VAc from PVAc-Co (acac)2 macroinitiator in the packed column with silica gel particles. Copolymerization reaction proceeds via a controlled characteristic with first-order kinetics with respect to monomers, predetermined molecular weight, and relatively narrow molecular weight distribution. GPC, 1HNMR, and DSC analyses demonstrated that the PVAc-b-P(MA-co-VAc) was formed with a blocky structure. Based on the analyses, it was found that the VAc content in the block copolymer progressively increased with increasing conversion in the constant VAc initial ratio, indicating that the second block copolymer had a gradient sequence distribution. Moreover, the VAc and MA reactivity ratios in the packed column with silica gel particles were calculated using the extended Kelen–Tudos method to be rMA = 4.98 and rVAc = 0.62, respectively. [ABSTRACT FROM AUTHOR]

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Graphene oxide sheets fixed over silica particles (SiGO) and their modification functionalized with C18 and endcapped (SiGO-C18ec) have been reported as sorbents for extraction and analytical columns in LC. In this study, a SiGO column was selected as the extraction column and a SiGO-C18ec as the analytical column to study the applicability and limitations of a column-switching system composed exclusively of columns packed with graphene-based sorbents. Pyriproxyfen and abamectin B1a were selected as the analytes, and orange-flavored carbonated soft drinks as the matrix. The proposed system could be successfully applied to the pyriproxyfen analysis in a concentration range between 0.5 to 25 µg/mL presenting a linearity of R2 = 0.9931 and an intra-day and inter-day accuracy of 82.2–111.4% (RSD < 13.3%) and 95.5–99.8% (RSD < 12.7%), respectively. Furthermore, the matrix composition affected the area observed for the pyriproxyfen: the higher the concentration of orange juice in the soft drink, the higher the pyriproxyfen the signal observed. Additionally, the SiGO extraction column presented a life use of 120 injections for this matrix. In contrast, the proposed system could not apply to the analysis of abamectin B1a, and the SiGO-C18ec analytical column presented significant tailing compared to a similar approach with a C18 analytical column. [ABSTRACT FROM AUTHOR]

The challenging task in our ecosystem is to reduce acidic gas emissions to some extent. Many gases are emitted from the industries like H2S, CO, CO2, SO2, NO, and NO2 as exhaust gases. Among these gases, CO2, NO2, and SO2 are acidic, which results in adverse effects on humans, animals, and plants. The increase in the emission of CO2 gases from both anthropogenic and industrial sources resulted in CO2 mitigation studies. CO2 absorption studies were carried out using iron oxide nanofluid with the novel structured packed absorption column. Iron oxide nanoparticles were synthesized and characterized using XRD, SEM, and TEM analysis. Ammonia is used as an absorbent along with iron oxide nanofluid of three different concentrations (0.0001 w/v%, 0.001 w/v%, and 0.0015 w/v%). It was found that the iron oxide nanofluid of 0.0015 w/v% showed an improved % CO2 removal efficiency. This enhanced % CO2 removal efficiency was due to the increased interfacial area of the ameliorated contact between the liquid and gas phases. In addition, the magnetic field was introduced along with the packed column, which increased CO2 removal efficiency by 1.5%.

The challenging task in our ecosystem is to reduce acidic gas emissions to some extent. Many gases are emitted from the industries like H2S, CO, CO2, SO2, NO, and NO2 as exhaust gases. Among these gases, CO2, NO2, and SO2 are acidic, which results in adverse effects on humans, animals, and plants. The increase in the emission of CO2 gases from both anthropogenic and industrial sources resulted in CO2 mitigation studies. CO2 absorption studies were carried out using iron oxide nanofluid with the novel structured packed absorption column. Iron oxide nanoparticles were synthesized and characterized using XRD, SEM, and TEM analysis. Ammonia is used as an absorbent along with iron oxide nanofluid of three different concentrations (0.0001 w/v%, 0.001 w/v%, and 0.0015 w/v%). It was found that the iron oxide nanofluid of 0.0015 w/v% showed an improved % CO2 removal efficiency. This enhanced % CO2 removal efficiency was due to the increased interfacial area of the ameliorated contact between the liquid and gas phases. In addition, the magnetic field was introduced along with the packed column, which increased CO2 removal efficiency by 1.5%. [ABSTRACT FROM AUTHOR]

An Egyptian gas-producing plant located in the north of Egypt on the coast of the Mediterranean Sea near Port Said city is designed mainly to receive and treat natural gas produced from offshore wells. The plant designed capacity is around 2800 million standard cubic feet per day (MMSCFD), which gives it a highly appreciated strategic importance. The primary plant process is removing H2S associated with the produced gas using amine solutions. The plant contains seven units called gas trains, which use packed columns for the removal. An additional acid gas removal unit was involved in the early production facility, which uses trays column. This study presented a comprehensive comparison study for the columns, packed versus trays, at different operating conditions, including gas flow rate, gas temperature, lean amine concentration, lean amine flow rate, and lean amine temperature. Two models simulating these systems were built using ASPEN HYSYS V12.1 simulation software. The reliability of the two models was verified by comparing the results with plant actual data. The results showed similar behavior trends with changes in operating conditions to optimize the production capacity. For the early production facility unit, the gas to contactor temperatures has been optimized at 29.5 °C, lean amine temperature at 52 °C with 44.5% concentration. The lean amine temperature for the gas train unit has been optimized at 41.5 °C with a concentration of 36%. Both units were compared under the same operating conditions to determine the economically practical unit.

In chemical processes, packed columns are frequently employed in various unit operations. However, the flow rates of gas and liquid in these columns are often constrained by the risk of flooding. To ensure the safe and efficient operation of packed columns, it is crucial to detect flooding in real time. Conventional flooding monitoring methods rely heavily on manual visual inspections or indirect information from process variables, which limit the real-time accuracy of results. To address this challenge, we proposed a convolutional neural network (CNN)-based machine vision approach for non-destructive detection of flooding in packed columns. Real-time images of the packed column were captured using a digital camera and analyzed with a CNN model, which was been trained on a dataset of recorded images to identify flooding. The proposed approach was compared with deep belief networks and an integrated approach of principal component analysis and support vector machines. The feasibility and advantages of the proposed method were demonstrated through experiments on a real packed column. The results showed that the proposed method provides a real-time pre-alarm approach for detecting flooding, enabling process engineers to quickly respond to potential flooding events. [ABSTRACT FROM AUTHOR]

The octanol-air partition ratio (K OA) is a fundamental property used for screening chemicals for concern, depending on their potential to bioaccumulate and harm living systems. With millions of chemicals used in commerce, unfortunately, less than 800 compounds currently have experimentally measured K OA values due to limitations in traditional measurement techniques. We aimed to develop a direct gas chromatography retention time (GC-RT) method using a custom-packed column, with octanol as the stationary phase, for rapidly measuring K OA. We installed the column into a GC-mass spectrometry system and isothermally measured retention times of 15 volatile organic compounds. We calculated K OA values at experimental temperatures from the retention times and extrapolated the results to values at 25 °C using the Van't Hoff equation. Our directly measured log K OA values at 25 °C spanned 3.66 log units (0.820–4.48). Except for alcohols, our measured values agree with literature log K OA values (root mean square error, RMSE = 0.50). The discrepancy probably arose from differences in how well our method versus the literature methods capture measurement artifacts, specifically, gas-phase adsorption to the octanol phase and hydrogen bonding interactions. This proof-of-concept study demonstrates that our direct GC-RT method is promising for rapidly measuring K OA to support chemical risk assessment. [Display omitted] • Developed a direct GC- retention time method to measure octanol-air partition ratios. • Measured log K OA values ranged from 0.820 to 4.48 for 15 volatile compounds. • Measured log K OA values agree reasonably well with literature values. • This proof-of-concept demonstrates that our method is promising to support chemical screening. [ABSTRACT FROM AUTHOR]

The simultaneous control of the molecular weight, separation, and purification of polyvinyl acetate was achieved using a cobalt-mediated radical polymerization (CMRP) in a packed column with silica gel particles (PC-CMRP). The controlled radical polymerization of VAc in the packed columns was evaluated from the linear time dependence of Ln[M]0/[M], linear increase of molecular weight with the increase in conversion, and narrow molecular weight distribution. PC-CMRP method was used to produce high-purity polymers with controlled molecular weight and narrow molecular weight distribution without requiring additional purification steps. The high ability of silica gel particles to adsorb free Co(acac)2 from the polymer matrix leads to the formation of pure polymers with decolorization efficiency = 91%. This method introduced a new capability for separation of polymers with known molecular weights and narrower molecular weight distributions, during the polymerization. Packed column in CMRP reactions can physically lead to the generation of long-lived propagating radicals and thus enhance the probability of producing polymers with a higher molecular weight and lower polydispersity index. [ABSTRACT FROM AUTHOR]

The objective of this study was to reduce the level of impurities in biogas to obtain a higher concentration of methane gas (CH4) in it. The biogas purification process was carried out in a packed scrubber using Monoethanolamine (MEA) compound as an absorbent. This research focused on the effect of the packing flow area and the optimum biogas flow rate for obtaining purified biogas with a high concentration of methane (CH4). The results of the study reveal that the packing flow area measuring 0.1963 cm² is more optimal in the purification process compared to 1.7633 cm² packing flow area. Different biogas flow rates at 0.3 L/min, 0.5 L/min, 1 L/min, and 12 L/min yield different results, and the highest concentration of CH4 at 90.141% is obtained from the slowest flow rate, which is 0.3 L/min. The slow flow rate and a small packing flow area equal to a longer contact time between MEA and the biogas flowing through it; hence, the absorption contact area is also greater compared to that with a faster flow rate; therefore, the highest level of CH4 is obtained at the slowest biogas flow rate. [ABSTRACT FROM AUTHOR]

Uncertainties due to maldistribution in the operation of packed columns are one of the major issues in column design. Thus, thorough knowledge of the liquid distribution and the mass transfer processes within the packed bed is necessary. Models able to predict maldistribution are crucial for avoiding extensive experimental investigations. In the present study, the TUM-WelChem cell model is expanded by the simulation of heat and mass transfer in a packed column operated as a cooling tower. The simulation approach is based on experimental data obtained at the Technical University of Munich using a Ø0.634 m random packed column. Temperature profiles and global outlet values of liquid and gas temperatures along with the humidities are evaluated and discussed for the Hiflow® ring 50–6 polypropylene. The presented study provides insight into the applicability of the heat and mass transfer calculation by validating the simulation results with experimental data. [Display omitted] • Simulation of heat and mass transfer in a random packed column using a cell model. • Usage of the TUM-WelChem cell model as basis for liquid distribution. • Sequential and simultaneous calculation of the heat and mass transfer phenomena. • Bayesian optimization for correlations for heat and mass transfer coefficients. • Comparison of simulated temperature profiles and outlet values with experiments. [ABSTRACT FROM AUTHOR]

Additive manufacturing is a promising tool for tailored solutions in chemical engineering. This applies in particular to the design of lab‐scale packed bed columns. We present experimental results to characterize a lab‐scale 3D printed structured metal packing and compare it to a conventional counterpart. The results indicate that necessary adjustments for the manufacturing process of the metal material have an influence on important operating parameters, resulting in higher specific pressure drop, slightly higher liquid holdup and lower mass transfer efficiency. [ABSTRACT FROM AUTHOR]

Graphene oxide sheets fixed over silica particles (SiGO) and their modification functionalized with C18 and endcapped (SiGO-C18ec) have been reported as sorbents for extraction and analytical columns in LC. In this study, a SiGO column was selected as the extraction column and a SiGO-C18ec as the analytical column to study the applicability and limitations of a column-switching system composed exclusively of columns packed with graphene-based sorbents. Pyriproxyfen and abamectin B1a were selected as the analytes, and orange-flavored carbonated soft drinks as the matrix. The proposed system could be successfully applied to the pyriproxyfen analysis in a concentration range between 0.5 to 25 µg/mL presenting a linearity of R2 = 0.9931 and an intra-day and inter-day accuracy of 82.2–111.4% (RSD < 13.3%) and 95.5–99.8% (RSD < 12.7%), respectively. Furthermore, the matrix composition affected the area observed for the pyriproxyfen: the higher the concentration of orange juice in the soft drink, the higher the pyriproxyfen the signal observed. Additionally, the SiGO extraction column presented a life use of 120 injections for this matrix. In contrast, the proposed system could not apply to the analysis of abamectin B1a, and the SiGO-C18ec analytical column presented significant tailing compared to a similar approach with a C18 analytical column.

The paper presents the results of experimental studies on one- and two-phase flow in packed columns. In the study, natural materials (LECA, pumice stone, cones, coconut fiber, wood chips, walnuts, shells), waste materials (plastic nuts, bricks, tiles), copper springs, and plastic acorns were used as packing. The relationship between the flow resistance coefficient and the Reynolds number is described. In the model, the relationship between the pressure drop on the sprayed packing and the pressure drop on the dry packing is presented. The characteristic values for the studied materials were obtained. The study constitutes the basis for further studies of packings of various origins in order to determine the influence of variable geometrical dimensions. [ABSTRACT FROM AUTHOR]

Often only small amounts of sample are available for spectroscopic analytical determinations. This work investigates the enhancement of signal in columns packed with silica particles. We propose that silica particles cause the light to scatter through the column, effectively increasing optical path length. Packed columns are shown to be effective with fluorescence spectroscopy, but results were inconclusive with absorbance spectroscopy. Graphical Abstract [ABSTRACT FROM AUTHOR]

Additive manufacturing is increasingly being used to develop innovative packings for absorption and desorption columns. Since distillation has not been in focus so far, this article aims to fill this gap. The objective is to obtain a miniaturized three dimensional (3D) printed packed column with optimized properties in terms of scalability and reproducibility, which increases process development efficiency. For this purpose, a flexible laboratory scale test rig is presented combining standard laboratory equipment with 3D printed components such as innovative multifunctional trays or the column wall with packing. The test rig offers a particularly wide operating range F=0.15Pa0.5...1.0Pa0.5 for column diameters between 20mm and 50mm. First results regarding the time to reach steady‐state, operational stability, and separation efficiency measurements are presented using a 3D printable version of the Rombopak 9M. Currently, further developed and newly designed packing structures are being characterized, which should exhibit optimized properties especially with respect to scalability and separation efficiency. [ABSTRACT FROM AUTHOR]

An experimental and simulation study using a packed column for CO2 sorption was conducted. The adsorption data of CO2 sorption from CO2/N2 mixture using activated carbon (NORIT RB1) were obtained at different operating conditions. The sorption equilibrium and breakthrough profiles were produced with a total pressure of 1.25 bars. The breakthrough and saturation time decreased with increasing temperature, feed rate, and inlet CO2 concentration. A linear driving force (LDF) model for mass transfer was used to calculate the mass transfer coefficient and reproduce the breakthrough curves. The findings of the LDF model were compared with experimental data produced at various operating conditions to predict the breakthrough curves. The experimental and predicted findings were analyzed by ascertaining the determination coefficient and mean error. The model consistently reproduced all the breakthrough curves and may be considered adequate for predicting the CO2 separation from a CO2/N2 mixture with R2 > 0.97 and mean error less than 5% under all the operating conditions. [ABSTRACT FROM AUTHOR]

In this study, CO2 reactive-absorption process is modeled into the NaOH-NH3-H2O solution in an absorption column. A non-equilibrium or rate-based model is used to simulate the process performance, and the predicted results are compared with the experimental data. In this model, the steady and nonlinear film models are utilized for high and low solubility components, respectively. The average relative deviation (ARD%) is decreased from 9.73 to 4.36 by increasing the number of column stages from 20 to 60 in the simulation. On the other hand, the predicted values by the film and enhancement factor models are compared, and it was concluded that the film model was more accurate than the other. The effects of axial position through the column and initial NaOH concentration on the liquid flow rate, mole fraction of components, and temperature of the gas and liquid phases are also investigated. As a main result, the temperature of the liquid phase and the CO2 concentration in the liquid phase decrease by increasing the axial position through the column. [ABSTRACT FROM AUTHOR]

The use of gasoline for primary energy consumption can reduce crude oil, contained in the earth. The development of alternative fuels such as biogas and biofuel is very critical to overcoming this problem. Biogas requires purification to remove some contaminant particles that interfere with the combustion process. The packed column is generally applied to absorb and separate gas and liquid mixture. It is more efficient due to the liquid flows down the column of steam naturally without the supply of energy from outside the system. This study focuses on determining the effect of the packed column biogas purification process. Biogas is applied as an alternative fuel in spark-ignition engines (SIE). The test is carried out using a chassis dynamometer to obtain power and torque data. The use of the packed column for biogas fuel purification can produce higher performance compared to unrefined biogas. The unrefined biogas still contains impurities that can interfere with the combustion process. This condition is proven by measuring the power and torque of the vehicle on the chassis dynamometer, where the filtered biogas produces higher power and torque. Tests were carried out both using the packed column and without the packed column. Variations from speed to torque, to power, to SFC and BMEP are considered. In this study, validation is in good agreement with previous studies. Overall, the results show that the average error between using the packed column and without the packed column for torque, power, SFC and BMEP is increased by approximately 7 %. Purification of biogas using the packed column using Ca(OH)2 can bind CO2 and obtain pure methane gas with a higher heating value. In conclusion, the packed column for biogas purification as fuel for motorcycle injection systems can be applied. [ABSTRACT FROM AUTHOR]

• Absorption of CO 2 with NH 3 in packed beds is investigated. • A novel algorithm based on a dynamic model is proposed to design the packed bed. • The underlying model considers mass transfer and ion speciation in liquid phase. • The algorithms are experimentally validated under different operating conditions. • Low computational loads are needed to design the column according to this method. A novel model-based approach to design packed beds for CO 2 absorption with NH 3 is proposed and experimentally validated. The two-film theory is adopted to model gas/liquid mass transfer while the thermodynamic equilibrium among ion species is considered in the liquid. Such strategy allows to simulate both CO 2 absorption and NH 3 evaporation, that represent the most important aspects to improve capture efficiency and process cost-effectiveness. The resulting ODEs system is a two boundary-value problem which is solved by means of the shooting method. The model is then exploited to develop a new algorithm that, based on the adopted operating conditions, evaluates the packed bed height as a function of the desired capture efficiency. The height calculated for different combinations of operating conditions is successfully compared with the real height of the experimental column, thus confirming the reliability of the developed tool which can be run with very low computational loads. [ABSTRACT FROM AUTHOR]

Emisi karbondioksida ke atmosfer dianggap sebagai penyebab utama perubahan iklim, termasuk pemanasan global dan permasalahan pertanian. Berbagai teknologi pemisahan CO2 banyak dikembangkan. Absorpsi kimia adalah teknologi pemisahan yang paling efektif dan banyak digunakan dalam industri kimia maupun petrokimia. Dimana pelarut yang telah digunakan dapat di regenerasi kembali di kolom stripper. Stripping adalah proses regenerasi termal pelarut dimana larutan tersebut dikontakkan dengan pelarut gas yang tidak larut terhadap cairan tersebut. Penelitian ini bertujuan untuk mengembangkan simulasi unit stripping CO2 dalam packed column skala industri dengan mengestimasi kinerja unit stripping CO2 yang dinyatakan dengan % efisiensi kolom stripping dan komposisi gas yang keluar dari stripper. Simulasi dilakukan secara teoritis dengan mengembangkan model matematis untuk proses stripping CO2 dalam packed column skala industri. Selanjutnya hasil simulasi divalidasi dengan data riil pada salah satu industri pupuk di Indonesia. Variabel-variabel yang digunakan adalah tekanan operasi kolom, temperatur rich solution dan laju steam. Hasil simulasi untuk tekanan stripper 2,56 atm dengan laju rich solution 2943316 kg/jam dan temperatur rich solution 390 K menunjukkan CO2 (% mol) 99,038%, sedangkan data pabrik menunjukkan 97,5862%.

A continuous study was carried out in the up-flow packed bed column to remediate the Reactive Orange 16 (RO16) using biochar derived from coconut shell as a low-cost adsorbent. The sorption mechanism in the continuous process was carried out by studying the influencing parameters namely bed depth, solute flow rate and initial dye concentration. The continuous study explored a maximum uptake capacity of 46.63 mg/g at a bed depth of 25 cm, a flow rate of 0.3 L/h and an initial dye concentration of 100 mg/L. Mathematical modeling such as the Thomas model, modified dose– response model and Yoon–Nelson model was performed to fit the experimental data. Regeneration studies were carried out using 0.01 M NaOH and resulted in 99.7% desorption efficiency. The sorption–elution study concluded that the biochar can undergo three sorption–elution cycles. [ABSTRACT FROM AUTHOR]

Mass transfer parameters are necessary for the design of absorption and desorption processes in packed columns. To determine the effective interfacial area and liquid side mass transfer parameters, CO2 absorption and desorption are frequently used. Reliable analytics for concentration determination are essential to obtain correct results. In this work two methods of CO2 liquid phase analysis are compared: first, the back titration of unreacted NaOH after prior precipitation of the bound CO2; secondly, the inorganic carbon analysis with a commercial inorganic carbon analyzer. [ABSTRACT FROM AUTHOR]

Liquid maldistribution is simulated with the TUM‐WelChem cell model for a Ø1,2 m packed column and compared with experimental data. The packing types Raflux ring 50‐5 metal, Hiflow® ring 50‐6 plastic and RVT metal saddle ring 50‐4 are investigated. Two calculation methods for lateral dispersion on each cell layer are used in the model: a sequential and a simultaneous method. A parity analysis and the interpretation of the relative deviation of the calculations from the experimental results provide insights into the assumptions and validity of the model. [ABSTRACT FROM AUTHOR]

• Hydrodynamics of two waste oils and PDMS in a structured packing was investigated. • Pressure drop in the loading zone was lower than 450 Pa m−1. • Loading and flooding velocities were relatively low, especially using the viscous lubricant. • Billet-Schultes correlations were efficient to predict the loading and flooding points and the pressure drop. • Scale-up calculations proved that transformer oil can be used in an industrial scale packed column. The purpose of this work was to study the hydrodynamic behavior of two viscous waste oils (a transformer oil and a lubricant characterized by viscosities of 19 mPa s and 79 mPa s at 25°C, respectively) and a silicone oil (20 mPa s at 25°C) in a laboratory-scale packed column (D col = 0.12 m). The column was filled with structured packing made of corrugated sheets (Flexipac® 500Z HC) and was operated at counter-current. Thus, the gas superficial velocities at the loading point were in the range from 0.40 to 0.65 m s−1 for liquid loads between 1 and 24 m3 m−2 h−1, and, at the flooding point from 0.56 to 1.07 m s−1 for liquid loads between 6 and 36 m3 m−2 h−1. Both loading and flooding points were particularly influenced by the solvent viscosity, leading to a narrow loading zone for the most viscous solvent (lubricant). The pressure drop values remained reasonable, lower than 450 Pa m−1 in the loading zone, even for the lubricant. Billet-Schultes correlations were used for the prediction of the loading and flooding velocities and of the pressure drop. The specific constants of the model were determined. These correlations enable accurate predictions of the loading and flooding points, with an average relative error around 7–8%, and of the pressure drop in the loading zone, with an average relative error of 15%. Simulations were performed with the Billet-Schultes correlations and showed that high liquid holdup and interfacial area would be obtained with these viscous solvents in the selected packing. Scale-up calculations proved that it would be possible to implement the transformer oil at industrial scale in a packed column filled with the studied structured packing. [ABSTRACT FROM AUTHOR]

Apart of new equipment's development such as absorption columns with higher efficiency, for chemical industry, there is a strong need for greenhouse gases reduction in order to assure the environmental protection and, consequently, many studies regarding the purification methods of exhausted gases have been performed. There are several types of reactors used for gases purification, such as: bubbling jet reactor, combined packed and spray tower absorber, cable wet scrubber and packed column. Among these, chemisorption in packed column was considered and analysed in this paper because of its increased absorption rate achieved by adding of activators and providing a good contact between liquid and gas phases. Using a validated model at industrial scale, the performance of a packed column under various conditions was assessed, aiming to establish the effects of several parameters as temperature, pressure, activator concentration, transformation degree, initial solution concentration, etc. on the purification process performance. Based on the obtained results, new reactors for purification of the exhausted gases generated from burning process of fossil fuels, can be designed. [ABSTRACT FROM AUTHOR]

Introduction: Hexavalent chromium is a highly toxic metal and it is considered one of the contaminants with the highest environmental impact. Bioadsorbents have been considered as a viable option for chromium removal, leading to the necessity to study the behavior of these adsorbents in unit operations similar to the ones employed in the industry. Objective: To study the potential of cassava peels as bio-sorbent in the adsorption of hexavalent chromium in a semi-continuous process in fixed bed columns. Methodology: The effect of parameters such as feed flow rate, initial concentration and bed column height on the response variables rupture time and removal capacity was analyzed using a laboratory scale experimental set-up. Results: Low feed flow rates, low initial concentrations, and higher bed height produce the best conditions for chromium removal. Additionally, three classical models for removal on the packed column were used to fit the dynamic behavior of this process and to obtain significantly physical parameters. However, the best fitting was obtained using the model of the response surface. Conclusions: The concentration of chromium in the feed stream is the experimental factor that has the most influence on removal capacity and rupture time in fixed bed columns packed with cassava peel.

Greenhouse gases emissions from large scale industries as well as gasoline based vehicles are mainly responsible for global warming since the 1980s. At present, it has triggered global efforts to reduce the level of GHG. The contribution of carbon dioxide (CO2) in polluting the environment is at a peak due to the excessive use of coal in power plants. So, serious attention is required to reduce the level of CO2 using advanced technologies. Carbon dioxide capture and storage may play an important role in this direction. In process industries, various carbon dioxide capture techniques can be used to reduce CO2 emissions. However, post-combustion carbon dioxide capture is on top priority. Nowadays the researcher is focusing their work on CO2 capture using hybrid solvent. This work highlights a review of carbon dioxide capture using various kind of hybrid solvent in a packed column. The various challenges for absorption efficiency enhancement and future direction are also discussed in the present work. It is concluded through the literature survey that hybrid solvent shows better efficiency in comparison to the aqueous solution used for CO2 capture. [ABSTRACT FROM AUTHOR]

• Pilot-scale experiments to investigate the performance of offshore columns. • The effects of liquid properties and operating conditions were analyzed. • An empirical reduction factor is proposed to capture the effects of permanent tilt. In this study, the effects of ship motion on the CO 2 absorption performance of the offshore columns (i.e., the separation columns installed on offshore floating units) are investigated. Specifically, a pilot scale column with 0.4 m diameter and 4 m packed height is used, and NaOH/air system is implemented to measure the CO 2 absorption performance of the column under both vertical and offshore conditions. The experimental results obtained from the vertical conditions are used to validate the mathematical model which can compute the effective surface area of the separation columns. Then, such model is used to produce the reference values for the experimental results obtained from the various offshore conditions, where tilt angle, roll motion conditions, liquid load, gas factor, liquid surface tension and liquid viscosity are used as the design variables. The reduction factor is proposed, which can describe the change in the absorption performance of the offshore columns with respect to the important factors. From our study, the tilt angle was shown to be the most important factor, and the mass transfer efficiency was reduced by 8.4% in average (compared to the value obtained under the vertical condition) when the tilt angle was 6°. It was also shown that the roll motion can enhance the absorption performance of offshore columns under certain operating conditions, and the maximum improvement (6.7%) in the mass transfer efficiency was achieved when the liquid load, roll motion amplitude and period were 14 m3/m2 hr, 8° and 45 s, respectively. [ABSTRACT FROM AUTHOR]

A methodical procedure for the development of additively manufactured innovative packing structures in laboratory scale is described. Since structural development is an evolutionary process, the focus of this publication is on the methodology of development strategies. Therefore, packing structures based on crystal lattices with flexible dimensioning are created with the visual basic for applications (VBA) tool in Autodesk Inventor®. For the characterization, computational fluid dynamics (CFD) simulations are applied to examine the dry specific pressure drop and the liquid distribution. Calculations of packing‐characteristic values with parameter studies and the above‐mentioned CFD simulations reveal indications of the efficiency of these packings. Selective laser sintering using polyamide 12 (PA 12) as material was applied for additive manufacturing of the packing and the column shell. [ABSTRACT FROM AUTHOR]

Abstract Hydrophilic interaction liquid chromatography, HILIC, is a relatively new HPLC mode. Compared with other HPLC modes, HILIC is a high resolution chromatographic mode with high peak capacity for separations of complex mixtures. Although the separation mechanism is still not completely clear, HILIC has been widely used for analysis of hydrophilic compounds which are difficult for reversed phase chromatography to retain and separate. In this study, we fabricated and investigated nanoHILIC columns in terms of separation efficiency, van Deemter curves and more importantly, we focused on long packed capillary columns, and studied their extreme resolution for protein digests. Using meter long nanoHILIC columns packed with 5 μm particles, we realized a high peak capacity of 130. Based on nanoLC-MS, we compared the resolution and protein identification capabilities of nanoHILIC and nanoRPLC. The results indicate both nanoHILIC and nanoRPLC can provide high resolution for protein sequencing but neither mode is significantly better than the other. Among the 99 digest peptides identified, 17 were uniquely identified by nanoHILIC-MS and 20 were uniquely identified by nanoRPLC-MS and 62 were identified by both methods. Although at this moment in time, nanoRPLC is the most popular microseparation tool in proteomics, the excellent complementarity of nanoHILIC and nanoRPLC suggests their combined use in achieving deep-coverage in MS-based proteomics. Graphical abstract Image 1 Highlights • The multiplex retention mechanism plays a key role in dynamics of nanoHILIC. • Extreme peak capacity of 130 can be reached using meter long nanoHILIC columns. • Low backpressure of nanoHILIC suggests long column length for extreme resolution. • NanoHILIC-MS and nanoRPLC-MS have complementary protein identification capability. • The meter long nanoHILIC column identified 3380 HeLa proteins in a single run. [ABSTRACT FROM AUTHOR]

• The TUM-WelChem Cell Model is applied in liquid distributor design. • Optimum design for minimized material usage and high free space for gas flow. • The optimum drip point density increases with the nominal size of random packing. • For a perfectly square grid, the highest possible is also the optimum wall spacing. • The optimum drip point density increases for smaller column diameters. Liquid distributors are the second most important internal in packed columns, as they ensure sufficient initial distribution, which is crucial to achieve optimum separation performance. In this work, a liquid distributor design method is presented, which applies the TUM–WelChem Cell Model to consider the interaction between the liquid distributor and the packing. Liquid distribution in the packing is estimated in dependence of the liquid distributor design. An overall maldistribution quality is determined as a characteristic value for evaluation. Two common methods, the coefficient of variation and the liquid distribution quality by Moore and Rukovena, are implemented for reference. A parameter study with an exemplary column design provides optimum drip point densities for different types of packing. Moreover, the spacing between the outermost drip points and the column wall is considered in detail, suggesting an optimum distribution quality for high wall spacing. Further application of the method suggests an increase of the optimum drip point density for smaller column diameters. Application of the TUM–WelChem Cell Model to liquid distributor design provides a potent tool for an optimized distributor layout with sufficient initial distribution at minimized material usage and high free space for the gas flow. [ABSTRACT FROM AUTHOR]

An up‐flow fixed column study was conducted to remediate Remazol Brilliant Orange 3R (RBO3R) from contaminated solutions using biochar derived from Ulva lactuca biomass. The influences of column parameters on dye sorption were studied in detail, which include initial RBO3R concentration, bed depth, and flow rate. Optimization experiments indicated that maximum RBO3R column uptake of 0.114 mmol/g was observed at 0.25 mmol/L (initial RBO3R concentration), 0.3 L/hr (flow rate), and 25 cm (U. lactuca bed depth). Modeling of column sorption data was performed using the Yoon–Nelson, modified dose–response and Thomas models. The spent biochar was desorbed and rejuvenated using 0.01 M NaOH. The elutant (0.01 M NaOH) exhibited 99.7% efficiency, and the process was completed in 115 min with high overall concentration factor of 8.4. Practitioner points: This study explores the impact of column parameters on the dye removal potential of U. lactuca‐derived biochar.At optimized condition, the biochar bed exhibited highest Remazol Brilliant Orange 3R uptake capacity of 0.114 mmol/g.The regeneration and desorption of U. lactuca‐derived biochar bed was possible with NaOH (0.01 M) as elutant. [ABSTRACT FROM AUTHOR]

The methodical procedure for the development of additive manufactured, innovative packing structures in laboratory scale is described with the focus on the methodology of development strategies. Packing structures, based on crystal lattices, with flexible dimensioning are created with the VBA‐tool in Autodesk Inventor®. For the characterisation CFD simulations are used to examine the dry specific pressure drop and the liquid distribution. For additive manufacturing of the packing with the shell, selective laser sintering as additive manufacturing method and polyamide 12 as material were selected. [ABSTRACT FROM AUTHOR]

Carbon dioxide has many benefits such as in the production of dry ice, fire fighting, welding, and the production of carbonated drinks. As a result of these, it is important to develop a method to capture it effectively by reactive absorption using tertiary amine compounds, methyldiethanolamine (MDEA). Compared to primary and secondary amines, tertiary amines are inexpensive with a higher absorption capacity ratio of 1:1 (1 mole of CO2/1 mole of MDEA). One of its demerits is its slow absorption rate which can be improved by adding diethanolamine (DEA) and glycine as promoters. The purpose of this research is to determine the effect, type and concentration of promoter, its absorbent flow rate and solution temperature on CO2, as well as its removal percentage using a packed column filled with raschig ring. The concentration of CO2 gas absorbed was examined using an analyzer. The equipment used consists of columns with a diameter of 2”, column height of 80”, and filled with ¼” type raschig ring. Mixture of gases (10 % CO2, 90 % air) is flowed into the column using a predetermined flow rate. The 40 % MDEA absorbent varies with the glycine and DEA promoter concentration and the absorbent flow rate also varies from 0.20 to 0.60 L/min. The promoter concentration varies from 0 (no promoter) to 5 % while the MDEA inlet solution temperature varies from 40°C to 60°C. Based on the analysis, the best operating conditions for CO2 absorption using a DEA promoter of 3 % at 40°C with a flow rate of 0.20 L/min showed CO2 removal of 42.7 %. [ABSTRACT FROM AUTHOR]

Highlights • Desorption/elution simulation of GSA was studied in COMSOL efficiently. • A superficial desorption rate constant was considered at the liquid–solid interface. • Equilibrium time is decreased by increasing the concentration of desorbent HCl. • The recycle percentage of GSA is acceptable in a series of adsorption–elution cycles. Abstract For several decades, plenty of iridoid glycosides including geniposide (GS) and geniposidic acid (GSA) in the gardenia yellow pigment extraction waste water was not recovered effectively. This study is aimed to supply an efficient GSA recycling route. In this study, a model incorporating a superficial desorption rate constant was applied to the batch GSA desorption process, i.e., recycling, for verification. Then, the model was further developed to research the feasibility in dynamic column elutions simulation through porous uniform media. The simulation approach was done by coupling velocity field and mass transfer equations using COMSOL Multiphysics™ Finite element method, with appropriate mesh refinement was employed to solve the equation system. The HCl solutions ranging from 0.03 mol/L to 0.06 mol/L were used to desorb/elute the GSA from a presaturated polymeric porous anionic resin D08. Good results were accomplished in terms of ion exchange desorption rate and GSA recovery. The pore diffusion model (PDM) considering counter ion was established to describe the desorption/elution kinetics in the batch/column experiment. By the least square fitting method, the superficial desorption rate constant K d of GSA/HCl reaction on the ion-exchange sites of porous resin was fitted to 0.116 L/(mol s). Subsequently, this value was sequentially applied in the simulation of the dynamic elution process. The individual pore diffusion coefficients for GSA and Cl− were estimated to be 5.07 × 10−10 and 1.77 × 10−9 m2/s, respectively. In order to validate the simulation feasibility of this pore diffusion model to a dynamic column elution process, the effects of HCl concentration, flow rate and column's height/diameter ratio on the column performance were investigated systematically. The results from this work should serve as motivation for further experimental and theoretical study in the scaling-up of GSA purification process. Finally, repeated adsorption–elution column cycles were simulated by the PDM model well. [ABSTRACT FROM AUTHOR]

In the chemical industry, real‐time flooding prognosis is a necessity for packed‐column operation because the flooding phenomenon interferes with the performance of production systems. In this work, the profile monitoring technique is utilized to capture the dynamic behavior of pressure drop, which is an important indicator for the flooding phenomenon. In each moving window, the pressure drop signals are described by using an exponential generalized autoregressive conditional heteroskedastic model. The onset of the flooding phenomenon is then indicated by changes in model parameters. Moreover, to efficiently capture the process change, a nonparametric approach is utilized to establish a statistical control chart. Experimental and comparison results show the advantages of the proposed method. [ABSTRACT FROM AUTHOR]