Intalox Saddles Research Articles

Direct numerical simulation of packed and monolith syngas catalytic combustors for micro electrical mechanical systems

In this work, a catalytic combustor for micro electrical mechanical system for syngas was designed and analysed using Direct Numerical Simulation (DNS) in conjunction with finite rate chemistry. The effect of catalyst (platinum (Pt), palladium (Pd), palladium oxide (PdO), and rhodium (Rh)), bed type (packed with twelve catalyst shapes and four catalyst monolith), shapes (packed: cylinder, hollow cylinder, four cylinder, single cylinder, single cylinder, cross-webb, grooved, pall-ring, hexagonal, berl-saddle, cube, intalox-saddle, and sphere, monolith: triangular, rectangular, hexagonal, and circular), and operating conditions (inlet temperature and velocity, fuel/air ratio, different concentrations CH4-H2-CO) on combustion efficiency and pressure drop were studied using different parameters (combustion efficiency (η), pressure drop, effectiveness factor (Ψ), and fuel conversions (H2 and CH4 conversions)). Analysis under different operating conditions reveals that the designed combustor can operate effectively with syngas of varying compositions with a high combustion efficiency of over 85%. Combustion mainly takes place on the surface of the catalyst without gas phase reaction with pressure drops between 18 Pa and 155 Pa. The intalox saddle shape catalysts resulted in the bed effectiveness factor 0.93.11An ideal reactor effectiveness factor is 1 which 0.5 is equivalent to 100% combustion efficiency and 0.5 is from 0% pressure drop at the combustor outlet. The Damköhler for hydroxyl radicals (OH) over the entire length of the reactor is uniformly distributed and well below 3, suggesting uniform combustion.

Study of axial dispersion on several modern structured and random packings

The study investigates the phenomenon of axial dispersion in a packed absorption column, which is known to reduce the efficiency of separation equipment by reducing the mass transfer driving force. The aim of the study is to determine the Bodenstein number, which represents axial dispersion, for five types of modern packings used in the column. The packings used in the study were random packings (NeXRing0.7 and NeXRing1.2) and structured packings (MellaPak350Y, 452Y, and 500Y). The data obtained from dynamic experiments in the form of a response to a step change in tracer substance concentration were compared to a diffusion-type differential equation, which was solved with boundary conditions for a closed system. By measuring the responses at two different packed bed heights and using convolution, the influence of the end effects was eliminated. The lowest axial dispersion was obtained for M452Y, and it is almost twice as low as for M250Y. It was found that the values of the Bodenstein number for standard series of Mellapak type packing (M250Y, M350Y and M500Y) have comparable axial dispersion, especially at low liquid rates. The axial dispersion obtained for random packings is generally higher compared to structured packings. However, compared to other random packings such as Pall rings (25 mm) and Intalox saddles (25 mm), NXR0.7 and NXR1.2 exhibit up to a two-fold reduction in axial dispersion.

Optimasi Laju Alir Tri-Ethylene Glycol terhadap Efisiensi Penyerapan Air pada Kolom Absorbsi Di PT. Pertamina Hulu Energi

Absorption was a separation process between gas fluids using liquid fluid media. The glycol contactor aims to separate the water content contained in the gas using tri-ethylene glycol media with process conditions at a pressure of 795-810 psi and a temperature of 85-110 o F . The contact process between fluids is assisted by the I ntalox S addle type packing which aims to maximize the contact process between fluids and it is hoped that the absorption process that occurs can be maximized. Tri-ethylene glycol which has absorbed the water content in the gas is regenerated in the glycol burner. This analysis used 4 packing variables (Raschig Rings, Pall Rings Plastic, Berl Saddles Ceramic, and Intalox Saddles Ceramic), 5 flow rate variables (1600, 1800, 2000, 2200, and 2400 BPD) and this analysis use the Hysys simulation program. Based on these variables, the absorption efficiency analysis results are obtained in the range of 93-94%, and the flooding percentage is 21-36%. It can be concluded that the type of packing is very influential on the percentage of flooding. Pall Ring Plastic was the type of packing with the lowest flooding percentage. According to research, lower flow rates increase the efficiency of H 2 O absorption.

Modelling and Simulation Studies of Multiple Packings Distillation Column

Large scale separation of liquid mixtures into their various components is one of the major operations in the process industries. Distillation remains one of the predominant separation techniques that is use for these separations. It accounts for about 90% of product recovery and purification in the process industries. The strength of the distillation technique lies on its simplicity, low capital investment, and low risk as compared to other traditional separation techniques. In the present study, the synergistic effects of multiple packings in binary distillation column operations was investigated. The investigation was done using Aspen HYSYS process simulation software. Specifically, the study was done to establish a packing order that will be required to achieve a reduction in energy consumption and the overall cost of separation processes that involve distillation operation. The packed distillation was simulated using Berl saddles, Intalox saddles, and Pall rings as the column internals. Single, dual and triple packing arrangements were evaluated. The multiple packing arrangement investigated were Berl/Intalox, Berl/Pall, Pall/Intalox, and Berl/Intalox/Pall. Binary mixtures of pentane and hexane was used as feed to the column. The results of this simulation revealed that the use of multiple packing arrangement had a significant effect on the energy consumption, the height of packing and hence the cost of equipment fabrication. For instance, the estimated cost of packings (USD) are 524.89 for Berl, 406.85 for Pall, 303.77 for Intallox, 427.09 for Berl/Intalox, 473.06 for Berl/Pall, 323.51 for Pall/Intalox, and 388.60 for Berl/Intalox/Pall. These results clearly revealed that multiple packing arrangements can be used to reduce the cost of column fabrication without compromising the performance of the equipment.

Treatment of Industrial Textile Wastewater in Biological Aerated Filters – Microbial Diversity Analysis

Investigated herein was the biodegradation of highly contaminated textile wastewater on a laboratory scale, with biological aerobic filters as a single treatment and in combination with the coagulation/flocculation process. Among the three support materials tested (Intalox saddles, ceramsite and beach shavings), the highest organic carbon compound removals (above 60% measured as COD and TOC) and steady operation were obtained for ceramsite. Effective and stable biological treatment was possible thanks to the development of biofilm of high bacterial and fungal diversity. The biodiversity of microflora was estimated on the basis of metagenomic analysis. The coagulation process with PAX 18 was effective in total phosphorus depletion (94%), while the coagulant Epoly CRD enabled up to 99% colour removal. The best results were obtained after the combined treatment, in which biodegradation was followed by coagulation (PAX 18). Such a combination enabled the removal of 98% of BOD5, 87% of COD, 88% of TOC, 48% of the total nitrogen, 98% of the total phosphorus, 98% of toxicity (towards Vibrio fisheri) and above 81% of colour.

Effect of the Tower Type on the Gas Sweetening Process

The removal of acid gases, CO2 and H2 S from natural gas streams is essential for environmental and health reasons. In this work, the simulated gas sweetening unit with Methyl-DiEthanolAmine (MDEA) solvent was studied to improve quality. Firstly, the effect of trays types and then, the effect of various packing and the effect of the packing size were considered on the flow rate of CO2 and H2 S in the main streams. Results show that with considering the different trays types in the regenerator tower, the flow rate of CO2 in the sweet gas stream with bubble cap tray is lower than other trays types. Also, with considering the different trays types in the absorber tower, the flow rate of CO2 in the sweet gas stream with bubble cap tray is lower than other trays types in the absorber tower. In considering with different types of packing, results show that the flow rate of CO2 with ballast ring packing and the flow rate of H2 S with Raschig ring packing are lower than other types of packing. However, in some types such as cascade miniring, Intalox Saddles and pall ring, there is no difference for the flow rate of CO2 or H2 S. In all cases, with increasing the size of the packing, the flow rate of CO2 and H2 S in the sweet gas stream increases, however, this increasing in the metal packing is very small.

Effective reclamation of vent gas in ethylbenzene dehydrogenation by coupling multi-stage circle absorption and membrane units

Ethylbenzene catalytic dehydrogenation can generate a large amount of hydrogen. Its vent gas is attractive with hydrogen content higher than 75 mol%. Nevertheless, styrene remaining in the vent gas is highly active to polymerize into oligomers, the gradual accumulation of which is harmful to hydrogen separation equipments. In this work, an integral separation process including absorption and membrane units is established to overcome this challenge. Absorption unit running with fresh ethylbenzene as the absorbent is proposed to deeply remove styrene, the residual content of which is reduced to less than 10 ppm. Thereafter, the generation and accumulation of styrene oligomers is restrained strictly to protect hydrogen separation equipments. Furthermore, the custom-designed absorption tower with a multi-stage cycle structure is used to reasonably improve styrene content in the used ethylbenzene at tower bottom, in the interest of reducing styrene recovery expense. For a 100 kt/a styrene plant with the vent gas flow rate up to 3180 N m3/h, a 5-stage tower is designed, which is 0.5 m in diameter, 5.0 m in height, and about 3.0 m in the total packing height of 25-mm metal Intalox saddles. Flow rates of liquids in the tower and the recycle routes are 1.19 m3/h and 1.05 m3/h, respectively. Finally, compressor and membrane for hydrogen recovery are optimized simultaneously with gross profit as the criterion. For compressor, its duty and outlet pressure are 520 kW and 1.85 MPa, respectively. For membrane separation unit, its area and permeation stage cut are 460 m2 and 0.84, respectively. According to the simulation research, this integrated system can behave excellently with an annual recovery of 162 ton styrene, 281 ton aromatic hydrocarbons and 2.1 × 107 N m3 hydrogen, with a gross profit up to 5.1 × 106 US dollars per year.

Axial dispersion model in predictive mass transfer correlation for random pulsed packed column

The continuous phase volumetric overall mass transfer coefficient in a ceramic intalox saddle pulsed packed extraction column using axial dispersion model was studied for two different liquid-liquid systems containing water/acetone/toluene and water/acetone/n-butyl acetate. The effects of pulsation intensity, continuous and dispersed phase flow rates on mass transfer coefficient were investigated. The experimental results indicated that the mass transfer coefficient was enhanced by increasing pulsation intensity and dispersed and continuous phase flow rates. The utilization of nonlinear least square method provided a new predictive correlation for the continuous phase overall mass transfer coefficient. The developed mass transfer model was validated via the comparison of the modeling data with experimental results with 18.7% average absolute relative error (AARE). Furthermore, one empirical correlation was developed for prediction of the continuous phase overall mass transfer coefficient as the function of the aforementioned operating variables.

Identification of Flow Regimes in a Concurrent Gas Liquid Upflow through Packed Beds

AbstractThe flow regimes bubble flow, pulse flow, and spray flow were identified by visual observation in a packed column. Three gas‐liquid systems (air/water, air/56 % glycerol, and air/monoethanolamine) and four column packings (Raschig rings, Intalox saddles, and two sizes of spheres) were investigated to cover wide ranges of physical properties of gas liquid systems and characteristics of column packings affecting the flow regime transition. Criteria for the flow regime transition were developed in terms of system and operating variables.

Interfacial area for concurrent gas–liquid upflow through packed bed

AbstractInterfacial area is measured for a large range of column packing (Raschig rings, Intalox saddles, and two sizes of spheres) for concurrent gas–liquid upflow through packed bed covering bubble, pulse and early spray flow regimes using air–aqueous sodium sulfite solution. It was observed that the interfacial area increased with increase in fluids flow rate and decreased with the increase in the particle size for the same type of packing. A correlation (3 ≤ Rel ≤ 165, 0.5 ≤ Reg ≤ 210) was developed using present data (120 data points) and literature data (100 data points), which predict the interfacial area with an rms deviation of 16%.

Gas and Liquid Axial Mixing in the Column Packed with Mellapak 250Y, Pall Rings 25, and Intalox Saddles 25 under Flow Conditions Prevailing in Distillation Columns

The axial dispersions of gas and liquid phase in a column of inner diameter 0.297 m packed with random packing of metal Pall rings 25 and Intalox saddles 25 and structured packing of Mellapak 250Y were measured using a dynamic method under hydraulic conditions common in distillation columns, i.e., liquid flow rate from 6.94 × 10−4 to 0.0111 m/s and gas flow rate from 0.25 to 2 m/s. The two-response method with a diffusion-type model was used to reproduce the experimental response curves. Axial mixing in the gas increases with gas and liquid rates for both random and structured packings, but the dependence on the gas rate is very weak for the structured packing. The largest gas mixing was found for the Pall rings at the highest gas rate; the least was found for the structured packing at the lowest gas and liquid rates. Liquid-phase axial mixing increases with decreasing liquid flow rate and is independent of gas flow rate for both random and structured packings. The largest liquid mixing was found for the Intalox saddles at the lowest liquid rate; the least was found for the structured packing. The correlations of BoL and BoG numbers deduced for all types of packings used reproduced the experimental data within ±22%.

Numerical investigation and experimental validation of the performance of a tubular packed bed reactor for hydrogenation of diene‐based polymers

AbstractA process which comprised a tubular reactor (that can be packed with different internal structures) has been modeled and theoretically analyzed for conducting the hydrogenation of nitrile butadiene rubber (NBR). The dynamics of the tubular reactor and the intrinsic hydrogenation kinetics are coupled, and detailed numerical simulations are performed under isothermal and isobaric conditions. The proposed model thus obtained involves coupled, nonlinear, partial differential equations (distributed parameter system). The effect of different reactor design parameters such as Peclet number, carbon–carbon double bond loading, mass transfer to reaction resistance, and solubility of hydrogen with respect to hydrogenation of the NBR has been investigated numerically. The conversions predicted using the proposed model for tubular packed bed reactor are compared with those possible in conventional plug flow reactor and continuous stirred tank reactor models. The optimal parameters and operating conditions for efficient production of hydrogenated NBR are suggested. Finally, the validity of the proposed model is confirmed by comparing the predicted and the experimental degree of hydrogenation obtained in a tubular reactor packed with Intalox saddles. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

Packing Characteristics for Mass Transfer in a Rotating Packed Bed

This work investigated the mass transfer of a rotating packed bed (RPB) with emphasis on the effects of the packing's size, shape, material, and surface property. Experimental results show that there is no obvious relationship between at and kLa. Among the various shapes of the packings, the mass transfer coefficients of Raschig rings and Intalox saddles are lower than those of the others, while the kLa of the wire meshes is the highest. As to materials, the mass transfer coefficients are similar for acrylic, glass, ceramic, and stainless steel beads. Besides, the kLa values of the hydrophobically treated packings are 8−27% lower than those of the original glass and ceramic packings. A modified correlation of kLa, which includes the effects of various packings, is proposed based on our RPB experimental results. Further, this correlation can also reasonably estimate most of the kLa data in the Higee literature.

Vapour- and liquid-side volumetric mass transfer coefficients measured in distillation column. Comparison with data calculated from absorption correlations

Volumetric mass transfer coefficients in liquid and vapour phases in distillation column were measured by the method consisting of a fitting of the concentration profile of liquid phase along the column obtained by the integration of a differential model to the experimental one. The mathematical model of distillation process includes mass and energy balances and the heat and mass transfer equations. The film model flux expressions with the convective transport contributions have been considered in the transfer equations. Vapour and liquid phases are supposed to be at their saturated temperatures along the column. Effect of changes of phase flows and physical properties of phases on the mass transfer coefficients along the column and non-ideal thermodynamic behaviour of the liquid phase have been taken into account. The concentration profiles of liquid phase are measured in the binary distillation of the ethanol–water and methanol–ethanol systems at total reflux on metal Pall Rings and Intalox saddles 25 mm in the column with diameter of 150 mm. The distillation mass transfer coefficients obtained by the fitting procedure are compared with those calculated from absorption data using Onda's, Billet's and Linek's correlations. The distillation heat transfer coefficients calculated from the model assuming saturated temperatures in both phases are compared with those calculated from the Chilton–Colburn and penetration model analogy between mass and heat transfer. The results have confirmed an agreement neither between distillation and from absorption correlations calculated mass transfer coefficients nor between analogy and from enthalpy balance calculated heat transfer coefficients. Also the concentration profiles obtained by the integration of the differential model of the distillation column using the coefficients from absorption correlation have differed from the experimental profiles considerably.

Modeling of packed absorption tower for volatile organic compounds emission control

Development of chemical industry and high vapor pressure of volatile organic compounds (VOCs) have been caused that these materials recently be considered as a source of air pollution. These are different methods for separation of VOC from air that absorption by suitable and selective solvent is an efficient method. In this research, mathematical modeling of a packed absorption tower for separation of VOCs from air has been presented. Then, acetone vapors separation in this tower and with Intalox saddle packing has been investigated. Concentration of acetone in inlet air stream was 1.5 mol % which has reduced to 150 ppm (0.015 mol %) in effluent air stream. The results show that the packed absorption tower with this type of packing can separate 99% of acetone vapors. Comparison of the results obtained by Intalox saddle packing with the results obtained by another type of packing (with trade mark of Kerapak patented by Sulzer Company) shows that the tower gives the same efficiency for acetone separation. Thus, the efficiency of absorption process, mainly, depends on solvent type, composition of VOC in feed air, desired composition of VOC in outlet air (or percentage of VOC separation) and pressure drop.

Effect of Packing Geometrical Details: Influence of Free Tips on Volumetric Mass Transfer Coefficients of Intalox Saddles

Volumetric gas- and liquid-side mass transfer coefficients measured by standard absorption systems (0.02 vol% SO2–air–1M NaOH and O2–air–water, respectively) and height equivalent to theoretical plate calculated from the mass transfer coefficents (for atmospheric distillation of isooctane–toluene, methanol–ethanol and ethanol–water) are presented for new types of Intalox metal saddles 25, 40 and 50. The data are compared with those for the original Norton Intalox metal saddles, which differ from the new ones in the number of free tips (spikes) created by cutting the middle strips in the packing elements. The free tips increase the number of jumping droplets in the packing and thus may improve the mass transfer efficiency. It is shown that this effect is significant only in the case of 25 mm packing where the highest number of free tips in the packing volume occurs (approximately 250 000 tips m −3 ). The results provide information on how packing geometrical details can influence transport properties in absorption or distillation packed columns.

Intensification of random packing via CFD simulation, PIV measurement and traditional experiments

AbstractIt is shown from CFD simulation and particle image velocimetry (PIV) measurements that the flow field around ring packing is impacted by their height/diameter ratio and inclination. The results indicate that it is better to decrease the height/diameter ratio of ring packing to intensify the separation processes in the packing bed. Based on a systematic study, a new Plum Flower Mini Ring (PFMR) was developed to meet the demands of separation column intensification.A comparison of the PFMR, Pall Ring and Intalox Saddle in a 600 mm diameter column with an air–oxygen–water system over a wide range of liquid loads is presented. It was shown from the experiments that the PFMR had a much lower pressure drop, much larger throughput and better mass transfer efficiency than Pall Rings and Intalox Saddles.© 2003 Society of Chemical Industry

Prediction of pressure drop in a packed bed dehumidifier operating with liquid desiccant

In this paper a more rigorous model, which is valid for both structured and random packing columns, is used for predicting the irrigated pressure drop in a desiccant–air contact system. Calcium chloride solution is considered as the desiccant. Four different random packing materials and three different structured packing materials are considered in the present study. The effects of random packing shape and the type of structured packing on the hydraulic performance are studied. The model has been validated for a wide range of operating values available in the literature. It is found that the structured packing has the lower pressure drop and higher capacity compared with random packings. Among the random packing materials considered in the present study, Intalox saddles can provide the least irrigated pressure drop and among the structured packing materials the sheet-type Mellapak 250 Y has the lowest pressure drop.

Entrance Effect and Gas-Film Mass-Transfer Coefficient in a Large-Diameter Packed Column

The effects of the bed height and the entrance section below the packing support on mass transfer in a 1.2-m diameter packed bed of 50-mm ceramic Intalox saddles were investigated under various gas flow rates from 1957 to 7828 kg·h-1·m-2 and liquid flow rates from 12 200 to 46 700 kg·h-1·m-2. The entrance effect accounted for 17% of the overall water vapor transferred from moist air to a calcium chloride solution in the tower, regardless of the packing height. For a 0.91-m high bed, the average mass-transfer coefficient was directly proportional to the gas rate and was proportional to the liquid rate to the power of 0.24. For a 1.8-m high bed, the average mass-transfer coefficient was proportional to the gas rate to the power of 0.89 and appeared to be independent of the liquid rate. The height of a transfer unit (HTU) for 50-mm ceramic Intalox saddles remained relatively constant under various gas rates used in the present study. The HTU was about 0.5 m for the short bed and 0.8 m for the tall bed.

Henry's constants and mass transfer coefficients of halogenated organic pollutants in an air stripping packed column

Both Henry's constants and volumetric mass transfer coefficients (KLa) of eight priority chlorinated organic compounds including 1,1-dichloroethene, methylene chloride, chloroform, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,4-dichlorobenzene in an air stripping packed column were investigated in this study. The liquid and gas phase EPICS (Equilibrium Partition in Closed System) and direct calculating methods were applied to determine the Henry's constants of VOCs. The interference of co-solute on Henry's constants was also investigated. Experimental results indicated that decrease in Henry's constants of VOCs was observed in the presence of humic acid but no apparent effect on Henry's constants was detected when there was NaCl and surfactant in solution. Four different configurations of packing media including Intalox Saddle, Super Intalox Saddle, Telleret, and Hedgehog made of polypropylene were respectively packed in the air stripping tower and investigated in the study. The dependence of hydraulic loading, air-water ratio, and configurations of packing media on mass transfer coefficients of VOCs was discussed.