Bottom Production Research Articles

Selective Hydrocracking Of Heavy Distillate To High Viscosity Index Lube Base Stock By Using Bi-Functional Catalysts

Hydroprocessing is the catalytic reaction of hydrogen with petroleum or other hydrocarbon materials. It may be carried out for a variety of objectives, including: saturation of olefins or aromaties, molecular rearrangement, or removal of impurity (1).Selective hydrocracking is one of this hydroprocessing to convert higherboiling distillate to lube base stock using a bi-functional catalyst containing both acid site and metal site. Those two active sites of bi-functional catalyst should promote the correct combination of hydrogenation, isomerization and limited hydrocracking function, resulting in the maximum yield of product in the lube oil range (2). The kinetics of this selective hydrocracking greatly depends on the operating conditions: such as feedstock composition, type of catalyst, temperature, pressure, hydrogen to hydrocarbon ratio, and space velocity (6).The versatility of the hydroconversion process with respect to the variety of feedstock are case to study: i.e. the feasibility of the hydroconversion of obtaining lube base stock from heavy distillate.In order to gain more information, an experiment has been carried out to study the selective hydrocracking of vacuum distillate (paraffinic and non paraffinic) by using bifunctional catalysts with various acidity at the following operating conditions: temperature: from 380 to 410 ° C, pressure: 100 kg/cm2 and hydrogen to hydrocarbon ratio: 1000 l/lt. A catatest unit operated in a continuous system was used in this experiment.Gas and liquid product samples were taken from gas and liquid samples, respectively. Liquid product was fractionated to get the following cuts: IBP-380°C and380°C with 30 theoretical plate fractionator, operating at 4/1 reflux ratio. The 380°C bottom product was treated by dewaxing, using methylisobutyl ketone as a solvent to obtain the lube base stock and wax.

Non-Intrusive Reduced Order Modelling for the fast simulation of gas reservoirs

Non-Intrusive Reduced Order Modelling (NIROM) is evaluated for the prediction of gas reservoir performance, including the time evolution of the pressure distribution within the reservoir. The NIROM projects simulation solutions into hyperspace using proper orthogonal decomposition (POD), then radial basis function (RBF) interpolation is used to describe the dynamics of the fluid flow in hyperspace. POD-RBF NIROMs have been used previously for the estimation of saturation distributions over time in oil reservoirs during pressure maintenance (e.g. by gas flooding) but have not been tested for gas reservoir depletion problems. In this work, the accuracy and efficiency of the NIROM were evaluated by comparing its outputs to those obtained from conventional simulations for two test cases: a homogeneous gas reservoir model with gas rate or bottom hole pressure production controls, and a realistic heterogeneous reservoir model with a similar geological description to the Norne field. We show that the NIROM can provide accurate estimates of pressure and saturation distributions as well as production data and it runs between 4 and 40 times faster. This is despite having been implemented using an interpreted language. We show that a 99.9% energy criterion can be used for determining the number of POD basis functions for pressure and saturation distributions, but more basis functions are needed for estimating production data. In all cases, the linear radial basis function gives the best estimation.

Top quark phenomena in association with new vector bosons

In this work, we study collider phenomenology of pair produced new heavy vector bosons further decaying into top quark pair and quartic top, top pair plus bottom pair production in proton-proton collisions at CERN LHC with 13 TeV center of mass energy in the presence of new color octet vector boson. The complete simulation chain analysis from parton to the detector level is done for the pair production, As for the four quark production through pair of the new heavy vector particles is doneat the matrix level. In doing so we have preparatory work . The extension of SM is implemented by Mathematica—FeynRule package. Calculations are done by MadGraph5 /+ Phythia6, Delphes / simulation program and results are analysed in ROOT CERN. In conclusion, we compared Standard model extension results with the SM.

Intelligent Control of an Industrial Debutanizer Column

AbstractA debutanizer column located at a refinery in Malaysia produces LPG as its top product and light naphtha as its bottom product. Control of the product compositions of the column is very important to maintain the desired purities. The current control design of the debutanizer column is based on the classical proportional integral derivative approach, which has been found to be less effective in controlling the variations in the column as the process is characterized by strong nonlinear and uncertain dynamics. Here, intelligent control based on an adaptive neuro‐fuzzy inference system (ANFIS) is investigated and compared against an artificial neural network, for the special case of limited training data of the industrial debutanizer column. The ANFIS‐based controller outperforms the other control configurations for both set point tracking and disturbance rejection cases and has better generalization performance even when trained with limited data samples.

Volumetric Scale-Up of a Packed-Bed Ion-Exchange System to Extract Phytate from Thin Stillage.

Phytate is the main form of phosphorus in corn ethanol coproducts and poses digestion issues in monogastric-animal feed. Extracting phytate as a commodity chemical will bring extra revenue to the corn ethanol industry and reduces potential phosphorus pollution from livestock waste management. We assessed a simplified scale-up approach of an ion-exchange separation system applied to extract phytate from thin stillage using volumetric parameters and simplifications of the van Deemter model. Thin stillage is one of the main byproducts generated on dry-grind corn-to-ethanol plants and accounts for the liquid portion of the bottom product generated in the ethanol distillation process. Thin stillage is rich in dissolved phytate, which served as the basis for an ion-exchange extraction system developed with a scalability factor of 50. Under the evaluated conditions, similar breakthrough profiles were obtained when similar Péclet and Stanton numbers were maintained for the scales studied, demonstrating that a simple and straightforward scale-up can be attained if special attention is given to maintaining both parameters as the basis of calculations of the plate numbers of ion-exchange columns.

Hysis Simulation Optimization of Distillation Desulfurization for Mixed Light Hydrocarbons in Tahe Oil Field

In order to improve the performance of distillation desulfurization unit for mixed light hydrocarbons in Tahe Oil Field, HYSIS simulation investigation was performed. The influences of feed temperature, operation pressure, reboiler temperature and plate number on sulfur content of bottom product, flow rate of product, energy consumption and saturated vapor pressure of light hydrocarbons were carefully discussed. It is indicated that the total energy consumption can be reduced by 45.78% if the unit is operated at the optimized conditions. Meanwhile, the sulfur content of the bottom product will be less than 0.05% and the flow rate of bottom product can be increased by 2.04 t/d while the flow rate of top gas product can be decreased up to 754.11 Nm3/d. In addition, the saturated vapor pressure of light hydrocarbons is lower than the operation pressure.

On the paleo footprint of Cape Darnley Bottom Water off MacRobertson Land Shelf, East Antarctica

Cape Darnley Bottom Water (CDBW) is a major contributor to Antarctic Bottom Water (AABW) formation in the MacRobertson Land continental shelf area, East Antarctica. As the production of CDBW is dependent on intense sea ice formation in the Cape Darnley Polynya Region, it is sensitive to climatic changes, such as global warming. Studying paleo-conditions of CDBW during Antarctica's transition from coolhouse to icehouse during the middle to late Miocene allows to gain knowledge about the onset of bottom water production in the Cosmonaut/Prydz Bay region as well as changes in the strength and outflow path of the CDBW.In order to study the paleo-conditions of the CDBW, we have investigated the formation history of a 200 km long, 70 km wide sediment drift (Darnley Drift herein) at the western flank of Wild Canyon. In the early Miocene, the upper rise was dominated by turbiditic channel-levee growth and large continental sediment supply off the MacRobertson Land continental shelf. Therefore, no indications of CDBW formation were observed. During the middle Miocene, the dominant sediment transport regime transformed from turbiditic to contouritic mode, mirroring Antarctica's climatic transition into an icehouse world. This climatic transformation caused the initiation of CDBW, which is inferred from the onset of Darnley Drift formation as a levee-drift and its growth to a maximum areal extent of 60,000 km2, four times the size of today. Since the late Miocene/early Pliocene the sedimentation rate has been strongly reduced and bottom current controlled deposition dominated. The growth of mixed levee-drifts along the continental slope-rise transition parallel to Darnley Drift suggests an intensification of paleo CDBW generation and outflow to be comparable to observations of recent CDBW, in addition to an intensification of the Antarctic Slope Front and Circumpolar Deep Water.

Effect of pH and surfactants on shear induced asphaltene removal

Asphaltene removal from sediments is essential for enhanced oil recovery from heavier crude oil reservoirs and tar sands and bitumen recovery from bottom products in downstream processes. Water injection or water flooding at high pressures exert shear forces that can overcome the adhesive forces between asphaltene and mineral surfaces. The adhesive forces are also affected by ions in the aqueous medium. In the current work we study asphaltene removal from silica surface using shear forces of aqueous media in a parallel plate channel. We demonstrate the effect of varying pH and surfactant conditions in aqueous media on asphaltene removal efficiency. We relate the removal efficiency with fractional asphaltene volume on the surface estimated from atomic force microscopy. The fractional asphaltene volume reduces to 0.12 at pH 10, which is approximately 50% lower than water at neutral pH at the same shear rate. We show that the water-soluble anionic surfactants are inefficient in asphaltene removal, whereas cationic surfactant reduces the asphaltene fraction to 0.30. We conclude that the removal efficiency is affected by the zeta potential of the asphaltene and the surface, where electrostatic repulsion between the asphaltene and the surface and increased wettability in the presence of cationic surfactant improves asphaltene removal.

Optimization of the Striping Section of Modular Refinery Operations in Nigeria

Nigerian crude oil type Okoro 2012 was applied in this study owing to its low API value 23.54 and high residual percentage value of 42.16% from conventional modular refinery operations in Nigeria. The residue acted as a precursor or feedstock to the hydrocracker reactor of the modified modular refinery operation, which is an hydrogenation catalytic process at operating conditions of 380°C and 183 bar respectively and the hydrogen gas applied is produced via steam-methane reforming since the operational feedstocks are available as methane is the first gaseous product from the modified modular refinery process. Thus, more valuable products such as liquefied petroleum gas, naphtha and diesel were produced from modified modular refinery thereby resolving the residue or bottom product issue associated with conventional modular refinery operation in Nigeria. Models were developed from the first principle through the application of the principle of conservation of mass to predict the performance of the hydrocracker reactor and the developed models were sets of ordinary differential equations, which were solved using MatLab ODE45 solver and validated using simulation data of Aspen Hysys software for the hydrocracker reactor. The results gave a minimum percentage absolute error (deviation) between model predictions and Aspen Hysys results of 4.45%, 5.0% and 2.02% for liquefied petroleum gas, naphtha and diesel products respectively. Hence, the model developed predicted the output performance of the hydrocracker reactor very closely and was applied in studying or simulation of the effects of catalyst effectiveness factor on the overall performance of the hydrocracker reactor.

Nonlinear Control of Refuse Discharge in a three-product Coal Jig

The paper presents the results of simulation tests of the dynamic characteristics of a three-product jig for coal separation and control systems for refuse discharge. The changes in the position of the stratified bed layers and the density of the separation layer in the product discharge zone as well as the static characteristics of the zone in two compartments of the jig were investigated. It was assumed that the main disturbance occurring in industrial systems are changes in the flow rate and the feed washability characteristics. The simulation model was verified in industrial tests in two coal preparation plants. An analysis of the effects of the control of the bottom product discharge system for nonlinear PI controllers and adaptive radiometric density meters with variable measurement time was carried out. The aim of control was to stabilize the density of the separation layer at the desired level. The parameters of the nonlinear PI controller depended on the direction of changes in the feed flow rate. The control effects were compared with linear control systems and meters with a constant measurement time commonly used in industry. Proposed system improves product quality and reduces product losses in waste compared to conventional systems.

Optimal Operation of Vapor-recompressed Batch Distillation Column under Total Reflux

This article addresses optimal operation of a vapor recompressed batch distillation (VRBD) column under total reflux. This system allows us to obtain high purity top and bottom products simultaneously, which is usually not possible in a VRBD system with product removal. In this paper, we propose a novel approach wherein trajectory optimization is combined with model-based control to achieve optimal operation. Specifically, key performance indices are defined to characterize operation and assess the trade-off between production and energy efficiency. Subsequently, one of these indices is maximized, in closed-loop, using a model predictive controller. The effectiveness and robustness of this approach is demonstrated using a simulation case study of benzene/toluene separation.

30,000 bpd Capacity Modified Modular Refinery Operations in Nigeria

The study investigated and classified twenty Nigerian crude oil types based on their products recovery volume at true boiling point temperature of 370&#730C using crude oil assay analysis data into Group A (crude oil with recovery volume above 80%), Group B (crude oil with recovery volume between 70% and 79%) and Group C (crude oil with recovery volume below 70%) respectively. Thus, twenty Nigerian crude oil types were simulated in a modified modular refinery (modified topping plant) of 30,000 bpd capacity and twenty-nine (29) column trays number using Aspen Hysys software. Furthermore, the residues from the conventional modular refinery were processed as feedstock or precursor into the hydrocracker reactor attached to the stripping section of the modified modular refinery to yield more valuable products of liquefied petroleum gas, naphtha, diesel and bottom (residue). The simulation results of the modified modular refinery were compared with conventional modular refinery in terms of their residual yield percentage as Nigerian Brass 2012 of API 40.62, recovery volume 88.78%, yielded residue of 11.22% and 1.29% for conventional modular and modified modular refineries respectively while Okoro 2012 of least API 23.54, recovery volume 57.84%, yielded residue of 42.16% and 4.92% for conventional modular and modified modular refineries respectively. Thus, the residual or bottom product issue associated with operational process of conventional modular refinery operations in Nigeria due to inefficient or non-operational conventional major refinery in Nigeria has been resolved to minimum or least amount with the operational process of modified modular refinery operations in Nigeria.

Experimental study on essential anise star oil purification in vacuum batch distillation

Vietnam is one of the world’s largest annual anise harvest countries. However, products from anise are mainly in the form of dried anise fruit and crude star anise essential oil with low economic value. The main component of the star anise essential oil is trans-anethole which needs to be purified to produce higher-value products. This study focused on building an experimental system for purifying star anise essential oil by a batch distillation column working at vacuum pressure. The products obtained during the purification process were analysed by gas chromatography-mass spectrometry (GC-MS). Analytical results were used to evaluate the ability to separate volatile impurities in the crude star anise essential oil. Results showed that the bottom temperature of the tower below 150oC, corresponding to a vacuum pressure of less than 0.1 bar, can reduce the thermal decomposition of essential oils. The volatile components, such as α-pinene, β-phellandrene, limonene, and linalool, were thoroughly separated at the top of the tower. The purified star anise essential oil was from the bottom of the distillation and had the anethole composition of over 88% of mass fraction (wt.%). Anethole recovery efficiency was 98.5 and 88.8% at a pressure of 0.1 and 0.08 bar, respectively. The bottom product can have a higher anethole composition if increasing the column height, the reflux ratio, and decreasing the pressure and the quality of impurities removed at the top is increased.The experimental results are helpful for the calculation, design, manufacture, and operation of an industrial-scale essential oil purification system.

Experimental and theoretical study on strengthening mechanism of coarse coal slime classification process with cone wall structure

The accurate classification of coarse coal slime is the premise of efficient separation. Deep Cone Hydraulic Classifier (DCHC) is a new classification equipment for coarse coal slime classification, the content of fine particles (-0.2 mm) in coarse coal slime can be effectively reduced through classification, so as to create suitable feeding granularity for teetered bed separator (TBS) sorting. The DCHC designed includes a column structure area, deep cone structure area, and flush water mode of “bottom water + central water”. Experiments on the impact parameters were carried out, the results showed that: the classification efficiency increased with the decrease of feed concentration and feeding speed, increased first and then decreased with the increase of flush water flow rate. When the feed concentration was 40%, feeding speed is 0.8 m/s and flush water flow rate was 4 m3/h, the classification efficiency reached 69.3%, the content of the −0.2 mm particles in the bottom flow products was only 1.9%. The classification mechanism showed that the column structure area realized fluidization of the flow field and the deep cone structure area supplied the movement trace for the particles. Particularly the −0.074 mm particles movement trace was clear along the cone wall and could be collected as an overflow. A part of the −0.125 mm particles could be collected as an overflow, whereas the remaining part returned to the bottom flow, and increased fine particles content. In addition, the +0.2 mm particles were mostly collected as a bottom flow, and the 0.2–0.3 mm particles content are obviously affected by operating parameters. The results not only provide a new idea for the development of new classification equipment, but also provide a pathway for the efficient classification of coarse coal slime.

Modelling and simulation of zero-gravity distillation units with metal foams

The zero-gravity distillation (ZGD) is a promising concept to realize a small-scale distillation process. In contrast to gravity in conventional distillation columns, capillary forces, e.g. created using metal foams, are employed to guide the liquid phase in countercurrent flow to the vapour phase. In this work, a predictive model for simulation of ZGD units is presented. It includes the momentum, heat and species transfer in the liquid and vapour phase. The feed stream as well as the distillate and bottom product streams are included into consideration. Furthermore, the thermal conduction in the unit walls is taken into account. The fluid dynamics of the vapour and liquid is captured in a simplified manner using the concept of hydrodynamic analogy. The developed model was implemented in the MATLAB® software. Simulations of ZGD units in two-dimensional approximation could be validated using experimental data from the literature for ZGD with total reflux. With the validated model, the influence of the wall material and the initial composition on the ZGD process was explored. The focus of a further parametric study was laid on the impact of varying reflux ratio and boil-up ratio.

Microscopic characteristics of water invasion and residual gas distribution in carbonate gas reservoirs

AbstractWe used the nuclear magnetic resonance online detection method to analyze the water invasion mechanism and residual gas distribution of a carbonate rock gas reservoir. The T2 spectra obtained by using the Carr‐Purcell‐Meiboom‐Gill (CPMG) pulse sequence were applied to characterize the invasion water and residual gas distribution. The results showed that (a) in the pore‐type gas reservoir, the water first invades the meso–macropores and then the small pores as the pressure decreases further. The fracture distribution in a fracture‐pore‐type gas reservoir has an effect on the water invasion mode. The water can enter the pores through the fracture wall after the water invades the fracture. (b) In the pore‐type gas reservoir, 37.7% of the residual gas resides in the small pores, while the rest resides in the macropores. While in the fracture‐pore‐type gas reservoir, 4.8% ~ 26.8% of the residual gas is in the smaller pores and 69.2% ~ 95.7% in the macropores. Barely, any residual gas resides in the fractures. The residual gas in the small pores is difficult to produce. (c) The residual gas is controlled by the fracture penetration, amount of bottom water, fracture width, and production rate. It is suggested the production rate decreased to induce the water to invade the meso–macropores after the gas well begins to produce water to reduce the amount of residual gas in the meso–macropores.

Variation of Isoprenoid GDGTs in the Stratified Marine Water Column: Implications for GDGT-Based TEX86 Paleothermometry

Isoprenoid glycerol dialkyl glycerol tetraethers (isoGDGTs) derived from archaea are lipid biomarkers that exhibit high sensitivity to changes in water temperature, leading to the widespread application of the isoGDGT-based tetraether index of 86 carbon atoms (TEX86) in surface seawater temperature (SST) reconstruction. However, there remain some uncertainties regarding the robustness of TEX86 under changing water conditions (e.g., variations in water depth, oxygen and pH). Here, we analyzed isoGDGTs in suspended particles at different depths of the East China Sea (ECS) during summer 2020, aiming to constrain the applicability of the TEX86 proxy in coastal waters. Our data showed that the isoGDGTs were mainly derived from planktonic Thaumarchaeota, as revealed by the low ratio of GDGT-0/crenarchaeol (<0.5). The vertical distribution of isoGDGT concentration depicted a downward increase from the surface to the bottom. This observation was likely shaped by Thaumarchaeota, which regulate the extent of ammonia oxidation based on the availability of ammonium. The occurrence of maximal isoGDGT concentrations in the bottom layer suggests that the isoGDGTs in sediments are mainly controlled by bottom archaeal production rather than surface archaeal production. By reanalyzing the published isoGDGT data of surface sediments in the ECS inner shelf, we found that the sedimentary TEX86 relates much better to the annual mean bottom seawater temperature (BST) than to the annual mean SST, indicating that sedimentary TEX86 is more inclined to be a proxy for the BST in the shallow ECS. In addition, the positive bias of TEX86 driven by low dissolved oxygen and low pH was observed under the pycnocline, indicating that the application of TEX86 to reconstruct seawater temperature should be carefully appraised in coastal environments with strong water column stratification.

Pre-design of Biphenyl Chemical Factory from Benzene with Capacity of 10.000 Ton Per Year

The design of a biphenyl chemical plant from benzene with a capacity of 10,000 tons/year will be built in Tuban, East Java with a land area of ​​10,010 m2. The raw material in the form of Benzene is obtained from Trans-Pacific Petrochemical Indotama (TPPI), Tuban. The factory is designed to operate continuously for 330 days, 24 hours per day, and requires 214 employees. Biphenyl preparation begins with reacting benzene (2,807.74 kg/hour) in a Pipe Flow Reactor (R-01) at a reactor temperature of 377 oC and a pressure of 2 atm. This reaction takes place with a conversion of 90% and is endothermic so that a Hitech heater is used to maintain the operating temperature. The products that come out of the reactor are biphenyl and hydrogen. It is then cooled and condensed in a Partial Condenser (CD-01) to a temperature of 151 oC. Then enter into Separator-02 (SP-02) to separate hydrogen from a mixture of benzene, toluene and biphenyl. Hydrogen in the gas phase as a result of the separtor. The bottom product in the form of benzene, toluene and biphenyl in the liquid phase is pumped and put into a distillation tower (MD-01) to purify the product with the bottom product in the form of biphenyl with a purity of 99.3%. The result of the distillation tower is benzene and its impurities are recycled as feed into the reactor with a temperature of 83 oC and a pressure of 1 atm. This factory requires Fixed Capital (FC) Rp. 34,341,856,338,- + US$ 4,195,836, Working Capital (WC) (Rp. 127,536,505,173,- + US$ 170,019), Manufacturing Cost (MC) (Rp. 254,092,040,390,- + US$ 816,090), and General Expenses (GE) (Rp. 33,990,417,539,- + US$ 81,609). Economic analysis shows the value of ROI before tax is 50.38 % and the value of ROI after tax is 32.75%. POT before tax is 1.65 years and POT after tax is 2.34 years. The BEP value is 43.11% and the SDP value is 23.75%. The interest rate in DCF for 10 years is 19% on average. Thus, from a technical and economic point of view, a biphenyl plant from benzene with a capacity of 10,000 tons/year is worthy of consideration.

Steam O2-enriched air gasification of lignite and solid recovered fuel in fluidized bed

Continuous steady-state gasification tests were performed, in which mixtures of lignite and solid recovered fuel (SRF) were fed to a bench-scale facility at atmospheric pressure, loaded with the bottom product of a high-temperature Winkler gasifier as the fluidized bed material. The O2/fuel and steam/fuel ratios were varied from 0.3 to 0.4 and from 0.25 to 0.35, respectively, and the effects of the temperature were examined at different levels (700, 750, and 800 °C). The objective of the experimental campaign was to evaluate the effects of above mentioned operating conditions on the (i) quality of syngas expressed in terms of gas yield (Ygas), cold gas efficiency (ηCG), and carbon conversion (XC); (ii) effectiveness in tar reduction; and (iii) improvement of the H2/CO molar ratio. Characterization analyses (grain-size distribution, scanning electron microscopy and energy-dispersive X-ray spectroscopy) were performed on the materials before and after the tests. Pressure-fluctuation signals were acquired during the tests to monitor the fluidization quality and diagnose the correlated incipient sintering or agglomeration of the bed particles. At 800 °C, the obtained results (Ygas=1.53;ηCG=79%;XC=92%;tar content = 7.35 g/Nm3; H2/CO molar ratio = 0.96) demonstrated the convenient feasibility of gasification with the SRF–lignite mixture as a fuel (SRF/lignite = 0.5 wt/wt) and helped define the operating conditions for future pilot tests aiming for liquid fuel synthesis, although the best results were obtained at 800 °C with SFR/lignite = 0.2 wt/wt (Ygas=1.79;ηCG=93%;XC=102%;tar content = 0.92 g/Nm3; H2/CO molar ratio = 0.84).

CO2 Capture from Flue Gas of a Coal-Fired Power Plant Using Three-Bed PSA Process

The pressure swing adsorption (PSA) process was used to capture carbon dioxide (CO2) from the flue gas of a coal-fired power plant to reduce CO2 emissions. Herein, CO2 was captured from flue gas using the PSA process for at least 85 vol% CO2 purity and with the other exit stream from the process of more than 90 vol% N2 purity. The extended Langmuir–Freundlich isotherm was used for calculating the equilibrium adsorption capacity, and the linear driving force model was used to describe the gas adsorption kinetics. We compared the results of breakthrough curves obtained through experiments and simulations to verify the accuracy of the mass transfer coefficient. The flue gas obtained after desulphurization and water removal (13.5 vol% CO2 and 86.5 vol% N2) from a subcritical 1-kW coal-fired power plant served as the feed for the designed three-bed, nine-step PSA process. To determine optimal operating conditions for the process, the central composite design (CCD) was used. After CCD analysis, optimal operating conditions with a feed pressure of 3.66 atm and a vacuum pressure of 0.05 atm were obtained to produce a bottom product with a CO2 purity of 89.20 vol% and a recovery of 88.20%, and a top product with a N2 purity of 98.49 vol% and a recovery of 93.56%. The mechanical energy consumption was estimated to be 1.17 GJ/t-CO2.