Solvent Flow Rate Research Articles

A semi‐automatic solid phase extraction system based on MIL‐101(Cr) foam‐filled syringe for detection of triazines in vegetable oils

In this study, several metal-organic framework-melamine foam columns were first developed and used as a laboratory-made semi-automatic solid phase extraction packed in syringe adsorber for the extraction of six triazine herbicides from vegetable oil samples coupled to high-performance liquid chromatography-tandem mass spectrometry. The metal-organic framework-foam columns were prepared using a simple approach by embedding the solid particles in melamine foam using polyvinylidene difluoride physical encapsulation. The method was applicable to a wide variety of metal-organic framework materials, and the incorporated materials retained their unique properties. Key factors that affect the extraction efficiency, including the MIL-101(Cr) amount, sample flow rate, type and volume of the eluting solvent, and flow rate of eluting solvent, were investigated. Under optimum conditions, the proposed method exhibited low limits of detection (0.017-0.096ng/mL, S/N=3) for six triazines. The relative standard deviations calculated for all herbicides ranged from 0.2 to 14.9%. This study demonstrated that the MIL-101(Cr)-foam column can be used as a high-quality adsorption material for the detection of triazines in vegetable oils.

Pressurized mixture of CO2 and propane for enhanced extraction of non-edible vegetable oil

Vegetable oils in neglected matrices (monguba seeds and immature green coffee beans) were extracted using a mixture of pressurized carbon dioxide (CO2) and propane. The yields, fatty acid profiles, and active compounds in the extracted oils were evaluated employing a Box-Behnken experimental design, considering the effects of temperature (20–60 °C), solvent flow rate (1.5–2.5 mL min−1), and propane amount (10–50%). The maximum yields were 42.83% for monguba oil and 10.83% for immature green coffee oil. Lower temperature (40–60 °C) and a higher propane fraction (50%) led to higher oil yields. Empirical models satisfactorily described the extraction kinetics. Treatment of the data using principal component analysis (PCA) revealed that the conditions that favored extraction of saturated fatty acids impaired the extraction of polyunsaturated fatty acids. Extraction with a mixture of pressurized CO2 and propane resulted in attractive fatty acid profiles and high oil yields, while preserving the active compounds.

Impact of blends of aqueous amines on absorber intercooling for post combustion CO2 capture system

Climate change is the biggest challenge of this century due to the global consequences of human activities on the ecosystem resulting in global warming. The emissions of greenhouse gases, mainly CO2 from the combustion of fossil fuels in the power plant is the main cause of global warming and to mitigate these emissions is the foremost challenge. Nowadays, the most preferred method is post combustion chemical absorption using amine-based solvents. However, high energy requirements for this method restrict its deployment. An efficient approach used for the reduction of the high energy requirement of post combustion CO2 capture process was absorber intercooling. Therefore, this research evaluates the effect of two configurations of intercooled absorber such as “simple” and “advanced” intercoolers for CO2 capture integrated with natural gas combined cycle power plant using aqueous alkanolamines, such as 30 wt.% monoethanolamine and 50 wt.% methyl-diethanolamine and their blends. For pure methyl-diethanolamine case, at lean loading 0.01 intercooling configurations; simple and advanced shows the highest reduction of 21.01% and 22.82% in the specific reboiler duty, respectively in comparison to other blends at the expense of highest liquid solvent flow rate. Simple and advanced intercooling configurations shows optimum results for the case with 40% monoethanolamine and 60% methyl-diethanolamine in a blend with decrease of 9.19% and 17.28% in solvent flow rate and a decrease of 9.42% and 16.83% in specific reboiler duty required for 90% CO2 capture rate, respectively. For pure monoethanolamine case at lean loading 0.2 absorber intercooling does not offer significant results.

Enhancing carbon dioxide absorption performance using the hybrid solvent: Diethanolamine-methanol

In this study, to appraise the performance of hybrid Diethanolamine-methanol solvent for the CO2 absorption process in the packed bed, the volumetric overall gas phase mass transfer coefficient (KGaV) and the absorption percentage (η) under different operating conditions were investigated including inlet solvent temperature 25–65 °C, reboiler temperature 75–115 °C, the inlet CO2 concentration 5–15 vol%, solvent flow rate 0.50–1.50 lit/min, gas flow rate 50–100 lit/min and solvent concentration 10–30 wt%. The results show that by reducing the reboiler temperature from 115 to 95 °C, the mass transfer coefficient reduces 1%, but the reboiler temperature reduces 17% instead. This issue has a great effect on energy saving in the desorption section. Moreover, by adjusting the operating condition, the maximum KGaV and η were 4.69 (kmol m−3 h−1. kPa−1) and 99.9%, respectively. The results of this study indicate that the use of DEA-methanol solution had equal and even higher absorption percentage (up to 99.9%) than the conventional MEA aqueous solution in addition to the lower regeneration temperature.

Simulation of an Extractor for the Extraction of Vegetable Oil from Palm Kernel

Industrial production of vegetable oil from palm kernel seed operational process was analysed in this research study with the extractor unit as the main focus of the study. The extractor unit consist of nine operational stages, which was modeled by applying the principle of the law of conservation of mass and energy respectively. The developed models were a set of ordinary differential equations, which were solved by using MatLab ODE 45 solver by applying industrial extractor plant data of Vegetable Oil Production Company. The developed models’ results were compared with the industrial extractor plant data in terms of mass fraction of oil and temperature of the raffinate and mass fraction of oil and temperature of the extract and these yielded an absolute percentage error (deviation) of 7.0, 9.52, 3.29 and 2.29 respectively. Thus, the deviations are within the acceptable limits, which shows that the developed models predicts adequately the extraction process of vegetable oil production. In addition, the effects of mass flow rates of raffinate and extraction solvent were studied with increase in mass flow rate of raffinate reduces contact time between extraction solvent and the cake thereby reducing the efficiency of the extraction process with maximum amount of oil been extracted at the minimum flow rate of 300Kg/hr.

Influence of supercritical CO2 flowrate in one-pot supercritical fluid extraction of Carica papaya linn. leaves: A broken-intact-cell approach

The presence of rich phytochemicals in Carica papaya linn. leaves are potentially beneficial in pharmaceutical, nutraceutical and food industries. This work aims to investigate the roles of solvent flowrate for the predictive behaviour of supercritical fluid extraction of essential oil-rich extracts by broken-intact-cell modelling approach. Through kinetic model fitting of experimental data, the adjustable parameters namely G, φk, Z and Y were determined through error minimization procedure. From the cumulative extraction curve at solvent rate from 4 – 8 mL/min, the values of mass transfer coefficients were in the range of 4.40 × 10−5 m2/s – 19.92 × 10−5 m2/s with an overall relative 8.67% AARD. The grinding index and end of fast extraction time period was within the range of 0.144 – 0.258 and 30.38 – 91.17 min respectively. The role of solvent flowrate played an influential role in the extraction of papaya leaves extract.

Application of Atmospheric Pressure Photoionization to the Determination of 1,1-Dimethylhydrazine Transformation Products by Liquid Chromatography/Mass Spectrometry

The behavior of eight nitrogen-containing toxic products of rocket fuel transformation (formaldehyde dimethylhydrazone, N,N-dimethylformamide, N,N-dimethylguanidine, 1,2,4-triazole, pyridine, imidazole, pyrazine, pyrazole) under conditions of dopant-free atmospheric pressure photoionization was studied. It was found that the analytes under study give intense signals of protonated molecules, while the efficiency of ionization largely depends on temperature, as well as on the solvent composition and flow rate. Based on a combination of atmospheric pressure photoionization with chromatographic separation on porous graphitized carbon, we proposed a new approach to the highly sensitive determination of rocket fuel transformation products. The developed approach is distinguished by minimal matrix interferences and was successfully tested in the analysis of real samples.

Integration of pressurized liquids and ultrasound in the extraction of bioactive compounds from passion fruit rinds: Impact on phenolic yield, extraction kinetics and technical-economic evaluation

Passion fruit rind is a by-product rich in bioactive compounds that can be recovered by high pressure extractions and ultrasound using nontoxic solvents in shorter process times. This work investigated Pressurized Liquid Extraction (PLE) and its combination with ultrasound (Ultrasound-Assisted Pressurized Liquid Extraction, UAPLE) to intensify the recovery of phenolic compounds from passion fruit rinds. The influences of process parameters such as temperature, pressure, ultrasonic intensity and solvent mass flow rate on the global yield (X0), total phenolic content (TPC) and antioxidant capacity were evaluated. The major phenolics were determined by UHPLC-QE HRMS. Kinetic extraction curves adjusted by the Spline and two-site models showed that in UAPLE (60 °C, 10 MPa and 360 W/cm2) with solvent flow rate of 10 g/min, 100% of TPC was recovered in 68.54 min of extraction. This condition also provided the greatest economic viability concerning total phenolics, with the lowest estimated manufacturing cost. Industrial relevanceSynthetic compounds in processed food have been increasingly rejected by consumers, who look for natural compounds that promote health benefits and are obtained with sustainable technologies. The bioactive compounds found in passion fruit rinds can meet this industrial demand as potential colorants, additives and natural preservatives in foods or beverages, incorporated in cosmetics, functional food and pharmaceutical supplements. In order to successfully recover bioactive compounds, it is recommended to apply selective extraction techniques in the target compound, thus providing final products with greater added value. In addition, the process optimization is crucial to achieve optimal extraction conditions to maximize the yield of the targent compounds. Given this context, searching for a more sustainable destination of the passion fruit agroindustrial waste and to increase its commercial value, this work proposes the combination of two extraction techniques, Ultrasound and Pressurized Liquid Extraction (UAPLE), to intensify the recovery of bioactive compounds from passion fruit rinds. The findings of this work reveal that UAPLE can enhance the extraction of phenolic compounds from passion fruit rinds even at moderate temperatures, thus encouraging the application of this technique for other agroindustrial by-products. Moreover, the economic evaluation of the UAPLE at the optimal conditions indicates its viability for industrial scale application.

Определение равновесности концентрации измеряемого вещества в сверхкритическом растворителе при динамическом методе исследования

At present, there is no universal method for studying the solubility of substances in supercritical fluid media. The expediency of combining certain methods of solution saturation and composition analysis is determined by the object of study, the range of concentrations. In the case of low solubility of solids in the solvent, a flow-through system or dynamic solubility measurement method is usually used to obtain the required amount of precision weighing material. The dynamic method for measuring the solubility of substances in supercritical carbon dioxide is not without its drawbacks, which primarily include the need to strictly control the mass flow rate of supercritical carbon dioxide in the cell with the substance being measured. With an increase in the consumption of supercritical dioxide from zero (static method) to a certain value, the concentration of the measured substance in supercritical carbon dioxide within the acceptable level of uncertainty for measuring the solubility of 4-6% can be considered unchanged. The plateau of the concentration of the measured substance in supercritical carbon dioxide from the flow rate obtained in the diagram corresponds to the saturation state of the solvent, which is carbon dioxide and the solute, which corresponds to the concept of solubility. However, with a further increase in the consumption of carbon dioxide, the concentration begins to decrease and it can no longer be considered equilibrium. This is due to the fact that at significantly high flow rates of carbon dioxide, which is a solvent, coming into contact with the substance being dissolved, it does not have time to saturate it and, accordingly, weakly dissolves it. This concentration does not correspond to the concept of solubility. Thus, the determination of the range of mass flow rate at which the conditional state of saturation of the solvent and the solute is reached is the most important stage in studies to measure the solubility of substances in supercritical fluids. Based on the results of experimental data measuring the solubility of tannin in supercritical carbon dioxide, the dependences of the concentration of tannin in supercritical carbon dioxide on the mass flow rate are presented. It follows from the results that, in the flow rate range of 0-0.6 g/min, the tannin concentration in supercritical carbon dioxide is practically independent of the solvent flow rate, which is evidence of the equilibrium of this concentration and its compliance with the concept of solubility.

Plant-wide assessment of high-pressure membrane contactors in natural gas sweetening – Part I: Model development

This paper presents a predictive mathematical model of high-pressure membrane contactor, with a view to developing a plant-wide model of natural gas sweetening including amine regeneration. We build upon an existing model of high-pressure membrane contactor by Quek et al. [Chem Eng Res Des132:1005–1019, 2018], which uses a combination of 1-d and 2-d mass-balance equations to predict the CO2 absorption flux and membrane wetting under lean solvent operation. For the first time, quantitative predictions of the CO2 absorption flux can be made under both lean and semi-lean operations. A 1-d energy balance that accounts for the solvent evaporative losses and the exothermic CO2 absorption into the amine is solved alongside the mass-balance equations, in order to predict the solvent temperature profile inside the contactor. The evaporative losses of water and amines can be quantified separately, as well as the absorptive losses of light hydrocarbons with the amine solvent. The model’s predictive capability is tested against data from a lab-scale module and a pilot-scale module that is operated under industrially relevant conditions at a natural gas processing facility in Malaysia. A close agreement between model predictions and measurements of the CO2 absorption flux, solvent temperature profile, and hydrocarbon loss is observed for a wide range of gas and solvent flowrates and compositions, thereby validating the modeling assumptions. The contactor model is combined in a plant-wide model of natural gas sweetening in the companion paper, where it is used for process integration and analysis.

Computational modelling of separation and purification of vanillin using microporous membranes

In this study, membrane based solvent extraction of vanillin as one of the most popular flavour was investigated theoretically using computational fluid dynamic technique. A mass transfer model and simulation was developed based on continuity and transport phenomena equations. The effect of operating parameters such as pH, type of solvent and feed flow rate as well as membrane specifications including fibres number, fibre length and porosity-to tortuosity ratio was investigated. There was good agreement between experimental data and modelling value in terms of vanillin extraction percentage. The results showed that butyl acetate is the best solvent and it had the highest vanillin extraction at pH of 7. It was found that increasing feed flow rate can decrease vanillin extraction due to reduction of residence time in the contactor. Change in the membrane specifications had positive impact on the vanillin extraction. Increase in all fibres length, number of fibre, and porosity-to tortuosity ratio because of improving residence time, mass transfer area, and increase in effective diffusivity, respectively led to the enhancement of vanillin extraction. The extraction was reached 44% when the fibre length became 5 times longer. Moreover, it was concluded that the membrane system showed better performance when the feed flows in the tube side of contactor.

Simultaneous enantiomeric analysis of five proton-pump inhibitors in soil and sediment using a modified QuEChERS method and chiral high performance liquid chromatography coupled with tandem mass spectrometry

This study presents a simple, sensitive, rapid, cheap and reliable method for the simultaneous quantification of five proton pump inhibitors (omeprazole, rabeprazole, lansoprazole, pantoprazole, and ilaprazole) at enantiomeric levels in environmental soil and river sediment by chiral high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The modified QuEChERS procedure, a very simple and efficient sample preparation method, was employed for the extraction and purification of the target analytes. To obtain satisfactory chromatographic performance and high extraction efficiency, several experimental variable parameters including the type and content of the organic modifier, the content of the additive, temperature and mobile phase flow rate, the type and volume of extraction solvent, and the type and content of clean-up sorbent were systematically optimized. Under the optimum condition, the simultaneous baseline separation of five chiral drugs was achieved on a Chiralpak IH column within 13 min. The method detection limits and quantification limits of the enantiomers were below 0.17 ng/g and 0.69 ng/g, respectively. Correlation coefficients (R2) ≥ 0.9905 were obtained for all enantiomers within the linearity range of 1–200 ng/g. The mean recoveries for all enantiomers ranged from 83.6% to 108.5% with intra-day RSD less than 11.6% and inter-day RSD less than 12.9%. Finally, the proposed method was successfully applied to authentic samples (green belt soil, agricultural soil, and river sediment) to analyze the enantiomeric composition of target chiral analytes, indicating its applicability and reliability for the enantioselective determination of proton pump inhibitors in environmental matrices. This research will help better elucidate the behavior of individual enantiomer and make an excellent risk assessment on the environment.

Multi-objective optimization of post combustion CO2 capture using methyldiethanolamine (MDEA) and piperazine (PZ) bi-solvent

Global warming is becoming a critical issue in 21st century which is mainly due to the growing rate of greenhouse gas emissions. This is mostly due to the large amount of CO2 emission from power generation activity using fossil fuels. One of the main methods of fighting global warming and reducing CO2 emission into atmosphere is to perform carbon capture, sequestration and utilization. Carbon capture can be performed through different ways, in which post combustion CO2 capture (PCC) has been developed and both economic and technically wise is in state of art. One of the disadvantages of PCC is its high efficiency penalty due to energy consumption in the reboiler for solvent regeneration. Many efforts have been done to reduce the consumption of energy in the reboiler via different strategies including process parameters optimization, solvent development and novel process configuration. This investigation used different blends of PZ and MDEA as solvent and process parameters optimization via evolutionary algorithm and multi-objective optimization. The optimization was performed on a conventional process flow diagram. CO2 capture efficiency and reboiler heat duty were used as the objective functions and main decision variables are solvent flowrate and MDEA/PZ concentration. Flue gas CO2 capture of 90, 91, 92, 93, and 94% corresponded to regeneration energy consumption of 2.68, 2.71, 2.72, 2.75, and 2.76 Eregen/tCO2; respectively. These optimized values showed a higher energy efficiency compared to MEA and MDEA/PZ in conventional process configuration.

Real-time detection of authenticity and adulteration of krill phospholipids with soybean phospholipids using rapid evaporative ionization mass spectrometry: Application on commercial samples

The functional food ingredient of krill phospholipids are easily adulterated with soybean phospholipids due to their similar appearance and physical behavior. In this study, a novel in-situ method was developed for real-time detection of authenticity and adulteration of krill phospholipids with soybean phospholipids using an electric heating probe based rapid evaporative ionization mass spectrometry (REIMS). The commercial samples could be directly analyzed without preparation. The REIMS conditions were optimized such that the cauterizing duration was 3 s, the temperature of the heating probe was 450 °C and the flow rate of auxiliary solvent was 100 μL min−1. The compositions of krill and soybean phospholipids were analyzed by mass spectrometry, and the obtained data was used to establish the multivariate statistical models. The results indicated that the krill phospholipids could be successfully distinguished from soybean phospholipids with accuracy ≥96.58% on the basis of the characteristic ions of m/z 279.23, 301.22, 629.45, 807.43, 831.43 and 833.44. The effectiveness of these marker ions was proved by blind sample tests. This method provides a reference for evaluating the adulteration of krill phospholipids in the market and expands the application field of REIMS technology.

Uncertainty and sensitivity analysis by Monte Carlo simulation: Recovery of trans-resveratrol from grape cane by pressurised low polarity water system

Abstract Mechanistic models used to describe heat, mass and momentum transfers involve output uncertainties, which arise from the assumptions made during the model development, and from the uncertainties in model input parameters. The objective of this study was to address the uncertainties and global sensitivities of the input parameters of a model which was developed for the pressurised low polarity water extraction (PLPW) system. Monte Carlo analysis with 1000 simulation was applied with a defined noise for each input parameters to visualise the uncertainty in the model predictions (total extraction time and extract concentration). Six sensitivity methods (scatter plot, standardised regression coefficient, correlation coefficient, Kruskal-Wallis test, differential analysis, and semi-variogram) were evaluated and compared to obtain the input parameters that were responsible for the output uncertainty. It was found that two (extraction solvent flow rate and particle porosity) out of the nine parameters were mainly responsible for the uncertainty. Results of the uncertainty and sensitivity analyses can be used to build reliable mechanistic models, interpret the model outputs, and prioritise future experimental efforts for PLPW system.

Preparation of All-Trans-Retinoic Acid-Loaded mPEG-PLGA Nanoparticles Using Microfluidic Flow-Focusing Device for Controlled Drug Delivery

In recent years, microfluidic devices present unique advantages for the development of a new generation of nanoparticle synthesis method compared to bulk methods. In this study, we report a microfluidic flow-focusing method for the production of all trans retinoic acid (ATRA)-loaded methoxy poly(ethylene glycol)-poly(lactide-coglycolide) (mPEG-PLGA) nanoparticles (NPs). Box–Behnken experimental design (BBD) was applied to optimize of formulation ingredients and process conditions with minimum particle size, maximum drug loading% (DL%) and encapsulation efficiency% (EE%). Polymer concentration, drug concentration and flow rates of solvent (S) and antisolvent (AS) were selected as independent variables. Based on optimization strategy, minimum particle size achieved shows average (SD) particle size of [Formula: see text][Formula: see text]nm with DL of [Formula: see text][Formula: see text]wt.% and EE of [Formula: see text][Formula: see text]wt.%, respectively. While maximum DL has been reported to be [Formula: see text][Formula: see text]wt.% with particle size of [Formula: see text][Formula: see text]nm and EE of [Formula: see text][Formula: see text]wt.%, respectively. Moreover, the results have shown that the AS/S ratio represents the most significant effect on particle size. Indeed, increasing the AS flow rate directly results in generating smaller particles. The AS/S ratio represents the least significant effect on DL%, such that, at fixed flow rates, higher DL was observed at high concentration of drug and lower concentration of polymer. In conclusion, optimization of the ATRA-loaded mPEG-PLGA NPs by BBD yielded in a favorable drug carrier for ATRA that could provide a new treatment modality for different malignancies.

Microfluidics nanoprecipitation of telmisartan nanoparticles: effect of process and formulation parameters

A continuous microfluidic nanoprecipitation process has been investigated to prepare nanosized particles of a poorly water-soluble drug telmisartan (TEL), thereby enhancing its solubility and bioavailability. The present work aims to overcome agglomeration of drug particles by controlling the surface forces between the particles using various polymers like Polyvinylpyrrolidone K-30 (PVP K-30), Polyvinylpyrrolidone K-90 (PVP K-90), Poloxamer 188, Poloxamer 407, and hydroxypropyl methylcellulose (HPMC). The effect of process parameters such as solvent-to-antisolvent ratio, polymer-to-drug ratio, microchannel length, and solvent flow rate on drug particle size and polydispersity index (PDI) has been studied. The drug–polymer interaction investigated through X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis revealed a significant reduction in peak intensity for Poloxamer 407 with no drug–polymer interaction. Also, the surface morphology of recrystallised TEL nanoparticles examined using field emission scanning electron microscopy (FESEM) showed clear and nearly uniform shaped particles. Poloxamer 407-based formulation of TEL exhibited minimum drug agglomeration with least particle size 369 nm and PDI value 0.049. The minimum particle size was achieved at solvent-to-antisolvent ratio 1:2, 1:1 polymer-to-drug ratio, microchannel length of 60 cm, and solvent flow rate of 30 mL/h. Thus, the microfluidic technique resulted in the production of TEL nanoparticles with narrow size distribution and useful morphological characteristics.

Efficient selection of conventional and phase-change CO2 capture solvents and mixtures based on process economic and operating criteria

The aim of this work is to exploit shortcut models in order to efficiently assess conventional and phase-change solvents and mixtures based on CO2 capture and upstream plant process and economic performance criteria. This is approached by exploiting a previously available shortcut model which is currently suitable only for solvents exhibiting vapor-liquid equilibrium (VLE) behavior. This model is extended to account for solvents which exhibit vapor-liquid-liquid equilibrium (VLLE), phase-change behavior and is implemented in 10 solvents and mixtures, including 2 phase-change solvents. The VLE behavior of conventional solvents and mixtures is represented using models obtained from literature or regressed from experimental data. The VLLE behavior of the phase-change solvents MAPA/DEEA (3-(methylamino)propylamine/2-(diethylamino)ethanol) and MCA (methyl-cyclohexylamine) is modelled through regression curves from experimental data. The performance criteria for solvent assessment include cyclic capacity, solvent flowrate and purchase cost, regeneration duty, net efficiency penalty and lost revenue of power plant from parasitic electricity due to capture. The performance of the phase-change solvents is validated based on literature data, whereas it is superior to that of conventional CO2 capture solvents. The net efficiency penalties of MCA and MAPA/DEEA are approximately between 2.9 and 3.3% points lower than MEA (monoethanolamine), whereas the lost revenue of the power plant due to the capture unit is 47% and 50% lower than MEA, respectively.

Reactive Distillation for Methanol Synthesis: Parametric Studies and Optimization Using a Non-polar Solvent

Reactive distillation (RD) for methanol synthesis offers the advantage of process integration by combining reaction and separation in a single equipment and utilization of the reaction exotherm in the separation. The feasibility of RD for methanol synthesis using a polar solvent has already been demonstrated in an earlier work by Ghosh and Seethamraju (Chem Eng Process - Process Intensif, 145:107673, 2019) using a polar solvent. Since reaction and distillation occur simultaneously in the same column, the effect of operating and design parameters of the column is crucial for its performance. In this paper, the effects of different operating and design parameters have been presented using squalane—a non-polar solvent. Performance of RD for methanol synthesis was evaluated in terms of conversion of reactants, productivities of methanol and water, and purities of the product streams. Operating parameters like reflux ratio, solvent flow rate, and feed temperatures, and design parameters like addition of reactive and non-reactive stages were found to affect the column performance significantly. Based on the results from the parametric studies, optimization of the RD column was performed to maximize the methanol production in the liquid distillate. Conversions of CO and H2 were found to increase respectively from 52.9% and 36.8% in the base case to 78.4% (48% increase) and 54% (47% increase) in the optimum cases. Methanol productivity also increased by 47% relative to the base case with enhancement in separation of the produced methanol.

Supercritical Extraction of Heracleum persicum Plant and Mathematical Modeling

Background: Supercritical CO2 is the most applicable solvent because of its unique properties such as; high selectivity, non-explosivity, non toxicity, low cost of purchasing and its unique critical points. The solubility of this solvent changed rapidly with only a small change in pressure and temperature especially in pressure. According to literatures, the method of supercritical extraction is the best technology for extracting sensitive constituents. Despite of numerous studies in the literature for extracting essential oil from plants, no studies can be found about this valuable medicinal plant by CO2 supercritical extraction method. Method: In this study, the extraction of main medicinal constituents from Heracleum Persicum and mathematical modeling was done using supercritical carbon dioxide. The experimental data were investigated was analyzed by using gas chromatography (GC) and mass spectrometer chromatography (GC-MS) methods. The model of seed and bed, which includes three parameters of mass transfer, axial dispersion, and effective penetration coefficients, were used for modeling the extraction process. This model was used based on the equilibrium of the fluid phase and solid phase to communicate with the experimental data. Then the obtained yield of supercritical technology was compared with the hydro distillation method. Results: The main extracted constituents of some different varieties of Heracleum by different methods and solvents have been determined. The extracted chemicals by supercritical fluid technology from the seeds of the Heracleum Persicum encompasses hexyl butanoate, octyl 2- methyl butyrate, octylisobutyrate and anethole which are so effective against epilepsy and has the most antibacterial, antiviral and antifungal effects. So supercritical fluid extraction is more selective than the other methods. Conclusion: Extracting of essential oil and mathematical modeling from H. persicum were performed under different operating conditions of temperature, pressure, particle size and solvent flow rate. Experimental and modeling results showed that the operating parameters used in different conditions had a different effect on extraction efficiency and model parameters.