Extraction of Kaempferitrin and Astragalin from Justicia Spicigera by Supercritical Fluid Extraction and Its Comparison with Conventional Extraction

A study of supercritical fluid CO2 extraction of kaempferitrin (KM) and astragalin (KG) from Justicia spicigera (muicle) was conducted. A 33 Box-Behnken design was used to analyze the effects of pressure (200-300 bar), temperature (40-60° C), and co-solvent flow rate (0.5-1.0 mL/min). The highest KM and KG concentration were achieved at a pressure of 300 bar, a temperature of 60° C, and co-solvent flow rate of 1.0 mL/min (ethanol 99.5 %), with a constant CO2 flow rate of 5 mL/min and extraction time of 180 min. Under these conditions, the experimental values for KM and KG (115.08±2.81 and 56.63±9.02 mg/100 g of dry powder, respectively) were similar to those calculated by the models (109.0 and 44.07 mg/100 g of dry powder, respectively). The use of 70 % ethanol as co-solvent in the supercritical extraction process considerably improved the yields of KM and KG (562.71±156.85 and 79.90±18.03 mg/100 g of dry powder, respectively) compared to the 99.5 % ethanol extractions. The conventional extraction showed the highest yields of KM and KG (574.20±65.10 and 113.10±15.06 mg/100 g of dry powder, respectively) at 70° C and extraction time of 120 min. Adequate yields were achieved of KM and KG by supercritical fluid extraction compared with conventional extraction (98 and 70 %, respectively); therefore supercritical fluid extract of J. spicigera could be used in the development of functional foods, as well as its possible use in traditional medicine by the health professionals.

Extraction of Fatty Acids and Phenolics from Mastocarpus stellatus Using Pressurized Green Solvents

Polyunsaturated fatty acids are well known for their protective properties in relation to different skin diseases. Although seaweeds possess a low lipid fraction, they could act as an alternative renewable source of polyunsaturated fatty acids whenever other valuable seaweed components are also valorized. In this study, a biorefinery process using Mastocarpus stellatus as a model seaweed was proposed. The process started with the supercritical carbon dioxide extraction of the lipid and phenolic fractions. The influence of pressure during extraction with pure supercritical CO2 was studied while operating at a selected temperature and solvent flow rate. Kinetic data obtained during the ethanol-modified supercritical CO2 extraction were fitted to the spline model. Sequential processing was proposed with (i) pure CO2 to obtain a product with 30% PUFA content and ω-3:ω-6 ratio 1:1, (ii) ethanol-modified CO2 to extract phenolics, and (iii) microwave-assisted subcritical water extraction operating under previously optimized conditions for the extraction of phenolics, carrageenan and protein fractions. The composition of the supercritical extracts showed potential for use in both dietary and topical applications in skin care products. The remaining solids are suitable for the extraction of other valuable fractions.

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.

Modelling and simulation study of CO2 capturing process in coal fired power plant using various amine solvents

In the present world, Scientists are very much concern on to reduce the concentration level of carbon dioxide in environment to save the world. In the present work, the CO2 capturing efficiencies of three different amine solvents were analyzed. The selected solvents were mono-ethanol amine (MEA), solvent containing mixture of methyl diethanol amine (MDEA) and piperazine (PZ) called activated -MDEA and aqueous ammonia (NH3) solution. Rigorous simulation method was considered in the current study. The effects of different key parameters for different solvents on the CO2 removal efficiency were analyzed. Packing height, solvent temperature and absorber height were the significant influential parameters for MEA system whereas for activated-MDEA (a-MDEA), those are the ratio of the solvent to feed quantity and the mixed solvent PZ concentration level. For aqueous NH3 solution, absorber and stripper’s temperature, CO2 loading, concentration of NH3, height of the absorber, lean and rich solvent flow rate, boil up ratio, regeneration energy, temperature of the condenser, and duty of the reboiler were considered. The comparative study showed that MEA process recovered the maximum CO2 from flue gas. But it was suffered by the maximum regeneration duty. a-MDEA with PZ recovered 91% CO2. Overall, technically, a-MDEA was the best choice as solvent. Compared to a-MDEA and MEA, aqueous ammonia was identified as more propitious and environment friendly solvent due to its satisfactory performance and easy availability.

Optimization of the Ratio of ω-6 Linoleic and ω-3 α-Linolenic Fatty Acids of Hemp Seed Oil with Jackknife and Bootstrap Resampling

In the present work, supercritical fluid extraction (SFE) of hemp (Cannabis sativa) seed oil at various ranges of SFE parameters is performed. These parameters and respective ranges are temperature (40–80) °C, pressure (200–350) bar, solvent (CO2) flow rate (5–15) g/min, particle size (0.43–1.02) mm and amount of co-solvent (ethanol) (0–10) % of solvent flow rate. Central composite design (CCD) suggests 32 experimental runs to perform through SFE. The obtained oil is analysed through gas chromatography to identify its fatty acids concentrations. The ratio of ω-6 linoleic and ω-3 α-linolenic fatty acids (ω-6/ω-3) is optimized through CCD to obtain the desired amount of 3:1 as this ratio is highly preferred for various health benefits. Ratio of ω-6/ω-3 is obtained in the range from 2.11 to 3.06:1 for all experimental runs. The effect of SFE parameters on this ratio is investigated. Further, cross-validation is peformed on the experimental data obtained for the concentrations of both fatty acids by jackknife and bootstrap resampling to authenticate the obtained data. Small value of standard deviation (~1), less standard error of the mean (SEM) (<0.8) and less variance coefficient (<0.11) confirms the validity of the obtained data. All the estimators’ values such as standard deviation, variance coefficients and SEM are observed in 95 % of confidence intervals.

Optimization in the Stripping Process of CO2 Gas Using Mixed Amines

The aim of this work was to explore the effects of variables on the heat of regeneration, the stripping efficiency, the stripping rate, the steam generation rate, and the stripping factor. The Taguchi method was used for the experimental design. The process variables were the CO2 loading (A), the reboiler temperature (B), the solvent flow rate (C), and the concentration of the solvent (monoethanolamine (MEA) + 2-amino-2-methyl-1-propanol (AMP)) (D), which each had three levels. The stripping efficiency (E), stripping rate ( m ˙ CO 2 ), stripping factor (β), and heat of regeneration (Q) were determined by the mass and energy balances under a steady-state condition. Using signal/noise (S/N) analysis, the sequence of importance of the parameters and the optimum conditions were obtained, and the optimum operating conditions were further validated. The results showed that E was in the range of 20.98–55.69%; m ˙ CO 2 was in the range of 5.57 × 10−5–4.03 × 10−4 kg/s, and Q was in the range of 5.52–18.94 GJ/t. In addition, the S/N ratio analysis showed that the parameter sequence of importance as a whole was A > B > D > C, while the optimum conditions were A3B3C1D1, A3B3C3D2, and A3B2C2D2, for E, m ˙ CO 2 , and Q, respectively. Verifications were also performed and were found to satisfy the optimum conditions. Finally, the correlation equations that were obtained were discussed and an operating policy was discovered.

Gloeothece sp. as a Nutraceutical Source—An Improved Method of Extraction of Carotenoids and Fatty Acids

The nutraceutical potential of microalgae boomed with the exploitation of new species and sustainable extraction systems of bioactive compounds. Thus, a laboratory-made continuous pressurized solvent extraction system (CPSE) was built to optimize the extraction of antioxidant compounds, such as carotenoids and PUFA, from a scarcely studied prokaryotic microalga, Gloeothece sp. Following “green chemical principles” and using a GRAS solvent (ethanol), biomass amount, solvent flow-rate/pressure, temperature and solvent volume—including solvent recirculation—were sequentially optimized, with the carotenoids and PUFA content and antioxidant capacity being the objective functions. Gloeothece sp. bioactive compounds were best extracted at 60 °C and 180 bar. Recirculation of solvent in several cycles (C) led to an 11-fold extraction increase of β-carotene (3C) and 7.4-fold extraction of C18:2 n6 t (5C) when compared to operation in open systems. To fully validate results CPSE, this system was compared to a conventional extraction method, ultrasound assisted extraction (UAE). CPSE proved superior in extraction yield, increasing total carotenoids extraction up 3-fold and total PUFA extraction by ca. 1.5-fold, with particular extraction increase of 18:3 n3 by 9.6-fold. Thus, CPSE proved to be an efficient and greener extraction method to obtain bioactive extract from Gloeothece sp. for nutraceutical purposes—with low levels of resources spent, while lowering costs of production and environmental impacts.

Parametric Evaluation for Extraction of Catechin from Areca Catechu Linn Seeds using Supercritical CO2 Extraction

Supercritical fluid extraction is an advanced extraction technique which has been proven its efficiency and selectivity in numerous studies. Dense gas with diffusivity nearing liquid and viscosity closed to gas phase, supercritical fluid can provide better performance in the extraction of natural and heat sensitive active compounds. Areca Catechu Linn or commonly known as betel nut can be easily found in tropical country especially in south-east and south of Asia with India as its world largest producer. Phenolic compound present in Areca Catechu Linn are condensed tannins and also catechin. Catechin is a highly active compound with several properties such as anti-depressant, anti-oxidant, anti-viral, anti-flammatory and anti-aging which are in demand by cosmetic and pharmaceutical industries. The aim of this study is to determine the best particle size, solvent flow rate, presence of modifier or co-solvent, and time of extraction for this pre-treatment study. Average particle size of 0.1774 mm (dp4) was detected as the best particle size for the extraction process with 3 mL/min solvent flow rate with 5% methanol added to solvent. Modifier presence enhances the extraction by improving the ability to extract more polar compound such as catechin. The best catechin recovery was observed at 3mL/min, solvent composition of 95:5 (SC-CO2:MeOH) at the temperature of 70ᵒC and pressure of 30 MPa with 47.38 μg catechin/g extracts.