Application Of Supercritical Carbon Dioxide Research Articles

Disinfection of ancient paper contaminated with fungi using supercritical carbon dioxide

Abstract Fungi continue to be the main cause of biodeterioration in libraries. In addition to degrading paper, fungi are an important health issue for librarians and even library users. The aim of this study was to investigate the application of supercritical carbon dioxide (SCCO 2 ) to ancient paper contaminated with fungi. For this purpose, SCCO 2 was applied in two processes to treat samples of paper pieces: addition of 4% and 8% ethanol (w/w) at a pressure of 150 bar and temperature of 40 °C for 1 hour. Control samples (no processing) and processed samples were directly plated onto culture media to evaluate the frequency of fungal growth. Morphological and molecular analysis of the 294 samples showing mold growth on paper revealed that Aspergillus niger , Aspergillus flavus , and Eurotium amstelodami were the most frequently isolated fungi. In the control group, 47.6% of the samples were contaminated with fungi. This percentage was only 1.9% after treatment with both processes. The difference between unprocessed control samples and samples treated under the two conditions was statistically significant ( P

The Application of Supercritical Carbon Dioxide for the Recovery of Residual Hydrocarbon Reserves at the Late Stage of Reservoir Engineering

The Application of Supercritical Carbon Dioxide for the Recovery of Residual Hydrocarbon Reserves at the Late Stage of Reservoir Engineering

The Application of Supercritical Carbon Dioxide and Ethanol for the Extraction of Phenolic Compounds from Chokeberry Pomace

Chokeberry (Aronia melanocarpa (Michx.) Elliot) is a fruit with exceptionally high levels of phenolic compounds which are accumulated mainly in the peel; hence, the majority remains in the leftovers after juice production. Extraction with the use of carbon dioxide in supercritical conditions was used to isolate phenolic compounds from the pomace. The effect of the process parameters (temperature; pressure; and the addition of ethanol) on the extraction yields and properties of the extracts was investigated. The anthocyanin and total phenolic compound content, as well as the scavenging activity against five selected radicals, were evaluated. The best results were acquired for 35 °C, 10 MPa, and 80% m/m ethanol addition, the yield of phenolic compounds was 1.52 g per 100 g of pomace. The amount of extracted phenolics and the antioxidative attributes of the extracts were highly correlated. The impact of supercritical carbon dioxide density on the amount of recovered compounds was confirmed. The use of supercritical CO2 led to a significant reduction in the volume of organic solvent required for extraction.

Investigation of essential oil extraction and antioxidant activity of Echinophora platyloba DC. using supercritical carbon dioxide

Essential oils of Echinophora platyloba DC. were extracted with application of supercritical carbon dioxide (SC-CO2) and hydro-distillation (HD) extraction methods. The effects of SC-CO2 experimental variables such as pressure (80–240bar), temperature (308–328K), particle size (0.30–0.90mm), and dynamic extraction time (30–150min) on the extraction yield and antioxidant activity of the prepared essential oils were investigated using a central composite design (CCD). The experimental data were fitted well to a second-order polynomial equation using regression analysis. The maximum yield obtained at the optimal conditions (1.1850±0.0550%) was more than that achieved by hydro-distillation method (1.120±0.0440%). The chemical compositions of the SC-CO2 and HD extracts were identified by GC–MS analysis and determined by GC–FID analytical method. The main components of the essential oil extracted by SC-CO2 method were found to be Linalool (16.02%), Trans-β-Ocimene (11.58%), α-Pinene (7.10%), Anisole, 2,4,6-trimethyl (6.98%) and Spathulenol (5.29%). Moreover, the components of the essential oil extracted by HD method were Trans-β-Ocimene (46.99%), Spathulenol (9.04%), β-Myrcene (6.24%), dl-Limonene (5.38%) and α-Pinene (4.55%). The antioxidant and free radical scavenging activities of the obtained essential oils were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH). Radical scavenging activity of the essential oils extracted by SC-CO2 and hydro-distillation methods exhibited an IC50 of 122.62μg/ml and 413.35μg/ml, respectively. To the best of researchers’ knowledge, the present study provides the first report addressing the essential oil extraction of Echinophora platyloba DC. using supercritical carbon dioxide technique.

The application of supercritical carbon dioxide for the stabilization of native and commercial polyphenol oxidases and peroxidases in cloudy apple juice (cv. Golden Delicious)

Abstract Supercritical carbon dioxide (SCCD) was applied for the native tissue and commercial enzyme inactivation in cloudy apple juice. The polyphenol oxidases (PPO) and peroxidases (POD) inactivation kinetics significantly depended on process parameters as well as the origin of enzymes. An increase in the temperature and pressure resulted in increasing of the k-value and decrease of D-value for both types of enzymes. POD turned out to be more thermal and pressure resistant compared to PPO. The lowest decimal reduction time (D-value), zT and zP-values were noted at 65 °C and 60 MPa for native PPO: 33.8 min, 90.3 °C and 112.6 MPa, respectively. The activation energy (Ea) generally decreased with increasing the pressure, whereas activation volume (Va) increased with increasing the temperature. Overall, SCCD treatment is a promising technique to obtain high quality apple juices with low enzyme activity. Industrial relevance Apple juice is one of the most frequently consumed juices in the world. It is commonly served as a clear juice, but there is a growing market for cloudy apple juices. Unfortunately, during cloudy juice processing and storage browning is initiated by enzymatic oxidation of polyphenols. Supercritical carbon dioxide (SCCD) is an interesting method among the innovative non-thermal technologies for the inactivation of native and commercial oxidoreductases in cloudy apple juice. In this study, the data proved that SCCD processing is a promising non-thermal technique for stabilization of fresh cloudy juices.

Experimental and theoretical analysis of a supercritical carbon dioxide jet on wellbore temperature and pressure

Along with the fast development of society, the demand for energy continually increases. Shale gas, a type of unconventional natural gas trapped within shale formations, is considered to be one of the best clean alternative fuels with the most potential because of large reserves all over the world. However, hydraulic fracturing, a widely used technology in shale gas exploitation, may cause serious environment issues. Therefore, the application of supercritical carbon dioxide (SC-CO2) instead of water to fracture shale has been mentioned. This novel approach could enhance shale gas recovery with no harm to the environment. To investigate the use of a SC-CO2 jet on the wellbore pressure and temperature, a series of experiments based on impinging theory have been conducted in the present study. In the first experiment, a specially designed apparatus with four visual windows was used to intuitively observe the jet's structure and character with a high speed video system recording the entire experimental process. In the second experiment, a high precision sensor was assembled in the vessel to measure the impinging pressure. The result shows that: (1) a SC-CO2 jet has a similar structure as a water jet, while a SC-CO2 jet dissipates slowly due to its low viscosity; (2) the impinging pressure increases with the increasing jet pressure, but the increasing rate is different because dissipation ratio decreases; (3) the ambient pressure affects the jet energy transfer rate though flow resistance and the ambient density. Under present experimental conditions, the critical pressure is 14.5 MPa; (4) a predictive equation is listed to calculate the impinging pressure based on the jet pressure and ambient pressure. Considering the application, the minimum jet pressure should be chosen to be more than 1.5 times the ambient pressure, and a suitable target distance for a SC-CO2 jet is no more than 7.5 nozzle diameters. These results help optimize the parameters of the SC-CO2 jet and promote the application of SC-CO2 in shale gas exploitation.

Application of supercritical carbon dioxide in catalyzation and Ni-P electroless plating of nylon 6,6 textile

Abstract In this study, an electroless deposition method including catalyzation in supercritical carbon dioxide (sc-CO2) and plating in sc-CO2 emulsified electrolyte was applied in metallization of Nylon 6,6 textile. In order to demonstrate the effects of the sc-CO2, the catalyzation was conducted either by the conventional method or the supercritical CO2 catalyzation (SCC) method with bis (2,4-pentandionato)-palladium. After the catalyzation process, either the conventional electroless plating or the electroless plating with supercritical CO2 emulsified electrolyte (ELP-SCE) was performed. Surface of the Ni-P coatings on the Nylon 6,6 was observed by an optical microscope and a scanning electron microscope. The Ni-P coating by the conventional catalyzation and the conventional electroless plating showed some cracks, nodules and rough structure. The Ni-P coating by the SCC and the conventional electroless plating showed smooth Ni-P coating on the surface of each fibers and had some peeled-off parts. On the other hand, uniform Ni-P coating on the surface of each fibers was obtained by the SCC and the ELP-SCE. These results demonstrated that the SCC is effective to impregnate Pd catalysts into the fibers, and the ELP-SCE can inhibit the nodule growth of the Ni-P. Thus, the proposed method can metallize the surface of each Nylon 6,6 fibers and has potential to give some functions on textiles.

Application of supercritical carbon dioxide to extract essential oil from Cleome coluteoides Boiss: Experimental, response surface and grey wolf optimization methodology

In this research, extraction of an essential oil from Cleome coluteoides Boiss aerial parts was investigated using supercritical carbon dioxide (SC-CO2) technique for the first time. Design of experiments and process optimization was carried out with response surface methodology (RSM) based on the central composite design (CCD). Influence of operating parameters including pressure (P=100–220bar), temperature (T=308–328K), particle size (dp=0.3–0.9mm) and dynamic extraction time (t=30–150min) on final response was evaluated. The experimental values were adequately fitted to a quadratic polynomial equation. Analysis of variance (ANOVA) results indicated that all factors were significantly affected the extraction yield of essential oil from C. coluteoides. Using a grey wolf optimization (GWO) algorithm, the optimal operating conditions were determined to be P=220bar, T=308K, dp=0.58mm and t=135min, under which conditions, the maximum yield of 0.6589 was obtained. Chemical compositions extracted by hydro-distillation (HD) and SC-CO2 methods were identified by gas chromatography/mass spectrometry (GC/MS) and determined by GC/FID. Comparing the two methods, the obtained results showed higher total extraction yield with SC-CO2 technique.

Application of supercritical carbon dioxide for the preservation of strawberry juice: Microbial and physicochemical quality, enzymatic activity and the degradation kinetics of anthocyanins during storage

Abstract Supercritical carbon dioxide (SCCD) was applied for strawberry juice preservation. SCCD under selected parameters was effective for microflora and enzyme inactivation. For storage studies samples preserved at 30 and 60 MPa, at 45 °C for 30 min were selected. Yeasts and moulds were not detected after SCCD treatment in these conditions, whereas TMC was ~ 1.7 log CFU/g. Polyphenol oxidases were inactivated, whereas peroxidases decreased by ~ 85%. SCCD treatment resulted in the hydrolysis of sucrose and ~ 30% losses of vitamin C, which was totally decomposed after the 4th week of storage. Anthocyanins were not affected by the SCCD process and the kinetic rate constant of degradation during storage ranged from 2.12 × 10 − 2 to 3.10 × 10 − 2 (days − 1 ), and the half-time from 22.4 to 32.7 days, depending on the monomer and pressure applied. Overall, SCCD treatment seems to be a promising technique to obtain high quality strawberry juice as a safe alternative to non-pasteurized juices. Industrial relevance Strawberries are highly appreciated for their nutritional quality, colour and taste. Strawberry compounds, i.e. anthocyanins and vitamin C, are heat sensitive. These nutrients as well as colour are degraded when the fruits are processed using high temperature treatment. Supercritical carbon dioxide (SCCD) is an interesting method among the innovative non-thermal technologies for the preservation of fruit products. In this study, the data proved that SCCD processing is a promising non-thermal alternative to pasteurization to preserve fresh cloudy strawberry juice.

ChemInform Abstract: Applications of Supercritical Carbon Dioxide in Materials Processing and Synthesis

AbstractReview: 117 refs.

Applications of supercritical carbon dioxide in materials processing and synthesis

Supercritical carbon dioxide (scCO2) is carbon dioxide that is held beyond supercritical conditions of 31.1 °C and 7.4 MPa. As a non-toxic and environmentally benign green solvent, it has been widely used in the food and pharmaceutical industries for extraction. However, scCO2 also has many unique properties and thus has great potential for advanced, green materials processing. This concise review focuses on its use as a solvent and an anti-solvent in materials processing and synthesis. Different experimental routes are described that are used to synthesize bulk materials, thin films, coatings, particle suspensions and powders. Examples from the literature are highlighted to illustrate the different experimental set-ups and applications of the resulting materials. This review endeavours to reveal the potential and versatility of scCO2 in materials processing and synthesis, aiming to encourage a wider application of scCO2 to open more opportunities in innovative green processing of both traditional and functional materials.

The supercritical carbon dioxide extraction of polyphenols from Propolis: A central composite design approach

The influence of different parameters on the Supercritical Carbon Dioxide (SCO2) extraction of Italian Propolis were studied with attention to extraction yield and chemical composition of obtained fractions. Operating parameters of SCO2 were optimized using central composite design. Analysis by multiple regression indicated that pressure and time have a major linear effect on the extraction yield and extract composition.Propolis SCO2 extracts present different chemical content compared to the ethanolic extract obtained with ultrasound assisted extraction (UAE). SCO2 extract can be used to perform further UAE ethanol extraction obtaining a flavonoid containing extract. These findings indicate two possible applications of supercritical carbon dioxide for Propolis extraction, one to obtain lipophilic fractions enriched in specific constituents, the other as pre-treatment of the crude material to facilitate the further extraction with ethanol.

Encapsulation of Food Compounds Using Supercritical Technologies: Applications of Supercritical Carbon Dioxide as an Antisolvent

The application of supercritical technologies as an alternative to conventional methods for encapsulating food compounds is an area of research that can lead to significant innovations in various segments of industrial food processing. The existing supercritical techniques are classified as follows according to the function of the supercritical fluid used in the process: solvent; antisolvent; cosolvent or solute; nebulization compound; extractor and antisolvent techniques. Supercritical carbon dioxide (scCO2) is the substance most widely used for obtaining micro/nanoparticles due to its unique characteristics, and among the existing encapsulation supercritical techniques, those using scCO2 as the antisolvent are more likely to be successful because food compounds are generally less soluble or even insoluble in scCO2. In this context, this review presents and discusses the applications of supercritical processes using scCO2 as the antisolvent for the encapsulation of substances of interest to the food industry.

Co-Precipitation of Beta-Carotene and Bio-Polymer Using Supercritical Carbon Dioxide as Antisolvent

The objective of this work was to investigate the application of supercritical carbon dioxide as antisolvent for the co-precipitation of β-carotene and poly(hydroxybutirate-co-hydroxyvalerate) (PHBV) with dichloromethane as organic solvent. For this purpose, the concentrations of β-carotene (1 to 8 mg.cm,-3) and PHBV (20 to 40 mg.cm-3) in the organic solution were varied keeping fixed temperature at 313 K, pressure at 8 MPa, solution flow rate at 1 cm3.min-1 and antisolvent flow rate at 39 g.min-1. The morphology of co-precipitated particles were spherical with very irregular and porous surface for some conditions and very smooth surfaces for others as verified by micrographs of scanning electronic microscopy (SEM). Results show that it is possible to achieve encapsulation efficiency values as high as 35 % just manipulating the concentration ratio of solute to polymer in organic solution. The methodology adopted for the quantification of β-carotene encapsulated was demonstrated to be adequate.

Investigation on supercritical CO2 extraction of phenolic-phytochemicals from an epiphytic plant tuber (Myrmecodia pendans)

Myrmecodia pendans (ant-nest) is an epiphytic plant with rich content of phytochemicals. In this work, the application of supercritical carbon dioxide (SC-CO2) for extracting several polyphenol and flavonoid compounds from ant-nest tuber include gallic acid, catechin, ferulic acid, caffeic acid, p-coumaric acid, quercetin, luteolin and kaempferol was investigated. Static-analytical extraction experiments were performed at pressures ranged between 9–22.5MPa and temperatures of 313.15–343.15K for 6–7h. Solubility data of total polyphenols (gram gallic acid equivalent (GAE)/L CO2) and total flavonoids (gram quercetin equivalent (QE)/L CO2) were modeled using Chrastil and Del Valle–Aguilera density-based equations. Both equations were able to represent actual solubilities satisfactorily in terms of correlation coefficient and parameter consistency. DPPH-scavenging test showed high antioxidant capacity of supercritical extract with an IC50 level of 3.62±0.12mg/mL. It was observed a positive linear correlation between bioactive contents of antioxidant extract and the potency of scavenger activity against DPPH free radical.

Improved Stokes–Einstein based models for diffusivities in supercritical CO2

The large interest and applications of supercritical carbon dioxide (SC-CO2) require the existence of transport properties for simulation and/or design. In this work, pure predictive models are proposed for the accurate estimation of binary diffusivities at infinite dilution in SC-CO2. They are three simple and straightforward expressions grafted on the Wilke–Chang, Scheibel and Lusis–Ratcliff equations, whose deviations to the Stokes–Einstein behavior in the supercritical domain are corrected by introducing two universal constants. Such modifications decrease the average errors from [11.70–23.16]% to [8.26–8.51]% for a large database of 150 systems and 4484 data points over wide ranges of temperature and pressure. The dispersion of the computed errors is also significantly lower, which highlights the reliability of our improved models to accurately predict tracer diffusivities.

Supercritical anti-solvent (SAS) micronization of Manilkara kauki bioactive fraction (DLBS2347)

Application of supercritical carbon dioxide in particle modification showed promising results due to less toxic solvent used and its relatively easy alteration on particle characteristic. Unfortunately, the use of this technology in herbal drugs or extracts is still limited. This research studied a new approach of herbal drugs processing technology. The micronization of Manilkara kauki L. Dubard's leaf extract (DLBS2347) using supercritical anti-solvent (SAS) was conducted with carbon dioxide as anti-solvent. Experiment results showed that type of solvents, pressure, temperature and carbon dioxide (CO2) mol fraction influenced its morphology and active compound concentration. Polar solvent such as dimethyl sulfoxide, methanol and ethanol produced sticky particle due to hygroscopic nature of simple carbohydrate that present in the product. Acetone precipitation of DLBS2347 has the highest active compound concentration. Lower pressure, temperature and CO2 mol fraction resulted small particle size (<1μm) of DLBS2347. In addition, precipitation of active compound is mainly affected by pressure that correlated to extract impurities. Taken together, optimum condition for micronizing DLBS2347 using SAS with acetone solution was at 40°C, 15MPa and 0.95mol fraction CO2.

Application of supercritical carbon dioxide–co-solvent mixtures for removal of organic material from archeological artifacts for radiocarbon dating

Archeological artifacts such as burial and embalmment materials are commonly dated by 14C labeling using accelerator mass spectrometry (AMS). The presence of contaminant organic matter can interfere with the accurate determination of an object's age, hence sample preparation is a critical step before radiocarbon-based dating. Both harsh acid and base treatments have been applied to remove contamination, such as humic acids, resin-based adhesives, and plant oils. Additional removal of carbon-laden material can also be affected by applying such methods as plasma oxidation. In this study, SC-CO2 with addition of a cosolvent has been applied to remove the above materials prior to plasma oxidation and subsequent dating via AMS. Initially, wood/charcoal samples were extracted using a modified-Isco SFX-2-10 extraction unit (Isco Inc., Lincoln, NE). Experiments were conducted using supercritical carbon dioxide/10% methanol at a pressure of 20.4MPa (3000psig) (pr=2.80) and 40°C (Tr=1.36), and carbon dioxide flow rates of ∼1.4±0.1ml/min. Comparison of the SC-CO2–methanol cosolvent treatment with traditional acid–base–acid sample pretreatment on identical wood-charcoal samples showed comparable radiocarbon dating results encompassing a period of 10,000 years. In addition, both Russian and Egyptian mummy gauzes and Russian textiles were similarly treated and the extracts analyzed by MALDI-TOF-MS and GC/MS to determine the chemical identity of the extracted material. A polyglycerol-based polymer was positively identified in addition to fatty acid moieties as their fatty acid methyl ester derivatives (FAMES), which potentially formed from the in situ reaction of the triglycerides present in the embalment materials with the SC-fluid mixture. Model extractions from spiked-linen gauze samples have verified removal of such materials as beeswax, coconut oil, frankincense, glycerol, and humic acids in varying amounts. Application of supercritical fluid extraction (SFE) appears to be a promising method to pretreat small samples for 14C radiocarbon dating where conservation of the archeological artifact is of importance. The SFE pretreatment has the potential to replace harsh acid–base pretreatment methods, and can be coupled with a non-destructive argon or oxygen plasma treatment for microgram carbon removal prior to accelerator MS isotope ratio age determination of the archeological artifact. This combination of techniques requires as little as 0.05mg of carbon-equivalent weight for the age determination of the artifact while minimizing sample degradation.

Intermolecular-Interaction-Dominated Solvation Behaviors of Liquid Monomers and Polymers in Gaseous and Supercritical Carbon Dioxide

The strong desire for the extensive application of supercritical carbon dioxide (scCO2) as an environmentally benign solvent in polymers synthesis and processing has spurred numerous attempts to discern and improve its solvability toward monomers as well as polymers. The detailed solvation processes along with the phase behaviors of a fluorinated liquid monomer (LM) of 2,2,2-trifluoroethyl methacrylate (TFEMA), as well as another 13 non-fluorinated LMs in gaseous and supercritical CO2, were respectively investigated by using a newly built high-pressure ATR-FTIR in situ monitoring system as CO2 pressure stepwise increased from 0 to 38.0 MPa. Interestingly, an unexpected vibrational absorption variation, especially a distinct blue-shift in the in situ FTIR spectra of the functional groups in each LM + CO2 binary system, was generally observed during the solvation process as CO2 pressure increased. A similar variation trend of the vibrational absorption of the C–F bond in the TFEMA + CO2 system was also obtained by ab initio calculation (MP2). We believe that the special evolution of the vibrational absorption is directly rooted in and dynamically induced by the variation of the intermolecular interactions in the LM + CO2 binary systems as the pressure and/or the temperature varied and is closely related to the solvation behaviors of the LM in CO2. Based on this cognition, the solvation mechanism of the LMs in gaseous and supercritical CO2 was systematically demonstrated by introducing the concepts of transition pressure (PT) as well as the resultant forces/interactions of σ(A–B) and σ(B–B). Poly(vinyl acetate) (PVAc), poly(hexafluoropropylene oxide) (PHFPO), and PTFEMA oligomers were prepared and characterized. The proposed mechanism was evaluated by investigating the solvation behaviors of the prepared oligomers and hexafluoropropylene trimer ((HFP)3) in CO2 and was successfully employed to expound the special CO2-philicity of the carbonyl compounds and the fluorinated organics (FOs).

Applications of Supercritical Fluid Extraction (SFE) of Palm Oil and Oil from Natural Sources

Supercritical fluid extraction (SFE), which has received much interest in its use and further development for industrial applications, is a method that offers some advantages over conventional methods, especially for the palm oil industry. SC-CO2 refers to supercritical fluid extraction (SFE) that uses carbon dioxide (CO2) as a solvent which is a nontoxic, inexpensive, nonflammable, and nonpolluting supercritical fluid solvent for the extraction of natural products. Almost 100% oil can be extracted and it is regarded as safe, with organic solvent-free extracts having superior organoleptic profiles. The palm oil industry is one of the major industries in Malaysia that provides a major contribution to the national income. Malaysia is the second largest palm oil and palm kernel oil producer in the World. This paper reviews advances in applications of supercritical carbon dioxide (SC-CO2) extraction of oils from natural sources, in particular palm oil, minor constituents in palm oil, producing fractionated, refined, bleached, and deodorized palm oil, palm kernel oil and purified fatty acid fractions commendable for downstream uses as in toiletries and confectionaries.