A “green” technique for high performance elastomers – fundamental investigation for hydrogenation of nitrile butadiene rubber in supercritical carbon dioxide

2002 ◽  
Vol 186 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Garry L. Rempel ◽  
Guanghui Li ◽  
Qinmin Pan ◽  
Flora T.T. Ng
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
High Performance ◽  
Butadiene Rubber ◽  
Nitrile Butadiene Rubber ◽  
Fundamental Investigation ◽  
Green Technique ◽  
Supercritical Carbon

scholarly journals Determination of Oleanolic and Ursolic Acids inHedyotis diffusaUsing Hyphenated Ultrasound-Assisted Supercritical Carbon Dioxide Extraction and Chromatography

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Ming-Chi Wei ◽  
Yu-Chiao Yang ◽  
Show-Jen Hong
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
High Performance ◽  
Extraction Yield ◽  
Extraction Time ◽  
Different Temperatures ◽  
Ultrasound Assisted ◽  
High Concentrations ◽  
Static Extraction ◽  
Supercritical Carbon

Oleanolic acid (OA) and ursolic acid (UA) were extracted fromHedyotis diffusausing a hyphenated procedure of ultrasound-assisted and supercritical carbon dioxide (HSC–CO2) extraction at different temperatures, pressures, cosolvent percentages, and SC–CO2flow rates. The results indicated that these parameters significantly affected the extraction yield. The maximal yields of OA (0.917 mg/g of dry plant) and UA (3.540 mg/g of dry plant) were obtained at a dynamic extraction time of 110 min, a static extraction time of 15 min, 28.2 MPa, and 56°C with a 12.5% (v/v) cosolvent (ethanol/water = 82/18, v/v) and SC–CO2flowing at 2.3 mL/min (STP). The extracted yields were then analyzed by high performance liquid chromatography (HPLC) to quantify the OA and UA. The present findings revealed thatH. diffusais a potential source of OA and UA. In addition, using the hyphenated procedure for extraction is a promising and alternative process for recovering OA and UA fromH. diffusaat high concentrations.

scholarly journals Polysulfone foam with high expansion ratio prepared by supercritical carbon dioxide assisted molding foaming method

RSC Advances ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 2880-2886 ◽  
Author(s):  
Zhengkun Li ◽  
Yingbin Jia ◽  
Shibing Bai
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
High Performance ◽  
Expansion Ratio ◽  
Supercritical Carbon

Polysulfone foam with high expansion ratio and high performance was prepared by new foaming method using CO2 and press vulcanizer.

Mechanical Design and Validation Testing for a High-Performance Supercritical Carbon Dioxide Heat Exchanger

2017 ◽  
Author(s):  
Shaun D. Sullivan ◽  
Jason Farias ◽  
James Kesseli ◽  
James Nash
Keyword(s):  
Carbon Dioxide ◽  
Heat Exchanger ◽  
Supercritical Carbon Dioxide ◽  
Heat Exchangers ◽  
High Performance ◽  
Mechanical Design ◽  
Great Promise ◽  
Heat Rejection ◽  
Very High ◽  
Supercritical Carbon

Supercritical carbon dioxide (sCO2) Brayton cycles hold great promise as they can achieve high efficiencies — in excess of 50% — even at relatively moderate temperatures of 700–800 K. However, this high performance is contingent upon high-effectiveness recuperating and heat rejection heat exchangers within the cycle. A great deal of work has gone into development of these heat exchangers as they must operate not only at elevated temperatures and very high pressures (20–30 MPa), but they must also be compact, low-cost, and long-life components in order to fully leverage the benefits of the sCO2 power cycle. This paper discusses the mechanical design and qualification for a novel plate-fin compact heat exchanger designed for sCO2 cycle recuperators and waste heat rejection heat exchangers, as well as direct sCO2 solar absorber applications. The architecture may furthermore be extended to other very high pressure heat exchanger applications such as pipeline natural gas and transcritical cooling cycles. The basic heat exchanger construction is described, with attention given to those details which have a direct impact on the durability of the unit. Modeling and analysis of various mechanical failure modes — including burst strength, creep, and fatigue — are discussed. The design and construction of test sections, test rigs, and testing procedures are described, along with the test results that demonstrate that the tested design has an operating life well in excess of the 100,000 cycles/90,000 hour targets. Finally, the application of these findings to a set of design tools for future units is demonstrated.

scholarly journals Effects of Ethanol on the Supercritical Carbon Dioxide Extraction of Cannabinoids from Near Equimolar (THC and CBD Balanced) Cannabis Flower

Separations ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 154
Author(s):  
Sadia Qamar ◽  
Yady J. M. Torres ◽  
Harendra S. Parekh ◽  
James Robert Falconer
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
High Performance ◽  
Low Density ◽  
Reverse Phase ◽  
Extract Yield ◽  
Rp Hplc ◽  
Carbon Dioxide Extraction ◽  
Chemical Profiles ◽  
Supercritical Carbon

In this study, supercritical carbon dioxide (scCO2) extractions of cannabinoids were conducted at four different densities (231, 590, 818, and 911 kg/m3) using ethanol (5% w/v) as a co-solvent. The chemical profiles of these cannabinoids were analysed via reverse-phase high-performance liquid chromatography (RP-HPLC). It was determined that scCO2, at low density (231 kg/m3), produced an extract yield of 6.1% w/v. At high scCO2 density (~818 kg/m3), the yield was 16.1% w/v. More specifically, the amounts of tetrahydrocannabinol (THC) and cannabidiol (CBD) in the scCO2 extract at 818 kg/m3 were 10.8 and 15.6% w/v, respectively. It was also found that the use of 5% w/v ethanol increased scCO2 extract yields at both low and high densities (7.6% w/v and 18.2% w/v, respectively). Additionally, the use of co-solvent increased this yield further under both low- and high-density conditions, to 13.7 and 19.1% w/v, respectively. Interestingly, higher scCO2 density (911 kg/m3) with and without ethanol did not improve the scCO2 extract yield or the amount of cannabinoids. Although this study provides new insights into the correlation between scCO2 density and ethanol co-extraction of CBD and THC, more studies are needed to determine how different scCO2 densities and co-solvents influence the extraction of cannabinoids.

scholarly journals Solubility Modelling pf Butterfly Wing Leaves (Christia Vespertilionis) in Supercritical Carbon Dioxide

2018 ◽  
Vol 7 (3.26) ◽  
pp. 9
Author(s):  
Izni A. A. Hamid ◽  
Norhuda Ismail ◽  
Ana N. Mustapa ◽  
Norazah A. Rahman
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Solubility Prediction ◽  
Anti Cancer ◽  
Empirical Density ◽  
Best Fitting ◽  
Pharmaceutical Industries ◽  
Green Technique ◽  
Supercritical Carbon

Medicinal herb Christia vespertilionis oil has been claimed to possess anti-cancer and anti-plasmodial properties and show interest in food and pharmaceutical industries. Being an important alternative medicine plant, solubility data of Christia vespertilionis oil is demanded in order to understand the separation process and is crucial for designing purposes. In this work, extraction and determination of the oil’s solubility were carried out using a green technique of supercritical carbon dioxide at a temperature range of 40 to 60℃ and 276 to 414 bar of pressure. The results demonstrated that the highest solubility was obtained at the highest temperature and pressure of 60℃ and 414 bar, respectively. For solubility prediction, experimental data were modelled using four empirical density-based models: Chrastil, del Valle and Aguilera, Adachi and Lu, and Sparks et al. models. In general, all the models were able to predict the solubility of Christia vespertilionis oil in supercritical carbon dioxide. The best fitting showed that Adachi and Lu model gave the best correlation with the lowest %AARD value of 1.61%.  

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