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1,3-Dipolar cycloaddition of azomethine ylides generated from aziridines in supercritical carbon dioxide

Gomes, Paulo J. S.; Nunes, Cláudio M.; Pais, Alberto A. C. C.; Melo, Teresa M. V. D. Pinho e; Arnaut, Luis G.
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Artigo de Revista Científica Formato: aplication/PDF
ENG
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96.56%
The 1,3-dipolar cycloaddition of azomethine ylides with DMAD in supercritical carbon dioxide is reported. The photolysis reaction conditions were optimized with a suitable adjustment of pressure, temperature, irradiation time and co-solvent concentration leading to a more efficient reaction than in neat acetonitrile. Similar results were observed using thermal reaction conditions. Supercritical carbon dioxide with a minute co-solvent addition is shown to be a very efficient medium for promoting this type of cycloadditions.; http://www.sciencedirect.com/science/article/B6THS-4K7FJ88-D/1/e5b9b60b4e9f3055fb5a425dfc759395

Extraction of bixin from annatto seeds using supercritical carbon dioxide

SILVA, G. F.; GAMARRA, Felix M. C.; OLIVEIRA, A. L.; CABRAL, F. A.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.45%
The solubility of 93% pure bixin in supercritical carbon dioxide (SC-CO2) and of the bixin present in annatto seeds (Bixa orellana L.) was measured. For the seeds, the measurements were made in a temperature range from 30 to 50ºC and pressure between 10 and 35 MPa and for the pure bixin, at 40ºC from 10 to 35 MPa. The main pigments of annatto seeds are bixin and norbixin, but the extracts only showed the presence of cis and trans-bixin, indicating that norbixin is not soluble in SC-CO2. The annatto seeds used in the experiments contained about 2.7% bixin and 3.1% oil. In the seeds, the crossover point of solubility was at about 28 MPa and values for solubility were about ten times higher than those of the pure bixin, giving evidence that the oil acted as a co-solvent with the CO2.; FAPESP

Hydrogen peroxide and supercritical carbon dioxide: a new bleaching stage for Eucalyptus kraft-O(2) pulps

FRANCISCO, Roberta Pacheco; COLODETTE, Jorge Luiz; CURVELO, Antonio Aprigio da Silva
Fonte: WALTER DE GRUYTER & CO Publicador: WALTER DE GRUYTER & CO
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.51%
Kraft pulp is currently bleached largely by the elemental chlorine free (ECF) technology with oxygen, chlorine dioxide, and hydrogen as active agents. This technology brought about significant environmental improvements in relation to standard processes based on chlorine gas and hypochlorite, but there is still need for further improvements. This study presents a novel environmentally friendly bleaching stage - the so-called `hydrogen peroxide in supercritical carbon dioxide`, P((SC-CO2)) - that can be adapted to current ECF bleaching processes, with preference in cases where hydrogen peroxide is already used. In this study, the P((SC-CO2)) stage was evaluated as a replacement to the last peroxide stage of the D(EP)DP bleaching sequence and to the first peroxide stage of the D(EP)DP sequence, for an oxygen delignified eucalypt kraft-O(2) pulp. The P((SC-CO2)) stage was run with 0.5% hydrogen peroxide, at 15% consistency, 70 degrees C, and 73 bar. The reaction time was 30 min. The performances of regular P stages and the new P((SC-CO2)) stage were compared. Promising results were observed with the DEP((SC-CO2))DP sequence; the P((SC-CO2)) decreased kappa number from 2.7 to 2.1, and the hexenuronic acid groups from 17.0 to 12.4 mmol kg(-1). The P((SC-CO2)) stage showed poor performance when applied in the D(EP)DP((SC-CO2)) sequence. It is concluded that the process presents potential but requires further optimization to improve selectivity and efficiency.; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); CNPq Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (National Council for Scientific and Technological Development); FAPESP Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (Sao Paulo Research Foundation); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hidrodescloração catalítica de bifenilas policloradas (PCB) em dióxido de carbono supercrítico; Catalytic hydrodechlorination of polychlorinated biphenyls (PCB) in supercritical carbon dioxide

Vale, Luiz Américo da Silva do
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 17/02/2014 PT
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96.71%
A reação de hidrodescloração catalítica (HDC) de bifenilas policloradas (PCB) foi estudada em diversos sistemas reacionais: solventes orgânicos, dióxido de carbono supercrítico, presença e natureza de aditivos (bases e co-solventes) a temperaturas na faixa de 25 °C a 100 °C e pressões de 1 bar até 250 bar. Os reagentes utilizados foram um composto modelo (2,4- diclorobifenil), misturas comerciais de PCB (Aroclor, Ascarel) e outros compostos halogenados (clorobenzenos e bromoclorobenzeno). Os catalisadores avaliados, paládio suportado em carvão ativo (Pd/C), paládio suportado em sílica mesoporosa (Pd/SiO2), nanopartículas ferromagnéticas de paládio (FFSiNH2Pd), e nanopartículas ocas de paládio (PdNP) e de platina (PtNP), mostraram-se versáteis nas mais diversas condições, quer sejam condições supercríticas, presença ou não de água, presença e natureza da base e diferentes doadores de hidrogênio. Em dióxido de carbono, dois regimes reacionais foram avaliados: dióxido de carbono subcrítico, onde o gás atua como agente expansor da fase líquida ao se dissolver nela permitindo que a reação ocorra em uma fase líquida rica em gás hidrogênio; e dióxido de carbono supercrítico, sistema onde a temperatura influencia fortemente a reação e a pressão tende a ter efeito negativo sobre a velocidade de reação...

Recuperação de tocoferois do destilado da desodorização do oleo de palma : fracionamento com dioxido de carbono supercritico; Recovery of tocopherols of the distilled one of the desodorization of the palm oil : fractionization with supercritical carbon dioxide.

Camila Arantes Peixoto
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 13/07/2004 PT
Relevância na Pesquisa
86.59%
O óleo de palma e seus subprodutos são fontes de tocoferóis. Os tocoferóis, por sua vez , são compostos de grande importância para a indústria alimentícia, farmacêutica e cosmética. Eles agem no organismo como vitaminas lipossolúveis essenciais na nutrição humana por inibirem a formação de radicais livres e seus efeitos nocivos sobre o organismo. Além disso, possuem aplicação tecnológica em alimentos pois são antioxidantes naturais, prevenindo e retardando a rancidez oxidativa dos óleos e também de alimentos com alto teor de lipídios.No refino do óleo de palma, a etapa de desodorização é responsável pela perda em 33% dos tocoferóis totais presentes no óleo, e o destilado formado (DDOP), não tem aplicação tecnológica nem valor comercial. A extração com fluido supercrítico utilizando CO2 como solvente tem sido considerada como uma alternativa para substituir os tradicionais processos de separação que utilizam solvente orgânico. Com a finalidade de verificar a possibilidade de extração de tocoferóis do DDOP utilizando CO2 supercrítico, foram realizados neste trabalho experimentos em um sistema de extração na forma estática para obtenção de dados experimentais de equilíbrio de fases deste sistema multicomponente. Foram realizadas medidas de solubilidade nas condições operacionais de 60 a 90ºC; 20 a 35MPa e tempo de equilíbrio de 6h...

Modelagem termodinâmica do equilíbrio de fases entre componentes graxos e dióxido de carbono supercrítico; Thermodynamic modeling of phase equilibria between fatty components and supercritical carbon dioxide

Daniela Caio André Gomes
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 10/08/2011 PT
Relevância na Pesquisa
96.69%
Corrigiu-se empiricamente o parâmetro a da equação de estado de Peng-Robinson para o CO2 em função da temperatura e pressão, para que a equação pudesse calcular corretamente a fugacidade do dióxido de carbono em condições supercríticas. Em princípio, o intuito foi verificar se a modelagem termodinâmica com esta correção poderia correlacionar melhor os dados de equilíbrio de fases de sistemas constituídos de dióxido de carbono supercrítico e substâncias de interesse presentes em alimentos. Para testar esta hipótese, os seguintes sistemas bifásicos constituídos de dióxido de carbono supercrítico e componentes graxos foram selecionados da literatura: CO2 ¿ esqualeno, CO2 ¿ ácido oleico, CO2 ¿ tricaprilina, CO2 ¿ éster etílico de EPA, CO2 ¿ éster etílico de DHA, CO2 ¿ alfa-tocoferol, CO2 ¿ alfa-tocoferol, CO2 ¿ trioleína, CO2 ¿ tripalmitina. Tais escolhas são decorrentes do crescente interesse de se recuperar esses componentes minoritários de óleos brutos ou dos subprodutos resultantes do processamento convencional de óleos e gorduras, devido a sua importância na manutenção da saúde humana. Além disso, tem crescido o interesse por produtos naturais isentos de solventes orgânicos indesejáveis. Nesse sentido...

Extraction of bixin from annatto seeds using supercritical carbon dioxide

SILVA, G. F.; GAMARRA, Felix M. C.; OLIVEIRA, A. L.; CABRAL, F. A.
Fonte: BRAZILIAN SOC CHEMICAL ENG Publicador: BRAZILIAN SOC CHEMICAL ENG
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.45%
The solubility of 93% Pure bixin in supercritical carbon dioxide (SC-CO2) and of the bixin present ill annatto seeds (Bixa orellana L.) was measured. For the seeds, the measurements were made in a temperature range from 30 to 50 degrees C and pressure between 10 and 35 MPa and for the pure bixin, at 40 degrees C from 10 to 35 MPa. The main pigments of annatto seeds are bixin and norbixin, but the extracts only showed the presence of cis and trans-bixin, indicating that norbixin is not soluble in SC-CO2. The annatto seeds used ill the experiments contained about 2.7% bixin and 3.1 % oil. In the seeds, the crossover point of solubility was at about 28 MPa and values for solubility were about tell times higher than those of the pure bixin, giving evidence that the oil acted as a co-solvent with the CO2.

High pressure vapour-liquid equilibrium of volatiles in supercritical carbon dioxide

Gurgenova, Karina; Bogel-Lukasik, R.; Wawrzyniak, Pawel
Fonte: Versita Ltd Publicador: Versita Ltd
Tipo: Artigo de Revista Científica
Publicado em //2013 ENG
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86.44%
Binary vapour-liquid equilibrium of thymoquinone and carbon dioxide at the isothermal conditions was carried out at temperature 323.15 K and pressures from 6 to 10 MPa. The experimental data were fitted to the Soave-Redlich-Kwong equation of state. Results could be used for selection of process parameters in separation of volatiles from raw oil or for evaluation of existing separation technologies.

Synthesis of dimethyl carbonate in supercritical carbon dioxide

Ballivet-Tkatchenko,D.; Ligabue,R. A.; Plasseraud,L.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2006 EN
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86.45%
The reactivity of carbon dioxide with methanol to form dimethyl carbonate was studied in the presence of the n-butylmethoxytin compounds n-Bu3SnOCH3, n-Bu2Sn(OCH3)2 , and [n-Bu2(CH3O)Sn]2 O. The reaction occurred under solventless conditions at 423 K and was produced by an increase in CO2 pressure. This beneficial effect is primarily attributed to phase behavior. The mass transfer under liquid-vapor biphasic conditions was not limiting when the system reached the supercritical state for a CO2 pressure higher than 16 MPa. Under these conditions, CO2 acted as a reactant and a solvent.

Efficiency of water removal from water/ethanol mixtures using supercritical carbon dioxide

Rodrigues,M. A.; Li,Jun; Almeida,A. J.; Matos,H. A.; Azevedo,E. Gomes de
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2006 EN
Relevância na Pesquisa
96.45%
Techniques involving supercritical carbon dioxide have been successfully used for the formation of drug particles with controlled size distributions. However, these processes show some limitations, particularly in processing aqueous solutions. A diagram walking algorithm based on available experimental data was developed to evaluate the effect of ethanol on the efficiency of water removal processes under different process conditions. Ethanol feeding was the key parameter resulting in a tenfold increase in the efficiency of water extraction.

Supercritical carbon dioxide extraction of pigments from Bixa orellana seeds (experiments and modeling)

Nobre,B. P.; Mendes,R. L.; Queiroz,E. M.; Pessoa,F. L. P.; Coelho,J. P.; Palavra,A. F.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2006 EN
Relevância na Pesquisa
96.55%
Supercritical CO2 extraction of the pigments from Bixa orellana seeds was carried out in a flow apparatus at a pressure of 200 bar and a temperature of 40 ºC at two fluid flow rates (0.67g/min and 1.12g/min). The efficiency of the extraction was low (only about 1% of the pigment was extracted). The increase in flow rate led to a decrease in pigment recovery. A large increase in recovery (from 1% to 45%) was achieved using supercritical carbon dioxide with 5 mol % ethanol as extraction fluid at pressures of 200 and 300 bar and temperatures of 40 and 60 ºC. Although the increase in temperature and pressure led to an increase in recovery, the changes in flow rate did not seem to affect it. Furthermore, two plug flow models were applied to describe the supercritical extraction of the pigments from annatto seeds. Mass transfer coefficients were determined and compared well with those obtained by other researchers with similar models for the supercritical extraction of solutes from plant materials.

Extraction of bixin from annatto seeds using supercritical carbon dioxide

Silva,G. F.; Gamarra,Felix M. C.; Oliveira,A. L.; Cabral,F. A.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 EN
Relevância na Pesquisa
96.45%
The solubility of 93% pure bixin in supercritical carbon dioxide (SC-CO2) and of the bixin present in annatto seeds (Bixa orellana L.) was measured. For the seeds, the measurements were made in a temperature range from 30 to 50ºC and pressure between 10 and 35 MPa and for the pure bixin, at 40ºC from 10 to 35 MPa. The main pigments of annatto seeds are bixin and norbixin, but the extracts only showed the presence of cis and trans-bixin, indicating that norbixin is not soluble in SC-CO2. The annatto seeds used in the experiments contained about 2.7% bixin and 3.1% oil. In the seeds, the crossover point of solubility was at about 28 MPa and values for solubility were about ten times higher than those of the pure bixin, giving evidence that the oil acted as a co-solvent with the CO2.

Extraction of essential oils from lime (Citrus latifolia Tanaka) by hydrodistillation and supercritical carbon dioxide

Atti-Santos,Ana Cristina; Rossato,Marcelo; Serafini,Luciana Atti; Cassel,Eduardo; Moyna,Patrick
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2005 EN
Relevância na Pesquisa
96.55%
In this work lime essential oils were extracted by hydrodistillation and supercritical carbon dioxide. In the case of hydrodistillation, the parameters evaluated were extraction time and characteristics of the plant material. In supercritical extraction, the parameters evaluated were temperature, pressure, CO2 flow, extraction time and material characteristics. Considering citral content, the best results for hydrodistillation were obtained with a distillation time of 3 hours using whole peels. The best results for supercritical extraction were found using 60ºC, 90 bar, at a CO2 flow rate of 1 mL/ min for 30 minutes using milled peels. The best yields of lime oil were obtained by hydrodistillation (5.45% w/w) and supercritical extraction (7.93% w/w) for milled peels.

Solubility of astaxanthin in supercritical carbon dioxide

Youn, H.S.; Roh, M.K.; Weber, A.; Wilkinson, G.; Chun, B.
Fonte: Korean Inst Chem Engineers Publicador: Korean Inst Chem Engineers
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
Relevância na Pesquisa
96.6%
The solubility of astaxanthin in carbon dioxide was measured under supercritical conditions of a pressure range from 80 to 300 bar, and temperature range from 303 to 333 K, by using a dynamic flow-type. The solubility of astaxanthin increasing from 0.42×10−5 to 4.89×10−5 with higher temperature and pressure maintains certain density of supercritical carbon dioxide. The solubility data obtained were applied to the Chrastil model, based on the density of carbon dioxide. The data fitted well with the Chrastil model at most experimental conditions.; Hyun-Seok Youn, Myong-Kyun Roh, Andreas Weber, Gordon T. Wilkinson and Byung-Soo Chun; The original publication can be found at www.springerlink.com

Mesoporous silica synthesis in sub- and supercritical carbon dioxide

Chun, B.; Pendleton, P.; Badalyan, A.; Park, S.
Fonte: Korean Inst Chem Engineers Publicador: Korean Inst Chem Engineers
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
96.56%
Mesoporous silicas were synthesized from sodium silicate (Na₂Si₃O₇) and tetraethylorthosilicate (TEOS) with Pluronic F127 (polyethylene oxide-polypropylene oxide-polyethylene oxide, EO₁₀₆PO₇₀EO₁₀₆) triblock copolymer using sub- and supercritical carbon dioxide (SubCO₂ and SCO₂) respectively, as solvents. Templates were removed using liquid carbon dioxide (LCO₂) and SCO₂. The most efficient template removal was achieved by LCO₂ − 92.7% (w/w), followed by LCO₂ with ethanol entrainer − 85.6% (w/w), and by methanol − 78.8% (w/w). The best efficiency of template removal by SCO₂ was 50.7%. Values of specific surface areas, ABET, were increased by 10% with the increase of an ageing time from 6 to 24 hours for Na₂Si₃O₇-based silicas at aqueous synthesis conditions, whereas the use of SCO₂ reduced this value by 19.4%. For TEOS-based silicas synthesized using SCO₂, A BET values increased by 3.8 times. Application of SCO₂ for synthesis of TEOS-based silicas resulted in higher mesopore volumes of 0.719 and 1.241 mL/g with an average mesopore width varying from 3.4 to 3.9 nm. Although Na₂Si₃O₇-based silicas have almost similar mesopore width range, their mesopore volumes were 7 times less than those for TEOS-based silicas. Formation of mesopores in Na₂Si₃O₇- and TEOS-based silicas was at the expense of micropores when synthesized in SCO₂.; Byung-Soo Chun...

Extração e fracionamento de compostos com principios ativos de propolis usando o dioxido de carbono supercritico; Extraction and fractionation of compounds with active principles of propolis using supercritical carbon dioxide

Losiane Cristina Paviani Diehl
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 14/10/2008 PT
Relevância na Pesquisa
76.61%
O objetivo deste trabalho foi investigar a influência da temperatura, pressão e porcentagem de etanol como co-solvente no processo de extração e fracionamento com dióxido de carbono supercrítico de princípios ativos presentes no extrato etanólico de própolis (EEPS) e da própolis bruta. Os experimentos foram realizados nas temperaturas de 20 °C, 35 °C e 50 °C, pressões de 150, 200 e 250 bar e adição de etanol como co-solvente nas proporções de 0 %, 5 % 10 % e 15 %. A identificação dos compostos presentes nos extratos foi feita por Cromatografia Líquida de Alta Eficiência (HPLC) frente a quatro marcadores (compostos fenólicos): ácido 3,5-diprenil-4-hidroxicinâmico (DHCA, também conhecido como Artepillin C), ácido 3-prenil-4-hidrocinâmico (PHCA), ácido 4-hidroxicinâmico (ácido p-cumárico) e 4?-metoxi-3,5,7-tridroxiflavona (canferide). A atividade antioxidante dos extratos foi baseada no sequestro do radical 2,2-difenil-1-picrilhidrazila (DPPH) pelos extratos de própolis analisados e o resultado é expresso em ED50. A atividade antimicrobiana in vitro foi avaliada pelo método de difusão em disco contra três microorganismos patogênicos: Staphylococcus aureus (ATCC 29213), Candida albicans (ATCC 10231) e Escherichia coli (ATCC 25922). O extrato etanólico de própolis teve um rendimento médio de 39...

Fracionamento de oleo de peixe com dioxido de carbono supercritico; Fracionamento of oil of fish with supercritical carbon dioxide

Ana Paula Antunes Correa
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 09/09/2003 PT
Relevância na Pesquisa
96.69%
Os ácidos graxos polinsaturados ômega-3 (EPA, DHA) são compostos com propriedades terapêuticas no tratamento e prevenção de doenças coronárias, hipertensão, arteriosclerose e artrite, além de serem essenciais para o desenvolvimento e manutenção das funções do sistema nervoso central. Os óleos de peixes de origem marinha são as fontes mais ricas em ômega-3 e por isso têm sido usados com freqüência para a obtenção de concentrados destes ácidos graxos. A deficiência de ômega-3 na dieta da população causada pela baixa ingestão destes ácidos graxos, através do consumo de peixes, toma interessante o enriquecimento de alimentos mais populares como a margarina, pães e produtos lácteos com esses ácidos graxos. A extração com fluido supercrítico é um processo de separação relativamente novo que traz vantagens em relação às técnicas convencionais. Para alimentos, o dióxido de carbono tem sido o solvente mais empregado, por ser inerte, relativamente barato e não inflamável e por possuir pressão e temperatura crítica moderadas (304,15 K, 7,38 MPa), evitando problemas de degradação térmica. Neste trabalho, estudou se o fracionamento com dióxido de carbono supercrítico do óleo de peixe em diferentes condições de temperatura e pressão. Os experimentos foram realizados de 14...

Determination of domain sizes in blends of poly(ethylene) and poly(styrene) formed in the presence of supercritical carbon dioxide

Thurecht, Kristofer; Hill, David Tom; Preston, Christopher; Rintoul, Llew; White, John; Whittaker, Andrew
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
96.51%
Well-mixed blends of poly(ethylene) and poly(styrene) have been synthesized using supercritical carbon dioxide as a solvent. The morphology of the blends has been conclusively characterized using differential scanning calorimetry (DSC), small-angle X-ray

Desorption of ethyl acetate from modified clays by supercritical carbon dioxide

Coelho,G.L.V.; Pawliszyn,J.
Fonte: Latin American applied research Publicador: Latin American applied research
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2004 EN
Relevância na Pesquisa
86.66%
The supercritical regeneration with carbon dioxide of modified and unmodified clays was experimentally studied after their use to adsorb ethyl acetate from aqueous solutions. Two quaternary amine modifiers (tetramethyl ammonium chlorine / TMA+ and hexadecyltrimethylammonium bromide/ HDTMA+) were used. The desorption of ethyl acetate adsorbed over the clays was performed with carbon dioxide at temperatures ranging from 301 K to 333 K and pressures ranging from 69.0 bar to 413.8 bar. The regeneration capacity was almost coincidental and high pressure was more favourable to regeneration. The effect of pressure and temperature was characterised under different conditions (gas, liquid and supercritical) and the supercritical has shown to be the best. A crossover effect was observed. The experimental data was fitted to a simple model, being the best results corresponding to desorption with carbon dioxide in its supercritical region.

Coenzyme Q10 microparticles formation with supercritical carbon dioxide

Ortiz-Estrada,C.H.; Díaz-Díaz,C. Y.; Cruz-Olivares,J.; Pérez-Alonso,C.
Fonte: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería Publicador: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2015 EN
Relevância na Pesquisa
96.49%
Coenzyme Q10 is a powerful antioxidant used on cardiovascular, neurodegenerative and cancer diseases. Its hydrophobic nature do limit its applications, because human body absorbs it with difficulty, that is why it was proposed to increase its bioavailability by diminishing the particle size using supercritical carbon dioxide. It was determined experimentally the phase behavior of the coenzyme in a supercritical system. The equilibrium data and a factorial 2k experimental design were utilized to find how the shape and t ize of the microparticles are affected by temperature, coQ10 concentration and nozzle diameter. Microparticles were characterized using infrared spectrometry and chromatography. For verify the fundamental chemical structure, the size and the shape of trie microparticles was used scanning electronic microscopy. It was found a significant decrease in particle size and a modification of physical structure. The antioxidant power of coQ10 after micronization was meas ured, showing an increase of this property. Finally, in order to evaluate the bioavailability, the kinetic of solubility was determined in elhanol, having a substantial increase on solubilization speed of micronized coQ10 compared with the commercial one.