974 resultados para SFE-CO2


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Hydrogenolysis of mono(cyclopentadienyl)-ligated rare-earth-metal bis(alkyl) complexes Cp'Ln-(CH2SiMe3)2(THF) (Ln = Y (1a), Dy (1b), Lu (1c); Cp' = C5Me4SiMe3) with PhSiH3 afforded the mixed hydride/alkyl complexes [Cp'Ln(mu-H)(CH2SiMe3)(THF)](2) (Ln = Y (2a), Dy (2b), Lu (2c)). The overall structure of complexes 2a-c is a C-2-symmetric dimer containing a planar symmetric Ln(2)H(2) core at the center of the molecule. Deprotonation of ArOH (Ar = C6H2-Bu-t(2)-2,6-Me-4) by the metal alkyl group of 2a-c led to formation of the mixed hydride/aryloxide derivatives [Cp'Ln(mu-H)(OAr)](2) (Ln = Y (3a), Dy (3b), Lu (3c)), which adopt the dimeric structure through hydride bridges with trans-accommodated terminal aryloxide groups.

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CO2-in-Water (C/W) emulsion was formed by using a nonionic surfactant of poly (ethylene oxide)-poly (propylene oxide)-poly (ethylene oxide) (P123), and palladium nanoparticles were synthesized in situ in the present work. The catalytic performance of Pd nanoparticles in the C/W emulsion has been discussed for a selective hydrogenation of citral. Much higher activity with a turnover frequency (TOF) of 6313 h(-1) has been obtained in this unique C/W emulsion compared to that in the W/C microemulsion (TOF, 23 h(-1)), since the reaction was taking place not only in the surfactant shell but also on the inner surface of the CO2 core in the C/W emulsion. Moreover, citronellal was obtained with a higher selectivity for that it was extracted to a supercritical carbon dioxide (scCO(2)) phase as formed and thus its further hydrogenation was prohibited. The Pd nanoparticles could be recycled several times and still retain the same selectivity, but it showed a little aggregation leading to a slight decrease in conversion.

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一种超临界CO↓[2]提取翅果精的方法是将富含有植物甾醇等不皂化物的翅果全果原料粉碎成10-40目的粉状物在萃取压力15~35MPa,萃取温度31.1~60℃条件下进行超临界萃取;在压力4~10MPa,温度10~80℃条件下分离得含植物甾醇的翅果混合萃取物;将此混合物在10-25℃静置沉析后,通过离心或过滤手段,进行固液分离,液体部分得翅果油,固体物得翅果精。本发明采用含外果皮的翅果全果为原料,获得了富含植物甾醇、维生素E等的翅果精及翅果油产品,可广泛应用于医疗、食品和化妆品等行业。

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Hexaalkylguanidinium halides exhibit an efficient catalytic activity in the synthesis of cyclic carbonates from, epoxides and carbon dioxide. By this method cyclic carbonates can be obtained in a high yield and a high selectivity at a low temperature and atmospheric pressure. This procedure is easy for the product isolation and recycling of the catalyst.

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一种超临界CO2流体干燥制备纳米ZrO2的方法是将氨水加入硝酸氧锆水溶液中,调节pH值到5-10,陈化,抽滤,用乙醇置换凝胶中的水,得醇凝胶;超临界CO2流体连续通过醇凝胶,含有乙醇的CO2分离器,乙醇析出回收,CO2循环利用,待分离器中不再有乙醇析出时得到原粉;将原粉升温至673-1073K,保温,冷却,得到ZrO2粉体。本发明具有生产成本,工艺简单,容易控制,易于实现工业化的优点。

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一种CO#-[2]-CH#-[4]共汽化制取合成气的方法是电源向等离子发生装置提供能量,在氩气为载气的条件下,使等离子体装置产生温度为1200K-1500K的高温裂解区,将体积比为1-3∶1的CO#-[2]和CH#-[4]混合气通入高温裂解区,得到由H#-[2]与CO组成的合成原料气;其中电源能量、氩气流量和混合气流量的比值为1KW∶5-20L/min∶1-100L/min。本发明具有工艺简单、设备小、污染小、投资少、原料利用率和合成效率高等优点。

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一种用超临界CO↓[2]制取高纯黄腐酸的方法,采用泥炭、褐煤和风化煤为原料,经化学反应及抽提后,固液分离;分离的液体再用超临界CO↓[2]抽提;抽提液去除夹带剂后经干燥得到高纯度黄腐酸。本发明首次采用化学反应与超临界抽提相结合的方法,既增加了黄腐酸抽提率,又避免了在制取过程中黄腐酸的损失和结构破坏,而且其纯度极高。

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A novel dissolving process for chitin and chitosan has been developed by using the ionic liquid 1-butyl-3-methyl-imidazolium chloride ([Bmim]Cl) as a solvent, and a novel application of chitin and chitosan as substitutes for amino-functionalized synthetic polymers for capturing and releasing CO2 has also been exploited based on this processing strategy.

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一种CO↓[2]气肥及其制备方法,气肥由固体硫酸(一份植物纤维素加0.2-5份工业硫酸)与当量的碳酸盐混合而成,固体硫酸由1份植物纤维素、0.2-5份工业硫酸制成。本发明成本低廉,安全简便,符合中国国情。