Simulated distillatin of atmospheric residues using short pyrex capillary columns

Simulated distillation of high-boiling petroleum fractions by capillary supercritical fluid chromatography and vacuum thermal gravimetric analysis

“…Efforts have been undertaken to extend the scope of the GC-SIMDIS methods by employing short, thin-film capillary columns (11,12,13). These columns are more favorable for the analysis of high-boiling fractions because of their increased phase ratio, which allows for a reduction of analysis time and column elution temperature.…”

“…C02 has been used for various hydrocarbon separations in SFC (22) and has a major advantage over other possible fluids in that it is compatible with FID. With regard to column selection, in this work, we have opted for a relatively nonpolar, 5% phenyl-, 95% methyl-dimethylpolysiloxane (DB-5) phase, similar to capillary GC phases used in SIMDIS by other workers (11,12,13). These columns are stable under conditions of SFC and, in conjunction with integral pressure restrictors (20), yield excellent precision of retention times.…”

A destilação simulada na indústria do petróleo

“…Luke e Ray 44 , por exemplo, utilizaram colunas de vidro de 0,32 mm de diâmetro interno na análise de resíduos atmosféricos, chegando a um PFE de 650 o C (o que corresponde à temperatura de eluição do C 60 ). Em trabalho posterior, Firor 45 , em um dos estudos pioneiros no uso sistemático das colunas capilares para destilação simulada, enumerou uma série de vantagens no emprego das mesmas: a) maior estabilidade da FE e conseqüente aumento no tempo de vida útil da coluna; b) tempo de análise reduzido; c) eluição de frações de petróleo com PFE acima de 538 o C; d) compatibilidade com injeção na coluna a frio automatizada e e) maior repetitividade.…”

High temperature gas chromatography: The development of new aluminum clad flexible fused silica glass capillary columns coated with thermostable nonpolar phases: Part 1

“…The "Dexsil" series of silicone-carborane polymers, so popular for the analysis of high molecular weight materials by gas chromatography using packed columns at temperatures up to 350-450°C plus, do not wet well on the surface Recently, Luke and Ray [5], and Trestianu and his colleagues [6], described the use of short (less than 15 meters) borosilicate glass capillary columns coated with methyl polysiloxane, a nonpolar stationary phase, for the separation of high molecular weight hydrocarbons at high temperatures. In the first report [!3l aC-90alkane was noted to emerge from the column at 390OC.…”