Conversion of a deasphalting unit for use in the process of supercritical solvent recovery

Abstract

In order to reduce energy consumption and to increase deasphalted oil yield, an old PETROBRAS deasphalting unit was converted for use in the process of supercritical solvent recovery. In-plant and pilot tests were performed to determine the ideal solvent-to-oil ratio. The optimum conditions for separation of the supercritical solvent from the solvent-plus-oil liquid mixture were determined by experimental tests in PVT cells. These tests also allowed measurement of the dew and bubble points, determination of the retrograde region, observation of supercritical fluid compressibility and as a result construction of a phase equilibrium diagram

Study on Solvent Deasphalting Process for Upgrading of Hydrocracking Unconverted Oil

“…32 Solvent recovery can generally be achieved by evaporation and supercritical solvent recovery. 33 The evaporation method needs to provide a large amount of latent heat to recover the solvent for phase change. In the process of supercritical solvent recovery, the solvent changed from liquid state to supercritical fluid state under supercritical conditions, and the solubility of DAO in the solvent decreased, thereby gradually separating from the solvent.…”

“…The energy consumption of the SDA process mainly comes from the solvent recovery process . Solvent recovery can generally be achieved by evaporation and supercritical solvent recovery . The evaporation method needs to provide a large amount of latent heat to recover the solvent for phase change.…”

Supercritical technology in Brazil: system investigated (1994–2003)

“…The sources of the reference data classified as discussed above were: analytical methods [6-9,34-38, ; extraction [2,[4][5][10][11]18,19,21,22,[24][25][26][27][28][29][31][32][33][39][40][41]45,50,52,53,55,[57][58][59]61,62,66,; thermodynamics and fundamental studies [3,[12][13][14][15][16][17]20,23,30,[42][43][44][46][47][48][49]51,54,56,60,[63][64][166][167][168]…”

Estudo do processo de desasfaltação em condições normais e supercríticas utilizando diferentes solventes de extração

“…O processo de desasfaltação a solvente tem sido continuamente usado e melhorado devido aos benefícios econômicos em relação aos "óleos combustíveis pesados" em produtos de alto valor agregado de resíduos de destilação a vácuo (WAINTRAUB et al, 2000).…”

“…Como consequência da diminuição do consumo de energia, a planta pode operar com altos valores de razão solvente/óleo, resultando em um aumento da produção e/ou qualidade do óleo desasfaltado. Com isso, a conversão de uma unidade de desasfaltação a solvente convencional para operação em condições supercríticas resulta na diminuição de custos operacionais para recuperação do solvente, permitindo um aumento no rendimento de óleo desasfaltado, para a mesma qualidade (WAINTRAUB et al, 2000).…”