Deasphalting solvent effect

Effect of the solvent on the yields and product properties resulting from a deasphalting operation. 

Temperature, solvent ratio, and pressure each have an effect upon the spHt point or yield of the oil and asphalt components (Table 3). Contrary to straight reduction which is a high temperature and low pressure process, propane deasphalting is a low temperature and high pressure process. 

Thus, although the use of both -pcntanc and w-heptanc has been widely advocated, and although n-heptane is becoming the deasphalting liquid of choice (ASTM, 1995), this is by no means a hard-and-fast rule. And it must be recognized that large volumes of solvent may be required to effect a qualitative and quantitative reproducible separation. In addition, whether -pentane or n-heptane is employed, the method effects a separation of the chemical components with the most complex structures from the mixture and this fraction should be correctly identified as n-pentane asphaltenes or as n-heptane asphaltenes. 

Solvent deasphalting processes have not realized their maximum potential. With on-going improvements in energy efficiency, such processes would display its effects in a combination with other processes. Solvent deasphalting allows removal of sulfur and nitrogen compounds as well as metallic constituents by balancing yield with the desired feedstock properties (Figure 8-16) (Flynn et al., 1961 Ditman, 1973). 

The MDS Process is a technical improvement of the solvent deasphalting process, particularly effective for upgrading heavy crude oils (Table 8-6) (Kashiwara,... 

MDS process a solvent deasphalting process that is particularly effective for upgrading heavy crude oils. 

Coylar, J.J. 2007. Effective integration of solvent deasphalting and ebuUated-bed processing. U.S. Patent 7,214,308, May 8. 

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