study and comparsion of solvent type effect on refiner vacuum bottom deasphalting

in the 1970 s, regulations in some counries forced usersof heavy residue to limit pollutant emissions at industrial sites, also forced producers to up grade their heavy products for export and domestic use. for this reason iran as a producer, exporter and consumer has to develop mew upgrading processes.the most common processes for upgrading heavy oil are catalytic processes, but existence of heavy metals, asphaltenes, sulfur and nitrogen compounds in heavy oil process several serious problems in the process. hence at first. the unwanted materials must lower to the acceptable limit in the feed. of all the techni[ues conceived and tested to separate asphaltenes from oily feed, only one has been developed industrially, deasphalting by light solvent. in this study, deasphalting of vacuum bottom of tehran and arak refineries were evaluatedusing light alkane solvents such as n-pentane, n-heptane and lsrg (light straight run gasoline). results show that pentane and heptanes are good solvents for asphaltene separation in deasphalted oil yield compared tp propane. hence dao produced by n-c5 and n-c7 is much better in quality.