Can solvent deasphalting units use C3 and C4 mixed solvents for subcritical extraction and supercritical recovery?
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Given the need to adjust the nature of the DAO product, it is proposed to replace the originally planned C4 solvent with a mixed C3/C4 solvent, while leaving the other process steps unchanged. Is this feasible?
It should be possible, but it is necessary to recalculate the operating parameters, thermal balance, and material balance, and then operate using the recalculated parameters.
It is possible, but the critical temperature of C3 is much lower than that of C4; therefore, the extraction temperature must be reduced to prevent C3 from reaching a supercritical state inside the extractor, as this would lead to a mixed phase and the production of black oil at the top of the tower. Additionally, the extraction pressure will increase, as will the pressure in the solvent storage tank, which could affect the operation of the stripping tower. There is also a significant difference in the selectivity between C3 and C4, so care must be taken regarding the ratio of these substances.
Are there any similar devices available in the country? The big shrimps