(Solved): Benzene, toluene, and other aromatic compounds can be recovered by solvent extraction with sulfur d ...

Benzene, toluene, and other aromatic compounds can be recovered by solvent extraction with sulfur dioxide. As an example, a catalytic reformate stream containing $70\%$ by weight benzene and $30\%$ non-benzene material is passed through the countercurrent extractive recovery scheme shown in Figure P6.3.22. One thousand kilograms of the reformate stream and $3000\mathrm{kg}$ of sulfur dioxide are fed to the system per hour. The benzene product stream contains $0.15\mathrm{kg}$ of sulfur dioxide per kilogram of benzene. The waste stream contains all of the initially charged non-benzene material as well as $0.25\mathrm{kg}$ of benzene per kilogram of the non-benzene material. The remaining component in the waste stream is the sulfur dioxide. a. How many kilograms of benzene are extracted per hour (are in the product stream)? b. If $800\mathrm{kg}$ of benzene containing $0.25\mathrm{kg}$ of the non-benzene material per kilogram of benzene are flowing per hour at point $\mathrm{A}$ and $700\mathrm{kg}$ of benzene containing $0.07\mathrm{kg}$ of the non-benzene material per kilogram of benzene are flowing at point $B$, how many kilograms (exclusive of the sulfur dioxide) are flowing at points $\mathrm{C}$ and $\mathrm{D}$ ? Product benzene includes $\frac{0.15\mathrm{kg}\mathrm{SO}}{\mathrm{kg}\mathrm{Bz}}$