Abstract: In a method for the solvent extraction of butadiene from a mixture of hydrocarbons having four carbon atoms per molecule, which method inherently produces tars, the extraction process is operated with a tar loading level, relative to the solvent employed, of no more than about 1.6 wt. %.

Abstract: A method for the solvent extraction recovery of an aromatic wherein an aromatic extract is formed that contains the aromatic and non-aromatics that are both lighter than and heavier than the aromatic, analyzing at least two separate groups of lighter and heavier non-aromatics in the extract, determining from the analyses the distribution of lighter and heavier non-aromatics present and whether the aromatic product that will be recovered from the process will be too far from its predetermined maximum non-aromatic content specification, and making process changes that will cause the process to produce the aromatic product with a non-aromatic content that is closer to its predetermined maximum non-aromatic content specification.

Abstract: A method for recovering a CO2 stream free of highly reactive volatile organic compounds from an ethylene oxide production process that employs a carbonate/bicarbonate mixture to separate CO2 and form a carbonate concentrate that is treated in a carbonate flash unit followed by a CO2 stripper, wherein at least one of 1) an additional flash unit is employed on the carbonate concentrate upstream of the CO2 stripper, and 2) a side draw CO2 stream is taken from the CO2 stripper.