Methods and processes for reducing alkylation catalyst poisoning are described herein. Such methods generally include providing a dehydrogenation system including a dehydrogenation reactor and a separation system, wherein the separation system includes a first column and a second column, introducing an alkyl aromatic hydrocarbon into the dehydrogenation reactor, contacting the alkyl aromatic hydrocarbon with a dehydrogenation catalyst disposed within the dehydrogenation reactor to form a dehydrogenation output stream comprising a vinyl aromatic hydrocarbon, passing at least a portion of the dehydrogenation output stream to first column, recovering a first overhead fraction including benzene and a first bottoms fraction from the first column, passing at least a portion of the benzene from the first column to an alkylation system including an alkylation catalyst, passing the first bottoms fraction from the first column to the second column, recovering a second overhead fraction and a second bottoms fraction from the second column, withdrawing offtest from effluent streams selected from the dehydrogenation output stream, the first bottoms fraction, the second bottoms fraction and combinations thereof to form withdrawn offtest and introducing the withdrawn offtest into the separation system downstream from the first column.