US Patent 8394277 Regenerative purification of a pretreated biomass stream

It is disclosed a process for removing at least a portion of the furfural and acetic acid in a first stream comprised of water, at least one compound selected from the group consisting of furfural and acetic acid, C5's and C6's. Such process comprises the steps of contacting the stream with an adsorption media which has been previously contacted with a second stream comprised of the same components and the adsorption media has been regenerated by exposing it to conditions, without being in contact with the second stream, such that at least 70% of the adsorbed furfural and acetic acid have each been desorbed and at least 60% of the C5's and C6's remain adsorbed on the media.