Patent ID: 8123952
Filing Date: 2012-02-28
Classification: B01D,C07C,C10G

Abstract:
1. A process for simulated moving bed (SMB) separation of a feed F in a SMB device having at least one column, said column being composed of a plurality of beds of adsorbant separated by plates P i each comprising a distribution/extraction system, in which process the feed F and a desorbant D are supplied, and at least one extract E and at least one raffinate R are withdrawn, the supply and withdrawal points being offset over time by a value corresponding to one bed of adsorbant, with a switch time ST, and determining a plurality of operational zones of the SMB, in particular the following 4 principal zones: a zone 1 for desorption of the compounds produced in the extract, comprised between the supply of the desorbant D and withdrawal of the extract E; a zone 2 for desorption of the compounds produced in the raffinate, comprised between the withdrawal of the extract E and the supply of the feed F; a zone 3 for adsorption of the compounds produced in the extract, comprised between the supply of the feed and the withdrawal of the raffinate R; a zone 4 located between the withdrawal of the raffinate R and the supply of the desorbant D; the device further comprising external by-pass lines L 1) in an operational zone where there is at least one closed by-pass line, a super-synchronicity of the flushing flow rate is established in all of the by-pass lines which are not closed belonging to the zone under consideration, said super-synchronicity being defined by the following formula: 2) if there is no closed by-pass line in the zone under consideration (in other words if all of the by-pass lines of the zone are open), then a flow is established in all of the flushing lines of said zone which corresponds to the synchronicity plus or minus 8%; V VL and ST denotes the switch time; and the super-synchronicity being defined by the formula: