Abstract: A method of separating a feed mixture in a simulated moving bed includes flowing fluid in a first flow configuration comprising: supplying the feed mixture downstream of a valve in a shut off position that stops fluid flow to a first column, removing a raffinate stream component, and supplying a remaining fluid flow to a second column; supplying a desorbent to a third column and removing an extract stream downstream; and passing a remaining liquid flow through a fourth column, and removing an intermediate stream. The method includes flowing fluid in a second flow configuration in which the valve is in a position that permits fluid flow to the first column, and supplying a desorbent and removing an extract stream downstream from the column to which the desorbent is supplied; and removing a raffinate stream.