(82c) Dividing Wall Column as Energy Saving Retrofit Technology

Dividing Wall Column (DWC) is a fully heat coupled single shell column that can replace two or more conventional columns connected in series. As proven in many industrial applications, a three product DWC enables on average 30 % saving in energy and an equivalent saving in capital, accompanied by nearly halving the required plot area compared to conventional two or three column sequences. This however is related to new designs, and only few applications have been reported where an existing column has been revamped. These, however, have been originally single columns with a side product, which, by the virtue of nature of a DWC, are obvious candidates for a revamp.

Present paper uses an aromatics plant base case to show that existing two or three column sequences can be transformed in a cost-effective way into DWCs to allow energy saving equivalent to that achievable in new designs. This makes DWC to an interesting retrofit option for existing plants confronted with the need to comply in foreseeable future with CO₂ emissions reduction requirements imposed by legislation.