Chemical Engineering Transactions (Oct 2018)
Optimal Operation of Dividing Wall Column using Enhanced Active Vapor Distributor
Abstract
Due to its outstanding energy and capital cost-saving potential, a dividing wall column (DWC) has gained importance for the last two decades. Unlike conventional distillation columns, the DWC has more design and operation variables, such as controlling liquid split and vapor split ratios. Liquid split and vapor split ratios need to be actively tuned during the operation to obtain optimal performance of DWC. However, it is not yet reported any active vapor split control device implemented in any existing industrially applied DWCs. Recently, Benit M has successfully developed an enhanced active vapor distributor (EAVD®) to overcome the existing problems of DWC associated with the vapor split control. In the EAVD®, the window opening area of the vapor flow path is hydraulically adjusted by changing the liquid level of a modified chimney tray. The adjustment of liquid level can be done by operating the control valve in each section of DWC. The EAVD® was tested under different operating conditions to demonstrate its reliability. The results showed that the EAVD® was able to actively adjust the desired vapor split ratio during operation along with the liquid split ratio variations. Currently, despite its great potential to notably reduce costs, only hundred DWCs are being operated in the industry. The EAVD® considerably aims to close this gap. Without any risk, the modification of existing DWCs also could be done easily by substituting the conventional chimney tray with the EAVD® to improve its operability and flexibility to maximize the benefit obtained by the advantages of DWC.