The Diaphragm/Membrane Cell requires lower voltage than the Mercury Cell to produce the NaOH. Therefore, there is a reported cost saving of 23% for the membrane process (Page No. 201, Dryden). However, the cost of the membrane is very high and the lifespan of the membranes is short. In summary, one needs to see the overall tradeoff for the Cost vs. Process and accordingly the technology be selected. Further, Mercury and Asbestos have environmental hazard issues and hence, these may have to be eliminated in the long run. Therefore, though it might be expensive to purchase membranes and replace them regularly, it might make the membrane based process to be more environment freindly with similar cost component.
General analysis of a chemical plant must include treatment costs for hazards. When these are included, the net process could be expensive than the novel technology. The novel technology might be expensive initially but in the long run would be beneficial with less environmenta
Dr. U. Ramagopal Date: