Utilising Six Sigma for energy conservation: a process industry case study

Abstract

In a global environment, organisations are under continuous pressure to control costs, maintain high levels of safety and quality, and save energy. Energy conservation is a means to control costs and increase efficiency. Process industries in general are big consumers of different kinds of energy. In this paper, Six Sigma methodology has been applied in a thermal power plant seeking energy conservation. De-mineralised (DM) water in these plants is an expensive input material. It has been found that a 0.1% increase in DM make-up water consumption increases the generation cost by approximately US$0.2 million per annum. DM water is taken as a main Critical-to-Quality (CTQ) factor. It is found that Six Sigma project recommendations brought down the mean make-up water from 0.90% to 0.54% of Maximum Continuous Rating (MCR), accruing with it a comprehensive energy savings of nearly US$0.74 million per annum.