Chapter 15 - Economics, Energy Analysis and Costs Evaluation in MD

Abstract

There are only few studies reported in the literature on the economics, energy analysis, and costs evaluations in membrane distillation (MD) process. MD is an energy-intensive technology that exhibits the advantage of using renewable energy sources such as solar and geothermal energy or any low-grade and industrial waste heat. For MD systems more investigations on economics of the process is conducted. Various factors should be considered to estimate adequately the water production cost (WPC) of an MD installation, including capital costs (system investment, auxiliary equipment investment, installation charges, feed pretreatment, security and control system, etc.), energy consumption both thermal and electrical, energy cost, capacity and feed water quality, membrane replacement and plant life, operating and maintenance (O&M), amortization, and annual operating costs. The capital cost depends on the capacity of the MD system and its design. There is no company selling modules for the different MD configurations. Furthermore, a commercially long life for the membrane is not yet guaranteed. Therefore, the logical first step is to produce working and reliable MD membrane modules for both laboratory and industrial scales. Furthermore, uniform economic analysis procedure should be followed for all MD systems to determine the WPC. MD is an energy intensive technology and so energy economy is an important issue. Unlike the pressure-driven separation processes, energy consumption in MD systems includes both thermal energy necessary to heat the feed aqueous solution and to cool the permeate aqueous solution or condensation and the electrical energy required to run the circulation pumps, vacuum pumps, or compressors.