Low-grade waste heat driven desalination technology

Abstract

Low-grade heat driven multi-effect distillation (MED) desalination is a very promising environmentally friendly, low emission technology. Many countries, such as Australia, are water short and conventional desalination technology is energy intensive. If a primary fossil fuel source is used, then desalination will significantly contribute to carbon dioxide emission. Low-grade waste heat from process plants and power plants generate minimal additional carbon dioxide. This source of energy is typically abundant at a temperature around 65–90 °C, which dovetails with MED technology. In this paper, we report on a new MED technology that couples perfectly with low grade waste heat to give at least a 25% freshwater yield improvement compared with conventional MED design. Typical applications and their expected improvement will also be reported.

Keywords

• distillation
• med
• waste heat
• low-grade heat
• sensible heat
• evaporator