Process integration is a term in chemical engineering which has two possible meanings. 1. * A holistic approach to process design which emphasizes the unity of the process and considers the interactions between different unit operations from the outset, rather than optimising them separately. This can also be called integrated process design or process synthesis. El-Halwagi (1997 and 2006) and Smith (2005) describe the approach well. An important first step is often product design (Cussler and Moggridge 2003) which develops the specification for the product to fulfil its required purpose. 2. * Pinch analysis, a technique for designing a process to minimise energy consumption and maximise heat recovery, also known as heat integration, energy integration or pinch technology. The techniqu