Improved Heat-Exchanger Networks for Energy-Conservation in Palm Oil Refineries

SummaryIn designing a network of heat exchangers for the recovery of waste heat, there is usually a‘pinch’ at which the minimum approach temperature difference limits energy recovery. Pinch technology emphasizes the importance of utility targets, which are independent of the network design, and so allow a very useful comparison with the utility requirements of actual networks. The design of a heat recovery network of exchangers used in palm oil refining has been examined using such pinch technology targeting procedures. The network was found to be well designed for the situation where steam is a cheaper utility than hot oil. As this was not the case, improved networks were designed. These allowed a significant reduction in heat exchanger surface area for the same energy consumption, or a 25% reduction in energy consumption for a modest increase in network area of about 10%.