Area-Wide Energy Saving in Heavy Chemical Complexes Using Area-Wide Pinch Technology

It has been common to adopt a single-site approach to identify the energy-saving potential within individual industrial sites in heavy chemical complexes, and measures have been studied to optimize conditions. It has often been believed that by using this approach, all possible energy-saving measures are considered and implemented, and there is no additional energy-saving potential in a complex. In a challenge to conventional thinking and to achieve further economies, a new concept (area-wide approach) of area-wide energy saving is developed here. In this concept, utility systems for multiple sites in a heavy chemical complex are fully integrated, and surplus heat across multiple sites is used. For the area-wide approach, area-wide pinch technology is an excellent analytical methodology that can be used for multiple sites in a complex, in which all individual sites are viewed together and treated as a single entity for analytical purpose. This technology, consisting of a study procedure, R-curve analysis and total site profile (TSP) analysis, is applied to major heavy chemical complexes in both Japan and Thailand to investigate their energy-saving potential. Despite very high efficiency of the individual sites, the use of area-wide pinch technology confirmed that there is great energy-saving potential, and mid- and long-term plans are developed to achieve further economies of energy consumption within the heavy chemical complexes.