Driving Sustainable Savings in Utility Operations through a Site-wide Energy Model

Sustainable savings are routinely captured by utility system operators at industrial facilities through regular implementation of real-time recommendations of a site-wide energy model solution.  We will describe an approach through which utility “Best Practices” are developed using the framework offered by the site-wide model.  This approach is the result of 25 years of continuous development specifically focused on utility operations improvement and has been implemented at over 50 sites worldwide.

A client case study will be used to illustrate the methodology leading to the proven benefits delivered at CEPSA’s San Roque, Spain chemical facility.  CEPSA operates a complex steam, fuel gas and hot oil network at its chemical complex producing Purified Terephthalic Acid (PTA) and related chemical products at San Roque.  CEPSA contracts with neighboring third party sites for steam and fuel gas purchase and sale.  The complexity of the utility system operation at San Roque presents a significant challenge to the operators responsible to controlling the operational cost at the site.

The structured approach employed at San Roque illuminated particular “handles” available to the CEPSA operators through which they implement changes to utility system operation required to maintain reliable, cost-effective, real-time operation.  These included the manipulation of boiler steam production, the export and import of steam, fuel gas import, and the management of hot oil/steam trade-off for process heating. 

The sheer number of available “handles” at the operators’ disposal introduces enormous complexity to the task of achieving the lowest cost real-time operating mode for the utilities.  An online model which considers plant control strategies and system reaction to changes in the utilities was developed and deployed in order to give the operators specific, real-time recommendations for needed changes to “handles” that would result in lowest cost, real-time operation of the utility system, resulting in significant energy cost savings as a result.