(34b) Modeling and Optimization of the Utilities Consumption in the Specialty Chemicals Industry

The utilities consumption of a monoproduct batch plant was investigated by using the Bottom-Up approach in order to analyze the energy-efficiency. The method is based on detailed measurements of steam, brine, water and electricity consumption on apparatus level and the building of corresponding transient models for single unit operations (UOs). This method was already tested successfully to model and optimize the steam consumption in a multipurpose batch plant (1).

The Bottom-Up method was implemented by modeling particular UO in a case study plant and validation was accomplished with direct measurements in both UO and building level. The principle of the Bottom-Up model is a detailed energy balance of each particular UO for which real process parameters measurements are used as input data. Models of utilities consumption were developed by including losses in the form of empirical parametric equations. These equations describe losses as radiation and thermal losses in the temperature control system. For each UO the parameters of the loss models were fitted during several batches and then used for the modeling of the utilities consumption during a period of 2 months. This approach aims to offer a simpler method to analyze the energy consumption and to spot potential energy optimization.

Reference:

(1) Andrej Szijjarto, Stavros Papadokonstantakis, Ulrich Fischer, and Konrad Hungerbühler: Bottom-up modeling of the steam consumption in multipurpose chemical batch plants focusing on identification of the optimization potential. Ind. Eng. Chem. Res., 2008, 47 (19), pp 7323?7334