(36c) Production-Data Based Energy Modeling and Support Tool for Optimization of the Energy Consumption in Chemical Multipurpose Batch Plants

With growing energy prices, the energy consumption becomes an important cost factor which in multipurpose batch plant can reach as high as 10 % of overall costs. The energy efficiency improvement which was driven by oil crisis in the 1970's is nowadays gradually shifted from the financial to environmental level (Kyoto protocol and engagements of the companies towards local authorities to reduce CO2 intensity of the production). Energy efficiency improvement of the chemical facilities requires support tools for decision makers in order to make quick and competent analysis of the current situation and indicate the highest energy saving potentials. A novel approach was developed using production data in electronic format as an input for the energy models allowing modeling of the energy consumption with minimal engineering effort while delivering highly detailed results. The energy utility consumption was corrected by the empirical loss term which characterizes the energy efficiency of the particular apparatus.

The set of production data obtained from the case study plant for a specified period representing particular product portfolio was preprocessed in order to get the durations and process parameters (temperature, pressure, mass levels) of the particular processes which are conducted in specific equipment units. The input data include the deviations in the process parameters and the durations of the operations for different batches and their influence on the overall utility consumption can be observed. The energy consumption of the chemical process contains two terms ? theoretical consumption (calculated from the production data) and the loss term. The loss terms for particular apparatuses were determined based on the measurement of the energy utility consumption and a database with the loss terms for particular apparatus was created (can be used for energy consumption modeling in other chemical multipurpose batch plants without necessity of measuring energy consumption for individual apparatus).

The result of the model allows to analyze the energy utility consumption batchwise and to identify the batch with minimal utility consumption. The analysis of the results was carried out in order to identify the operations with highest energy saving potential and possible optimization of the energy consumption.