Retrofit of Crude Distillation Unit Using Process Simulation and Process Integration
Crude distillation unit is the basic processing step in oil refinery and is a highly energy-intensive process and represents one of the most important areas for energy integration in a refinery.
The HEN of the Distillation unit considered here consists of a crude preheat-exchanger network and flashing section, atmospheric distillation section, and vacuum distillation section. Because some of the heat exchangers in this unit have a relation to the S.R.G. unit we consider this unit, too.
In the paper the approach is to produce different acceptable scenarios of retrofit using an integrated instrument: process simulator and process integration software. In this case Aspen Plus environment integrated with Aspen Pinch software are used to illustrate the pinch methodology.
The incremental area efficiency methodology was used for the targeting stage of the design and the design was carried out using the network pinch method consisting of both a diagnosis and optimization stage.
The stream data consists of 21 hot and 10 cold streams and cost and economic data required for the analysis were specified. The targeting stage using incremental area efficiency sets the minimum approach temperature at 33°C, thereby establishing the scope for potential energy savings. To achieve a practical project, the number of modifications is limited. The modifications include resequencing (changing the order of exchangers on a stream), addition of new heat exchanger units, repiping of existing exchanger and split of stream in best option we can save about 9.2464% of overall energy consumption in furnace.