Page 242 - Sustainability in the Process Industry Integration and Optimization

CHAPTER 10

Examples and

Case Studies

his chapter provides a selection of problems that have been
collected by the authors over twenty years of teaching and
Tconsulting. The problems include step-by-step solutions,
which provide guidance for mastering the methodology. Space
limitations make it impossible to cover all aspects or to provide fully
comprehensive solutions, for which an entire book would be required.
The representative problems selected for presentation here are
divided into five groups: Heat Pinch Technology, Total Sites,
integrated placement of processing units, utility placement, and
Water Pinch Technology.

10.1 Heat Pinch Technology

The first group of problems involves heat Process Integration, known
also as Heat (and, in Australia and South Africa, as Thermal) Pinch
Technology.

10.1.1 Heat Pinch Technology: First Problem

Problem 1: Task Assignment
A chemical process is served by a Heat Exchanger Network (HEN),
as displayed in Figure 10.1. The figure shows the supply and the
target temperatures at the start and end of each stream. For this
problem, the minimum allowed temperature difference ΔT = 10°C.
min
The following tasks should be performed:
(a) Completion of the network description. (1) Convert the network
representation to a grid diagram. (2) Calculate the missing
temperatures and heat loads for the recovery heat exchangers,
heaters, and coolers.
(b) Identification of the Network Pinch. (1) Find and write down a
path that connects a heater and a cooler through a recovery
heat exchanger. Derive expressions for the heat loads and
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