Page 19 - Sustainability in the process industry

xviii Pr ef a c e

materials reuse-recycling); supply chains; CO emissions targeting;
2
regional resource management; heat-integrated power systems with
decarbonization and low-temperature energy systems; and the
integration of reliability, availability, and maintainability with
process design. An example is given of a real-life PI problem involving
pressure-drop considerations during heat transfer enhancement.
Several recent applications are mentioned, including a Locally
Integrated Energy Sector and extended Total Sites with multiple
energy carriers.
Chapter 7 presents an overview of process optimization from the
perspectives of Mathematical Programming (MPR) and the P-graph.
The main features of these frameworks are analyzed, and it is shown
that the P-graph is better suited than MPR for solving combinatorial
optimization problems and, in particular, problems involving the
synthesis of process networks. Optimization of process scheduling is
the next topic. The most popular models and representations of
process schedules are analyzed, and an efficient tool for obtaining
them is introduced: the S-graph.
Chapter 8 presents an integrated view of PI and optimization. It
discusses how to efficiently apply them jointly in process synthesis
and how to combine them. The chapter presents a number of examples
of the P-graph and S-graph frameworks applied to combinations of
PI and optimization. These applications are grouped thematically:
(1) optimal process synthesis, including examples on reaction networks,
green biorefineries, and azeotropic distillation; (2) synthesis of
general energy systems involving Heat Integration and optimal
retrofit; (3) optimal scheduling for maximizing throughput and
revenue; (4) minimizing emissions via optimal synthesis of advanced
energy conversion systems using Fuel-Cell Combined Cycles; and
(5) availability and reliability features.
Chapter 9 reviews the software tools for process modeling,
integration, and optimization. The engineering field of sustainable
design is complex in terms of scales and relationships, which makes
information technology and computer software essential for solving
problems—preferably with a user-friendly interface. The chapter
reviews a wide spectrum of tools, as follows: (1) graph-based process
optimization (process network synthesis solutions implementing
P-graphs and the S-Graph Studio software); (2) Energy and Mass
Integration tools designed to optimize the implementation of Heat
Integration (SPRINT, HEAT-int, HEXTRAN, SuperTarget, spreadsheet-
based tools), Total Site Integration (STAR, SITE-int), power generation
and combined heat and power (STAR, WORK), and water systems
integration (WATER); (3) process flowsheeting and simulation
packages developed or supported by the major players (Aspen Plus,
HYSYS and UniSim, gPROMS, CHEMCAD, PRO/II); (4) general-
purpose optimization systems (GAMS, MIPSYN); (5) computer
algebra systems; and (6) other tools.