Jean Pimentel

Budapest University of Technology and Economics · Department of Chemical and Environmental Process Engineering

P-graph is a popularly used framework for process network synthesis (PNS) and network topological optimization. This R&D notes introduces a Python interface for P-graph to serve as a linkage to modern programming ecosystems. This allows for a wider application of the fast and efficient P-graph solver, to provide structural and topological enumerati...

Herein, the formula proposed for quantifying the resilience of engineering systems, including processing systems, is general in several aspects. The structure of a system can be highly complex where the numbers of loops, raw materials, and products are not limited. The mathematical models of the operating units can be either linear or nonlinear for...

This chapter proves that the conventionally used directed graph representation is not appropriate for process synthesis; therefore, P-graphs are introduced to overcome this difficulty. The mathematical definition of P-graph is given together with the set operations associated to the graphs.

In this chapter, the theoretical hindrances to effect automated process synthesis are summarized. It is shown that the conventional mathematical optimization approach is inappropriate for process synthesis because the optimal solution of the mathematical model cannot be verified as the best result for the original problem. The main components of th...

The fundamentals of algorithm MSG, which rigorously constructs the maximal structure (superstructure) of a process synthesis problem, were given in Chap. 4. In this chapter, a formal proof of Algorithm MSG is developed on the basis of the axioms of combinatorially feasible process structures. Thus, it is guaranteed that algorithm MSG always generat...

In this chapter, a new algorithm, Look Ahead Branch-and-Bound Algorithm (LABBA), is presented to further enhance the efficiency of the general purpose ABB algorithms for a specific class of PNS problems. The new algorithm improves both the branching, and the bounding aspects of algorithm ABB. Different branching decisions can lead to smaller branch...

Algorithm ABB has been presented in Chap. 6. The algorithm guarantees the optimal solution with regard to the model implemented. The efficiency of algorithm ABB can be enhanced by improving the bounding procedure. This chapter introduces algorithm ABB-RB, which incorporates a refined bounding procedure to determine a sharper bound for the partial p...

In this chapter, the concept of inside-out modelling is introduced. Five combinatorial axioms are presented for reducing the search space of process synthesis problems. It is shown that the structure of each feasible solution of a process synthesis problem must satisfy these axioms. The maximal structure is defined as a rigorous superstructure of p...

The maximal structure is the smallest structure that contains the structures of all feasible solutionsd of a process network synthesis (PNS) problem. However, sometimes the solution procedure of a PNS problem can be enhanced by solving a smaller, yet equivalent, problem. This chapter describes the method of merging reduction that is capable of gene...

Designers often consider several indicators for the selection of the process configuration in addition to cost. Some indicators, e.g., sustainability, can be embedded into the mathematical model in a manner similar to cost. Other indicators, however, require additional tools for their incorporation. This is especially true for indicators such as re...

This chapter illustrates the use of the P-graph framework for the conceptual design of a process, i.e., process network synthesis (PNS). Herein, a methodology for PNS is discussed and applied to the identification of alternative process networks (flowsheets) yielding adipic acid, one of the most employed precursors in the chemical industry. Two typ...

The set of all solution-structures of a process network synthesis (PNS) problem always contains the best, or n-best, solutions. If the maximal structure exists for a PNS problem, algorithm SSG, presented in this chapter, is capable of generating all solution-structures exactly once. The best solution, or n-best solutions, of a synthesis problem can...

A plausible approach for determining the optimal solution, or the n-best solutions, of a synthesis problem is by evaluating each individual solution-structure generated by algorithm SSG and make the selection as elaborated in Chap. 5. In this chapter, it is shown that the combinatorial properties of feasible process structures can further be exploi...

The first paper related to the P-graph framework dates back to the late 1970s. Since then, multiple contributions concerning the framework have been published by numerous researchers worldwide. The main concepts, definitions, and algorithms of the P-graph framework were introduced in Part I of the book. In this chapter, a thorough literature review...

Chapter 5 introduced Algorithm SSG which is capable of identifying all combinatorially feasible process structures of any process network synthesis (PNS) problem. In this chapter, a formal proof is given for algorithm SSG.

Because the maximal structure gives an appropriate model of process network synthesis (PNS), the first step of process synthesis based on P-graphs is always the determination of the maximal structure. This chapter presents algorithm MSG, an efficient, i.e., polynomial algorithm, to generate the maximal structure. The operation of the algorithm is i...

Chapter 6 discussed the accelerated branch-and-bound algorithm that was created to exploit the combinatorial and structural properties of the P-graph framework for accelerating the solution search. This chapter contains the formal proof of algorithm ABB.

Wastewater treatment consists of three or four sequential stages: preliminary, primary, secondary, and tertiary. Each stage can comprise multiple alternative technologies that can perform the same tasks with different efficiencies, operating times, and costs. Thus, we propose a systematic approach for designing wastewater treatment networks by util...

Reduction of CO2 emissions from industrial facilities is of utmost importance for sustainable development. Novel process systems with the capability to remove CO2 will be useful for carbon management in the future. It is well-known that major determinants of performance in process systems are established during the design stage. Thus, it is importa...

The resilience of a system is defined as the system’s capability of recovering from failures. Traditionally, only predictable aspects are considered when designing processing systems. Evaluation of these aspects is performed via assessment of exact indicators and enumeration of all cause-effect options. However, such evaluation is not appropriate f...

Valorization of the productive chains based on crops is a key target for countries with potential for generating products from agricultural resources. This contribution explores the valorization of sugarcane through the diversification of products for one of its derivatives: the lactic acid. A set of chemical processes was synthesized by means of t...

P-graph framework that was originally developed for processing network synthesis (PNS), has been extended to heat exchanger network synthesis (HENS). On the basis of the new formulation, PNS and HENS can be solved simultaneously by adapting the formerly developed P-graph algorithms. Therefore, the optimality of the overall synthesis procedure can b...

We illustrate the optimization of synthesis routes by means of RNS based on P-graphs [1] with the production of benzaldehyde from toluene [2]. We select a set of industrially-significant chemical reactions (Figure 1); we assume that both liquid-phase and vapor-phase oxidations occur at three distinct temperatures to incorporate the effect of temper...

The design of sustainable manufacturing processes and supply chains is rapidly becoming a critical issue. The reason is the necessity of providing for the needs of a growing human population which is increasingly prosperous across the globe. To this purpose, this review article explores the most important elements of sustainability science and coup...

Benzaldehyde is a chemical of significant importance in a variety of industries, which is mainly manufactured from toluene. In this work, authors develop process flowsheets in terms of profit for the production of benzaldehyde from toluene via process-network synthesis by deploying an algorithmic method based on P-graphs. First, the best reaction c...