# Ferenc FriedlerSzéchenyi István University, Gyor · JKK

Ferenc Friedler

Doctor of Science

## About

210

Publications

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Introduction

**Skills and Expertise**

## Publications

Publications (210)

P-graph is a popularly used framework for process network synthesis (PNS) and network topological optimization. This short communication 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...

Heat exchanger networks in real industrial processes often have to be designed for varying parameters of the process streams that renders multiperiod heat exchanger network synthesis essential in industrial realization. However, three standing issues must be considered in the synthesis procedure. (1) The generated network should be efficient in all...

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...

In this paper, driving strategy optimization for a track is proposed for an energy efficient battery electric vehicle dedicated to the Shell Eco-marathon. A measurement-based mathematical vehicle model was developed to simulate the behavior of the vehicle. The model contains complicated elements such as the vehicle’s cornering resistance and the ef...

In this paper, the design and vehicle model implementation of a spiral path steering system for a lightweight vehicle is presented. The lateral sliding caused by imperfect rolling in corners means considerable loss, for lightweight vehicles. A spiral path steering mechanism provides an alternative solution for steering generated loss reduction. The...

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.

Biofuel from microalgae is one of the promising solutions on addressing climate change by its possibility of reducing the fossil fuel dependency. Till-date, the overall competitiveness of microalgae based biorefinery is the major concern due to its unique operational mechanism, especially the biological growth of microalgae that fluctuates towards...

In the case of autonomous and semi-autonomous unmanned ground vehicles (UGVs), the military application of these systems is becoming more evident and is expected to play an increasingly important role in the future. This paper aims to present and analyse the military applicability and resilience of currently available autonomous ground vehicle perc...

Heat Exchanger Network (HEN) synthesis is a powerful tool for the development of more efficient processes with high utilization of mass and energy resources. The implementation of compact heat exchangers with enhanced heat transfer into the industrial flowsheets can provide more efficient and economically feasible solutions. Plate Heat Exchanger (P...

The energy consumption and CO2 emission of urban vehicles are highly dependent on their operation. Vehicle models can be used for optimizing driving strategy for emission reduction. This paper proposes a novel vehicle model of a one-seat electric vehicle dedicated for Shell Eco-marathon (SEM), the most famous and largest race of energy efficient ve...

The energy consumption and environmental impact of urban vehicles are influenced by the applied driving strategy. In this paper, Hybrid Driving Strategy Optimization (HDSO) is
proposed, where simulation methods are combined with cognitive infocommunications. The presented methods were applied on a purpose-made lightweight electric vehicle dedicated...

Analysis on the alternative designs on top of the optimal network has proven valuable and meaningful for the decision-makers in determining the most suitable options which fulfill a wide range of objective functions. On the basis of an extension of the P-graph framework, a procedure was developed previously for multiple-solution heat exchanger netw...

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...

We propose a process graph (P-graph) approach to develop ecosystem networks from knowledge of the properties of the component species. Originally developed as a process engineering tool for designing industrial plants, the P-graph framework has key advantages over conventional ecological network analysis techniques based on input-output models. A P...

The synthesis of heat recovery networks traditionally results in an optimal or suboptimal solution for the supplied set of streams and simplifying assumptions. In the current work, the assumption of a single optimal solution is replaced by the goal of generating an ordered set of optimal or quasi-optimal networks. This enables industrial engineers...

We propose a process graph (P-graph) approach to develop ecosystem networks from knowledge of the properties of the component species. Originally developed as a process engineering tool for designing industrial plants, the P-graph framework has key advantages over conventional ecological network analysis (ENA) techniques. A P-graph is a bipartite g...

The P-graph framework was developed to solve Process Network Synthesis (PNS) problems in plant design. It provides a powerful engineering toolbox based on the constituent Maximal Structure Generation (MSG), Solution Structure Generation (SSG) and Accelerated Branch-and-Bound (ABB) algorithms. During the four decades of its development, the P-graph...

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...

Reliability is naturally one of the most important properties of processing systems, still there is no general method that is capable of simultaneously considering the reliability during the design procedure. Consequently, the optimality of the decisions in process design cannot be guaranteed. The main reason of the lack of general method is that t...

Because of the ever increasing complexity of processing systems, the reliability becomes a key aspect in selecting the best process during process design. This is especially crucial if heat integration is also part of process design, because it increases the complexity of the system that may reduce its reliability. Since the selection of a process...

Environmental pollution specifically wastewater is gaining attention both in the developed and developing countries. Malaysia is considered as one of the major palm oil producers in the world. Therefore, it is important to develop an environmental friendly and economic method to treat palm oil mill effluent (POME). The wastewater can serve as an ec...

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...

Reliability is one of the most important properties of processing systems, still there is no general method that is able to simultaneously considering the reliability during the design procedure. The proposed method is capable of synthesizing processing networks simultaneously taking into account reliability constraints or generating all Pareto opt...

The P-graph framework is a combinatorial approach to synthesising and optimising process networks. It is very efficient in handling problems with high combinatorial complexity and has shown great superiority in reducing the related computational burden. Over the years, it has proven its efficiency in solving topologically and combinatorically chall...

Due to the increasing complexity of human developed systems computer aid plays key role in engineering design involving process synthesis and analysis. The P-graph framework provides effective algorithms implemented in software to synthesize optimal process systems constructed from potential building blocks leading from the available resources to t...

The increase of the global population has a negative impact to the environment due to the direct correlation between the amount of solid waste generated and the population growth. In order to create a more sustainable future, an adequate waste management system is necessary. Utilisation of biomass that have potential to be converted into various fo...

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...

Nowadays, mankind is facing several environmental challenges such as climate change, pollutions, etc. In order to create a more sustainable future, an adequate waste management system is necessary. One of the major solid waste sources is biomass, which have the potential to be converted into energy and several kinds of value-added products. Therefo...

The P-graph or process graph framework is both a representation and a methodology that can be shown to be extremely useful as a modelling tool in various areas. P-graphs are directed bi-partite graphs that give an unambiguous representation of any process that can be expressed as a network. It is based on rigorous axioms and combinatorial analysis....

We present a computer-aided methodology for designing sustainable supply chains using the P-graph framework to develop supply chain structures which are then analyzed using cost, the cost of producing electricity, and two sustainability metrics: the ecological footprint and the emergy input. These metrics respectively represent environmental burden...

At the outset, the design of an organization-based multiagent system is modeled according to the framework of Organization Model for Adaptive Complex Systems (OMACS). Subsequently, this design model is transformed into a process-network model. Eventually, the resultant process-network model in conjunction with the P-graph-based methodology give ris...

The use of the P-graph (process graph) framework together with sustainability and profitability considerations for the design of supply chains is discussed. A P-graph contains two types of nodes, nodes for materials (Ms) and nodes for operating units (Os). The lines between the nodes signify that a material is input to or output from an operating u...

A computer-aided methodology for designing sustainable supply chains is presented using the P-graph framework to develop supply chain structures which are analyzed using cost, the cost of producing electricity, and two sustainability metrics: ecological footprint and emergy. They represent environmental burden in terms of land use and energy resour...

A new modeling technique is presented here for handling multi-period operations in process-network synthesis (PNS) problems by the P-graph (process graph) framework. Until now, the P-graph framework could only handle single-period operating units. It means that the operating conditions and the load of each unit remain unchanged throughout its opera...

Semiconductor manufacturing has recently attracted an increased attention in process optimization research. Various MILP and constraint programming methods were published to solve the scheduling problem arising in the wet-etching systems. In the present work, improvements are given to these state-of-the-art models, furthermore, the general purpose...

Glycerol is a waste by-product from the transesterification involved in biodiesel synthesis. Converting it to high value-added products can ease its over-supply. This can be accomplished by reforming glycerol into high purity hydrogen for which nickel-based catalysts are most often deployed. Nevertheless, the coexistence of both acidic and basic ac...

Methodology and computer aid are proposed for designing sustainable supply chains in terms of sustainability metrics by utilizing the P-graph framework. The methodology is an outcome of the collaboration between the Office of Research and Development (ORD) of the U.S. EPA and the research group led by the creators of the P-graph framework at the Un...

Waste to Energy (WTE) carries a trade-off between energy generation and the energy spent on collection, transport and treatment. Major performance indicators are cost, Primary Energy Savings (PES), Carbon Footprint (CFP). This presentation analyses the trade-off introducing a new indicator - the Waste Energy Potential Utilisation (WPU). The results...

The determination of reaction pathways is one of the most important functions that should be performed in exploring the kinetics of catalyzed chemical reactions or biochemical reactions, the latter being generally catalyzed by enzymes. It is proven that the terms, "type-I extreme pathway" and "structurally minimal pathway", both introduced to chara...

A collaboration consisting of the Office of Research and Development (ORD) of the U.S. EPA and the research group led by the founders of the P-graph framework at the University of Pannoniahas developed a methodology for designing sustainable supply chains based on an optimization using the p-graph framework constrained by integrated sustainability...

The formation of HBr has long been widely regarded as proceeding via a chain-reaction pathway comprising the initiation step, activated catalytically, thermally, electrically, photonically or collisionally, the propagation steps, and termination step. In recent years, however, it has been recognized that this chain-reaction pathway or mechanism doe...

The primary aim of process-network synthesis, or PNS in short, is to determine the best process network achieving a desired goal, e.g., producing a set of desired products or satisfy demands. PNS has a long history, and numerous methods for executing it are available. Its acceleratedly increasing importance can be attributed to the need to respond...

The current work reveals a methodology that provides an adequate basis to portray and model supply chains mathematically and formally as well as to synthesize optimal and alternative supply scenarios algorithmically while taking into account structural redundancy. The proposed methodology is based on the combinatorial foundations of algorithmic pro...

An effective strategy comprising two phases is proposed to determine the thermodynamically dominant pathways in a metabolic network of a given phenotype, involving several metabolic reactions. In the first phase, stoichiometrically feasible metabolic pathways are exhaustively identified through the flux balance analysis and the graph-theoretic meth...

A reaction-pathway identification procedure has two distinct phases. The first phase enumerates exhaustively the feasible candidate pathways, and the second phase identifies the ultimate feasible pathway or pathways among them. Probably the most efficient way to execute the first phase is to algorithmically generate the networks of feasible candida...

Hitherto, no attempt has been made to identify exhaustively feasible pathways for any mechanism of a given reaction catalyzed by a catalyst with multiactive sites. Two stoichiometically exact and definitely feasible mechanisms have been proposed to date for the hydrogenation of ethylene to ethane on biactive-site or triactive-site platinum catalyst...

The efficient management of renewables to reduce utilisation of energy sources with high impact on the envi