Ismael Díaz

Turbidimetric and intrinsic viscosity study of EVA copolymer–solvent systems

Both Hansen solubility parameter and Flory–Huggins interaction parameter of two EVA [Poly(ethylene-co-vinyl acetate)] copolymers with different vinyl acetate content have been obtained by means of intrinsic viscosity measurements. To calculate this last parameter it was also necessary to determine the theta solvent at different temperatures of the two EVA copolymers with turbidimetric measurements. The results indicate that the vinyl acetate content is a variable which influences the composition of the theta solvent and Flory–Huggins parameter (the higher the vinyl acetate content, the lower the Flory–Huggins parameter), although its influence over the Hansen solubility parameter is almost negligible.

Industrial Methanol from Syngas: Kinetic Study and Process Simulation

Abstract In this study, a detailed rigorous kinetic model is proposed for the industrial production of methanol taking into account changes in total mole flowrate. The kinetic model proposed is compared with the one proposed in literature (Rezaie et al., Chem Eng Process Process Intensification 2005;44:911–21), showing significant differences in terms of compositions and total mole flow. A complete simulation of the methanol production process is developed with a commercial software. The rigorous reactor model is integrated in the simulation using the CAPE OPEN standard. Flowsheet simulation is carried out, and results show small differences with those found in previous studies (Luyben, Ind Eng Chem Res 2010;49:6150–63).

Biomass pyrolysis kinetics through thermogravimetric analysis

Abstract The objective of this work is to produce a semi-empiric kinetic model for the pyrolysis of five biomass feedstocks widely generated in the Mediterranean area. These include olive stone, pine wood, paulownia wood, cardoon and vine shoots. The biomass samples were characterized for their elemental composition. Thermogravimetric analyses (TG/DTG) were conducted under inert atmospheric conditions. The experimental results were fitted in order to determine the kinetics parameters in terms of reaction order ( n ), specific rate constant ( k ) and activation energy ( E a ) for each considered reaction.

Fault-Tolerant Self-Reconfigurable Control System

Abstract Control systems faults in a process plant means that its goals cannot be achieved. This situation leads to alarms firing, emergency shutdown or even accidents. In order to avoid these consequences an analysis of both the process and the control system must be performed. However, the complexity of both systems together with their interactions makes this analysis a hard task. The D-higraph functional modeling methodology is presented, this technique integrates functional and structural information of the plant. In this paper D-higraphs is used to reconfigure the control system of a process plant under faulty situations, which means improving systems robustness and autonomy.

Model Based Engineering of Process Plants using SysML

Abstract The motivation of this work is the constant evolution in the industry. Nowadays we are in what is called the fourth industrial revolution. This revolution is being fostered in many countries to get a more competitive industry. Industry 4.0 target is to make more efficient and flexible plants, reduce times and costs of projects and products lifecycle. Under this framework models appear as a core component in every new development. Using a systems engineering methodology the developed model will be the one that guarantees the consistency and derives the different applications needed in every stage of the lifecycle, from simulation, to risk assessment or even documentation maintenance. The objective of our work is to develop a model of a process plant using SysML. This model will follow a systems engineering approach, starting from the requirements and will cover the whole lifecycle of the Project. In this paper we present the development of the SysML model of a process plant (the production of ehtylbenzene from benzene and ethylene). The model includes the requirements as well as the structure, behaviour and activity diagrams. In this work an automatic transformation from the SysML model to a process simulation language (in this case Aspen Plus) has been built. This allows for the analysis of the process in the design and developement phases. The results of the simulation are fed back to the SysML model and this information is stored for further uses.

A New Functional Systems Theory based Methodology for Process Hazards Analysis

Abstract This paper presents a new methodology to cope with complex systems hazards analysis. Process safety is an important problem and has traditionally been tackled as a failure problem. Existing methodologies use a chain of events approach to analyse the system’s safety. Today, with more complex and interacting systems, this approach has serious limitations because it does not consider, among others, systemic failures. To overcome these limitations, system based approach called STPA (Systems Theoretic Process Analysis) has been developed at MIT (Massachusetts Institute of Technology). In this work we present this methodology, apply it to a process system and integrate it with the use of functional models, a technique that allows to have a more direct, automatic and comprehensive analysis.

Active Learning of Process Control

Abstract Process Control is a course that needs a thorough understanding of how the different unit operations work and what are the implications of changing operation variables in a process. This paper presents how education innovation can help students to improve their learning and understanding of the different concepts and thus to get better results in the subject and to achieve the desired outcomes. The Process Control Course is taught in the Bachelor Degree in Chemical Engineering at the Technical University of Madrid. Different methodologies have been integrated and used in the course as: flipped classroom, peer instruction, and gamification. In order to implement the mentioned methods, the following material has been developed: screencasts, concept tests, trivia contest and simulations besides the traditional material (slides and text). First year results show high student motivation, higher participation in class and better results (marks) in the subject.

Model transformations and integration for process plant simulation, optimization and visualization

Abstract Industry is in constant evolution. Nowadays we are in what is called the fourth industrial revolution (called Industry 4.0 or connected industry). Its target is to make more efficient and flexible plants, reduce times and costs of projects and products lifecycle. It is an integrated engineering approach were different software tools are interconnected during the whole lifetime of the project, reducing inconsistencies and developing times. To have a central neutral model of a process plant that is available during the whole lifecycle of the system (process + product) and that can be transformed automatically to specific models suited for different applications. To achieve this goal we use a Model Based Systems Engineering approach, starting from the model requirements and covering the whole lifecycle of the project. This central model is specified using the Systems Modelling Language (SysML). This language is a profile of the Unified Modelling Language (UML developed by the Object Management Group) that is neutral and domain free. The developed model is partially generated in SysML and partially constructed using existing specific models. Having a single central model guarantees the consistency and allows for traceability at any stage of the lifecycle. First, we present the architecture developed to implement this system. After, we create a SysML model of a process plant (the production of ethylbenzene) starting with the requirements. This model includes the behavioural (block definition and activity diagrams) and structural (internal and block definition diagrams) aspects of the model. Once the model is created automatic transformations (bidirectional) from it to some applications are performed. The applications are: • Process design. Transformation to a steady state model used (specifically an Aspen Plus model) in a process simulation environment(Previous work presented in other conferences). • Risk assessment. Transformation to a functional model to perform risk analysis (HAZOP). • Process optimization. Automatic generation of the objective and constraints. We use Melody to integrate the SysML with the optimization model. In this case Matlab is being used for the optimization (Previous work presented in other conferences). • Process visualization. Transformation from the 3D model to SysML. We use Syndeia to achieve the integration. The 3D models are done using PTCreo. In this work we will put more focus on the development of the 3D modelling integration in the proposed architecture. This work shows the potential of having models at design time, central and consistent and coherent models. Industry trends look for models that generate virtual plants that can be “operated” and that allow to discover design mistakes at early design phases. Thus providing, when constructed, more robust, consistent and efficient plants. Model development effort is reduced and data exchange between different applications is facilitated keeping a central and consistent model.

Control strategy for the Super Heat Integrated Distillation Column

Abstract Distillation is the most widely used in the separation section of a process. It consumes an important amount of energy (close to 40% of the energy of chemical process). Many different configurations to increase its thermodynamic efficiency have been proposed. The first modification was to add side heat exchangers and reboilers to reduce the duties of condenser and reboilers then a pressurized rectifying section was proposed so that the heat duty of the side condenser could be supplied to the side reboiler. This is basically the concept of what is called Heat Integrated Distillation Column (HIDiC). Recently Toyo Engineering Corporation has patented a new HIDiC called SuperHIDIC column concept, where it realizes the heat integration concept in a simplified manner. Using this column energy conservation is around 50% and greenhouse gas emissions are significantly reduced. Objective is to develop a dynamic simulation of the column and to design the control structure. This will based on a methyl ethyl ketone separation column. First, we present the dynamic model, the designed column parameters and its performance in terms of energy consumption. After, we design and implement the control structure. This structure is evaluated under different production scenarios and disturbances and it is optimised for minimum total annual cost. This work shows the potential of heat integrated columns and specifically of the recently developed by Toyo Eng. Corp. A control structure that minimises costs (capex and opex) is proposed and analysed showing possible operation problems and how interactions between the different control loops affect the column performance.

COSMO-derived descriptors applied in ionic liquids physical property modelling using machine learning algorithms

Abstract An application of machine learning algorithms for the prediction of physical properties of ionic liquids is presented herein. Molecular descriptors obtained from quantum-chemistry calculations (COSMO theory (Klamt, 2004)) containing both structural and energetic information are used as input parameters. In this sense, a set of COSMO-based descriptors is proposed by reduction of the original σ-profile (51 descriptors reduced to 9 bins). A critically evaluated set of viscosity data is used for a large number of ionic liquids (159). Artificial neural networks are then trained for the correlation of liquid viscosity and compared with available tools (QSPR).