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This paper discusses the process of water purification from harmful impurities by using electrical discharge machining (EDM) metal balls in an aqueous solution. The mathematical model has been developed for the water purification process. The control action was optimised using a mathematical model. To achieve the optimisation an extremal controller has been used. As a result of the process water purification optimisation, the electricity cost was minimized.

Recent studies address the structural modifications occurring in the thermal processing of food to interact with the development of aroma and taste compounds. Food sensory science is often related to statistical analysis of panel tests and subjective human responses. From a chemical engineering perspective, food can be treated like a chemical reactor. Bread can be one example of “food chemical reactor”, which enormously changes its density (from high to low depending on the leavening process), its aroma (driven from Maillard and other reactions involving carbohydrates, proteins and fats), its color (caramelization and Maillard), its structure (starch gelatinization, gluten hardening), etc. Indeed, transport phenomena and chemical kinetics are consistently involved in this process. A detailed study on the chemical kinetics of bread aroma development can be helpful to achieve an objective quality marker, which can be monitored and controlled dynamically through the process conditions and variables. The identification of the most relevant aroma compounds and the relative production paths description is the key to the kinetic approach. This would be beneficial for industrial purposes: the result of the research is the scientific description of a quantitative-sensorial aspect. This feature can be useful for further integration with physical/phenomenological models and texture models, to achieve an innovative holistic viewpoint for the product development and process control on the industrial scale breadmaking.

A recent guideline from the European Commission declared that several highly energy consuming domestic equipment should be better regulated or avoided at all in the near future. Together with this, several EU nations are abandoning the gas ovens in favour of the electric ones, also due to the home energy rating regulations, that make impossible to get the highest rating with gas ovens. Due to this fact, the study of the technologies related to the energy efficiency in cooking is increasingly developing. The combination of several energy sources (e.g. forced convection, irradiation, microwave, etc.), as well as optimisation of each of them, is an emerging target for oven manufacturers, in matter of oven design and better use of the oven capabilities. Within this context, an energy consumption analysis and optimisation is targeted in this work, by the application of a bread baking model, validated on experimental data. Each source of energy is given the due importance and the practically applicable process solutions are compared. A basic quality standard is guaranteed by taking into account some quality markers, which are relevant on the basis of a consumer point of view. This work is a part of a more comprehensive study on oven cooking and energy integration, and could lead to practical applications in the design of energy efficient cooking programs.

The search for sustainable raw material is of critical importance with the ever-growing environmental concerns together with the diminishing fossil fuel resources. Lignocellulosic biomass is nowadays being considered as one of the most promising alternative feedstocks for the production of engineered composite materials. In this regard, various pretreatment technologies have been employed to increase the accessibility of polysaccharide portion of lignocellulose but development of an effective and environmental benign innovative pretreatment process remains challenging. Ionic liquids (ILs) have been emerged as novel solvent for green processing of lignocellulose for its effective utilization in biocomposite materials. In this work, effect of IL-assisted pretreatment of lignocellulosic biomass on the mechanical properties of thermo-moulded biocompoiste board was evaluated. Lignocellulosic residue oil palm frond (OPF) was pretreated with ILs: 1-butyl-3-methylimidazolium chloride [Bmim][Cl] and 1-ethyl-3-methylimidazolium diethyl phosphate [Emim][DEP] and fabricated into biocomposite board by using thermoplastic starch as biopolymer binder. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) was performed to understand the effect of IL treatment on the OPF fibre. Mechanical properties (flexural strength and flexural modulus) of composite board made from untreated and treated fiber were measured. It was noted that IL pretreatment significantly improved the thermal stability of OPF fiber as well as the mechanical properties of the composite board. Thus, flexural strength of the biocomposite board fabricated from [Bmim][Cl] and [Emim][DEP] treated fiber was increased by 82 % and 70 % respectively as compared to untreated fiber composite board. ILs were successfully recycled and could be re-used. The present paper demonstrates that IL-assisted pretreatment could be a highly promising and green technology for effective utilization of lignocellulose in biocomposite field.

This article is devoted to the study of optimal control strategies for reverse osmosis membrane modules with recirculation. To develop a control system, a reverse osmosis membrane model, previously developed, is used. In detail, this work studies the membrane module with recirculation, investigates the possibility of controlling the impurities concentration in the permeate using an advanced control strategy and, finally, proposes a solution to optimize the recycling time through the use of model predictive control.

The development of food processes, ingredients and formulations is a daily topic for the food industries. Model-based product, process and equipment design are getting increasing industrial attention, due to the high potential in matter of time and money saving. Bringing these advantages to the consumers’ table by the application of this approach is one of the ultimate challenges of food and bioprocess engineering. This work aims to consider roast beef cooking as a practical, widespread, case study. A computational model, which correlates temperature, time and weight loss for a standard piece of meat cooked in oven, is developed and validated with experiments. The thermal properties are derived with a general approach, applicable to other food. The heat and mass transport equations are based both on conservation laws and on the cooking conditions.

This paper evaluates the predictive performance of modern Computational Fluid Dynamics (CFD) methods in cyclone vortex-separation flows. Computer simulations are performed with the Eulerian-Eulerian (E-E) as well as Eulerian-Lagrangian (E-L) multiphase models, available is STAR-CCM+ CFD solver. Tested momentum closure strategies included typical two-equation isotropic turbulence models as well as high-order Reynolds Stress Models (RSM) and Large Eddy Simulation (LES) technique. The calculated results show satisfactory agreement compared to corresponding Laser Doppler Velocimetry (LDV) measurements and experimental values for the separation efficiency (?).

In this study a multi-scale simulation of the propane aromatization process is presented. The recent interest in this technology derives from the development of new conversion routes of third generation biomass. Advanced processes for the production of drop-in biofuels from vegetable (e.g. algal) oils are based on hydrogenation reactions, which lead to the production of green diesel, and selective cracking reactions that maximise the production of bio-jet fuels C10-C15 fractions. These catalytic processes involve the cracking of triglycerides, saturation of double bonds, heteroatoms rejection (especially deoxygenation) and isomerization. Moreover, while glycerol is the low added value co-product for oils transesterification (Bianchi et al., 2009), propane represents more than 30 % of the final product in the hydrotreatment of the lipid fraction. Propane can be upgraded by catalytically convert it to aromatics, which are additives for jet- fuels and bulk feedstock for the chemical industry. The low selectivity towards aromatics strongly reduces the efficiency of the overall process, caused by a large production of cracking gases. In general, zeolites with MFI pore structure are used due to their high resistance to deactivation (Pirola et al., 2010) with metal components, such as gallium, added to enhance the dehydrogenation function. Kinetic studies of propane aromatization over H-ZSM-5 at 500 °C and atmospheric pressure in a wide range of conversions are reported in the literature (Nguyen et al., 2006). Based on these and similar results (Bhan et al., 2005), a general kinetic model for propane aromatization has been developed. In this work the revised kinetic model is presented and embedded in the multi-scale simulation of a propane aromatization process, performed with the commercial code Invensys PRO/II. Several technologies have been designed to directly convert LPG into aromatics (BTX). In this study the Cyclar process (Giannetto et al., 1994) developed by UOP and BP was selected.

Recently, many researchers are focusing their attention to food process modelling as a tool for optimizing not only the energetic and economic aspects, but also the final product texture, flavour and nutritional value. Modelling is also a valid instrument for better understanding the different scales of the cooking process. Due to its wide consumption, bread is one of the most studied foodstuffs, whose estimated production is about 9 billion kg/y (Heenan et al., 2008). The objective of this work is to analyze some of the main phenomena related to bread baking and to characterize cause-effect relationships between selected operating conditions and the final bread quality. From this viewpoint, an important role is played by the identification of the right markers that have to be taken into account for the representation of the bread quality, both from a consumer perception (Gellynck et al., 2009), from a nutritional perspective (Gellynck et al., 2009) and from that of engineers (Mondal and Datta, 2008). In addition to this, it is of relevant importance to properly characterize the most relevant physical and chemical aspects. This step is related to the analysis, choice and implementation of the models for reproducing the dynamics of the main involved phenomena. Heat exchange, water evaporation, weight loss, crust formation and browning, starch gelatinization, odours development, to quote a few, are directly depending from the baking conditions. Some of them have been modelled by several authors with different degree of detail. Assembling some of the literature models, a general model for temperature and water content/weight loss dynamics is obtained and validated with experimental data. Some correlations are used for the representation of other phenomena such as starch gelatinization and other chemical reactions, like those related to protein-sugars interactions and the following compounds development (Maillard Reaction). The present work represents a first step towards the achievement of a more comprehensive study for modeling and understanding food cooking in domestic ovens. A special attention will be addressed to the development of a reliable chemical kinetic scheme.

Dynamic simulation, design improvements and control issues in solar power plants might compete with special considerations on storing techniques along with optimal store technically and from economic point of view. In order to provide the stability in production of power in spite of inconsistency in the source of energy, i.e., sun, overall concerns in the details of solar power plant, competition and comparison of common storing technologies should be taken into account in designation of the plant and plantwide control based on the performance of the storage in charging and discharging periods for the delivery and produce the electricity steadily. This research activity is mainly focused on the simulation of solar power plant for direct thermal energy storage technologies (double-tank and single-tank storage technologies) with DYNSIM™ suite to simulate dynamics and control the entire of plant and FLUENT™ for computational fluid-dynamics studies of thermocline effects in single-tank storage. Assessment of effectiveness, controllability, and flexibility of different direct technologies are brought together with the development of ad hoc control strategies to manage optimally.

A revised, detailed kinetic scheme for the pyrolysis and oxidation of sulfur compounds is proposed and contextualized to thermal furnace of sulfur recovery units. The kinetic scheme differs from the literature schemes since its kinetic parameters accounts for the presence of light hydrocarbons, ammonia, and other species usually present in the feedstock of industrial sulfur recovery units. The scheme is validated on the literature as well as industrial data acquired from more than 10 different Claus processes.

Sulfur recovery units are particularly difficult to model since they are usually characterized by poor field instrumentation and the phenomena governing their main units and reactions are very complex and quite cumbersome to be explained by first-principles relationships. Specifically, the thermal reaction furnace is the key-element of these processes but there is still not full understanding on its general behavior and on the interactions of the complex phenomena that take place in it. This paper is aimed at proposing an overall sensitivity analysis of the thermal reaction furnace by means of detailed kinetics schemes (800+ reactions). The results are the essential guidelines to improve the operability and safety of sulfur recovery units.

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