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Achieving independence from fossil fuels and reducing emissions by increasing energy efficiency and utilizing green vehicles, such as hybrid electric vehicles and alternative green fuels, are among the main goals of energy policies globally. Although electric cars were introduced many years ago, agricultural electric vehicles have recently gained attention. Beyond emissions reductions, the benefits of agricultural electric vehicles include precise control, continuous variable speeds, and overload capability functionality. Moreover, such technology paves the way for the emergence of autonomous connected vehicles, which enhance work quality and increase operator comfort. Along with the electrification of agricultural vehicles, on-site production of renewable energy to supply their required power enhances the benefits in terms of increased efficiency and energy independence as a future-oriented approach. This paper outlines the trends in development and future perspectives of autonomous farm vehicles premised on green energies, with on-site energy production as a byproduct. [ABSTRACT FROM AUTHOR]

Nowadays, efforts for substitution of fossil fuel vehicles have fixed the attention of both individual and governmental levels on seeking new sustainable energy resources. In this regard, several power sources, such as fuel cells (FCs), batteries, and gensets, have come under attention to be used in vehicles with low or zero emissions. Generally, every energy source comes with a set of challenges, which are mainly associated with the efficiency, availability, durability, and cost. This paper is going to touch on the principle of employing a modular energy system (MES), and how this principle is helping the above-mentioned sources to deal with their limitations. MESs refer to independent power sources, which can work together. The aim of a MES is to distribute the power among the components and/or to split the energy storage into several standardized modules, which leads to several economical and technical benefits. Various examples of MESs in real applications are explored, and their advantages are discussed in this manuscript. Moreover, a special attention has been paid to the prospects of employing modular FC systems coupled with a battery pack since such a system has the advantages of a MES while it has no serious environmental impacts. [ABSTRACT FROM AUTHOR]

Sources of renewable energy such as wind energy are indigenous and can help in decreasing the reliance on non-renewable energy sources. After introducing the history of wind energy production in Egypt and worldwide besides its techno-economic importance, this paper presents a comparative review on the wind energy conversion systems (WECS). The horizontal and vertical types of wind turbines with their mathematical dynamic models are discussed. Different types of electrical generators used in WECS in addition to their advantages and disadvantages are illustrated. The various AC-AC converters topologies for WECS are explained with a detailed discussion for their features. [ABSTRACT FROM AUTHOR]

Since the ambient temperature and solar irradiance are not constant, and the P-V characteristic curve of a photovoltaic (PV) module is nonlinear, it is hard for a photovoltaic system to operate at the maximum power point (MPP). In fact, using a maximum power point tracking algorithm (MPPT) to reach the MPP is significant when the climatic conditions change during the day. This paper presents a novel approach for grid-connected PV systems based on a Practical Swarm Optimization (PSO) metaheuristic algorithm to ensure the MPPT functionality as well as generating the reference power for the DC-Bus voltage regulation. The proposed method is compared with the conventional MPPT method Perturb and Observe (P&O) under different irradiance variations. The three-phase, two-level voltage source inverter (VSI) is controlled by a finite set model predictive controller (FS-MPC). The simulation results show that the proposed system is more efficient than the conventional method and has good dynamic performances. [ABSTRACT FROM AUTHOR]

This paper deals with site selection problems for hydrogen production plants and aims to propose a structural procedure for determining the most feasible sites. The study area is Adrar province, Algeria which has a promising wind potential. The methodology is mainly composed of two stages: the first stage is to evaluate and select the best locations for wind-powered hydrogen production using GIS and MCDM technique. the AHP is applied to weigh the criteria and compute a LSI to evaluate potential sites, and the second stage is applying different filtration constraints to select the suitable petrol stations for such hydrogen refueling station modification. The result map showed that the entire Adrar province is almost suitable for wind-powered hydrogen production with varying suitability index. The LSI model groups sites into three categories: High suitable areas, Medium suitable areas, and Low suitable. As a result, 2.95 % (12808.97 km2) of the study area has high suitability, 54.59 % (236320.16 km2) has medium suitability, 1.12 %(4842.94 km2) has low suitability and 41.34 % (178950.35 km2) of the study area is not suitable for wind hydrogen production. By applying the constraints, about 4 stations are suitable for wind-powered hydrogen refueling system retrofitting in Adrar province. [ABSTRACT FROM AUTHOR]

Over the past decades, meta-heuristic optimization techniques have become surprisingly very popular due to their flexibility and local optima avoidance capability. This paper uses the Whale Optimization Algorithm (WOA), a swarm-based technique to tune the Proportional-Integral (PI) based Maximum Power Point Tracking (MPPT) controllers of a grid-connected solar Photovoltaic (PV) system. The results of the PI-based Incremental Conductance (IC) MPPT technique are compared with both the conventional incremental conductance and the Perturb & Observe (P&O) MPPT techniques. Various modes of the PI controller are used. I, PI and Fractional order PI (FOPI) gain parameters are determined using WOA. Performance indices are applied to estimate the best parameters of the PI controller. This paper aims to show the effect of using PI-based MPPT controllers on enhancing the performance of a 400-kW grid-connected PV system. Simulation results show the capability of PI-based MPPT controllers on improving the performance of the PV system. It demonstrates the superiority of FOPI controllers over the other modes in enhancing system performance. The proposed work is simulated using MATLAB SIMULINK. [ABSTRACT FROM AUTHOR]

Today, the world suffer from air pollution due to the presence of chemicals, particulate matters and biological materials in the air. All these elements have negative impacts on human health, environment and economy. Vehicle emissions are considered a major source of air pollution. Transportation is one of the main sources of air pollution around the world. Vehicle pollution takes two forms, the emission of greenhouse gases (global impact on the environment, global warming) and particulate emissions (local impact, deterioration of air quality). In order to tackle this problem, the solution is to encourage the development of hybrid vehicles. This paper will shed light on a new hybrid generator topology, equipped with a photovoltaic energy conversion system, a battery with its DC / DC converter is adopted to replace the fuel cells in order to solve the problems which are: high consumption with a high cost in terms of energy. Another contribution of this work consists in the use of fuzzy logic; indeed the use of the fuzzy logic system which is used as an autonomous control device. Fuzzy logic has been used primarily to adapt control parameters in order to improve the overall robustness of the system while maintaining its stability. [ABSTRACT FROM AUTHOR]

Hybrid renewable electric energy generation system become essential to the most of electric networks and the stand-alone systems like the water pumping and telecommunication systems. The renewable sources usually required storage system due to change in the power outputs during the day. Due to increase in demand of using batteries, the charging process of battery system needed to be well managed through an adaptive controlled energy managing system. In this paper a standalone system using photovoltaic, wind generation, fuel cell and storage batteries are contributed in supplying the desired load and the charging balance of batteries is achieved by using AI techniques to enhance battery charging controller performance. The main goal of this paper is to design and implement an integrated smart artificial controller, this controller is responsible for controlling both the battery charge voltage using the boost converter and the other controller is to control the charging current of the battery through DC to DC converter using (ANFIS) and (GA) techniques. This study is implemented using MATLAB /Simulink and the results are presented to show the applicability and effieciency of the proposed technique. [ABSTRACT FROM AUTHOR]

The intensive energy requirements, the mismatch between the energy supply and demand and the nocturnal temperature drops are all crucial issues in the greenhouses solar heating. This paper seeks to evaluate the effect of a solar air heater with thermal latent storage on the greenhouse microclimate by pursuing the evolution of the internal climate before and after the heating. In this context, an experimental hydroponic greenhouse (HYDGR) and a solar air heater (SAHLSE) were realized in the Thermal Processes Laboratory in the Research and Technology Center of Energy of Borj Cédria in Tunisia. The solar heating with thermal energy storage enhanced the microclimate of the greenhouse and the temperature didn't drop less than 32 and 15°C respectively the day and at night. The realized solar collector with thermal latent storage offered higher temperature even when the sun is unavailable and increased the internal temperature by more than 5°C. The studied solar system realized good improvement in the hydroponic greenhouse and appeared to be a beneficial alternative for ensuring optimal microclimate. [ABSTRACT FROM AUTHOR]

In this paper, a new design to enhance the thermal performance of residential water heaters is suggested and investigated. The new design consists of using a mixer inside the water tank driven by electrical power. To proceed, experimental measurements are made by using thermocouples implemented in a water heater to study the thermal behavior. It is proved that the mixer could reduce the heating time about 20 min to heat water from 25 °C to 70 °C. In addition, the temperature homogeneity is also studied and it was shown that the temperature without the mixer could not be homogeneous within the water volume. [ABSTRACT FROM AUTHOR]

In recent years, net zero or plus-energy buildings (PEB) have been widely analyzed and discussed for their benefits of increasing energy savings and reducing greenhouse gas emissions. A successful transition to energy-efficient buildings must, however, develop an efficient method that examines technical, economic, environmental and social criteria. In this paper, a method for design optimization based on spatial analysis combined with multi-criteria decision-making was proposed for achieving plus-energy buildings in Algeria. To apply the proposed method, a single family residential building was chosen. First, the annual energy consumption of the building at 40 locations was evaluated and the results are then interpolated for the whole country. The best energy efficiency measures and renewable energy are then chosen using the Analytic Hierarchy Process (AHP) method. Finally, energy balance and spatial analysis were carried out based on the geographical information system. The results showed the energy plus target was achieved in large parts of the country using a high-performance envelope, more efficient appliances and solar energy (solar photovoltaic and thermal). In addition, the southern provinces, mainly Adrar, Tindouf, Bechar, Ouargla, and Illizi, have identified the most suitable areas for setting up new buildings with an energy-plus target. In addition, applying the method will reduce the overall energy demand by 43 % and reduce GHG emissions in the country by around 23 % by 2030. Therefore, the method will have a significant impact on sustainability locally and worldwide. [ABSTRACT FROM AUTHOR]

Magneto-convection heat transfer mode inside a partially open-ended 2D enclosure, which is filled with conducting fluid, is considered as suitable research model in order to scope out our understanding into frequent decisive practicable applications in sustainable and renewable energy domains, especially solar energy collectors. Nevertheless surprising, continuously there is no existing literature dealing with it. Further, for Computational Fluid Dynamics (CFD)'s approaches, it is a considerable defiance to predict and anticipate this coupled complex physical engineering problem in MagnetoHydroDynamic (MHD) configurations. In the current numerical prototype, we introduce the lattice Boltzmann method (LBM) in the aim to overcome such engineering simulation difficulty. It is to be noted that this mesoscopic approach becomes nowadays an essential attractive and alternative for CFD approaches to simulate complex numerous fluid flow problems.) has become an alternative and attractive approach to simulate numerous fluid flow problems. This paper intends to provide a brief review of researches on application of MHD convection with LBM on the prediction of thermodynamic behavior identifying more opportunities for future research. Besides, some new results are highlighted within this paper. To begin, the present LB model is validated against existing benchmark tests in literature. With the handout of this in house Fortran 90 LB code, we investigate the effects of Hartmann number, Rayleigh number, Prandtl number and the position of the partially open-ended side in the magneto-convective partially open ended y filled with conducting fluid cavity primly. It is established that these elements all impact flow and temperature fields patterns significantly. The obtained results can serve crucial theoretical prototypes for the related future practical magneto-convective applications. Our finding will be a useful tool allowing identifying opportunities for future research related to the considered engineering area. [ABSTRACT FROM AUTHOR]

This paper deals with fractional multi-input, multi-output systems which guarantees a very small number of parameters that can reduce the computation time. It focuses in particular on the state-space representation of systems which highlights the state variables and allows to study the internal behavior with taking into account the initial state. It also discusses the discretization of this type of system to finally adapt the Robust Model Predictive Control (RMPC) to apply it and show its efficiency and performance in these systems. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the possibility of integration of Electric Vehicles EVs supply's with electricity and/or hydrogen in the road transport sector and estimate the energy supply derived from solar irradiation by using solar roads technology. The case study is road Est-Oust (road E-O) of Algeria. A Geographic Information System and spatial analysis tools are combined with spatial data and technical models to carry out these calculations. The results of this study demonstrate that solar road panels, which are integrated into the road E-O, produce over to 804 GWh/year which equivalents to 13778 tons of hydrogen per year.by using FCEVs will saving over then 41.103 liter of fossil fuels (regular gasoline); and reduce GHG emission (CO 2) in the transportation sector by 216 tons per year. [ABSTRACT FROM AUTHOR]

The work in this paper revolves fundamentally around the main axes of fuzzy control of the type Takagi-Sugeno (T-S) zero order for dynamic, complex nonlinear systems. In this paper, we present method for designing Fuzzy controller rule base using a new swarm intelligence algorithm, which is based on the Bat algorithm. The Bat algorithm is one of the most recent swarm intelligence based algorithms that simulates the intelligent hunting behavior of the bats found in nature. The main objective is to design the fuzzy rule base of fuzzy controller respecting the desired performance. To demonstrate the efficiency of the suggested approach, a control of a Magnetic Ball Suspension System is selected. Simulation results shows that the proposed approach could be employed as a simple and effective optimization method for achieving optimum determination of fuzzy rule base parameters. [ABSTRACT FROM AUTHOR]

The classical diagnosis approaches, deeply spread in the industrial environment, are based on the Fourier analysis of the steady-state current, the basis of the proposed methodology consist of analysing the current demanded by the machine during the connection process (startup transient); the objective is to extract the characteristic evolution during the transient of some harmonic components created by the fault; this evolution is caused by the dependence of these components on the slip (s). In this paper the induction motor under dynamic and mixed eccentricity type is modeled with high precision using (CMC) approach. [ABSTRACT FROM AUTHOR]

In this paper, three advanced modelling approaches will be performed to well describe the actual behavior of photovoltaic (PV) cells, in which some total solar irradiance changes are considered. The first one uses a specific solar cell provided by the Sim-Electronics tool of the Matlab software. It is used to simulate the actual behavior of PV cells instead of the conventional electrical circuit based on either single or double diodes. The second approach adopts some physical components provided by the Simscape library to reach the same above mentioned goal. The third approach uses the Simulink blocks to build the mathematical equations describing the PV cell behavior, in which some mathematical operators and functions are used. The three proposed models have the ability to predict the actual behavior of PV cells under different weather conditions. This can improve the extraction of the maximum power and contribute even to the synthesis of the appropriate controller. The performances assessment of each proposed model is established in term of the provided output power as well as the generated current and voltage. [ABSTRACT FROM AUTHOR]

In the present paper, a new approach to the management of energy resources in the Research and Technology Centre of Energy (CRTEn -Tunisia) is proposed and evaluated by the monitoring of a PV installation realized for the cooperation project DE.DU.ENER.T, using renewable energy and economic criteria. The aim of this project is to improve energy efficiency order to minimize the electricity cost consumed at the CRTEn laboratory. According to the bills of electricity received, we noticed that there is a high consumption of electrical current. So, we targeted to install a photovoltaic field of 12KWc to reduce these bills by using the sustainable, green and clean sources. A theoretical study of the PV system sizing realized in order to know in the first hand the compatibility between the different equipment of this installation and to compare the results with those found by the SMA Sunny Design and PV*SOL software in the second hand. The experimental results show that the performance factor of the proposed system is 84.6%. Meanwhile, the cost of the energy generated by the proposed system is 0.045 USD/kWh, which means that the payback period, is about 11 years. The conclusion from this study is that the price of energy generated by PV systems in Tunisia is lower than the subsidized price of energy generated by fossil fuel. [ABSTRACT FROM AUTHOR]

Hybrid AC/DC microgrids (MGs) represent a significant step to go fast through the evolution of smart grids. The type, size, and location of distributed generation units (DGs) have significant impact on the operational cost and the gas emissions in hybrid AC/DC MGs. DGs can be used to supply AC and/or DC electrical energy to their MG local loads. In addition, DGs can supply AC electrical energy to the utility grid during grid-connected mode. With appropriate DGs fuel options, the operating cost and the gas emissions can be minimized. Furthermore, the power system reliability increases. This paper proposes a scheduling algorithm for hybrid AC/DC MGs with multiple fuel options. The operational cost and the gas emissions have been considered as multi-objectives based on particle swarm optimization (PSO) optimization. The approach was applied to a typical hybrid AC/DC MG as a case study, and the effectiveness of the proposed method was verified. [ABSTRACT FROM AUTHOR]

This paper proposes the Direct Torque Control (DTC) of a Wind Energy Conversion System (WECS) based on a Doubly Fed Induction Generator (DFIG) with power factor control strategy. The proposed technique aims at controlling the generator electromagnetic torque and rotor flux while controlling the power factor at the stator terminals. The proposed control is achieved through generating the referential electromagnetic torque from the Maximum Power Point Tracking (MPPT) control so that the maximum power is extracted for each different wind speed, and the referential rotor flux from the reactive power reference. [ABSTRACT FROM AUTHOR]

It is vital in the prevention of the ferroresonance to consider this phenomenon from new side. The design of the equipment needs deep studies to avoid such disturbance. This paper presents a new way in ferroresonance studies, by the use of the Root Cause Analysis (RCA) in a systematic step by step process to discover the true cause of this problem. A fault tree is built to identify all possible causes leading to the unwanted top event, that is the False Trip Analysis (FTA). Among large statistics of disturbances, the probability of occurrence of ferroresonance is stated, and using the most studied causes of this event, the tree of analysis is built till reaching the main disturbance. In each step, well-known possible causes are shown. Then, a barrier or possible solution corresponding to the cause is presented. The new probability of occurrence is then calculated. The obtained result is compared to the initial probability and a set of protection system is proposed. The advantage of this study is the possibility to reduce the occurrence of the ferroresonance by gathering the maximum detailed amount of possible causes and by choosing the best barrier corresponding to the cause. [ABSTRACT FROM AUTHOR]

Wind is one of the most widely used non-conventional sources of energy. The majority of wind farms use a variable speed Wind Turbines Generator (WTGs) equipped with Doubly-Fed Induction Generator (DFIG) due to their advantages over other WTGs. The analysis of Wind Energy (WE) dynamics with the DFIG – Wind Turbines (WTs) has become an interesting research issue during transient faults. This paper investigates the effects of the different faults on transient stability. The analysis is performed on a 6-bus test system during transient faults and loss of excitation in synchronous generators. The stator-flux oriented vector control approach used for both stator and Rotor Side Converter (RSC) is proposed to mitigate DFIGs impacts on the system stability. The dynamic performance of DFIG variable speed WT under faults conditions are simulated using Neplan® program, considering different disturbance natures. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present a command approach of a typical double-stage grid-connected PV system functioning under normal conditions and Symmetrical Grid Voltage Dips (SGVD). In Normal Operation Mode (NOM), the command developed rises the relatively low solar voltage to a suitable level corresponds to the Maximal Power Point Tracking (MPPT) and regulates, respectively, the dc-link voltage and the output inverter currents. It permits to inject energy into the grid at unity power factor and a current with low harmonic distortion. Under SGVD, the control strategy approach should ensure a stable connection as long as possible and inject some reactive power to support the grid faults. This command calculates dynamically active and reactive powers that inverter can deliver according to the level of voltage dips and inverter rating currents. Those values are used as reference to control output inverter currents, the dc-link voltage and to deactivate the MPPT command. To validate and to prove the effectiveness of the control strategy, some experimental results are also presented. [ABSTRACT FROM AUTHOR]

Metaheuristic Optimization Techniques (MOTs) such as the Artificial Bee Colony (ABC) algorithms and Grey Wolf Optimizer (GWO) can be conveniently used for reaching the Maximum Power Point Tracking (MPPT) of Wind Energy Conversion System (WECS). This paper presents an enhanced control strategy for both Rotor Side Converter (RSC) and Grid Side Converter (GSC) of the Doubly Fed Induction Generator (DFIG)-based WECS using the ABC and the GWO algorithms to ensure the MPPT for the WECS. The control strategy for the RSC and GSC are verified via 9 MW DFIG Wind Turbine (WT) using MATLABTM/Simulink. The dynamic performance improvement of the DFIG depends on the appropriate choice of the optimal PI controllers' gains. The numerical simulation results show the superiority of the proposed GWO-PI and the ABC-PI optimal controllers over the traditional PI regulators towards enhancing the DFIG system dynamic performance. [ABSTRACT FROM AUTHOR]

Modern power conversion devices have realized several significant attributes such as high efficiency and reliability for high power (HP) applications. Traditionally, boost converters (BC) are required to operate as an intermediate interface to drive high power loads through available low voltage (LV) sources such as a fuel cell (FC), photovoltaic or battery based energy system. This paper addresses the complementary operation of parallel connected boost converters (PCBC) for high power applications considering wide spectrum of low voltage source conditions. The mutual sharing of load current between parallel connected converters is guaranteed by the appropriate placement of LC based passive equalization filter (LCEF) therefore offloading stress from individual converter and increasing efficiency and reliability drastically. To validate the performance of proposed topology in real-time scenarios, an experimental setup consisting of programmable source, electronic load, boost converters and filter circuit has been synthesized and studied in various operating conditions such as FC energy system based HP and LV application. The experimental results clarifies and validates the necessity of parallel connected converters based power splitting strategy and LC equalization filter topology for high power loads especially with low voltage source conditions. [ABSTRACT FROM AUTHOR]

This paper proposes technical guidelines, modelling, and control of an ultra-high-speed-switched reluctance motor- generator for automotive turbo-charged assistance and energy recovery. Creation of an ideal model using electromagnetic finite element analysis and conducting a low cost/ low scale experiment is proposed. The first objective focuses on the transient simulation process. The second objective focuses on an investigation of the proposed control criteria. The modelling and analysis of a "Switched Reluctance Motor" (SRM) is an initial task for the selection of the coupled mover. Two controllers are selected for the experiment which consists of a generally low-cost solution and an optimized development board for prototyping optimization. The low-cost control solution is implemented with an Arduino Uno and an assortment of relays configured into an asymmetrical half bridge. The second controller is the "Digilent Zed Board Zynq-7000 ARM/FPGA SoC Development Board" (Zed board). ANSYS 2D, 3D modelling, data simulation for the stator and rotor are implemented. Current, voltage, and flux for all phases waveforms are included. Rotor dynamic simulation, machine transient simulations, and some other characteristics are depicted through 3D figures. [ABSTRACT FROM AUTHOR]

Finding solutions for energy saving has become one of the most demanding issues facing almost all the governments, decision makers and stakeholders all over the world. Energy saving solutions in building industry could be applied in all the construction phases – Pre-design, design, pre-construction, construction, and post-construction. Energy management in the post-construction (operation) phase - in particular - is the key point for energy saving. This paper is focusing on employing green rating systems to guide the process of the commissioning for buildings in order to save energy during the operation and maintenance of buildings. Moreover, the research highlights on the important process that should be taken into consideration during the other phases. LEED (Leadership for Environmental and Energy Design) is suggested and discussed here in order to be employed in this regard. The LEED fundamental commissioning system is discussed briefly while a detailed explanation for the processes, tasks and responsibilities of each stakeholder in building projects is presented. Commissioning helps to review Design Documentations and make recommendations to the design team and pertaining to functionality and workability of commissioned systems. In addition, it aids to review Owner Project Requirements (OPR) and Basis Of Design (BOD). This ensures the achievement of high levels of professionalism and technicalities in the different construction phases of buildings. The paper presents at the end a designed chart for the entire commissioning processes that can aid the process of assuring energy efficiency in buildings. [ABSTRACT FROM AUTHOR]

Abstract The poultry industry generates a large quantity of litter, which consists of a mixture of manure, waste bedding and feathers, and can be used for recovery of energy. Recent studies suggest that gasification is a promising technology for an effective conversion of poultry litter to energy. This paper aims to assess the environmental impacts of generating electricity from the gasification of poultry litter in a small-scale integrated gasification combined cycle (IGCC) plant. Gasification of poultry litter has been simulated with ASPEN Plus® software and life cycle assessment has been used to determine the carbon footprint and primary energy demand of the system. The following life cycle stages have been considered: collection and storage of poultry litter, its gasification, syngas cleaning, production of electricity and co-production of ash as a fertiliser. The carbon footprint and primary energy demand of generating 1 kWh of energy by poultry litter gasification plant are estimated at 42 g CO2 eq./kWh and 0.14 MJ/kWh, respectively. Compared to electricity from fossil fuels, this system has 91%-96% smaller carbon footprint and 98%-99% lower primary energy demand. The energy payback period is estimated at 1.5 years. [ABSTRACT FROM AUTHOR]

Abstract The global production of poultry is predicted to grow considerably in the future. Intensive poultry farming poses significant challenges to traditional waste disposal methods (i.e. direct land application) leading to environmental impacts. This paper discusses the result of low temperature (350-450 °C) pyrolysis of representative chicken litter as the feedstock. Four different feedstocks comprised of 50% organic chicken manure and 50% bedding materials (i.e. hay, straw, rice husk and wood shavings) have been experimentally investigated. The products of the pyrolysis process consist of char, gas and liquid (bio-oil). Maximum char production from the rice husk mix is over 67 wt.%, while the wood shavings mix feedstock resulted in the highest liquid yield of 44.4 wt.% at a temperature of 400 °C. Chicken litter and its char product are analysed by elemental analyser and bomb calorimetry. The composition of the evolved gases and bio-oil are analysed by micro gas chromatography (µ-GC) and gas chromatography-mass spectrometry (GC-MS), respectively. In addition, the mass and energy balance of the pyrolysis process are presented. [ABSTRACT FROM AUTHOR]

Abstract Nowadays, all industry, including the agri-food sector, faces the urgent need to increase its competitiveness in order to survive in a global market. In this context, it is vital to ensure a strong, renewed and innovative industrial base throughout all stages of the value chain, capable of competing internationally and differentiating itself by the quality of its products and services. Since wealth generation cannot be dissociated from productivity, which in turn is closely related to the trinomial: processes, technologies and quality, it is concluded that the implementation of this strategy requires a commitment to the qualification of organizational management, operational management, project management and processes and productive systems themselves and associated technologies. This paper presents the characterization of the energy consumption and technologies in bakery and pastry sector, one of the most significant in the Portuguese agri-food sector. [ABSTRACT FROM AUTHOR]

Abstract Instant coffee manufacture involves the aqueous extraction of soluble coffee components followed by drying to form a soluble powder. A challenge that arises from the process is the loss of volatile aroma compounds during evaporative drying. One method of retaining aroma is to first steam strip the volatiles from the coffee and add them back to a concentrated coffee solution just before the final drying stage. Understanding the impact of process conditions on the aroma content of the stripped solution offers engineers the ability to target desirable compounds and maximise their yield. This paper presents a multiscale model for aroma extraction that describes: (i) release from the matrix, (ii) diffusion through the coffee grain, (iii) transfer into water and steam, and (iv) advection through the stripping column. Results reveal how aroma physiochemistry determines the limiting kinetics at industrial extraction conditions. The interaction with the soluble matrix can also inhibit extraction, but this effect varies for the different aromas studied. [ABSTRACT FROM AUTHOR]

Abstract Reducing food waste and increasing resource efficiency have become worldwide targets as highlighted by the United Nations Sustainable Development Goal 12 – Responsible consumption and production. Food packaging, in particular plastics-based, is a key component of food-related waste: packaging increases the amount of total waste, but also reduces potential food waste by protecting food products and prolonging their shelf life. Therefore, it is important that packaging is designed as to satisfy both technical and environmental criteria. Hence, this paper seeks to develop a decision-support framework and key metrics to aid development and selection of new innovative food packaging within a circular economy context. A set of indicators is proposed, integrating techno-environmental and circular economy criteria to help designers as well as food and packaging manufacturers develop more sustainable products. The methodology is illustrated through a prototype new plastic packaging developed as part of this project, considering its use for two types of product – raspberries and meat – as illustrative examples. [ABSTRACT FROM AUTHOR]

Abstract In 2017, 11.41 million refrigerators and 1.85 million freezers were sold in USA alone; each unit consuming approximately 500 kWh/year with an average life expectancy of 12 years. Traditionally, fridges and freezers have been insulated with polyurethane foam (thermal conductivity >0.020 W/m.K). There is a significant scope of reducing the heat gain by the cooled interior space from external environment by employing better insulation materials such as vacuum insulation panels (VIPs) than polyurethane foam. VIPs can achieve a thermal conductivity of <0.002 W/m.K. This paper presents an overview of heat transfer theory for VIPs and historical research into VIPs suitable for fridges, freezers and reefer trucks. A refrigerator with 56% of its external surface area covered with VIPs is reported to reduce the energy consumption by 21% compared to that consumed when using polyurethane foam. This means a potential energy saving of 1260 kWh p over the lifetime of a refrigerator and 5 billion kWh p if 25% of all fridges were VIP insulated. A proportionate reduction in the concomitant carbon emissions is predicted. [ABSTRACT FROM AUTHOR]

Abstract In this paper, the performances of a typical R744 booster configuration, a R744 parallel-compressor booster refrigeration system, and a R717/R744 cascade system configuration are presented based on the 1st and 2nd law of thermodynamics, for food retail applications. The results for a supermarket application with a total 145 kW cooling capacity show that the typical booster system and parallel-compressor booster system have better performances than the cascade system. However, for convenience store applications with 30 kW total cooling capacity the cascade system shows better performance beyond 26 °C ambient temperature which limits the applications of the cascade system for low capacity systems and the parallel refrigeration system solution appears to be a better option. In addition, the most critical components of each system based on the 2nd law are identified in this paper. [ABSTRACT FROM AUTHOR]

Abstract This paper compares three different natural refrigerants based system configurations in terms of cooling performance, total equivalent warming impact per year and annual power consumption for the proposed refrigeration systems. Two different cooling load levels were selected to represent a typical supermarket and a convenience store applications. The systems selected in this study include the R717/R744 cascade system configuration, a typical R744 booster configuration and a R744 parallel-compressor booster refrigeration system. The weather conditions of London, UK and Larnaca, Cyprus, were used for the modelling of energy consumption and environmental impacts to represent moderate and warm climatic conditions respectively. [ABSTRACT FROM AUTHOR]

Abstract As a main component in a refrigeration system, finned-tube CO2 gas cooler plays an important role to the system performance and thus needs to be thoroughly investigated. To achieve this, some effective parameters including the CO2 and air fluid velocity fields, temperature profiles and heat transfer characteristics at different operating conditions are predicted and analysed by means of Computational Fluid Dynamics (CFD) modelling and simulation. It is noted that CFD modelling can accurately obtain the local heat transfer coefficients of both air and refrigerant sides, which are difficult to be predicted by conventional empirical correlations. This paper investigates the effect of varied operational parameters on local heat transfer coefficients and temperature profiles of the working fluids in a finned-tube CO2 gas cooler by means of CFD modelling. As one of the simulation results, it is found that the approach temperature decreases with increased air inlet velocity. The model has been compared and validated with experimental measurements and literature correlations. The research methods and outcomes can be used for further investigation and optimization in this area. [ABSTRACT FROM AUTHOR]

Abstract The Circular Economy is an economic and industrial system in which resources are used for as long as possible. This typically involves businesses implementing a range of alternative business models, such as remanufacture. With the manufacture of Refrigerated Display Cabinets (RDCs) being a material and energy intensive process, there is scope for remanufacturing to support a more resource-efficient production of RDCs. Despite the potential, the remanufacture of RDCs in the UK is uncommon. Many Retailers and RDC Manufacturers typically have unfavourable attitudes towards the purchase and production of remanufactured RDCs. However, more favourable attitudes could increase their Behavioural Intentions towards the purchase and production of remanufactured RDCs, which could lead to the adoption of remanufacturing across the industry. This paper gives an overview of interventions that could be implemented to encourage Retailers and RDC Manufacturers to adopt the pro-circular behaviours. The three interventions discussed in this paper are: Financial Incentives, Quality Standards and Process-Supporting tools. [ABSTRACT FROM AUTHOR]

Abstract An approach considered in recent years to improve the efficiency of open-type refrigerated display cabinets is to install air guiding strips at the front face of the shelves with a single layer air curtain. This paper presents experimental results comparing a conventional open-type vertical refrigerated cabinet and a cold shelf innovation, which integrates both air-guiding strips and air supply at the front of individual shelves. In addition, a comprehensive and detailed Computational Fluid Dynamics model using ANSYS Fluent has been created to further investigate the influence of the cold shelve innovation on the performance of vertical multi-deck refrigerated display cabinets. The experimental results showed energy savings of 16.7 kWh/24 hrs for the guiding strips and cold shelf innovation compared to the conventional cabinet due to the more efficient air curtain and lower air temperature entering the evaporator coil. [ABSTRACT FROM AUTHOR]

Abstract The paper presents the development of an experimental research facility based on a transcritical single stage vapour compression refrigeration cycle with CO 2 as the working fluid. The experimental setup includes instrumentation and controls which enable tests in a broad range of operating conditions. The measurements presented refer to external temperatures between 21.0°C and 33.5°C; in this latter operating point, energy and exergy analysis allowed the breakdown of irreversibilities. In particular, the gas cooler contributes to the 42.6% of the total exergy losses while the share due to the high-pressure expansion valve is 27.2%. In order to improve the performance of the refrigeration system, a theoretical model was developed including an ejector as the replacement of the expansion valve. The results show that the Coefficient of Performance (COP) is strongly dependent on the entrainment ratio; a value of greater than 0.6 seem to lead to higher COP values, even at low external temperatures. [ABSTRACT FROM AUTHOR]

Abstract The dairy processing and slaughterhouse industries consume large volumes of water and their waste effluents often contain high levels of chemical oxygen demand (COD), biochemical/biological oxygen demand (BOD) and fertilising nutrients. Therefore, water treatment is necessary to reduce the levels of these contaminants prior to discharge or reuse of the water. In this short review paper we provide a brief overview of electrocoagulation (EC) technology and summarise the current literature relating to the use of EC treatment to clean dairy processing and slaughterhouse wastewaters. [ABSTRACT FROM AUTHOR]

Abstract The human relationship with food is an under-acknowledged contributor towards climate change and environmental degradation. However, citizens' choices and actions regarding food consumption and production in urban settings are shaped by the economic, cultural and infrastructure systems in which they live. The purpose of this paper is to examine, from the perspective of prosumers, the socio-technical factors that affect urban food production and associated energy, water and waste services. A residential development on the urban fringe of Australia's subtropical Gold Coast was used as a case study. A mixed methods approach was utilised to gather quantitative and qualitative data through estate maps, development planning documents, visual observations, interviews and surveys. Data was analysed around the themes of food production, consumption and development infrastructure (physical and social). The estate's food production demonstrated high biodiversity and highlighted three common challenges: biological, knowledge and water/climate. Food consumption incorporated self-consumption, sharing/trading and a range of other typical and atypical sources found in cities. An integrated approach to land-use, energy, water and waste was instrumental in enabling food production, highlighting issues that affect the ability of urban prosumers to incorporate sustainability into their food practices. The paper raises the possibility of a 'sharing-economy' food production typology for urban areas and proposes an initial performance indicator framework (people, planet, prosperity, governance and propagation) to understand, develop and manage urban prosumers in the context of integrated energy, water, waste and food services. [ABSTRACT FROM AUTHOR]

Abstract The purpose of this paper (parts I and II) is to examine the socio-technical factors that affect urban food production and associated energy, water and waste services. Part I introduced the growing role of prosumers, discussed the context of the human relationship with food and demonstrated how citizens' choices and actions regarding food consumption and production in urban settings are shaped by the economic, cultural and infrastructure systems in which they live. A residential estate on the urban fringe of Australia's subtropical Gold Coast was described, setting the context for a mixed methods analysis of quantitative and qualitative data gathered through estate maps, development planning documents, visual observations, interviews and surveys. Part II presents the results, analysed around the themes of food production, consumption and development infrastructure (physical and social). An integrated approach to land-use, energy, water and waste was instrumental in enabling ubiquitous high biodiversity food production, highlighting planning decisions that affect the ability of urban prosumers to incorporate sustainability into their food practices. The case study demonstrates that an integrated approach to urban infrastructure can support and enable urban prosumer food practices. A framework to evaluate urban neighbourhoods in terms of potential for creating synergies between land use, water, waste and energy infrastructure is presented and an initial performance indicator framework is proposed, to understand, develop and manage prosumer-driven urban agriculture in the context of integrated energy, water, waste and food services. [ABSTRACT FROM AUTHOR]

Abstract This paper presents systematic design procedure and features of a sun simulator developed for testing low concentrating linearly focusing solar photovoltaic concentrators. The designed solar simulator comprises of a xenon short arc lamp and paraboloidal reflector for uniform radiative flux distribution on focal plane at desired radiation intensity. Initial inputs to the design process include reflector geometry (shape and size), surface properties of the reflector surface (reflectivity), distance of the reflector aperture from the illuminated area, rated lamp power, lamp geometry and orientation. These specifications were inputted in a ray tracing analyzer using COMSOL Multiphysics. The angular distribution of radiative intensity from the lamp was also accounted for. The proposed design is able to deliver a radiative intensity of 500 W/m2 to test photovoltaic concentrators with aperture of up to 140 mm x 50 mm with a spatial non-uniformity of 4.5%. [ABSTRACT FROM AUTHOR]

Abstract Thermal energy storage (TES) using phase change materials (PCMs) is a dynamically growing research area. The interest in this research field can be illustrated by the increasing number of research papers published in the last few years. In this comprehensive paper the latest reports in the field of phase change materials studies and their application in thermal energy storage are discussed. Main review articles on PCMs properties and applications are provided. Special attention is given to very recent publications providing information on PCMs nano, micro and macro encapsulation as well as on materials aspects critical for PCMs application in TES. This paper may be a useful guide for the researchers towards a short overview of current status of PCM science and technology. [ABSTRACT FROM AUTHOR]

Abstract This paper focuses on predicting centrifugal compressor performance in the supercritical region of real gas. For this purpose, thermodynamic changes have been considered in the sub-regions of the supercritical space. It is known that some properties (e.g. compressibility or density) of supercritical fluids behave anomalously in a narrow temperature-pressure band, shaped by pseudocritical lines, which start at the critical point and extend to higher T and P values. To accurately predict the performance of supercritical carbon dioxide (sCO 2) turbomachinery, the fluid behavior, in three regions (liquid-like, pseudocritical and vapour-like) created by pseudocritical lines, should be considered. For this purpose, computational fluid dynamics (CFD) is employed to calculate compressor performance in different regions of the supercritical space. The selected compressor geometry is the compressor impeller tested in the Sandia sCO 2 compression loop facility. The results illustrate that operating points in the liquid-like region achieve the highest pressure rise. In addition, fluctuations in two fluid properties, density and speed of sound, have been observed wherever their pseudocritical lines have been crossed. However, the reason for these variations needs more investigation. The study considers the sudden changes occurring in the supercritical region and should lead to more accurate prediction of compressor performance,. [ABSTRACT FROM AUTHOR]

Abstract This paper addresses the need of bridging between fundamental energy research and industrial exploitation of technologies by presenting a state of the art experimental facility to investigate pilot heat exchangers and plants dealing with high temperature waste heat recovery and conversion. The facility comprises a 830 kW process air heater with an exhaust mass flow rate of 1.0 kg/s at 70 mbar g and maximum temperature of 780 °C. The heater has a 2.0 m long test section for the installation and characterization of waste heat recovery heat exchangers. The heat sink is a 500 kW water dry cooler with full control of flow rate and temperature of the cooling stream. The high-temperature heat to power conversion facility hosts a 50 kWe power conversion unit based on the simple recuperated Joule-Brayton cycle with supercritical CO 2 (sCO 2) as working fluid. The packaged, plug and play sCO 2 system utilizes a single-shaft Compressor-Generator-Turbine unit. The paper discusses the main design features of the test facility as well as operation and safety considerations. [ABSTRACT FROM AUTHOR]

Abstract The paper focuses on understanding the performance of a vaned diffuser in a supercritical CO 2 compressor using real gas assumptions. The rapidly changing properties of CO 2 in the non-ideal thermodynamic region can have a significant impact on the performance of the diffuser. To account for this, the relationship between the flow properties (i.e. fundamental derivative) and the local geometry (i.e. cross-sectional area of the nozzle) has been discussed theoretically. To examine it analytically, the study has considered the influence of real gas properties on the performance of a vaned diffuser using computational fluid dynamics (CFD) modelling. The selected compressor stage geometry is similar to the compressor impeller tested in the Sandia sCO 2 compression loop facility. The effect of changes in the number of blades and the corresponding changes in the cross throat area on the flow properties such as density and speed of sound were investigated and discussed. The results illustrate that a diffuser with a higher number of blades (smaller throat area) compared to a diffuser with a wider throat area has a higher probability of creating flow instability in the passage stage. [ABSTRACT FROM AUTHOR]

Abstract Carbon dioxide (CO 2) is becoming an important commercial and industrial working fluid as a potential replacement of the non-environmental friendly refrigerants. For refrigeration and power systems, the minichannel heat exchangers are becoming attractive for transcritical CO 2 Rankine cycle and supercritical CO 2 Brayton cycle, due to their highly compact construction, high heat transfer coefficient, high pressure capability and lower fluid inventory. This paper employs three-dimensional numerical models to investigate the heat transfer and pressure drop characteristics of supercritical CO 2 in minichannels. The models consider real gas thermophysical properties and buoyancy effect and investigate the effect of cross-section geometry on the thermohydraulic characteristics. Six minichannel cross-section geometries with the same hydraulic diameter of 1.22 mm are considered. The geometries include circle, semicircle, square, equilateral triangle, rectangle (aspect ratio = 2) and ellipse (aspect ratio = 2). The inlet temperature, outlet pressure and wall heat flux are 35 °C/75 bar/100 kW/m2 and 35 °C/150 bar/300 kW/m2 for heating conditions and 120 °C/75 bar/-100 kW/m2 and 120 °C/150 bar/-300 kW/m2 for cooling conditions. Comparisons of local Nusselt number and friction factor with those employed empirical correlations are made and useful information and guidelines are provided for the design of compact heat exchangers for supercritical CO 2 power system applications. [ABSTRACT FROM AUTHOR]

Abstract This article summarizes the design, the manufacturing and the testing of a small scale Organic Rankine Cycle using Concentrated Solar Power as the heat source. First, the choice of the nominal point of the cycle is detailed, including the operating environment of the ORC (characteristics of the solar field and ambient temperature) and the constraints of operation. The paper presents the design of a radial turbine with a power of 3 kW and the numerical simulations of flow in the fluidic part of the turbine (nozzle, wheel etc). It also deals with system engineering, the calculation and the selection methodology of main components such as exchangers, pumps, and sensors. In the second part, the results of the laboratory tests is presented. The experiment was performed using as hot source, a thermal oil boiler. The analysis of the results shows isentropic efficiency around 40% on a rather large range of pressure drop, and a cycle efficiency of 5 % which, is encouraging in view of the first test conditions. [ABSTRACT FROM AUTHOR]

Abstract The printed circuit heat exchanger is currently the preferred type of recuperative heat exchanger for the supercritical CO 2 Brayton cycle due to its highly compact construction, high heat transfer coefficients and its ability to withstand high pressures and temperatures. This paper employs a three-dimensional numerical model to investigate the thermohydraulic performance of supercritical CO 2 flow in a printed circuit heat exchanger. This numerical model considers entrance effects, conjugate heat transfer, real gas thermophysical properties and buoyancy effects. The inlet temperature and pressure are 100 °C/150 bar on the cold side and 400 °C/75 bar on the hot side while the mass flux is varied from 254.6 to 1273.2 kg/(m2·s). The overall performance of the heat exchanger and comparisons of local heat transfer and friction pressure drop with predictions from the empirical correlations are presented and discussed. Overall, this paper provides useful information that can be employed in the design of recuperators for supercritical CO 2 Brayton cycle applications. [ABSTRACT FROM AUTHOR]