An innovative tool to evaluate and optimize GHG emissions in the food supply

Food systems’ contribution to GHG emissions is estimated to be around 30% of the total emissions. Heating and cooling technologies in food supply chains are highly important in maintaining the safety and quality of perishable food, but these operations are also energy-intensive and GHG emitters. Simulation tools can be essential for the evaluation of the efficiency and sustainability of food supply chains. Such tools can help in identifying critical points in those chains where efforts should be concentrated to reduce energy consumption and emissions. The software tool presented in this paper can perform a detailed analysis of the food supply chains with a focus on quality, energy consumption, and CO2 emissions. Based on a tool previously developed in the European FRISBEE project about refrigeration technologies, the software is extended to the simulation of non-perishable foods, heating processes, use of renewable energy sources, and use of heat recovery. This simulation tool will suggest possible improvements of simulated chains to reduce GHG emissions, based on roadmaps developed in ENOUGH European project

Energy savings potential using the thermal inertia of a low temperature storage

24ième Congrès International du Froid ICR 2015, Yokohama, JPN, 16-/08/2015 - 22/08/2015International audience50% of the energy consumed in food cold chain are for chilling, freezing and storage steps. For cold storage facilities, refrigeration is the main source of energy consumption with an average of 50 kWh/m3/year. A possible strategy to reduce their energy consumption is to take advantage of the variation of performance of the refrigeration systems during a day due to external and internal temperature variations. Electricity cost can also widely change during a day, depending on the local production. This strategy can be based on additional storage capacities to delay the refrigeration running period, but also on the use of the thermal inertia provided by the storage warehouse itself and the products stored. An experimental test has been performed in a frozen warehouse storage facility to evaluate the potential energy savings of such a strategy. Using coupled models of the building, products and refrigeration system, using weather forecasts and products flux statistics, a predictive control algorithm was developed and applied to determine periodically the optimal set-points of the storage warehouse. Technical implementation of the control system is presented. Energy savings potential and impact on products of the temperature fluctuations are also discussed

Model of a continuous crystallization process for a sorbet by the moments methodology

La etapa de precongelación es un importante paso en el proceso de manufactura de helados y sorbetes dado que las condiciones de operación tienen una fuerte influencia sobre la microestructura y por consecuencia sobre los atributos sensoriales del producto final. Esta etapa de precongelación es llevada a cabo en un intercambiador de calor de superficie raspada donde la calidad del producto es fuertemente influenciada por las condiciones de operación tales como la temperatura de evaporación de un refrigerante, el gasto másico de la alimentación, la velocidad del raspador y una presión provocada por la introducción de aire. Con la finalidad de estudiar la pertinencia de un sistema de control basado en la influencia de las variables del proceso sobre la calidad del producto, este trabajo presenta un modelo para una cristalización continua de un sorbete utilizando la metodología de momentos, el cual es validado con datos experimentales. El modelo realizado por esta metodología de momentos es capaz de representar la influencia de las condiciones de operación durante la cristalización de sorbete sobre las características finales del producto tales como el tamaño de cristal y la temperatura de salida del intercambiador de superficie raspada (ICSR) en ausencia de aire. El modelo basado en momentos se estudia, entonces, como la reducción del modelo de la ecuación de balance de población e incluye los fenómenos de nucleación heterogénea y crecimiento. De este modo, el modelo desarrollado representa requerimientos computacionales mínimos y está altamente adaptado para tareas de optimización y/o control del proceso.Freezing is an important step in the manufacturing process of ice-cream and sorbet, since the operating conditions have a strong influence on the micro-structure, and consequently on the sensorial attributes of the final product. This steep of freezing is carried out by a scraped surface heat exchanger (SSHE) where the product quality is conditioned by process conditions as the evaporation temperature of a refrigerant fluid, the mix flow rate, the dasher speed and the cylinder pressure due to the air introduction. In order to study the relevance of a control system based on the influence of process variables on product quality, this paper presents a model for a continuous crystallization of a sorbet using the method of moments, which is validated by experimental data.The model created by this methodology has been able to represent the influence of the process conditions during the crystallization of the sorbet on the final product characteristics such as crystal size and the draw temperature in the outlet of the SSHE in absence of air. The model based in moments is studied as a reduced model of the population balance equation and includes the phenomena of heterogeneous nucleation and growth. This model developed represents minimal computational requirements and is highly adapted for optimization and/or process control tasks.Peer Reviewe

Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated by Joule effect

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]SPEEInternational audienceA methodology has been developed based on periodic excitation by Joule effect and infrared thermography measurement. It has been applied to measure heat transfer coefficients of water flowing in a round tube and in a multiport-flat tube. Models were developed to deduce heat transfer coefficient from wall temperature amplitude and heat flux measurement. For the round tube and for the multiport flat tubes, Reynolds number investigated ranges respectively from 2000 to 14000 and from 800 to 10000 and heat flux from 5 W to 29 W and from 10 W to 70 W. The good agreement between experimental and theoretical results has demonstrated the reliability of the methodology. This methodology also present the advantage to require a low heat flux, is not intrusive and fluid independant

Life cycle assessment of salmon cold chains : comparison between chilling and superchilling technologies

24ième Congrès International du Froid ICR 2015, Yokohama, JPN, 16-/08/2015 - 22/08/2015International audienceThe cold chain is defined as a set of refrigeration steps that maintain the quality and safety of food product. Refrigerant leakage and the use of fossil fuels to produce electrical power for refrigeration equipment contribute greatly to ozone depletion and global warming. Thus, new and emerging refrigeration technologies are developed to provide better energy efficient and environmentally friendly alternatives to current technologies. Superchilling is a concept where the temperature is reduced 1-2 °C below the initial freezing point of the product. The small amount of ice formed within the product (10-15%) serves as a heat sink, eliminating the need for ice during storage and transport. In this work, Life Cycle Assessment (LCA) is applied to the chilling and superchilling salmon cold chains. The superchilling cold chain presents an important improvement compared to the chilled one because of the augmentation of available volume for transportation

Energy mapping of large refrigerated warehouses co-located with renewable energy sources across Europe

Powering refrigerated warehouses by renewable energy sources (RES) turns from an extravagancy to a routine. RES intermittency requires suitable energy storage for both off-grid and on-grid applications. Cryogenic energy storage, integrated synergistically with RES and large refrigerated warehouses, is a promising environmentally friendly technology (addressed by the EU CryoHub project). Hence, studies were carried out to identify where large energy-intensive refrigerated warehouses are situated across Europe and how much power they consume. By employing diverse instruments and data sources, some 1049 warehouses were established, while 503 energy intensive ones were mapped and further co-located with 3200 solar PV and 11700 onshore wind parks to discover the best areas for RES integration across EU28. As compared with similar international surveys, the CryoHub statistics covers simultaneously warehouse capacity, geographical location and energy data, which permit a comprehensive analysis and strategic planning in both food refrigeration and energy sectors

Multi-objective optimization of storage temperature of apple to minimise energy use

Low temperature storage is widely employed to increase the storage life of apples. However, the use of refrigeration accounts for up to 15% of the global use of electricity. Increasing the storage temperature by 1°C can significantly reduce the total cost of electricity during apple storage. In this study, a multi-objective optimization approach is used to suggest new storage temperature of apple, taking into consideration the cost of electricity and the quality of the apple at the end of storage. Energy use was calculated using vapor pressure compression cycle models. Apple firmness was selected as the most important quality indicator for apple grading. The quality of the apple at the end of storage was converted to money value in €, based on the current grading system of apples in Belgium. Firmness was calculated using the firmness model developed by Gwanpua et al. (2012).The objective was to optimize storage temperature by minimizing the electricity usage, while minimizing quality losses (i.e. by maximizing the money value of the apple at the end of storage). This was done for different storage duration, and also for cool rooms with different storage capacity. New storage temperatures of apple, that will reduce the use of energy, were suggested

Neurospora from natural populations: Population genomics insights into the Life history of a model microbial Eukaryote

The ascomycete filamentous fungus Neurospora crassa played a historic role in experimental biology and became a model system for genetic research. Stimulated by a systematic effort to collect wild strains initiated by Stanford geneticist David Perkins, the genus Neurospora has also become a basic model for the study of evolutionary processes, speciation, and population biology. In this chapter, we will first trace the history that brought Neurospora into the era of population genomics. We will then cover the major contributions of population genomic investigations using Neurospora to our understanding of microbial biogeography and speciation, and review recent work using population genomics and genome-wide association mapping that illustrates the unique potential of Neurospora as a model for identifying the genetic basis of (potentially adaptive) phenotypes in filamentous fungi. The advent of population genomics has contributed to firmly establish Neurospora as a complete model system and we hope our review will entice biologists to include Neurospora in their research

Hybridization and adaptive evolution of diverse Saccharomyces species for cellulosic biofuel production

Additional file 15. Summary of whole genome sequencing statistics

A quality, energy and environmental assessment tool for the European cold chain

According to 5th Informatory Note on Refrigeration and Food published by the International Institute of Refrigeration, 20% of the global losses in perishable products was due to lack of refrigeration. It is expected that increased use of refrigeration to reduce these losses will help meet the increasing food demands of the growing world population. However, the use of refrigeration already accounts for about 15% of world’s electricity usage. In addition, the use of refrigeration significantly contributes to global warming via emission of CO2. In this paper, a software tool was developed to assess food quality and safety evolution, energy usage and CO2 emission of different refrigeration technologies along the European cold chain. A reference product was chosen for the main different food categories in the European cold chain. Software code to predict the products temperature using the room temperature as input, based on validated heat and mass transfer models, were written in Matlab (The Mathworks Inc., Natick, USA). Also, based on validated kinetic models for the different quality indicators of the reference products, a software code was written to calculate the quality and safety evolutions of the food product, using the predicted product temperature as input. Finally, software code to calculate the energy usage and Total Equivalent Warming Impact (TEWI) value of different refrigeration technologies was also written in Matlab. All three software codes were integrated, and a graphical user interface was developed. Using the graphical user interface, a user can tailor a cold chain scenario by adding different cold chain blocks. Each cold chain block has properties that can be modified. The tool can be used to compare different cold chains with respect to quality, safety, energy usage, and environmental impact