Andrés Urrutia - Academia.edu (original) (raw)

Papers by Andrés Urrutia

Fluids

The fluidization of certain biomasses used in thermal processes, such as sawdust, is particularly... more The fluidization of certain biomasses used in thermal processes, such as sawdust, is particularly difficult due to their irregular shapes, varied sizes, and low densities, causing high minimum fluidization velocities (Umf). The addition of an inert material causes its Umf to drop significantly. The determination of the Umf of the binary mixture is however hard to obtain. Generally, predictive correlations are based on a small number of specific experiments, and sphericity is seldom included. In the present work, three models, i.e., an empirical correlation and two artificial neural networks (ANN) models were used to predict the Umf of biomass-inert mixtures. An extensive bibliographical survey of more than 200 datasets was conducted with complete data about densities, particle diameters, sphericities, biomass fraction, and Umf. With the combined application of the partial dependence plot (PDP) and the ANN models, the average effect of sphericity on Umf was quantitatively determined ...

IOP Conference Series: Earth and Environmental Science, 2022

In recent years, local microbreweries are increasingly capturing the consumer’s interest with a w... more In recent years, local microbreweries are increasingly capturing the consumer’s interest with a wide range of different types of beer. Because of the insertion of microbreweries scattered around the country, large amounts of spent grains have been made available locally to be used, for instance, as animal feed. However, those spent grains, which are mainly formed by malting barley (or malt), are materials suitable for further valorization. Turning the spent grains from waste to a raw material that can be later used to produce non-traditional flour requires a thermal treatment, i.e. a drying process. A natural convection solar dryer (NCSD) was evaluated as an alternative to a conventional convective electric drying system for the dehydration process of local microbrewer’s spent grains. Two types of breweries’ spent grains-BSG-(Golden Ale and Red Ale) were dried at different daytime hours. Sustainability indexes, Specific Energy Consumption (SEC), and CO2 emissions of the conventional...

Mecánica Computacional, Nov 17, 2019

Fluids, 2021

This work studies the performance of two open-source CFD codes, OpenFOAM and MFiX, to address bub... more This work studies the performance of two open-source CFD codes, OpenFOAM and MFiX, to address bubbling fluidized bed system at different temperature and heat transfer conditions. Both codes are used to predict two parameters that are relevant for the design of fluidized units: the minimum fluidization velocity as a function of the temperature of the bed and wall-to-bed heat transfer coefficient from a lateral wall and from internal tubes. Although the CFD solvers are structuraly similar, there are some key differences (available models, meshing techniques, and balance formulations) that are often translated into differences in the fields prediction. The computational results are compared between both codes and against the experimental data. The minimum fluidization velocity can be correctly predicted with both codes at different temperatures while, in general, for the heat transfer and the fluidization patterns, MFiX shows slightly more accurate results compared to OpenFOAM but with...

Se utilizo la licencia academica del software ANSYS-Fluent 13.0 para simular el comportamiento de... more Se utilizo la licencia academica del software ANSYS-Fluent 13.0 para simular el comportamiento de una unidad de lecho fluidizado a escala laboratorio instalada en PROMES (Laboratoire PROcedes Materiaux et Energie Solaire), CNRS, Francia. Se llevo a cabo el estudio fluidodinamico del lecho fluidizado bajo diferentes condiciones operativas, tipicas de los procesos de incineracion de materiales tales como biomasa, carbon, residuos domiciliarios, entre otros. Se acoplo a este estudio el analisis termico del lecho debido a que resulta necesario el suministro de calor al mismo de manera de lograr una condicion termica adecuada para el desarrollo del proceso de incineracion. La temperatura de operacion de la unidad fluidizada experimental se mantiene mediante la accion de resistencias de potencia variable ubicadas alrededor de la pared del lecho. Para la fluidizacion se utiliza aire cuya temperatura de entrada puede seleccionarse mediante la activacion de un sistema calefactor secundario. ...

Fil: Reyes Urrutia, Ramon Andres. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Cen... more Fil: Reyes Urrutia, Ramon Andres. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Patagonia Norte. Instituto de Investigacion y Desarrollo En Ingenieria de Procesos, Biotecnologia y Energias Alternativas; Argentina. Universidad Nacional del Comahue. Facultad de Ingenieria; Argentina

Particulate Science and Technology, 2021

Particulate Science and Technology, 2020

Abstract An experimental fluid-dynamic study of sand-forest biomass mixture fluidization was cond... more Abstract An experimental fluid-dynamic study of sand-forest biomass mixture fluidization was conducted. Different proportions of biomass/sand were tested. Sawdust from the Abra Ancha sawmill, located in the town of Aluminé, Argentina, was adopted as the forest biomass material. In parallel, computational fluid dynamics (CFD) simulations of the fluidization process of these mixtures were performed to obtain exhaustive knowledge of their fluid-dynamic behavior. As a result, sand incorporation, even at low concentrations, reduces the cohesion and bonding forces between biomass particles and decreases the segregation and preferential channel formation in sawdust, thus improving fluidization. Satisfactory qualitative results were obtained in relation to the agitation state, bed expansion, and formation of bubbles in the different fluidized mixtures analyzed. The occurrence of two different fluidization regimes was confirmed in both the biomass and biomass-sand mixtures. This phenomenon allows the definition of the incipient ( ) and complete ( ) fluidization velocities. The potential of ANSYS-Fluent software as a simulation tool of sand-sawdust mixture fluidization was verified, and a suitable simulation methodology for predicting the minimum fluidization velocity was developed. This study constitutes the first and most indispensable stage to achieve complete simulation, including chemical reactions, of a sawdust fluidized bed gasification reactor.

Journal of Environmental Management, 2020

A macro-thermogravimetric analysis (macro-TGA) was applied to analyse the non-isothermal drying o... more A macro-thermogravimetric analysis (macro-TGA) was applied to analyse the non-isothermal drying of different bio-wastes (quince solid waste, grape marc and pumpkin shell from different enterprises located in San Juan Province, Argentina). The experimental data were obtained at three heating rates (5, 10 and 15 K/min) and two different initial moisture contents (30 and 50% w/w). These data were fitted using the Coats-Redfern and Sharp methods. The D2 model showed the best fitting for all experiments when using the Coats-Redfern method. It is assumed that drying occurs on the solid boundary. The predicted Ea values ranged from 43.60 to 64.50 kJ/mol for the three bio-wastes under the different experimental conditions. The Ea value slightly increases with the increase in heating rate because the wastes require more energy to undergo drying. Deff increases moderately with temperature at the beginning of the dehydration process; then, this increasing behaviour is significant due to the loss of continuous moisture channels. Otherwise, Deff increases with the initial moisture content, showing that the humidity of the samples did not reach the saturation content.

International Journal of Numerical Methods for Heat & Fluid Flow, 2019

Purpose The purpose of this study is to assess the performance of ANSYS Fluent® and OpenFOAM®, at... more Purpose The purpose of this study is to assess the performance of ANSYS Fluent® and OpenFOAM®, at their current state of development, to study the relevant bubbling fluidized bed (BFB) characteristics with Geldart A, B and D particles. Design/methodology/approach For typical Geldart B and D particles, both a three-dimensional cylindrical and a pseudo-two-dimensional arrangement were used to measure the bed pressure drop and solids volume fraction, the latter by digital image analysis techniques. For a typical Geldart A particle, specifically to examine bubbling and slugging phenomena, a 2 m high three-dimensional cylindrical arrangement of small internal diameter was used. The hydrodynamics of the experimentally investigated BFB cases were also simulated for identical geometries and operating conditions using OpenFOAM® v6.0 and ANSYS Fluent® v19.2 at identical mesh and numerical setups. Findings The comparison between experimental and simulated results showed that both ANSYS Fluent®...

El objetivo general de este trabajo consiste en proponer un esquema híbrido de dos componentes pa... more El objetivo general de este trabajo consiste en proponer un esquema híbrido de dos componentes para la generación de energía eléctrica: la primera componente consiste en un gasificador de lecho fluidizado para el tratamiento térmico de residuos de biomasa forestal; la segunda, compuesta por un colector energía solar de alta concentración. Ambos sistemas tienen el fin de elevar la temperatura de una suspensión densa de partículas de carburo de silicio que será finalmente utilizada para aportar el calor en un ciclo Rankine convencional destinado a generar potencia eléctrica preestablecida. Se construirán esquemas de simulación de ambas componentes, fundamentalmente en base a Fluidodinámica Computacional, apropiadamente validados por vía experimental. El planteo de los balances de masa y energía térmica en función de esa potencia, para cada equipo integrante del sistema se desarrollará de manera global.

Journal of environmental management, Jan 15, 2019

Soybean oil is widely used as cooking oil, whereas the soybean cake is a valuable ingredient for ... more Soybean oil is widely used as cooking oil, whereas the soybean cake is a valuable ingredient for animal food. The extraction of soybean oil is an energy-intensive process, with additional significant impact on the environment via the wastewater and hexane emissions. The research investigated different ways to minimize the energy consumption. In a traditional process, both direct (live) steam and indirect steam heating (jackets, tubular exchangers) are used to deliver the required heat duty. Direct steam injection is restricted to the first evaporator and the stripper, for a total of 620 kg/h. Indirect steam is also applied in the evaporators for a total of 6.44 MW. The desolventizing process requires a steam energy input of 8.15 MW. Integration of a heat exchanger network in the evaporation and stripping part of the process reduces the amount of direct steam usage from 620 kg/h to 270 kg/h and of the indirect heat duty from 6.44 to 5.05 MW. In the cake desolventizing part of the pro...

Processes, 2022

Spent grains from microbreweries are mostly formed by malting barley (or malt) and are suitable f... more Spent grains from microbreweries are mostly formed by malting barley (or malt) and are suitable for a further valorization process. Transforming spent grains from waste to raw materials, for instance, in the production of nontraditional flour, requires a previous drying process. A natural convection solar dryer (NCSD) was evaluated as an alternative to a conventional electric convective dryer (CECD) for the dehydration process of local microbrewers’ spent grains. Two types of brewer’s spent grains (BSG; Golden ale and Red ale) were dried with both systems, and sustainability indices, specific energy consumption (eC), and CO2 emissions were calculated and used to assess the environmental advantages and disadvantages of the NCSD. Then, suitable models (empirical, neural networks, and computational fluid dynamics) were used to simulate both types of drying processes under different conditions. The drying times were 30–85 min (depending on the drying temperature, 363.15 K and 333.15 K) ...

Waste and Biomass Valorization, 2015

PurposeFluidized bed combustion is currently intensively developed throughout the world to produc... more PurposeFluidized bed combustion is currently intensively developed throughout the world to produce energy from several types of solid fuels, while significantly reducing pollutant emissions with respect to conventional combustion units. Accurate models must be formulated at both bed and particle levels to operate efficiently such units, since local phenomena such as particle temperature and combustion rate are crucial aspects for process improvement and control. In this sense, this article proposes a classification of local scale models to represent the evolution of char heterogeneous combustion of any carbonaceous particles.MethodsExisting models are described and classified based on the characteristics of the governing equations, the thermal behavior of the gas and solid phases and the description of both the burning particle and the surrounding gas, under a heterogeneous or pseudo-continuous assumption. Criteria for choosing one model instead of others are also considered, depending on the case. The so-called Intrinsic Reactivity Models are described in detail for evaluating the pertinence of their simulated results. The use of CFD to build a simulation scheme of the solid combustion process at local scale is also presented and discussed.ResultsA complete description of the solid fuel burning process is given, along with useful information concerning the evolution of different variables, such as particle internal temperature that governs the reaction rate and gas composition.ConclusionsThis comparative analysis gives a strong basis to select the appropriate modeling approach. Finally, recommendations are proposed for model application and future development.

Chemical Engineering Research and Design, 2016

In the search for greater efficiency and storage capacity improvements in solar energy concentrat... more In the search for greater efficiency and storage capacity improvements in solar energy concentration plants, a new concept for fluid transfer was proposed. This concept consists of a dense suspension of SiC particles (dp = 6.4 × 10−5 m) that is air fluidized, which allows operation at higher temperatures than the fluids currently used, such as molten salts, water, oils and air. The suspension, as a fluid, also provides energy storage. The upward flow of the SiC–air suspension inside a steel tube is achieved using a circulating fluidized bed dense regime. Concentrated solar radiation impinges the walls of the tube, increasing the temperature of the granular material up to 200–250 °C. The system in this study is part of a prototype in the PROMES Laboratory in France. Maintaining low fluidization velocities guarantees high solid fractions throughout the tube (0.28–0.45). This study simulates heat transfer between the wall and the suspension using computational fluid dynamics (CFD) (ANSYS-Fluent 14.5) for different operating conditions. The Euler–Euler model is used as the multi-phase model. The average experimental temperature in the emulsion at the exit of the heat transfer zone compares well with the temperature obtained in the CFD simulation. The global heat transfer coefficients obtained in the simulation are in good agreement with those obtained experimentally for all operating conditions. These results show that the developed simulation approach is a good representation of the real process and provides relevant information related to the movement of particles in the tube and its relation to heat transfer in the prototype.