Main Operating Conditions Research Articles

Determination of dynamic loading of bearing structures of freight wagons with actual dimensions

The determination of the dynamic loading of the bearing structures of the main types of freight wagons with the actual dimensions under the main operating conditions is carried out. The inertial coefficients of the bearing structures of the wagons are determined by constructing their spatial models in the SolidWorks software package. Two cases of loading of the bearing structures of the wagons – in the vertical and longitudinal planes – have been taken into account. The studies were carried out in a flat coordinate system. When modeling the vertical loading of the bearing structures of wagons, it was taken into account that they move in the empty state with butt unevenness of the elastic-viscous track. The bearing structures of the wagons are supported by bogies of models 18-100. The solution of differential equations of motion was carried out by the Runge-Kutta method in the MathCad software package. When determining the longitudinal loading of the bearing structures of wagons, the calculation was made for the case of a shunting collision of wagons or a "jerk" (tank wagon). The accelerations acting on the bearing structures of the wagons are determined. The research results will help to determine the possibility of extending the operation of the bearing structures of freight wagons that have exhausted their standard service life. It has been established that the indicators of the dynamics of the load-carrying structures of freight wagons with the actual dimensions of the structural elements are within the permissible limits. So, for a gondola wagon, the vertical acceleration of the bearing structure is 4.87 m/s2, for a covered wagon – 5.5 m/s2, for a flat wagon – 5.8 m/s2, for a tank wagon – 4.25 m/s2, for a hopper wagon – 4.5 m/s2. The longitudinal acceleration acting on the bearing structure of a gondola wagon is 38.25 m/s2, for a covered wagon – 38.6 m/s2, for a flat wagon – 38.9 m/s2, for a tank wagon – 27.4 m/s2, for a hopper wagon – 38.5 m/s2. This makes it possible to develop a conceptual framework for restoring the effective functioning of outdated freight wagons. The conducted research will be useful developments for clarifying the existing methods for extending the service life of the bearing structures of freight wagons that have exhausted their standard resource

Three-dimensionalization via control of laser-structuring parameters for high energy and high power lithium-ion battery under various operating conditions

Laser-structuring is an effective method to promote ion diffusion and improve the performance of lithium-ion battery (LIB) electrodes. In this work, the effects of laser structuring parameters (groove pitch and depth) on the fundamental characteristics of LIB electrode, such as interfacial area, internal resistances, material loss and electrochemical performance, are investigated. LiNi0.5Co0.2Mn0.3O2 cathodes were structured by a femtosecond laser by varying groove depth and pitch, which resulted in a material loss of 5%–14% and an increase of 140%–260% in the interfacial area between electrode surface and electrolyte. It is shown that the importance of groove depth and pitch on the electrochemical performance (specific capacity and areal discharge capacity) of laser-structured electrode varies with current rates. Groove pitch is more important at low current rate but groove depth is at high current rate. From the mapping of lithium concentration within the electrodes of varying groove depth and pitch by laser-induced breakdown spectroscopy, it is verified that the groove functions as a diffusion path for lithium ions. The ionic, electronic, and charge transfer resistances measured with symmetric and half cells showed that these internal resistances are differently affected by laser structuring parameters and the changes in porosity, ionic diffusion and electronic pathways. It is demonstrated that the laser structuring parameters for maximum electrode performance and minimum capacity loss should be determined in consideration of the main operating conditions of LIBs.

Numerical, Mechanical, and Metallurgical Investigation of an Innovative Near Net Shape Titanium Selective Laser Melting Engine Component and Comparison with the Conventional Forged One

Selective laser melting (SLM) can be used to manufacture near net shape (NNS); the main benefits are a remarkable weight reduction, a lower environmental impact, the opportunity to integrate some functions, and an improvement of the performances. The current article covers the development of a Ti6Al4V NNS engine component produced by SLM. Finite element analyses of the main relevant operating conditions are performed to reach a topological optimization of the part. The main target is weight reduction keeping the same safety performances. The weight reduction achieved is 45% and 15% with respect to steel and titanium forging by replacing the original “H” section with an SLM multibranch structure. Other benefits are the manufacturing of the connecting rod (conrod) into two separate parts, avoiding the difficult machining to separate the cap from the main body and the integration of conformed cooling channels into the conrod. Then, the SLM components are produced and mechanical and metallurgical properties are investigated and compared with the titanium hot forging ones. Both the macrostructures present equiassic and isotropic behavior due to the heat treatment transformation. No defects are observed for both the technologies. The mechanical properties are verified to be aligned with the design targets.

Effects of different simulation models on pyrolysis performance predictions for regenerative cooling applications

The one-dimensional plug flow reactor (PFR) model is commonly used in regenerative cooling simulations. However, the extreme operational conditions in regenerative cooling channels may affect the predictive accuracy of PFR, in which the effects of turbulent flow and heat transfer were not considered. In this study, we compared the chemical reaction predictions from PFR and Computational Fluid Dynamics (CFD) in regenerative cooling channels, and studied the effects of the main operating conditions on predictive accuracy, namely: pressure, flow rate, and heat flux. Experiments were performed to validate the CFD model and illustrate the predicative deviations in PFR under different operating conditions. Additional simulations with special operational conditions were also carried out to analyze the key factors. Results revealed that turbulence and radial temperature heterogeneity caused by turbulent flow and convective heat transfer influenced the pyrolysis predictions in different ways. The intensities of the two competitive effects changed with the operating conditions, which affect the accuracy of PFR model. Besides, the importance of heat transfer effects was emphasized in predicting the changing regularity of heat sink. This work is expected to provide novel understandings of reacting flow to engineering applications.

Investigation of particulate bed dynamics inside a rotating drum using discrete element method

The present article describes a numerical study conducted to investigate particle movement inside a rotating drum under different operating conditions. The discrete element method (DEM) was used in order to describe granular flow dynamics. The effects of the main operating conditions (i.e., rotating speed and fill level) on the dynamic angle of repose were studied. It was found that the dynamic angle of repose increased by increasing the rotating speed and fill level. The results showed that by increasing the rotation speed, fraction of particles in the active area increased. While, by increasing the fill level, fraction of particles in the active area decreased. Also, granular temperature of the solid bed was calculated in order to characterize the velocity fluctuation of particles in the rotating bed. It was found that the granular temperature increased by increasing the rotating speed. Furthermore, the effect of the friction coefficient on the dynamics of granular particles was investigated. When the particle-particle and particle-wall friction coefficients are increased, the dynamic angle of repose is slightly increased. Also, the results showed that granular temperature increased as the friction coefficient decreased.

Continuous SO2 absorption and desorption in regenerable flue gas desulfurization with ethylenediamine-phosphoric acid solution: A rate-based dynamic modeling

The amine-based flue gas desulfurization (FGD) method is a competitive and promising technique to realize SO2 removal and sulfur recycling from flue gas. To study the steady and transient state behaviors of continuous SO2 absorption and desorption processes with ethylenediamine-phosphoric acid solution, a rate-based system model including main units for regenerable FGD was developed and validated with experimental data. The influence of main operating conditions on the dynamic characteristics of technological parameters was investigated, moreover, a comprehensive analysis was performed to reveal the mechanism behind the parameter evolution. The results indicate that simulation results agree well with experimental data and the absorption efficiency, desorption efficiency, lean loading, and rich loading are correctly predicted, respectively. Both absorber and desorber are driven by transfer properties, and the latter is operated in a lean-pinch mode. Either the rich-SO2 loading or the gas-liquid equilibrium significantly affects the desorption performance, and an increase in rich-SO2 loading is beneficial to lower the reboiler heat duty. The normal desulfurization operation could be maintained during load-reduction scenario by cooperating with reasonable reduction of reboiler duty and moderate solvent flowrate. This work could provide engineering guidance to design the control system of amine-based FGD process for upscale exploration and input for a deep processing of SO2 product subsequently.

Numerical Investigation of a Novel Plate-Fin Indirect Evaporative Cooling System Considering Condensation

An indirect evaporative cooling system combining with thermoelectric cooling technology (i.e., TIEC system) is proposed, in which a counter-flow plate-fin indirect evaporative cooler is inserted with thermoelectric cooling (i.e., TEC) modules. In hot and humid climate, condensation may occur on the dry channel surface of the cooler. For the TIEC system, with the aid of TEC technology, the surface temperature of the dry channel can be much lower than that of a traditional indirect evaporative cooler, thus, the condensation from the primary air is more likely to take place. A numerical model of this novel TIEC system is developed with specifically taking condensation from primary air into account. Detailed performance analysis of the TIEC system is carried out. Analytical results found that the condensation from primary air reduces the dew point effectiveness by up to 45.0% by weakening the sensible heat transfer but increases the coefficient of performance by up to 62.2% by increasing the latent heat transfer, under given conditions. The effects of main operating conditions, such as the electrical current I and number n of TEC modules, inlet temperature Tp,i, humidity ratio RHp and velocity Vp of the primary air, and the mass flow rate ratio x of secondary to primary air, are investigated under non-condensation and condensation states. It is shown that condensate is more easily produced under higher I, n, Tp,i, RHp, x and lower Vp.

Improvement Methods and Ways of Manipulator Electromechanical Force Compensating System

In paper electromechanical system for force compensating medium manipulator used in industry for motion different cargo was presented. Working purpose is determination of research method of manipulator with force compensating control system. Improvement methods and ways of current force compensating manipulator sys-tem are concerned. Research showed that now light-weight structures of manipulators with elastic mechanical transmissions are used. Low stiffness of mechanisms increases elastic mechanical vibration of cargo. Active methods of compensation are used using an electric drive with a force control system in executive mechanism of manipulator for realization of compensation of cargo weight and damping of elastic mechanical vibrations. Control system is recommended to build with main force feedback in elastic element. Multifactorial method is rational to use during choosing device of manipulator electromechanical module. This method considers the most main operating conditions of manipulator. Problem solution of control influence synthesizing must make with correctors with differentiating properties. Studies have shown that proposed methods for improving force compensating manipulators will make structure as lightweight, reduce inertia, increase working area of manipulator, and improve quality of operations for moving various cargos

Modelling of changes in ship’s operational condition during transportation of oversized and heavy cargo

The object of research is the operational condition of the ship and its changes that occur in the process of transportation of oversized and heavy cargo under the influence of multiple accidental events. A significant problem is the negative impact of the system of factors on seaworthiness and technical condition of the ship, the integrity of the cargo. Therefore, ensuring the safety of the ship, its functional reliability as a technical object is among the priorities which are extremely relevant in the process of transportation of oversized and heavy cargo. In the course of the research the identification of the basic conditions of the surveyed ship in the process of operation was carried out. The ship in the process of transportation is defined as an aggregate of two objects – «ship – cargo». The decomposition of the stated condition into two variants «in norm» and «having problems», with three components: «seaworthiness of the ship», «technical condition of the ship», and «cargo and lashing systems». Six main operational conditions of the ship in the process of transportation of oversized and heavy cargo were established. The model of changes in the operational condition of the ship during the transportation of oversized and heavy cargo has been developed. This model enables to establish the relationship between these conditions, which are identified and formalized in the form of a single-ordered Markov process model. The process is considered as a process with a discrete time and the presence of a rotational condition with the absence of the property of ergodicity. Experimental investigations were carried out for various initial conditions and the most probable changes in the operational condition of the ship were determined for a specified number of hourly periods. The proposed process model enables experimental investigations for various initial conditions and identification of the most probable changes in the ship’s operational condition through a specified number of hours. It allows to estimate risks and make decisions on support of ship’s operational condition during transportation of oversized and heavy cargo as a theoretical basis.

GPU-based DEM simulation for scale-up of bladed mixers

GPU-based DEM is used to study large-scale particle mixing in bladed mixers. A bladed mixer is scaled-up to three different sizes by maintaining the geometric similarity. Four Froude numbers are selected as the main operating conditions of bladed mixers with different sizes. The results demonstrated that the mixing quality across different mixer sizes is similar at the same Froude number, but it requires a longer mixing time to achieve similar mixing performances as the mixer becomes larger. Correlations to predict the mixing rate, average particle velocity, average total forces, average contact forces and average blade torque as functions of the scale-up ratio and Froude number (or rotation speed) are proposed. A similarity study shows that maintaining the dynamic or kinematic similarity does not produce a similar mixing performance, while maintaining the mixing rate produces a similar mixing performance across all mixers.

Numerical simulation of commercial scale autothermal chemical looping reforming and bi-reforming for syngas production

Autothermal Chemical Looping Reforming (a-CLR) is an emerging technology that facilitates CO2 capture and minimizes energy losses in syngas production. The dual-fluidized bed process uses a bubbling fuel reactor (FR) and a riser air reactor (AR). A 1-D multiscale model was developed that couples fluidized bed hydrodynamics with intrinsic reaction kinetics, including catalyst deactivation by oxidation and coke formation. An a-CLR unit with a capacity equivalent to 50 conventional reformer tubes was considered to demonstrate feasibility. The effects of the catalyst activity, main operation conditions and CO2 co-feeding on the performance were then analyzed. The results confirm a-CLR is feasible with realistic reactors dimensions and solids circulation rate. To avoid the risk of sintering and catalyst deactivation, the oxygen carrier should only be slightly oxidized in the AR. Autothermal operation then requires an oxygen-to-CH4 feed ratio of around 1.2. The high catalyst-to-gas feed ratio in the FR and bubble-emulsion phase mass transfer limitations result in a low sensitivity of the methane conversion to the catalyst activity. A low H2O-to-CH4 feed ratio introduces a risk for coke formation in the bottom of the FR, but part of the feed methane is fully oxidized, producing H2O and CO2 in the emulsion phase and mitigating this risk. Co-feeding CO2 with CH4 and H2O is seen to allow adjusting the H2/CO-ratio of the syngas, but increases the risk of coke formation. Finally, heat recovery from the flue gas and syngas from both reactors by preheating the feed gases further increases the energy efficiency.

A solid sampling approach for direct determination of Cl and S in flour by an elemental analyzer

Direct analysis of flour was proposed for the determination of Cl and S by an elemental analyzer for the first time. The main operational conditions of the direct solid sampling elemental analysis (DSS-EA) were optimized and calibrated by standard solutions, rather than by certified reference material (CRM). Accuracy was evaluated by the analysis of CRM of rice flour and by comparison with analyte determination by independent techniques, i.e., ion chromatography and inductively coupled plasma optical emission spectrometry; both were carried out after microwave-induced combustion. Sample mass from 0.5 to 260 mg was used and limits of quantification of 1.2 µg g−1 for Cl and 0.2 µg g−1 for S were achieved. Wheat, whole wheat, potato and corn flour were analyzed by DSS-EA. Concentrations of Cl and S ranged from 4.8 to 685 µg g−1 and from 13 to 1328 µg g−1, respectively.

Effect of Enhanced-Oil-Recovery Chemicals on Oil/Water-Separation Processes, from Laboratory Scale to Flow-Loop Scale

With the use of chemically based enhanced-recovery methods, water management, which has always been a major point in the production-operation processes, needs to be considered and adapted because the whole water cycle will be affected by the backproduced additives. Enhanced-oil-recovery (EOR) chemicals such as alkali molecules, high-molecular-weight polymers, or surfactant formulation will dramatically modify pH, viscosity, and phase behaviors of produced fluids. The main issues encountered in oil/water-separation processes are directly related to the risk of tight emulsion formation, which might considerably complicate the surface-water-treatment processes. The objective of this paper is to underline the effect of one of these chemicals, a surfactant formulation, on the produced-water cycle when they are backproduced first at a laboratory scale and second on a large-scale separation unit using an industrial-size flow loop and a well-instrumented separator. Our goal is first to investigate the impact of surfactant on the water/oil mixture separation efficiency, and second, to find an efficient demulsifier specific for this case. At the laboratory scale, the impact of surfactant within produced fluids on oil/water separation (regarding separation kinetics but also oil/water phase qualities) will be evaluated by performing bottle tests. Those laboratory bottle tests enabled us to screen different parameters, such as the surfactant concentration, the water cut that can strongly affect the type of formed emulsion [oil in water (O/W) or water in oil (W/O)], and its stability. The oil/water phase qualities were quantified and correlations with parameters related to the large-scale experiment were drawn, helping us in defining the key parameters for this campaign. Indeed, to get closer to a field case, a semi-industrial-scale test platform was used. The flow loop reproduces separation process conditions encountered in a field treatment facility, including the production separator, the controlled temperature, and the oilfield chemical injection rate. The main operating conditions are liquid flow rates and temperature. The influence of different parameters can be studied, such as the surfactant concentration, mixing conditions, residence time, water cut, and the presence of chemicals that will help the separation process. Different types of emulsions were formed depending on the conditions, and their stability was evaluated through the measurement of separation profiles using a single electrode capacitance probe (SECAP) within the separator. The results obtained show how the surfactant, as well as the demulsifier concentration, have led to different types of emulsions and have affected the oil/water separation processes. These tests have confirmed that separation is more difficult in the presence of surfactant and that water quality was degraded. It has also been shown that separation processes can be greatly improved by adding some EOR-compliant demulsifier to recover a better water quality compared with the surfactant case. Laboratory workflows, as well as experiments performed at large scale using an industrial size separator, could help to minimize risks of operations to mitigate these challenges in terms of separation issues. This work illustrates that water management is a major challenge for produced fluids containing EOR chemicals that need an integrated approach and should be studied beforehand.

Production of MCM-41 Nanoparticles with Control of Particle Size and Structural Properties: Optimizing Operational Conditions during Scale-Up.

The synthesis of Mobil Composition of Matter 41 (MCM-41) mesoporous silica nanoparticles (MSNs) of controlled sizes and porous structure has been performed at laboratory and pilot plant scales. Firstly, the effects of the main operating conditions (TEOS –Tetraethyl ortosilicate– addition rate, nanoparticle maturation time, temperature, and CTAB –Cetrimonium bromide– concentration) on the synthesis at laboratory scale (1 L round-bottom flask) were studied via a Taguchi experimental design. Subsequently, a profound one-by-one study of operating conditions was permitted to upscale the process without significant particle enlargement and pore deformation. To achieve this, the temperature was set to 60 °C and the CTAB to TEOS molar ratio to 8. The final runs were performed at pilot plant scale (5 L cylindrical reactor with temperature and stirring speed control) to analyze stirring speed, type of impeller, TEOS addition rate, and nanoparticle maturation time effects, confirming results at laboratory scale. Despite slight variations on the morphology of the nanoparticles, this methodology provided MSNs with adequate sizes and porosities for biomedical applications, regardless of the reactor/scale. The process was shown to be robust and reproducible using mild synthesis conditions (2 mL⋅min−1 TEOS addition rate, 400 rpm stirred by a Rushton turbine, 60 min maturation time, 60 °C, 2 g⋅L−1 CTAB, molar ratio TEOS/CTAB = 8), providing ca. 13 g of prismatic short mesoporous 100–200 nm nanorods with non-connected 3 nm parallel mesopores.

Concentrates from citrus juice obtained by crossflow microfiltration: Guidance of the process considering carotenoid bioaccessibility

This work focused on an eco-friendly process to concentrate carotenoids from a citrus juice formulated with clementine and pink grapefruit. It is based on crossflow microfiltration associated with enzymatic liquefaction, diafiltration and pasteurization. The aim was to evaluate the impact of the main operating conditions on the process performance and on the nutritional quality of the final concentrate taking into account the bioaccessibility of β-carotene, β-cryptoxanthin and lycopene. First, the best enzyme/pressure/membrane combination was chosen in order to maximize permeate flux during microfiltration (>100 kg.h−1.m−2 at 2.6 bar with tubular inorganic membranes). Second thanks to a Plackett-Burman experimental design applied to the whole process, we showed the enzymatic dose was the most impacting parameter on carotenoid bioaccessibility and it decreased it. An optimal dose of enzyme had to be defined in order to obtain a good compromise between the process performance and the nutritional quality of the citrus concentrate.

Experimental study of a thin water-film evaporative cooling system to enhance the energy conversion efficiency of a thermoelectric device

In the study, a new method to enhance the performance of a thermoelectric generator (TEG) device by utilizing the water-film evaporative cooling is proposed. An experimental device was constructed by incorporating a water-film cooling pond with a commercially available TEG. Experiments were performed to investigate the effects of the main operating conditions (ambient temperature Tamb was 25 °C), TEG hot-side temperature (TH = 50–100 °C), ambient relative humidity (RH = 15–90%), and water-film thickness (twater = 1–9 mm) on the TEG output performance. Additionally, the output performance of TEG under different cooling methods was compared. A TEG prototype device was constructed to generate electricity/steam using seawater evaporation cooling without external electrical energy. The results indicated that TEG hot-side temperature and water-film thickness significantly affected output performance. However, the ambient relative humidity did not considerably affect TEG output performance. Given TEG hot-side temperature TH = 100 °C, ambient relative humidity RH = 15%, the TEG prototype device-generated open-circuit voltage of Uopen = 1.55 V, maximum output power of Pmax = 290.32 mW, and a steam generation rate of 9.82 mg/s. The results showed that evaporative cooling is an innovative method to improve the performance of TEG.

A Discussion of Possible Approaches to the Integration of Thermochemical Storage Systems in Concentrating Solar Power Plants

One of the most interesting perspectives for the development of concentrated solar power (CSP) is the storage of solar energy on a seasonal basis, intending to exploit the summer solar radiation in excess and use it in the winter months, thus stabilizing the yearly production and increasing the capacity factor of the plant. By using materials subject to reversible chemical reactions, and thus storing the thermal energy in the form of chemical energy, thermochemical storage systems can potentially serve to this purpose. The present work focuses on the identification of possible integration solutions between CSP plants and thermochemical systems for long-term energy storage, particularly for high-temperature systems such as central receiver plants. The analysis is restricted to storage systems potentially compatible with temperatures ranging from 700 to 1000 °C and using gases as heat transfer fluids. On the basis of the solar plant specifications, suitable reactive systems are identified and the process interfaces for the integration of solar plant/storage system/power block are discussed. The main operating conditions of the storage unit are defined for each considered case through process simulation.

Biomass Chemical Looping Gasification of pine wood using a synthetic Fe2O3/Al2O3 oxygen carrier in a continuous unit

Biomass Chemical Looping Gasification is a novel technology allowing high quality syngas production at autothermal conditions without CO2 emissions to the atmosphere and low tar generation. This work compiles gasification results corresponding to 38 h of continuous operation in a 1.5 kWth unit using pine wood as fuel and a synthetic Fe-based oxygen carrier, Fe20Al. The main operating conditions such as temperature (T = 820–940 °C), steam-to-biomass ratio (S/B = 0.05–0.65), and oxygen-to-biomass ratio (λ = 0.2–0.6) were analyzed at steady state conditions using a novel method for controlling oxygen in the process. A syngas composed by 37% H2, 21% CO, 34% CO2 and 7% CH4, and tars below 2 g/Nm3 could be obtained at autothermal conditions, leading to a syngas yield of 0.8 Nm3/kg dry biomass and a cold gas efficiency of 68%. The material maintained a high reactivity although some Fe lost was observed.

Numerical analyses of concrete thermal energy storage systems: effect of the modules’ arrangement

This paper is focused on modularized concrete sensible thermal energy storage systems with thermal oil as heat transfer fluid; the thermal storage systems have been conceived to be integrated into a concentrated solar power plant. This work is mainly focused on the effect of the modules’ arrangement on the overall performance of the thermal energy storage system. Series and parallel arrangements are investigated, to determine the most performant solutions in terms of exchanged thermal energy as a function of the main operating conditions: oil mass flow rate and pressure drop, both in heating and cooling phase. Two different boundary conditions are considered: adiabatic and diabatic external walls. The simulations are carried out using an extended version of a model proposed by the present authors for a single concrete block, that was validated with experimental data. The exchanged thermal energy, the oil mass flow rate, the pressure drops, and the duration of the process are changed to evaluate the storages under different operating conditions. The best thermal energy storage configuration is determined by a thermal energy assessment: it coincides with the first one that reaches the asymptotic values with the minimum number of elements. Furthermore, in the diabatic case, the loss heat flux toward the environment has a significant role and highlights the differences between charging and discharging phases, its presence contributed to a more aware choice of the most suitable and performant modularized system.

Pressurized GRAS solvents for the green extraction of phenolic compounds from hibiscus sabdariffa calyces

An environmental friendly extraction procedure has been tested to extract phenolic compounds from H. sabdariffa calyces using pressurized GRAS solvents. A central composite rotatable design (CCRD) was performed to evaluate the influence of the main operational conditions: temperature (40–200 °C) and solvent composition based on aqueous hidroalcoholic solutions (0–100% ethanol). Phenolic composition of experimental extracts analyzed by HPLC-ESI-QTOF-MS showed that higher temperatures and greater ethanol percentages drove to solvents with lower dielectric constants, which resulted in extracts with major quantities of phenolic compounds. An exception was the extraction of cyanidin-3-sambubioside that could only be quantified in extracts performed at the lowest temperature (40 °C) due to its thermal sensibility. In addition, a RSM was carried out with the aim to maximize the extraction of total phenolic content. To this end, the predicted optimal extraction conditions by RSM were 200 °C and 100% (v/v) of ethanol. Results showed that temperature and ethanol percentage had a significant influence on the extraction of total phenolic compounds (p value < 0.05). The mathematical model pointed out 200 °C of temperature and 100% of ethanol as the optimum conditions to perform the isolation of phenolic compounds by means of pressurized GRAS solvents.