• Energy Research
• Restricted close
• other engineering and technologies close
• JP close

MgO/H2O/Mg(OH)2 chemical heat storage of waste energy from industrial processes is a promising technology in view of a more efficient use and saving of primary energy sources. A new approach was used to develop a hybrid heat storage material made of magnesium hydroxide (Mg(OH)2) and exfoliated graphite (which is used to improve the heat transfer with its high thermal conductivity). Mg(OH)2 nanoplatelets were directly grown on graphite surface via a deposition–precipitation method to increase the compatibility between the two materials. The material thus obtained, named DP-MG, was experimentally tested to determine its heat storage and output capacities. An improvement of the material efficiency was obtained with a higher storage capacity at lower reaction temperature and a higher heat output rate.

MgO/H2O/Mg(OH)2 chemical heat storage of waste energy from industrial processes is a promising technology in view of a more efficient use and saving of primary energy sources. A new approach was used to develop a hybrid heat storage material made of magnesium hydroxide (Mg(OH)2) and exfoliated graphite (which is used to improve the heat transfer with its high thermal conductivity). Mg(OH)2 nanoplatelets were directly grown on graphite surface via a deposition–precipitation method to increase the compatibility between the two materials. The material thus obtained, named DP-MG, was experimentally tested to determine its heat storage and output capacities. An improvement of the material efficiency was obtained with a higher storage capacity at lower reaction temperature and a higher heat output rate.

A three-dimensional Navier-Stokes solver is used to investigate the flow field of a high pressure ratio centrifugal compressor for turbocharger applications. Such a compressor consists of a double-splitter impeller followed by a vaned diffuser. Particular attention is focused on the analysis of the vaned diffuser, designed for high subsonic inlet conditions. The diffuser is characterized by a complex three-dimensional flow field, and influenced by the unsteady interaction with the impeller. Detailed Particle Image Velocimetry (PIV) flow measurements within the diffuser are available for comparison purposes.

A three-dimensional Navier-Stokes solver is used to investigate the flow field of a high pressure ratio centrifugal compressor for turbocharger applications. Such a compressor consists of a double-splitter impeller followed by a vaned diffuser. Particular attention is focused on the analysis of the vaned diffuser, designed for high subsonic inlet conditions. The diffuser is characterized by a complex three-dimensional flow field, and influenced by the unsteady interaction with the impeller. Detailed Particle Image Velocimetry (PIV) flow measurements within the diffuser are available for comparison purposes.

The aim of this work was to develop a model for optimizing the life cycle cost of biofuel supply chain under uncertainties. Multiple agriculture zones, multiple transportation modes for the transport of grain and biofuel, multiple biofuel plants, and multiple market centers were considered in this model, and the price of the resources, the yield of grain and the market demands were regarded as interval numbers instead of constants. An interval linear programming was developed, and a method for solving interval linear programming was presented. An illustrative case was studied by the proposed model, and the results showed that the proposed model is feasible for designing biofuel supply chain under uncertainties.

The aim of this work was to develop a model for optimizing the life cycle cost of biofuel supply chain under uncertainties. Multiple agriculture zones, multiple transportation modes for the transport of grain and biofuel, multiple biofuel plants, and multiple market centers were considered in this model, and the price of the resources, the yield of grain and the market demands were regarded as interval numbers instead of constants. An interval linear programming was developed, and a method for solving interval linear programming was presented. An illustrative case was studied by the proposed model, and the results showed that the proposed model is feasible for designing biofuel supply chain under uncertainties.

Abstract This work investigates the coupling of hydrothermal carbonization (HTC) and supercritical water gasification (SCWG) as a combined process to fully valorise digestate from anaerobic digestion. Firstly, HTC was performed at three different temperatures (180, 220 and 250 °C) to convert digestate to hydrochar (HC) and aqueous HTC liquids (AHLs) and then, SCWG was performed on AHLs to produce a H2-rich gas. Different SCWG temperatures (500, 550 and 600 °C), residence times (15, 30, 60 and 90 s) and AHLs concentrations (6.7, 13.6 and 20.0%) were tested. Increasing SCWG temperature resulted in an increase of the carbon yield and H2 content in the gas phase, for increasing residence time the carbon yield in the gas phase decreased, while increasing the feedstock concentration led to a higher gas generation rate without affecting the carbon yield of the gas. The maximum carbon yield in the gas phase (51%) was reached for tests run at 600 °C, 15 s, and 6.7% of AHLs, the maximum hydrogen content in the gas phase (79%) was reached at 600 °C, 30 s, 6.7% of AHLs, the maximum gas generation rate (9.33 mL min−1) was reached at 600 °C, 30 s, 20.0% of AHLs.

Abstract This work investigates the coupling of hydrothermal carbonization (HTC) and supercritical water gasification (SCWG) as a combined process to fully valorise digestate from anaerobic digestion. Firstly, HTC was performed at three different temperatures (180, 220 and 250 °C) to convert digestate to hydrochar (HC) and aqueous HTC liquids (AHLs) and then, SCWG was performed on AHLs to produce a H2-rich gas. Different SCWG temperatures (500, 550 and 600 °C), residence times (15, 30, 60 and 90 s) and AHLs concentrations (6.7, 13.6 and 20.0%) were tested. Increasing SCWG temperature resulted in an increase of the carbon yield and H2 content in the gas phase, for increasing residence time the carbon yield in the gas phase decreased, while increasing the feedstock concentration led to a higher gas generation rate without affecting the carbon yield of the gas. The maximum carbon yield in the gas phase (51%) was reached for tests run at 600 °C, 15 s, and 6.7% of AHLs, the maximum hydrogen content in the gas phase (79%) was reached at 600 °C, 30 s, 6.7% of AHLs, the maximum gas generation rate (9.33 mL min−1) was reached at 600 °C, 30 s, 20.0% of AHLs.