Epoxycyclopentane hydrate for sustainable hydrate-based energy storage: notable improvements in thermodynamic condition and storage capacity

The thermodynamic stability and storage capacity of the novel epoxycyclopentane hydrate are superior to those of THF or cyclopentane hydrate.

Reaction Kinetics of Mg2Si in the Laser Welding Pool of Aluminum Alloys

The metallurgy reactions in the weld pool were analyzed with the application of reaction kinetics. Furthermore a formula to quantificationally calculate the amount of Mg2Si was generated. By means of calculating the thermodynamic condition of the reaction and combined with the verification testing, this article indicates that the metallurgical product Mg2Si was created in the liquid weld pool but not separated out from the arborescent crystal during its solid state. This thesis summarizes the precipitation mechanism of Mg2Si and explains the configuration, amount and location where Mg2Si was separated out by analyzing the phase diagrams and constitution diagrams. Relevant data suggests that: the content of Mg2Si is slightly less than Mg.

Thermodynamic Condition and Behavior of Precipitates in Al2O3p/7055 Composites with Cryogenic Treatment

The thermodynamic condition and behavior of precipitates were discussed about the Al2O3 p/7055 composites subjected to cryogenic treatments. A kind of software named Thermo-Calc was employed to calculate and analyze the mass amount of several main precipitates based on the thermodynamic balance theory. The results demonstrate that when the temperature decreases from 300K to 77K the precipitated amount of T(AlZnMgCu) and θ (Al2Cu) phases will increase. For S(Al2CuMg) phase, at 175K there is a transverse point from increasing tendency to the opposite. It should be noted that η (MgZn2) is the main precipitated phases in compistes ,which accounts for more than eleven weight percent in one mole material. But the balance mass amount lower a little from 300K to 77K. It is analyzed that the volume shrinkage and lattice contract are the main driving forces for precipiting. Due to the difference of heat expansion coefficient among various phases the anisotropic shirinkge lead to micro voids that will act as the nucleation cores,which faciliate the precipitation.

Thermodynamic Studies on Selective Oxidation of Nb, P and C in Dephosphorization of Low Niobium Hot Metal

The main problem with the efficient utilization of Nb resource in the Boyan Obo Ore lies in the selective oxidation of [Nb], [P] and [C]. In this work, thermodynamic studies have been conducted to determine the conditions of selective oxidation of [Nb], [P] and [C] in low niobium hot metal in the process of oxidizing dephosphorization. The thermodynamic condition for dephosphorization was determined as: The condition for retaining Nb from oxidation is: The oxygen activity for oxidation of Nb, C and P is relevant to the initial [C] content in hot metal. The equilibrium oxygen activity of Nb-O reaction increases with an increase of the [C] content, whereas the equilibrium oxygen activity of C-O and P-O reactions varies oppositely with the [C] content. The reduction ofresults in a decrease of the [C] content required for removing P and retaining Nb, as well as makes the process of dephosphorization more feasible. The increase of temperature decreases the [C] content of selective oxidation of Nb and P, but is unfavorable to dephosphorization.

Thermodynamic Research of Boron Oxide Reducing with Carbothermic Method

Based on the phase diagrams analysis, the activity model of Fe-C-B ternary system was established with the ion and molecule coexistence theory. The activities of Fe, C, B, Fe3C, FeB, FeB2 and B4C in melt were calculated by analyzing the model. We have researched the thermodynamic condition of boron oxide reducing with carbothermic method and analyzed the effects of CO partial pressure, B2O3 content and slag type for the lowest smelting temperature. In normal pressure, the carbon content is high in melt, so it needs 2000°C for decarbonizing and chrome remaining. When CO partial pressure is 0.1 kPa and CaO content is less 60%, the lowest temperature of smelting ferro boron could be below 1600°C.