Solving Environmental Problems by Recycling the Cut Chalk To Lime in a Rotating Furnace

A technology of processing chalk from the Lebedinskoye deposit into high quality lime by roasting in a rotary kiln is proposed. A procedure has been developed for the thermodynamic calculation of the specific heat of decomposition of carbonates contained in chalk. The material and heat balances of the operating rotary kiln have been compiled. All the main parameters of its operation and the optimal fuel consumption for chalk processing have been determined.

Energetic Characterization of Decomposing Sample Using Simultaneous Thermal Analysis

A simultaneous thermogravimetric analyzer was used to investigate the gravimetric and energetic behavior of a decomposing sample under inert atmosphere. Materials tested in the study included liquid chemicals, polymers and composite samples. Mathematical models were developed from the first law of thermodynamics to quantify the energetic characteristics of a decomposing sample. Along with the effect of evolved gas products, the temperature dependent thermal and physical properties were included in the development of the mathematical models. Models were used to obtain the heat of melting, standard heat of decomposition, heat of decomposition, and heat of gasification of the solid materials. It was determined that the heat of decomposition of a sample is different than the area difference of the apparent and sensible heat flow curves, an approach that is currently used in the literature. The standard heat of decomposition was measured and validated against the standard heat of evaporation of known chemicals. The standard heat of decomposition of a sample was found to be a constant quantity, irrespective of the sample heating rate, initial mass of the sample and the inert content (ash) in the initial mass of the sample. Thus, the standard heat of decomposition is proposed as a unique energetic property of a sample.

Production of MgO From Residues of Saline Pools in “Las Coloradas” Yucatan, Mex. Using Thermochemical Energy Storage

This paper proposes a method of thermochemical-energy storage from magnesium sulfate recovered from salt ponds of sea water. The idea develops from a project originally thought to obtain magnesium oxide from a salt plant in the Yucatan Peninsula, Mexico. The new idea is based on the exploitation of the heat of decomposition of magnesium sulphate. In the traditional literature, closed-loop, reversible reaction is considered, whereas in this work, an open-loop is proposed; that is, sulphur dioxide is separated from the magnesium oxide before cooling down to 700°C; in this way, magnesium oxide is obtained by thermal decomposition, and at the same time, the high heat of decomposition is used to store thermal energy for electricity generation; magnesium oxide, sulfuric acid and hydrogen are co-products of the process if another iodine reaction cycle is considered. This second process is again a modification of an open-loop traditional process, to a closed-loop process where no sulphuric acid is required.