METHOD FOR DETERMINING COMPOSITION OF A MULTI-COMPONENT MEDIUM

摘要

Methods to determine a quantitative composition of a multi-component medium are described. These methods provide for placing a sample into a cell of a differential scanning calorimeter and injecting a liquid into the cell, the liquid has a known volume thermal expansion coefficient and a known volume heat capacity. A total heat capacity and a total volume thermal expansion coefficient are determined for the sample and the fluid inside the cell. Solving system of equations it is possible to determine volumes of components composing the sample.

主权项

1. A method for determining composition of a multi-component medium comprising:
measuring a mass and a volume of a sample of the multi-component medium; placing the sample into a cell of a differential scanning calorimeter; filling the cell with a liquid having a known volume heat expansion coefficient and a known volume heat capacity; increasing and decreasing a temperature of the cell in a sequential manner; measuring a heat effect in the cell produced by increasing and decreasing the temperature; calculating a total heat capacity for the liquid having the known heat expansion coefficient and the known volume heat capacity and the sample inside the cell; increasing and decreasing pressure in the cell with the sample step by step by injecting a liquid into the cell; measuring a heat effect resulting from increasing and decreasing the pressure; calculating a total thermal volume expansion coefficient for the sample and the liquid having the known thermal expansion coefficient and the known volume heat capacity inside the cell; and determining volumes of components of the sample solving the following system of equations:v=∑i=1nvim=∑i=1nρivic=∑i=1ncivi+clvlα=∑i=1nαivi+αlvl where n is a number of the components of the sample, vi—are volumes of the components of the sample, ρi—are densities of the components of the sample; ci—are volume heat capacities of the components of the sample, αi—are thermal volume expansion coefficients of the components of the sample, v—is a volume of the sample, m is the sample mass, α—is the total thermal volume expansion coefficient of the sample and the liquid having the known thermal expansion coefficient and the known volume heat capacity inside the cell, c—is the total heat capacity of the sample and the liquid having the known thermal expansion coefficient and the known volume heat capacity inside the cell, vl—is a volume of the cell filled with the liquid having the known thermal volume expansion coefficient and the known volume heat capacity, αl—is a volume heat expansion coefficient of the liquid having the known thermal volume expansion coefficient and the known volume heat capacity, cl—is a volume heat capacity of the liquid having the known thermal volume expansion coefficient and the known volume heat capacity.