# How to Estimate Thermal Conductivity of Liquid

Thermal conductivity of a material is a measure of its ability to a particular material conduct heat. In the international system of units (SI), thermal conductivity is measured in watts per meter-kelvin (W/(m.K)). In imperial units, thermal conductivity is measured in BTU/(h·ft·oF).

## Thermal Conductivity of Solids

Solid composition, shape, structure all affect how well it conduct heat. Many handbooks provide thermal conductivity of solids for frequently used engineering materials.

## Thermal Conductivity of Liquid

Equation below can be used to estimate thermal conductivity of liquid.

Where:

k = thermal conductivity (W/(moC))

M = molecular weight

Cp = specific heat capacity (kJ/(kgoC))

ρ = density (kg/m3)

Example

Estimate the thermal conductivity of benzene at 30oC.

Solution

Density of benzene at 30oC = 875 kg/m3

Molecular weight of benzene = 78

Specific heat of benzene = 1.75 kJ/(kgoC)

Therefore, thermal conductivity:

Thermal conductivity = 0.12 W/(moC)

Therefore, the density of benzene at 30oC is estimated 0.12 W/(moC). This value is closed to the experiment in known handbooks, which is 0.16 W/(moC).

Reference:

Sinnot, R.K., Chemical Engineering Design Volume 6 Fourth Edition, Elsevier Butterworth-Heinemann, 2005.