Abstract: A method of separating and purifying conjugated diene, including the steps of: obtaining a first bottom product by distilling a hydrocarbon mixture including 80% or more conjugated diene under an environment in the presence of a polymerization inhibitor in a lower boiling distillation column 14; obtaining a second bottom product and distillation portion by distilling said first bottom product under an environment in the presence of a polymerization inhibitor in a higher boiling distillation column 16; measuring concentration of a polymerization inhibitor included in said first bottom product and second bottom product respectively; controlling the concentration of the polymerization inhibitor included in said first bottom product and/or second bottom product by changing a supply amount of the polymerization inhibitor to said lower boiling distillation column 14 and/or higher boiling distillation column 16 in accordance with said measured concentration of the polymerization inhibitor included in said first bott

Abstract: A method of separating and purifying conjugated dienes includes a step of obtaining a first bottom product by taking out a hydrocarbon mixture including conjugated diene under an environment in the presence of a polymerization inhibitor including at least one of nitrite and di-lower aklylhydroxylamine in a first extractive distillation column; a step of obtaining a second bottom product and a distillation portion by distilling the first bottom product in a first diffusion column; a step of obtaining a third bottom product by taking out the distillation portion under an environment in the presence of the polymerization inhibitor in a second extractive distillation column; a step of obtaining a fourth bottom product by distilling the third bottom product in a second diffusion column; a step of recovering the second bottom product and fourth bottom product and supplying to the first extractive distillation column and/or second extractive distillation column; a step of measuring concentration of a polymerization

Abstract: A method and apparatus measures thermal conductivity of a material effected by measuring a change in the temperature of the material in contact with a heat source maintained at a predetermined temperature. A temperature change characteristic is obtained from the result of the temperature measurement, and the thermal conductivity is obtained by comparison of the temperature change characteristic and unsteady heat transfer characteristics of solid bodies previously determined in consideration of the heat transfer resistance of the interfaces. The present invention is suitable for the measurement of extensive materials, metallic materials to heat insulating materials, specifically suitable for the measurement of materials of high thermal conductivity and heterogeneous or anisotropic and is capable of accurately measuring the thermal conductivity without any special consideration on the interface heat transfer resistance at the measurement stage.