Patent ID: 6409882
Filing Date: 2002-06-25
Classification: B01D,D21C

Abstract:
An improved process for refining crude tall oil produced by a wood pulping process employing anthraquinone as a pulping additive comprising fractionating the crude tall oil by using at least one heat exchanger and at least one refinery tower with an upper cooling zone to remove a pitch fraction therefrom and separating the remaining crude tall oil into a distilled tall oil fraction, tall oil rosin fraction, tall oil fatty acids fraction, and heads fraction whereby the heads fraction exiting the upper cooling zone forms a process stream directed through the heat exchanger and wherein the anthraquinone condenses in the cooling zone and solidifies in the heat exchanger and wherein water is used to cool the process stream, wherein the improvement comprises a method of reducing or eliminating said anthraquinone condensation and solidification in an indirect contact heat exchanger by controlling the temperature of the water circulating therethrough within a range from about 60Â° to about 210Â° F. and wherein the water cools the heads fraction by its circulation through one side of the heat exchanger via a cooling water loop to remove heat from the heads fraction which circulates through an opposing side of the heat exchanger wherein the temperature of the water in the cooling water loop is controlled by temperature sensors that turn on and off valves that, when turned on, permit injection of steam into the cooling water loop.