Method and apparatus for the on-stream analysis of total sulfur and/or nitrogen in petroleum products

Abstract

An improved on-stream analyzer for monitoring sulfur or nitrogen content of liquid petroleum or beverage products is described. It consists of the following main components: a sample injector for injecting predetermined fixed volumes of the liquid into a thermal oxidizer (pyrolyzer) at a preset, controlled rate, a thermal oxidizer in which an inert carrier gas and oxygen are introduced at measured and preset, controlled rates to thermally oxidize the sample at a temperature of about 1050° C., sample conditioner to control the relative humidity and temperature of the resulting gas mixture, an electrochemical cell sensitive to sulfur dioxide (SO ) or NO to measure the concentration of SO or NO in the gas mixture, and a programmable logic controller (PLC) to calculate the sulfur content of the original sample and manage the analyzer. Although the analyzer is designed primarily for monitoring sulfur content of petroleum and beverage products, it is recognized that essentially the same equipment can be used to analyze any liquid having a suitable viscosity and capable of being completely thermally oxidized under the conditions specified.