Hcl monitoring apparatus and method for process gas streams

Abstract

An HCl monitor is provided for the extractive analysis of high-temperature, high-pressure, coal-derived process streams. The monitor is capable of HCl concentration measurement in the presence of all known coal gasification products, with detection being based on the ability of HCl to protonate a high boiling alcohol (solvent) and, thus, enhance the conductivity of the alcohol. Conductivity is then related to HCl concentration. The observed high degree of sensitivity that can be achieved is a result of analyte preconcentration prior to the conductivity measurement due to the fast dissolution rate of HCl into the alcohol solvent, coupled with a large analyte gas-to-solvent ratio.

What is claimed is: 
     
       1. A method for monitoring the amount of HCl in a HCl containing gasification process stream or in other HCL containing process gas streams, said method comprising: measuring the initial conductivity of a high boiling point alcohol solvent capable of being protonated by HCl at a high temperature;   mixing the solvent with the HCl containing process stream at high temperature to protonate the solvent and thereby increase the conductivity therefrom; and   measuring the increased conductivity of the solvent as an indication of the amount of HCl in the process stream.   
     
     
       2. A method as claimed in claim 1 wherein said solvent comprises a cis-and-trans mixture of 1,3 cyclohexanodiol. 
     
     
       3. A method as claimed in claim 1 wherein the steps of measuring the initial conductivity of the solvent, mixing of the solvent with the process stream and measuring the increased conductivity of the solvent are performed using a conductivity cell. 
     
     
       4. A method as claimed in claim 3 further comprising using a mass flow controller to control the flow of the process stream to the conductivity cell, said method including the steps of separating water vapor and the solvent from the process stream prior to control of the flow by said mass controller.