Development of an Extractive, Continuous Monitor to Analyze Hydrogen Chloride in Coal-Derived Process Streams.

摘要

An HCl monitor has been developed at the Morgantown Energy Technology Center for the extractive analysis of high-temperture/high-pressure, coal-derived process streams. This monitor can measure HCl concentrations in the presence of all known coal gasification products. Detection is 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. Preconcentration is caused by the apparently fast dissolution rate of HCl into the alcohol solvent coupled with a large anlyte gas-to-solvent, volume flow rate ratio. The linear dynamic range of the HCl monitor is two orders of magnitude. However, since the degree of preconcentration can be adjusted by changing either the solvent or analyte gas flow rate, the HCl monitor has an extended operating range of six orders of magnitude (parts per billion (ppB) lower limit, percentage upper limit). The practical lower detection limit for the HCl monitor is estimated to be 50 parts per billion, volume (ppbv). Precision is good: typical relative average deviations are about three parts per hundred. Although the HCl monitoring method was originally designed for analyzing gasification process streams, the system can be adapted for use with a variety of process gas streams. 40 refs., 8 figs., 3 tabs. (ERA citation 13:054059)