Determination of total mercury in exhaust gases
US5879948A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 1997 |
| Grant date | Mar 9, 1999 |
| Priority date | — |
| Expiry date | May 12, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/25875
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention relates to a system, apparatus, and process to reduce the oxidized mercury in an exhaust gas to elemental mercury and to prevent its reoxidation by congeneric components in the exhaust gas prior to the photometric measurement of said elemental mercury. In the process, the sample stream flows through a reactor heated to preferably about 800.degree. C. in which a stream of hydrogen is introduced directly into a hot portion thereof. The congeneric oxidized mercury species, i.e, HgCl.sub.2, and HgO are thermally reduced quantitatively to elemental mercury. The hydrogen reacts in situ with oxygen to form water vapor and with chlorine to form hydrochloride gas. The hydrochloride gas is effectively absorbed by the water vapor and consequently prevents the reoxidation of elemental mercury. The concentration of total mercury in a stream can then be determined by the intensity of radiation absorbed by a UV spectrometer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.