Mercury Control

DeMercTM
Scrubber Additive for Hg Capture

INTRODUCTION

DeMercTM is an Inorganic Sulfide based additive that is introduced into the Scrubber Recycle stream and sprayed with the scrubber liquor. DeMerc is not only a re-emission suppression agent but it also directly captures elemental Hg and sequesters it with the Gypsum.

DEMERCTM IS THE FIRST AND ONLY ADDITIVE TECHNOLOGY THAT NOT ONLY PREVENTS RE-EMISSION OF OXIDIZED MERCURY (Hg) IN THE SCRUBBER, BUT ALSO CAPTURES ELEMENTAL MERCURY (Hg) AND A VARIETY OF OTHER METALS.

DeMercTM Reagent

The DeMerc reagent is a complex ionic-polymeric colloid that is mixed just-in-time at the mixing manifold before being injected into the scrubber recycle stream. The two chemi- cals that are mixed are DeMercTM-A1 and DeMercTM-B25. DeMercTM-A1 is a stabilized Calcium Polysulfide, which is manufactured and stabilized to specification. DeMercTM-B25 is Mono- Calcium Phosphate, which is mixed on site from Phosphoric Acid, Water, Lime Milk and other additives, based on the application needs.

Hg Capture and Sequestration

The DeMercTM reagent is dispersed in the Scrubber liquor droplets through the top sprays and comes in contact with the flue gas. The reagent looks like a lipid to Hg in the gas stream.

This promotes a phase transfer of the Hg from the gas stream into the liquid droplet. Once inside the droplet, the Hg quickly attaches to a Sulfur molecule to form HgS. HgS molecules then combine in long chain lattices and start to crystallize forming Cinnabars.

As these Crystal lattices get com- pressed in both the dimensions, the crystal itself becomes more stable.

DeMercTM Reagent Injection System

The DeMercTM reagent injection system consists of tanks for reagent storage, pumps and an injection man- ifold where the two primary reagents are mixed and then pumped directly into the scrubber recycle loop.

Summary

DeMercTM Scrubber additive technology for Hg:

  • Inorganic Sulfide Technology
  • Prevents Hg Re-emission
  • Captures 50 – 75% elemental Hg
  • Captures a broad spectrum of heavy metals
  • Is safe and non-toxic
  • Sequesters the Hg into the scrubber solidscapture over 98% of oxidized Hg and between 50 to 75% of the Elemental Hg

DOWNLOAD our DeMERC Brochure.

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