HBS Injection^TM is a technology for mercury oxidation and control that reduces or eliminates reliance on costly powdered activated carbon (PAC) for MATS compliance.

A patented process offered exclusively by AECOM Process Technologies, HBS Injection^TM involves the injection of a halogen-based solution (HBS) into flue gas, which reacts in-situ to form halogen species that effectively oxidize elemental mercury to a water-soluble species. The process has been demonstrated at full-scale to reduce elemental mercury levels in the flue gas by more than 75%, with a corresponding reduction in stack mercury emissions for plants operating wet (or semi-dry) FGD processes.

The proprietary liquid injection system ensures effective dispersion and utilization of the HBS solution, minimizing chemical costs and balance-of-plant impacts. Tests conducted in AECOM Process Technologies laboratories show effective mercury oxidation with or without SCR and at both high and low flue gas temperatures, allowing for injection either before or after the air preheater.

The halogen-based solution can be co-injected with the SBS Injection^TM process, greatly simplifying the system design and capital cost; or it can be injected using a simple stand-alone system.  When combined with the SBS Injection process, mercury emission reductions of up to 90% can be achieved.