BioLargo Engineering > Projects > mercury oxidation


Project Desciption

BioLargo Engineering was contracted to verify the effectiveness of the EMO™ technology on a coal-fired steam generating unit (SGU) located in Minnesota. The unit is a 25 Megawatt unit that produces power for the corn ethanol production plant. BioLargo Engineering performed a proof-of-concept field trial tailored to the unique characteristics of the unit. The field trial provided preliminary validation of oxidation and removal of mercury under conditions specific to the plant’s fuel type and process configuration (i.e., process design, equipment type, and combustion conditions). An overview of the field sampling and resulting analytical data from this field trialis presented in this report.

CategoryPollution Control Systems



EMO Field Trial Process

The field trial evaluated the technical feasibility of utilizing the EMO post-combustion injection system for reducing mercury in stack emissions at the Heron Lake facility. The testing and evaluation project consisted of sampling the flue gas stream for the following target parameters: Oxides of nitrogen (NOX), Sulfur dioxide/sulfur trioxide (SO2/SO3), Carbon monoxide (CO), Mercury speciation [total mercury (HgT), elemental mercury (Hg0), and oxidized mercury (Hg+2)], Filterable particulate matter (FPM) and condensable particulate matter (CPM), Halogens and hydrogen halides (Cl2, Br2, HCl, HBr, HF), and Ammonia (NH3) slip.

Selected pollutants were measured in conjunction with other stack gas parameters to determine the gas stream concentrations, mass emission rates, and removal efficiencies. In addition to gas stream data, samples of coal and fly ash were also analyzed. The analytical data from the solids materials were used to estimate a material balance across the process. All sample data was then correlated with process data (ammonia injection, sorbent injection, boiler steam production rate, and final product rates) to determine optimal system conditions.

Work Scope

Specific tasks that were performed by BioiLargo’s Engineering team included:

  • The system performed to meet all existing and anticipated mercury emission limits for the unit and a full scale.
  • A permanent system is being designed for the site
  • Highest standards in cost control

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