By definition, biomass power production uses organic materials like wood, agricultural waste, and leftover plant matter to fuel the furnaces that generate electricity. On the spectrum of energy sources, biomass power is one of the cleaner options. But as with any combustion, the process behind biomass power production releases various emissions that often need to be mitigated for your plant to stay within regulations. Motus Group is very familiar with what biomass plants emit and can create a bespoke solution to amend your current setup so you can mitigate these gases.
Dioxins, furans, and dioxin-like polychlorinated biphenyls (PCBs) are the abbreviated names for a family of chemicals with similar toxicity and shared chemical characteristics. These chemicals occur as a byproduct of the chemicals made when burning hardwoods, household trash, or with the chlorine bleaching of pulp and paper (just a few examples). Prior to their banning in 1979, PCBs were manufactured as insulator fluids for heat exchangers, hydraulic fluids, and additives to paints and oils. Since their outlawing, they are no longer manufactured but are still very present in the environment as they work their way through ecosystems and food chains.
All of these chemicals remain in the environment even though they are no longer manufactured. As the emissions settle into the soil, they integrate with plant life which is then eaten by animals, upscaling through various ecosystems. We have already done the best thing we can do to reduce PCB impact by banning their production.
Sulfur Dioxide (SO2) – Dry Sorbent Injection (DSI – Hydrated Lime, Trona, and Sodium BiCarbonate)
You will typically see sulfur dioxide when burning coal or oil, but we’ve also seen it when burning biomass with sulfur compounds like woods and leafy greens (insert flatulence joke here). In all seriousness, because of the potential respiratory issues tied to SO2, it often sees the most regulation. Plants will typically treat emitted gases to remove sulfur before they are released.
We usually advise a Dry Sorbent Injection system (DSI) to distribute Hydrated Lime, Trona, and Sodium BiCarbonate to neutralize the harmful components of sulfur dioxide. Modern plants usually have some kind of system in place, but we have retrofitted older plants with equipment to help them reduce their emissions.
Mercury – Activated Carbon Injection (ACI – Activated Carbon) and Pre-Combustion Halogen Additives (Calcium Bromide – CaBr2; M-Prove – Potassium Iodide)
We have come a long way in developing ways to minimize the release of mercury from power plant emissions. Mercury is most often seen in the emissions from oil and coal power production or through the burning of iron ore, coke, and limestone in arc furnaces. But you can also find mercury naturally occurring in some wood products that are burned in biomass, not to mention the burning of contaminants that make their way into some biomass fuels. An Activated Carbon Injection (ACI) system and pre-combustion halogen additives are the ideal solutions to scrub mercury from your emissions.
With any chemical reaction – like burning fuels to produce energy – there will always be some kind of remnant that you aren’t sure what to do with. Biomass releases gases, but scrubbers, electrostatic, and catalytic reduction systems are just a few of the ways we can reign in what gets emitted to keep your plant within regulatory standards.