Technical Material · Gas TreatmentIn cleaning combustion and industrial process gases, lime captures SO₂, HCl and other acid gases. Understand how desulfurization (FGD) works and why the reactivity and specific surface area of the lime define capture efficiency.
Wherever there is combustion or a process that generates acid gases, there is a need to capture them before they reach the atmosphere. Lime is one of the central reagents in this work — in boilers, incinerators, furnaces and industrial plants that must meet ever-stricter emission limits.
Desulfurization (FGD)
The sulfur dioxide (SO₂) generated by burning sulfur-bearing fuels is captured by lime, forming calcium sulfite and sulfate. There are wet routes (scrubbers, where a lime slurry contacts the gas) and dry and semi-dry routes (where powdered or atomized hydrated lime reacts with the gas). The choice of route depends on the pollutant concentration, the gas flow and the plant's economics.
Other acid gases
Beyond SO₂, lime captures hydrogen chloride (HCl), hydrogen fluoride (HF) and other acid gases — relevant in waste incineration and in processes that release halogens. The principle is the same: the alkali in the lime neutralizes the acid and fixes it as a solid salt, removed afterward from the gas stream.
Why reactivity and specific surface area rule
Gas capture is a surface reaction: the gas must meet the lime particle and react. The greater the surface area and reactivity of the hydrated lime, the more efficient the capture for the same amount of reagent. High-specific-surface hydrated limes are sought precisely for this — they capture more per kilo, cutting consumption and waste generation. The form of the product (the grading of the hydrate, the injection method) is as important as the chemistry.
Product form
Gas treatment predominantly uses calcined lime — quicklime to prepare a slurry, or hydrated for dry injection. The quality of the calcination and the hydration defines the reactivity, which defines the capture efficiency. It is a sector where "any lime" will not do: the technical specification of the reagent is directly tied to meeting the emission limit.
Nova Ita produces lime with calcination-process control and an in-house lab, supplying a reagent of predictable character for applications where environmental compliance admits no variation. For gas-treatment projects, the right specification should be set together with the system's engineering — and it is in that technical dialogue that Nova Ita positions itself as a supplier, not a mere seller of tonnes.
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