Desulfuración de Gases de Combustión (Lavado Húmedo con Caliza)

Eliminación de SO₂ de los gases de escape de las centrales eléctricas para prevenir la lluvia ácida

Environmental & Water Treatment Global Industrial Scale $20 billion

Descripción general

Flue gas desulfurization (FGD) removes sulfur dioxide from coal-fired power plant exhaust using limestone or lime slurry scrubbing. The wet limestone process is the most widely deployed FGD technology, removing >95% of SO2 and producing synthetic gypsum as a saleable byproduct. FGD is the primary technology responsible for reducing acid rain in North America and Europe since the 1970s. More than 300 GW of coal-fired power capacity worldwide is equipped with FGD systems.

Proceso químico

Flue gas from the boiler passes through an absorber tower where it contacts a recirculating slurry of crushed limestone (CaCO3) in water. SO2 dissolves in the slurry and reacts with limestone to form calcium sulfite. Forced oxidation with air converts calcium sulfite to gypsum (CaSO4.2H2O). The gypsum is dewatered by hydrocyclones and vacuum filters for sale to wallboard manufacturers.

SO2 + H2O -> H2SO3 (absorption)
CaCO3 + H2SO3 -> CaSO3 + CO2 + H2O
CaSO3 + 1/2O2 + 2H2O -> CaSO4.2H2O (forced oxidation to gypsum)

Materias primas

  • Limestone (CaCO3) — Quarrying (Alkaline sorbent (low cost, widely available))
  • Air (O2) — Atmosphere (for forced oxidation) (Oxidizing agent to form gypsum)
  • Water (H2O) — Plant water supply (Slurry medium)

Productos finales

  • Synthetic gypsum (CaSO4.2H2O) — Wallboard/drywall manufacturing, cement additive (>95% purity, replaces mined gypsum)
<path stroke-linecap="round" stroke-linejoin="round" d="M12 9v3.75m-9.303 3.376c-.866 1.5.217 3.374 1.948 3.374h14.71c1.73 0 2.813-1.874 1.948-3.374L13.949 3.378c-.866-1.5-3.032-1.5-3.898 0L2.697 16.126zM12 15.75h.007v.008H12v-.008z" />

Environmental Impact

FGD has reduced SO2 emissions from US power plants by over 90% since the 1970 Clean Air Act. Synthetic gypsum production displaces gypsum mining. However, FGD increases water consumption and generates wastewater containing mercury, selenium, and other trace elements. FGD wastewater treatment is now required under EPA regulations.

Consideraciones de seguridad

Innovaciones recientes

Seawater FGD uses natural alkalinity of seawater, eliminating limestone costs in coastal plants.
Dry and semi-dry scrubbing (lime spray dryer absorbers) reduce water consumption.
Multi-pollutant control combining SO2, NOx, and mercury removal in a single system is being developed.

Más en Environmental & Water Treatment

Frequently Asked Questions

What industry uses Desulfuración de Gases de Combustión (Lavado Húmedo con Caliza)?
Desulfuración de Gases de Combustión (Lavado Húmedo con Caliza) is used in the environmental & water treatment sector at global industrial scale scale.
What process is involved in Desulfuración de Gases de Combustión (Lavado Húmedo con Caliza)?
Flue gas from the boiler passes through an absorber tower where it contacts a recirculating slurry of crushed limestone (CaCO3) in water. SO2 dissolves in the slurry and reacts with limestone to form calcium sulfite. Forced oxidation with air converts calcium sulfite to gypsum (CaSO4.2H2O). The gyps
What is the economic significance of Desulfuración de Gases de Combustión (Lavado Húmedo con Caliza)?
Desulfuración de Gases de Combustión (Lavado Húmedo con Caliza) has a market value of $20 billion.
What is the environmental impact of Desulfuración de Gases de Combustión (Lavado Húmedo con Caliza)?
FGD has reduced SO2 emissions from US power plants by over 90% since the 1970 Clean Air Act. Synthetic gypsum production displaces gypsum mining. However, FGD increases water consumption and generates wastewater containing mercury, selenium, and other trace elements. FGD wastewater treatment is now
What raw materials are used in Desulfuración de Gases de Combustión (Lavado Húmedo con Caliza)?
The main raw materials include: Limestone (CaCO3), Air (O2), Water (H2O).