SOx & NOx & HCL reduction method in CO2 capture process

Usually, SOx & NOx are removed by scrubbers. But some quantity can get to the absorbent. It pollutes the absorbent and the further liquid gas. These substances are aggressive and can damage the equipment and have the negative effect on the further purification process.

The technology is in protecting of the absorbent by adding soda (sodium carbonate, sodium bicarbonate ) to the absorbent solution for reaching PH>9 or other.
It will protect absorbent from SOx&NOx and some other components and will remove them from the mixture.

The method and the device works as the following:

SO2 + O2 + Na2CO3 → Na2SO4 + CO2;
SO2 + O2 + NaHCO3 → Na2SO4 + CO2 + H2O;
NO + O2 + Na2CO3 → NaNO3 + CO2;
NO + O2 + NaHCO3 → NaNO3 + CO2 + H2O;
NO2 + O2 + Na2CO3 → NaNO3;
NO2 + O2 + NaHCO3 → NaNO3 + H2O;
HCL + Na2CO3 → NaCl + CO2;
HCL + NaHCO3 → NaCl + H2CO3 → NaCl + CO2 + H2O.

The method creates small amount of solid bottoms which shall be removed from the lower part of the absorber in every cycle or by accumulation.

Advantages of the technology:

• Sodium carbonate and sodium bicarbonate are safe for human and for equipment
• The technology is simple and cheap
• The technology is good for popular absorbents in working plants, which are sensitive to SOx,NOx, etc.
• The technology let to produce more pure product safer using cheaper, safer, and energy efficient absorbents.