Influence of BaCO3 on chlorine fixation, combustion characteristics and KCl conversion during biomass combustion

- BaCO3 had better performance on chlorine fixation from simulation and experimental results.
- Observation of BaSO4 and BaCl2 showed that BaCO3 fixed chlorine and sulfur simultaneously.
- The index S increased with the addition of BaCO3 in TG/DTG analysis.
- The appropriate additive ratio between biomass, NH4H2PO4 and BaCO3 could be K:P:Ba = 1:1.5:1.

The influence of BaCO3 on chlorine fixation and combustion characteristics was investigated in a fixed bed system and thermal analyzer. Both simulation and experimental results show the stability of BaCl2 was much better than CaCl2 at temperature higher than 800 °C. The chlorine fixation of cotton stalk was improved 5.35 times by BaCO3. The barium chlorides in the ashes were mainly BaCl2 and Ba(ClO2)2. Obvious peaks of BaSO4 showed the ability of BaCO3 for fixing both chorine and sulfur simultaneously. With the addition of BaCO3, the Tf and S increased and the E decreased in different degree. The reactivity of elements in KCl, NH4H2PO4 and BaCO3 were deduced as: Cl-Ba < Ba-P < K-P. Excessive addition of BaCO3 may decrease the production of potassium phosphates. The reasonable additive ratio between biomass, NH4H2PO4 and BaCO3 could be K:P:Ba = 1:1.5:1.