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Bio-waste utilization is essential, and pyrolysis is a prominent way for its effective utilization. However, the gradual accumulation of ash compounds in the intermediate products probably affects the thermal conversion characteristics of bio-waste. In the present study, beech wood and disposable chopsticks were selected as bio-waste samples. The effects of typical ash components (Ca-compounds) on volatile formation behavior were investigated during the molten salts thermal treatment of bio-waste. Results demonstrated that about 80% mass of initial bio-waste was gasified into the volatiles at 300 °C. The introduction of Ca-compounds in the molten salts slightly decreased the total yield of gaseous products. More specifically, Ca²⁺ could improve the generation of CO₂ and suppress the generation of other gases (CO, H₂, and CH₄), and this is accompanied by a reduction in the low heating value (LHV) of the gases. The possible reason is that Ca²⁺ might act on the -OH bonds, phenyl C-C bond, methoxy bond and carboxylic acid -COOH bonds of the bio-waste to promote CO₂ release. In contrast, the introduction of CO₃²⁻ and OH- tended to relieve the inhibition effect of Ca²⁺ on the generation of H-containing gases. Meanwhile, the introduction of Ca²⁺ can promote the conversion of bio-waste into liquid products as well as increase the saturation level of liquid products. Moreover, as a vital form of carbon storage, CO₂ was found to be abundant in the pyrolysis gases from molten salts thermal treatment of bio-waste, and the concentration of CO₂ was much higher than that of direct-combustion or co-combustion with coal. It’s a promising way for bio-waste energy conversion as well as synchronized CO₂ capture by using molten salts thermal treatment, while the introduction of small amounts of Ca-compounds was found to have no significant effect on the change of CO₂ concentration.