Thermal Dissociation of Trioctylamine Hydrochloride Catalyzed by 5A Molecular Sieve

Coupled process of mineralization of CaCl₂ waste by reaction extraction crystallization will be beneficial for waste recycling and mineralization of CO₂, which has a broad application prospect. The key to low cost operation of reaction-extraction-crystallization coupling mineralization process is the effective regeneration of organic amine extractant. Solid acid catalyst is used to strengthen the pyrolysis regeneration process to realize the regeneration of organic amine. At the same time, the coupled process also produce valuable HCl gas, improving the economy value of the process. The effect of heating temperature, carrier gas flow, stirring speed, diluent amount and catalyst amount on the thermal dissociation of trioctylamine hydrochloride by 5A molecular sieve were investigated. The results showed that the pyrolysis of trioctylamine hydrochloride catalyzed by 5A molecular sieve conformed to the first-order kinetic model. The thermal dissociation reaction rate was accelerated and the conversion rate increased with the increasing of thermal dissociation temperature, carrier gas flow, diluent naphthalene and catalyst amount, and the effect of rotational speed on the thermal dissociation reaction was not obvious. Considering the conversion rate and energy consumption, the optimized pyrolysis conditions were as follows: reaction temperature 180 ℃, carrier gas flow 300 mL/min, rotating speed 150 r/min, mass ratio of triactylamine hydrochloride and naphthalene to 5A molecular sieve 1∶4 and 10∶1, respectively. Under the optimal conditions, the conversion rate reached 95% at 4 h and 99% at 8 h. The results of five cycles experiments showed that 5A molecular zeolite still had good catalytic activity.