Effective treatment of residue of acrylic acid production using a fluid-bed/fixed-bed system with low energy consumption

In order to effectively deal with large amounts of complex organic pollutants in the harmful distillation residues with low energy consumption, a novel two-stage fluid-bed/fixed-bed system was designed to catalyze oxidation of acrylic acid production residue. The effects of fluid-bed temperature, gaseous hourly space velocity (GHSV), and oxygen excess rate on the purification of acrylic acid production residue in the two-stage fluid-bed/fixed-bed system were studied to prove the feasibility of the method. The chemical oxygen demand (COD) of the discharged liquid was <100 mg/L, and the volatile organic compounds (VOCs) of the discharged gas amounted to <10 mg/m³ with a fluid-bed temperature of 380°C, emulsified residue's GHSV of 0.28 L/(kg_cat·hr), and O₂ excessive rate of more than 4.32. The result of techno-economics indicates the feasibility of the long-term operation of process. Results further illustrate the advantages of the proposed two-stage fluid-bed/fixed-bed system, which can treat acrylic acid production residue with high efficiency (COD < 100 mg/L, VOCs < 10 mg/m³) and low energy consumption (~24,856 kw·hr/ton) in the chemical industry. Practitioner points: A novel two-stage fluid-bed/fixed-bed system was developed for acrylic acid production residue treatment. No extra energy was required at low temperature in the two-stage fluid-bed/fixed-bed system. Purification of residue could be finished at low temperature by the catalytic pyrolysis and catalytic oxidation process. The two-stage system did not produce toxic gases and particulate matters.