Determining catalyst deactivation involves a comprehensive assessment based on both general characteristics and specific testing parameters. The key methods are as follows:
Assessment of Reaction Conditions
Typical signs of deactivation include a gradual downward shift in the reactor bed's peak temperature zone, a significant reduction in the overall temperature rise, a noticeably slower reaction rate under identical operating conditions, a marked drop in target product conversion and yield, pollutant concentrations at the outlet exceeding limits, and an abnormal increase in electric heating energy consumption.
Physical State Inspection
Direct visual inspection of the catalyst; signs such as sintering, fragmentation, agglomeration, discoloration, or pore blockage due to carbon deposits indicate structural damage and a high probability of deactivation.
Specific Parameter Testing
Using specialized instruments to measure parameters such as specific surface area, pore volume, and active component content; if these values deviate from design specifications, the loss of activity can be precisely determined.
Typical Characteristics in Specific Scenarios
Automotive three-way catalysts: Deactivation is indicated by pungent, black exhaust fumes; reduced power and increased fuel consumption; synchronized voltage readings between upstream and downstream oxygen sensors; and the absence of a significant temperature difference across the catalytic converter.
Industrial desulfurization catalysts: Deactivation is confirmed if outlet gas sulfur content exceeds limits or if activity metrics fail to meet standards.
