Temporal and Oscillatory Behavior Observed during Methanol Synthesis on a Cu/ZnO/Alsubspan style=quot;font-family:Verdana;quot;2/span/subspan style=quot;font-family:Verdana;quot;O/spansubspan style=quot;font-family:Verdana;quot;3/span/subspan style=quot;font-family:Verdana;quot;(60:30:10) Catalyst

摘要

style="text-align:justify;"> The rate of Methanol synthesis over a Cu/ZnO/Al _{style="font-family:Verdana;">2} style="font-family:Verdana;">O _{style="font-family:Verdana;">3} style="font-family:Verdana;"> (60:30:10) catalyst has been measured using CO _{style="font-family:Verdana;">2} style="font-family:Verdana;">/H _{style="font-family:Verdana;">2} style="font-family:Verdana;"> (10:90) and CO/CO _{style="font-family:Verdana;">2} style="font-family:Verdana;">/H _{style="font-family:Verdana;">2} style="font-family:Verdana;"> (10:10:80) streams at 433, 443, 453, 463 and 473 K. Using the CO _{style="font-family:Verdana;">2} style="font-family:Verdana;">/H _{style="font-family:Verdana;">2} style="font-family:Verdana;"> stream, it requires 12 × 10 style="font-family:Verdana;">3 style="font-family:Verdana;"> s to achieve style="font-family:Verdana;">steady style="font-family:Verdana;">- style="font-family:Verdana;">state "=""> style="font-family:Verdana;"> performance;this time reduces to 5.4 × 10 style="font-family:Verdana;">3 style="font-family:Verdana;"> s on increasing the temperature to 463 K. Using the CO/CO _{style="font-family:Verdana;">2} style="font-family:Verdana;">/H _{style="font-family:Verdana;">2} style="font-family:Verdana;"> stream, steady State performance is not achieved even after 14.4 × 10 style="font-family:Verdana;">3 style="font-family:Verdana;"> s at 433 K but is achieved after 9 × 10 style="font-family:Verdana;">3 style="font-family:Verdana;"> s at 463 K. Significant deviations from style="font-family:Verdana;">steady state style="font-family:Verdana;"> behavior (~40% of style="font-family:Verdana;">steady state style="font-family:Verdana;">) are observed only at 453 K and only using the CO _{style="font-family:Verdana;">2} style="font-family:Verdana;">/H _{style="font-family:Verdana;">2} style="font-family:Verdana;"> feed when gas chromatography (GC) is the analysis system. When the reactor output is connected directly into a flame ionization detector (FID), style="font-family:Verdana;">oscillation style="font-family:Verdana;">is "=""> style="font-family:Verdana;"> observed at all temperatures studied using a CO _{style="font-family:Verdana;">2} style="font-family:Verdana;">/H _{style="font-family:Verdana;">2} style="font-family:Verdana;"> stream. Injection of CO into the CO _{style="font-family:Verdana;">2} style="font-family:Verdana;">/H _{style="font-family:Verdana;">2} style="font-family:Verdana;"> stream, which is synthesizing methanol at 473 K, produces a sharply spiked increase in the rate of methanol synthesis followed by an oscillatory relaxation to style="font-family:Verdana;">steady state style="font-family:Verdana;"> behavior. At 433 and 443 style="font-family:Verdana;"> K style="font-family:Verdana;">, "=""> "=""> style="font-family:Verdana;">the injection of CO into the CO _{style="font-family:Verdana;">2} style="font-family:Verdana;">/H _{style="font-family:Verdana;">2} style="font-family:Verdana;"> stream again style="font-family:Verdana;">produce style="font-family:Verdana;">s style="font-family:Verdana;"> the sharply spiked increase in the rater of methanol synthesis, which returns to the baseline value without oscillations.