This process was repeated, however, gradually diminished yields were obtained through the 4 th to 7 th runs. After the 7 th run, the interior structure of the ABS-SO3H plug collapsed or deteriorated to such an extent that solution could not flow through the plug. The carbon fiber reinforced ABS printed catalyst (ABS(CF)-SO3H) was also used in the pinacol rearrangement of epoxide 1 (Table ). Using a similar procedure as the ABS-SO3H catalyst, the conversions provided yields over 90% for ten consecutive batches. The results confirmed that the ABS(CF)-SO3H printed catalyst exhibited better durability in the flow chemistry. This may be a consequence of the greater thickness of the chamber walls (required for printing the plug with obtained. Thus, the ABS(CF)-SO3H printed catalyst worked continuously for two days producing a quantitative yield of ketone 2. When the pure fractions were combined, an 82% overall yield was obtained. No effort was made to optimize this yield or process.