about 7 crystalline borosilicate molecular sieve in the form of an extrudate 1 16 inch was calcined overnight at 500 u00b0 c the calcined extrudate was crushed and sieved to 18 40 mesh a tubular quartz reactor was charged with 3 27 grams 5 cc of the sieved particles the tubular quartz reactor approx 10 mm inside diameter was equipped with a quartz thermowell terminating at about the midpoint of the catalyst bed a liquid feed solution was prepared in a pressurized 50 ml autoclave using 11 13 grams of paraformaldehyde 95 15 94 grams of methanol and 1 80 grams of water contents of the autoclave were stirred and heated to temperatures of 130 u00b0 to 140 u00b0 c for 1 hour and then cooled the resulting solution was fed by a syringe pump into a preheat zone above the catalyst bed using mass flow controllers a gas feed mixture of dimethyl ether and nitrogen was also fed to the top of the reactor liquid products from the reactor were collected in a cool 0 u00b0 c 25 ml flask for subsequent weighing and gc analysis gases exiting the collection flask were analyzed by on line gc using both tcd and fid detectors samples of liquid products were collected during sampling intervals of 2 hours over an approximately 16 hour period of operation gas analyses were obtained by gc during each sampling interval two samples were collected while temperature of the catalyst bed was controlled to three progressively higher temperatures each sample was about 7 grams operating conditions and results are summarized in tables i iii net conversion of the methoxy moiety net meo percent is an indication of the conversion of groups regardless of.