Production of formaldehyde

Claim 1

A PROCESS PRODUCING FORMALDEHYDE BY OXIDIZING DEHYDROGENATION OF METHANOL IN THE PRESENCE OF A SILVER CATALYST AT ELEVATED TEMPERATURES, WHEREIN THE REACTION IS CARRIED OUT AT A TEMPERATURE OF 550* TO 750*C AND DURING THE REACTION AN ADDITIONAL VAPOR MIXTURE HEATED TO AT LEAST 70*C AND CONSISTING OF 0.05 TO 0.8 MOLE OF WATER AND 0.005 TO 0.6 MOLE OF OXYGEN BASED ON 1 MOLE OF FEED METHANOL IS INTRODUCED, INTO THE VAPOROUS METHANOLIC STARTING MIXTURE WHICH HAS BEEN HEATED TO AT LEAST 60*C AND CONTAINS WATER IN A MOLAR RATIO OF 0.09 TO 1.8 AND OXYGEN IN A MOLAR RATIO OF 0.35 TO 0.5, BASED ON 1 MOLE OF METHANOL, BEFORE SAID STARTING MIXTURE ENTERS THE CATALYST BED, THE SPACE VELOCITY BEING 0.9 TO 3 METRIC TONS OF METHANOL, CALCULATED 100%, PER SQUARE METER OF CATALYST BED CROSS-SECTION PER HOUR, SAID REACTION BEING CARRIED OUT IN A PLURALITY OF REACTORS ARRANGED IN PARALLEL, EACH REACTOR HAVING A BED OF SAID SILVER CATALYST OF A DIAMETER OF AT LEAST 0.5 METER SAID STARTING MIXTURE BEING FED TO THE RESPECTIVE REACTORS VIA A BRANCH LINE CONNECTING EACH RESPECTIVE REACTOR WITH A MAIN SUPPLY PIPE FOR SAID STARTING MIXTURE, AND SAID ADDITIONAL VAPOR MIXTURE BEING FED INTO AT LEAST ONE OF SAID REACTORS AT A POINT AHEAD OF THE ENTRY OF SAID STARTING MIXTURE INTO SAID CATALYST BED.