The invention relates to the field of
chemical production, and in particular relates to an environment-friendly
formaldehyde preparation process which comprises the following steps: gasifying
methanol, mixing with air, and conveying the
mixed gas into a preheater, wherein the preheating temperature is 100 DEG C; then reacting, wherein the temperature inside a reactor is 200 DEG C, an iron-
molybdenum catalyst is used as a catalyst, and the reaction time is 2-5 minutes; keeping the temperature inside the reactor to be 270-300 DEG C, reducing the temperature of
formaldehyde discharged from the reactor to 100-120 DEG C, feeding into an absorbing
tower, diluting inside the absorbing
tower, sucking out when the concentration is 37-50%, circulating 20% of
formaldehyde back to the absorbing
tower, and pumping the other part of formaldehyde as a product to a formaldehyde
storage tank; recycling 60-90% of the gas discharged from the top of the absorbing tower by using a blower; and feeding the other part of the gas into a
tail gas reactor for oxidation reaction at 200-300 DEG C. According to the process, the heat in production is sufficiently utilized, the parameters are strictly controlled, the
methanol conversion rate of the process is greater than 98%, the purity of formaldehyde is 37-50%, the content of formaldehyde,
methanol and
carbon monoxide in the
tail gas is all zero, and the content of
carbon dioxide is also effectively controlled.