The Formaldehyde Production Process is: sending methanol to
the gasifier with a pump, the methanol is vaporized by heating the vapor coil of
the gasifier, the vaporized methanol and air mixture flows out from the top of
the gasifier, and water vapor is added to make the methanol The ratio of air and
water vapor is 1: 1.8 ～ 2.0: 0.8 ～ 1.0 (φ). This mixed gas passes through the
heater and flame arrester and enters the oxidation reactor at the temperature of
115 ～ 120 ℃. The oxidation reaction is at 600 ～ 650 ℃, 0.3 ～ 0.5MPa. The
thickness of the silver catalyst bed in the reactor is generally 10-50mm, and
the service life is 3-8 months. The reactor is a tube-type, the material is
stainless steel, the reaction heat is carried out in the form of steam, and the
single-pass methanol conversion rate is 60%. ~ 85%, the selectivity of
formaldehyde is 91% ~ 93%, the methanol decomposition rate is 7% ~ 8%, and
carbon dioxide, carbon monoxide and methane are generated at the same time.
After the material exiting the oxidation reactor is rapidly cooled to 80-85 ° C,
it enters the bottom of the absorption tower, and the process water enters from
the top of the tower. After absorption, about 37% of the formaldehyde solution
is sent to the formaldehyde distillation tower, and the distilled methanol is
circulated to the gasifier. After the bottom material is treated with anion
exchange resin, a product containing 55% formaldehyde and less than 1% methanol
is obtained.
Formaldehyde Production Plant
As a Formaldehyde Production Plant, I would like to tell you
that the current level of production of silver formaldehyde plants in China is
not far behind the advanced foreign production levels, especially the
large-scale formaldehyde plants constructed in recent years. Qualified products
within hours. After driving for a period of time, according to statistical data,
the unit consumption reached below 0.455, the alcohol content was about 1%, and
the acidity was 0.01%; the energy consumption was 25-27Kw / t, and the
investment cost was low. Of course, to achieve the above objectives, it is
necessary to integrate factors that are not conducive to production, formulate
reasonable process conditions, select equipment that meets the process
conditions, implement a management system, create a good production environment,
and overcome as much as possible on the process and equipment. There are
problems in order to obtain satisfactory results.
The consumption of raw material formaldehyde is an important technical and
economic indicator. It accounts for 80% of the cost. The average unit
consumption in the industry has dropped from 475Kg / t to the current 460Kg / t,
and many companies have a unit consumption of 455-445Kg / t.
1. When purging and igniting, the catalyst surface temperature should be
high. The general formaldehyde operation process stipulates that the overheating
temperature during purging and ignition is higher than 100 ℃. Due to the heat
loss of the pipeline from the superheater to the reactor, the actual temperature
of the raw material vapor to the catalyst surface is very low, which causes
methanol to be condensed and adsorbed on the catalyst surface during purging.
During ignition, the actual oxygen and alcohol on the adsorption surface is
relatively low, and the combustion is incomplete, forming carbon deposits.
Affects catalyst activity. Therefore, the insulation of the equipment must be
intact, and the waste heat boiler must be preheated and maintained under
pressure before starting to keep the catalyst temperature above 80 ° C when the
catalyst is ignited. It is also equipped with a suitable igniter heating power,
so that the formaldehyde production is in a better oxygen-to-alcohol ratio when
ignited, and there is a good external condition to match it.
Our company also has Silver Contact Formaldehyde Plant for
sale, welcome to consult.
