Additionally referred to as the acetylenic aldehyde method, this procedure is a conventional method for producing BDO and is divided right into timeless technique and boosted approach
( 1) Timeless technique
Under the problems of high pressure (13.8 ~ 27.6 MPa) and 250 ~ 350 ℃, acetylene and formaldehyde react in the presence of a driver (generally cuprous acetylene and bismuth on a silica service provider), and after that the intermediate is responded with Raney nickel stimulant L, 4-butynediol is hydrogenated to create BDO. The regular theoretical yield (based on acetylene) of the entire procedure is 91%. The characteristic of the classic approach is that the stimulant and item do not require to be separated and the operating expense is reduced. Nevertheless, the partial stress of acetylene is high and there is a threat of surge. The safety variable of the reactor design is as high as 12 to 20 times. The tools is huge and costly, and the investment is high. Acetylene will polymerize to develop polyacetylene that shuts down the stimulant and obstructs the pipeline, thus triggering a production cycle. reduced and generate decreased.
( 2) Improvement method.
In the first step, acetylene and formaldehyde are positioned in an activator made up of a number of slurry bed reactors attached in collection, and an improved Cu catalyst is used to respond at 79 to 90 ° C and 0.12 to 0.13 MPa to generate butyne diol. After purification, the driver continues to be in the reactor after separation from the catalysts, and the fluid stage product drains of the activator and is detoxified before going into the following activator. The conversion rate of formaldehyde in this response is 98%, and the yield of 1,4-butynediol is 95%.
In the second action, a boosted Pd/C stimulant is utilized in the slurry bed. Butyne diol is hydrogenated at 60 ~ 70 ° C and 2.0 ~ 2.5 MPa to create butene diol and BDO, and then in the filled up activator, Ni is utilized as a stimulant to hydrogenate butene diol at 120-150 ° C to generate BDO. Lastly, BDO is cleansed via distillation and slim film dissipation. The purity of BDO is ≥ 99%. The technical attributes of the boosted approach are:
a. Utilizing an improved Cu catalyst and low-pressure procedure, the decomposition stress of acetylene itself does not surpass 0.14 MPa, which streamlines outside safety and security centers and removes the requirement for high-pressure containers and compressors;
b. The reactor is outfitted with an unique purification system to facilitate the splitting up of driver and catalysts in the reactor;
c. Butyne diol utilizes a better Pd/C driver and is hydrogenated to create butene diol and BDO. Butene diol is hydrogenated and exchanged BDO utilizing Ni as the driver;
d. The feed make-up is a lot more adaptable. The formaldehyde web content in the formaldehyde liquid remedy can be 2 to 10%. No inert gas dilution is needed when feeding acetylene. According to estimates, running costs and financial investment are decreased by 10 to 20% compared to the timeless approach
This process was efficiently created by Japan’s Mitsubishi Chemical Company in the 1970s. Proceed in 3 steps:
( 1) Utilizing Pd-Te/activated carbon as a driver at a temperature of 60 ° C and a stress of 6.9 MPa, butadiene undertakes an acetyl oxidation response with acetic acid and oxygen to generate 1,4-ethylenediacetoxy in a fixed-bed reactor Base-2-butene;
( 2) The response option after removing acetic acid is catalytically hydrogenated in a repaired bed activator at the same temperature and pressure to create 1,4-ethylenediacetoxybutane;
( 3) BDO and 1-acetoxy-4-hydroxybutane are created by hydrolysis with a cation exchange material, and the latter is deacetoxylated and cyclized right into THF using an ion exchange resin. The regular academic return (based on butadiene) is 80% to 85%. The process features of this approach are that the raw material sources utilized are abundant, there are no safety hazards, and the yields of intermediate items and items are high. By changing the hydrolysis conditions, the production proportion of BDO and THF products can be changed.
This procedure was developed by Japan’s Kurali Business. Leondell, which primarily creates propylene oxide, acquired a patent certificate for this modern technology and developed a factory in Texas, United States. The process course is: catalytic isomerization of propylene oxide to create allyl alcohol, hydroformylation of allyl alcohol in the existence of rhodium stimulant, and the product is hydrogenated in the presence of Raney nickel catalyst to create BDO. The regular theoretical return is 93%. This process has reduced financial investment, straightforward process, high application value of byproducts, recyclable rhodium-based stimulants, lengthy life, high 1,4-butanediol return, low steam consumption, and hydroformylation and hydrogenation are fluid phases. response, it is easy to change the procedure load, and the result of 1,4-butanediol can be readjusted according to the market. The business economics of the process depend greatly on the rate of the raw material propylene oxide.
This procedure is a production method that incorporates the gas stage oxidation technique of n-butane to produce maleic anhydride and the hydrogenation innovation of maleic anhydride. n-butane is oxidized under a vanadium and phosphorus combined oxide catalyst to generate maleic anhydride, which is after that quenched with water to create maleic acid, and then catalytically hydrogenated in a fixed-bed activator to produce BDO. This process eliminates the maleic anhydride dehydration, filtration and esterification procedures, and decreases the main processes from 8 to 4, consequently shortening the whole process and reducing the number of equipment. The investment expense can be minimized by 20%, and the manufacturing expense can be conserved by 25 ~ 40%. This procedure has couple of by-products and can convert mostly all maleic anhydride into BDO. In the hydrogenation, recovery and filtration processes, THF can also be produced by suitably adjusting the process problems.
The Ding art has 3 steps:
( 1) n-butane is oxidized by air to maleic anhydride under the activity of a stimulant, and after that the maleic anhydride undertakes an esterification reaction with ethanol under the action of the stimulant to develop maleic anhydride diethyl ester;
( 2) Diethyl maleic anhydride is hydrogenated under the activity of a catalyst to produce BDO, γ-butyrolactone and THF;
( 3) Splitting up and filtration of response products. By readjusting the procedure conditions, the ratio of BDO, γ-butyrolactone and THF can be altered.
The BDO production of this procedure has actually set you back benefits, a lot of new devices have actually been constructed utilizing this process in recent times, which is also the major advancement pattern of BDO manufacturing procedure.
