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