1,4-butanediol Reppe process

Diol Components. Ethylene glycol (ethane 1,2-diol) is made from ethylene by direct air oxidation to ethylene oxide and ring opening with water to give 1,2-diol (40) (see Glycols). Butane-1,4-diol is stiU made by the Reppe process acetylene reacts with formaldehyde in the presence of catalyst to give 2-butyne-l,4-diol which is hydrogenated to butanediol (see Acetylene-DERIVED chemicals). The ethynylation step depends on a special cuprous... 

Butanediol is commercially produced by several different processes [7], The most prevalent process for making BDO is known as the Reppe process. This process uses acetylene, generated from natural gas, as its primary feedstock, according to the following ... 

The most recent entrant-to the. club of commodity chemicals is 1,4-butanediol (BDO), a petrochemical used in some of the more specialized applications such as chemical intermediates for the production of tetrahydro-furane and gama-butyrolactone, polybutylene terephthalate, and the more familiar polyurethanes. Traditionally, the Reppe process was the primary route to BDO, based bn acetylene and formaldehyde feeds. More recently, the share of BDO from butane and propylene oxide based production has grown rapidly. 

This Reppe process using acetylene for 1,4 butanediol is currently being replaced with processes that start with propylene oxide (C3H60), butadiene (C4H(.), or butane (C4H10). 

Reppe process - [NICKELCOMPOUNDS] (Vol 17) -butanediol om [ACETYLENE-DERIVED CHEMICALS] (Vol 1) -use of metal carbonyls [CARBONYLS] (Vol 5)... 

Butanediol is manufactured by way of hydrogenation of butynediol (the Reppe process) ... 

The Reppe process is used to make 1,4-1 butanediol from acetylene. In this process, acetylene and formaldehyde are reacted in the presence of a copper-bismuth catalyst. The resulting intermediate, 2-butyne-l,4-diol is hydrogenated over a Raney nickel catalyst ... 

Povidone is manufactured by the Reppe process. Acetylene and formaldehyde are reacted in the presence of a highly active copper acetylide catalyst to form butynediol, which is hydrogenated to butanediol and then cyclodehydrogenated to form butyrolactone. Pyrrolidone is produced by reacting butyrolac-tone with ammonia. This is followed by a vinylation reaction in which pyrrolidone and acetylene are reacted under pressure. The monomer, vinylpyrrolidone, is then polymerized in the presence of a combination of catalysts to produce povidone. 

Finally, The dehydrogenation of butanediols to y-butyrolactone is an important commercial reaction that was developed by BASF and named the Reppe process. The most probable reaction mechanism via the y-hydroxybutyraldehyde intermediate clearly shows that the reaction proceeds via two separate alcohol dehydrogenation steps with a rearrangement step taking place in-between (Table 1, Scheme 12) [49]. The reaction is usually performed in the gas phase with hydrogen as carrier gas, to reduce catalyst deactivation, which is a characteristic problem. Thus, extensive research is now being conducted in the liquid phase [50,51]. In addition to a lower catalyst deactivation rate, liquid phase reaction also reduces the number of side-products. The drawbacks are, of course, lower activity but also abrasion problems with the catalyst. The catalyst is preferably stabilized as a powder in a silica matrix (Ludox R) [51]. The catalyst most often encountered in the patent literature is a Cu-Cr with a promoter such as Ba or Mn. The catalyst is also preferably doped with Na or K and pretreated very carefully in a reducing atmosphere [52]. 

The worldwide market for butanediol (EDO) in 2003 was about 800,000 MT, of which more than half of the production used the Reppe process, which uses acetylene and formaldehyde as the raw materials. However, the industry is moving toward the cheaper technology of using maleic anhydride obtained from butane as the raw material [85]. Although other commercial processes are used to synthesize EDO starting from butadiene, dichlorobutene, or propylene oxide, we limit ourselves to processes where carbon-supported catalysts are used the... 

The oldest industrial process for 1,4 butanediol is the Reppe process developed in Germany in the 1930s. It makes use of acetylene and formalde-... 

The Reppe process is based on acetylene as a raw material. These reactions were developed by Reppe et al. [2]. In accordance with the rise of the petrochemical industry, most processes switched from acetylene to olefins as raw material. However, only the 1,4-butanediol production process continued to rely on the Reppe process. Mitsubishi Chemical Corporation developed a totally different production method that uses 1,3-butadiene to produce 1,4-butanediol and THF. Commercial production was launched in 1982 and has been continued ever since. This process ended the over-half-century monopoly of the Reppe method. The Mitsubishi Chemical method has an advantage over the Reppe method with respect to the handling of raw materials and production costs, but in recent years, Chinese companies that can take advantage of inexpensive natural gas and coal have built a new production plant by using the Reppe method and international competition is getting more intense. 

The Reppe process is a method that was developed in the 1940s and typical manufacturers include BASF, Ashland, and Invista. Cu-Bi catalyst supported on silica is used to prepare the 1,4-butynediol by reacting formaldehyde and acetylene at 0.5 MPa and 90-110 C (Eq. (10.2)). The copper used in the reaction is converted to copper(I) acetylide, and the copper complex reacts with the additional acetylene to form the active catalyst. The role of bismuth is to inhibit the formation of water-soluble acetylene polymers (i.e., cuprenes) from the oligomeric acetylene complexes on the catalyst [5a]. The hydrogenation of 1,4-butynediol is accom-pUshed through the use of Raney Ni catalyst to produce 1,4-butanediol (Eq. (10.3)). The total yield of 1,4-butanediol production is 91% from acetylene [5b]. Since acetylene is a highly explosive compound, careful process control is necessary. 

BD is synthesized by reacting acetylene with formaldehyde to produce 1,4-butyn-ediol through what is called the Reppe process. This 1,4-butynedioi is hydrogenated into 1,4-butanediol, see Figure 7.19. 

Diacetoxy-2-butene. Mitsubishi commercialized a new proces, the acetoxy-lation of 1,3-butadiene, as an alternative to the Reppe (acetylene-formaldehyde) process for the production of l,4-diacetoxy-2-butene. l,4-Diacetoxy-2-butene is tranformed to 1,4-butanediol used in polymer manufacture (polyesters, polyurethanes). Additionally, 1,4-butanediol is converted to tetrahydrofuran, which is an important solvent and also used in polymer synthesis. 

The 1,3-butadiene-based 1,4-butanediol process was reviewed in this chapter. This method ended the half-century monopoly of the acetylene-based Reppe method. This development was in line with the switch from coal to petroleum feedstock. Because the acetoxylation of 1,3-butadiene was the first successful commercial... 

Conventional processes for the synthesis of butanediol use petrochemical feedstocks for their starting materials. For example, acetylene is reacted with 2 molecules of formaldehyde in the Reppe... 

---