Caprolactam from butadiene

The DuPont direct hydrocyanation of butadiene process for the production of hexamethylene diamine can also be adapted for the production of caprolactam. Partial hydrogenation of the adiponitrile intermediate in which only one cyanide group is converted to the amine, followed by hydrolysis of the remaining cyanide group and ring closure can produce s-caprolactam. The process has not been developed commercially. It is also possible that a two-stage butadiene car-bony lation process to produce caprolactam, developed by DSM and Shell, may be further developed. 

Caprolactam is polymerized to produce nylon 6 by opening the ring with high temperature water at 250°-280°C to give co-amino acid [NH2(CH2)4C00H]. The amino acid can later react with either a second acid molecule or a caprolactam molecule. Temperature control and the water content of the mixture are important parameters during the polymerization process. 

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ALTAM A process for making caprolactam from butadiene and carbon monoxide. Developed by DSM in the late 1990s and subsequently improved by Shell Chemicals, which contributed catalyst know-how. In the first two steps of the process, butadiene undergoes two hydroformylations with carbon monoxide, followed by reductive animation with ammonia and then cyclization to caprolactam. First commercialization was expected in Taiwan. A joint venture with Chiyoda Corporation, to further develop and commercialize the process, was announced in 2002. 

Nylon-12. Laurolactam [947-04-6] is the usual commercial monomer for nylon-12 [24937-16-4] manufacture. Its production begins with the mixture of cyclododecanol and cyclododecanone which is formed in the production of dodecanedioic acid starting from butadiene. The mixture is then converted quantitatively to cyclododecanone via dehydrogenation of the alcohol at 230—245°C and atmospheric pressure. The conversion to the lactam by the rearrangement of the oxime is similar to that for caprolactam manufacture. There are several other, less widely used commercial routes to laurolactam (171). 

Commercial routes from acrylonitrile and from caprolactam have also been developed. This diamine may also be prepared from furfural and from butadiene. 

Alternatively, caprolactam can be produced from butadiene, via homogeneous nickel-catalysed addition of HCN (DuPont process) followed by selective catalytic hydrogenation of the adiponitrile product to the amino nitrile and vapor phase hydration over an alumina catalyst (Rhodia process) as shown in Fig. 1.49 [137]. 

Butadiene is trimerized with a Ziegler-Natta catalyst to give 1,5,9-cyclo-dodecatriene which is then hydrogenated to cyclododecane. Dodecyl lactam is then obtained by a series of reactions similar to those used to prepare caprolactam from cyclohexane (Section 9.2.2.5). 

Another contrarian, DSM in the Netherlands, had been a state-owned company before it became privatized, a process that began in 1989 and was completed in 1996. From its past it had inherited positions in fertilizers, industrial chemicals, and such intermediates as melamine and caprolactam as well as polyolefins, with access to basic olefins through its own crackers in Geleen, Netherlands. In 1997 DSM acquired the polyethylene and polypropylene operations of FIuls (VEBA) with the Gelsenkirchen site. The company had also diversified into elastomers, having purchased in the United States the Copolymer Rubber and Chemical Corporation, which contributed to DSM s expansion into the fields of ethylene propylene, styrene butadiene, and nitrile rubbers. DSM is also a supplier of industrial resins and engineering... 

In terms of sustainability, the process starting from propene would be preferable, since it avoids the risks connected with the use of HCN in the butadiene route, even if produced on demand. However, the butadiene route to produce adiponitrile (ADN) is more cost-effective, owing to the need to use an electrochemical reaction for acrylonitrile dimerization. The problem of cost, however, is highly dependent on several factors, including sensitivity to natural gas prices (which influences butadiene cost), the market for acrylonitrile, and soon. The acrylonitrile route is used by Solutia, BASF and Asahi Kasei. New plants to make caprolactam, using ADN as intermediate, are under construction in Asia. 

Etiiylene or propylene and their copoljmiers Block copolymers such as butadiene-stjrene or stjrene-butadiene-styrene Polyetiier polyols block copolymers prepared from reaction of ethylene oxide or propylene oxide witii polyhydric alcohols used for polyuretiiMie preparation Poljmierization of S-caprolactam Polyetiiylene-propylene copolymer Formaldehyde resin (UF, MF, PF)... 

Other chemical products, often referred to as connnodity chemicals, are required in large quantities. These are often intermediates in the manufacture of specialty chemicals and industrial and consumer products. These include ethylene, propylene, butadiene, methanol, ethanol, ethylene oxide, ethylene glycol, ammonia, nylon, and caprolactam (for carpets), together with solvents like benzene, toluene, phenol, methyl chloride, and tetrahydrofuran, and fuels like gasoline, kerosene, and diesel fuel. These are manufactured in large-scale processes that produce billions of pounds annually in continuous operation. Since they usually involve small well-defined molecules, the focus of the design is on the process to produce these chemicals from various raw materials. 

Nylon 6 (poly (e-caproamide), polycaprolactam) can be made by anionic polymerization of caprolactam using strong bases, e.g. NaOH. This technique is mainly confined to RIM (section 1.4). Nylon 6 is made commercially by the ring-opening polymerization of caprolactam in the presence of water (via the intermediate H2N(CH2)sCOOH). Nylon 12 is made by the ring opening of lauryllactam which is obtained from the butadiene trimer, cyclododecatriene (CDT). It has a very low water absorption and is used for oil-resistant tubing. 

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