Caprolactam production

Economic Aspects and Uses. Almost all ammonium sulfate is used as a fertilizer for this purpose it is valued both for its nitrogen content and for its readily available sulfur content. In 1986/1987 United States consumption of ammonium sulfate was 0.57 million metric tons (34) world consumption during the same period was estimated at 13.3 million metric tons. In North America ammonium sulfate is largely recovered from caprolactam production. 

Estimated worldwide aimual caprolactam production capacities are shown in Table 3. New plant constmction is plaimed in Korea, Taiwan, India, China, and Indonesia. Total new capacity over the next 10 years could exceed 500,000 tons per year. 

Estimated aimual cyclohexanone production capacities are shown in Table 3 the production is greater than 90% captive for caprolactam production (13). The aimual cyclohexanol production is only 10 thousand metric tons. These production figures do not include KA-od (cyclohexanol-cyclohexanone) production for adipic acid. Worldwide annual capacity for cyclohexanone is approximately 3.0 million metric tons, also primarily for caprolactam production. Projected new capacity for caprolactam could add 0.5 million metric tons worldwide in this decade. 

Rosa Llusar was born on September 20th, 1960 in Almenara (Spain). She studied chemistry at the University of Valencia (Spain) where she graduated in 1983 with the highest honors. Her doctorate work was devoted to the chemistry of cubane-type molybdenum and tungsten sulfides and she received Ph.D. degrees from Valencia University in 1987 and from Texas A M University (USA) in 1988, under the guidance of Prof. F. Albert Cotton. After working in the Research and Development Department of a Caprolactam Production Plant in Castello (Spain) for three years, she spent one year (1992) with Prof John D. Corbett at the... 

Residues from caprolactam productions have been proposed as surfactants [1772]. 

V. P. Belov, V. V. Zhivaeva, and K. K. Egorov. Use of caprolactam production wastes as a plasticizer of plugging slurries, /zv Vyssh Ucheb Zavedenii, Neft Gaz, (4) 15-18, April 1989. 

Production processes for chemical commodities exist often already for decades and are continuously enhanced as shown in the following example from the 1970s. Commodity production processes this time already have been rather complex composed by multiple reactions and interim steps as shown in the following example of Caprolactam production, an intermediate product for Polyamide (Sittig 1972, p. 139) in fig. 35. 

Continuous Production Process for Caprolactam Production via Nitrocyclohexanone and Aminocaproic Acid... 

Estimated annual cyclohexanone production capacities were 665x Iff1 t in 1992 the production is greater than 90% captive for caprolactam production. The annual cyclohexanol production is only 10 thousand... 

Catalytic synthesis of hydroxylamine from nitrogen oxide and hydrogen is widely used in industry as a constituent part of caprolactam production. The reaction is conducted in aqueous sulfuric acid solution saturated with NO and H2 at 40°C and a pressure of approximately 1 atm. Platinum supported on porous graphite, in the form of fine particles suspended in the intensely stirred solution, is used as a catalyst. The main direction of the reaction is... 

Of the total US ammonium sulfate capacity, 75% is a by-product of caprolactam production. The balance comes primarily from the sources shown in Table 12.3. Direct synthesis accounts for less than 15% of US capacity. AS demand will probably fluctuate in the range of 2.2 to 2.6 million tons per year for the foreseeable future. And it has been in this same range since 1970. Any real demand growth may be more a factor of increased supply as a by-product of the caprolactam marker243. 

Figure 21.2. BASF caprolactam production. (Reproduced by permission of Wiley-VCH)...

The Shell DeNO process as an add-on process is of interest for a wider range of applications. In addition to the treatment of gases from combustion sources such as furnaces and boilers, we may also consider NO removal from heaters, gas turbines, stationary reciprocating gas engines, etc. The modular construction of the PPR and LFR makes these types of reactor suitable for a wide range of reactor sizes, down to relatively small ones. We may also foresee applications in the treatment of NO -containing waste gases from the chemical industry, e.g., in nitric acid and caprolactam production or in catalyst manufacture. 

This cyclic amide is of major importance as the single monomer used to produce nylon 6, which rivals nylon 6,6 in utility and in volume of production (Chap. 21). Cyclohexanone is required as the starting material for s-caprolactam production. The mixture of cyclohexanol and cyclohexanone obtained initially from the air oxidation of cyclohexane for the second stage en route to adipic acid may be used. Subjecting the mixture to dehydrogenation converts the cyclohexanol component to cyclohexanone producing suitable starting material for this process (Eq. 19.61). 

Caprolactam production, like that of hexamethylenediamine, is dedicated to the production of a single product, in this case the various forms of nylon 6,6. 

Batch and continuous processes are also used for the preparation of nylon 6 resin. To initiate the process, caprolactam and water are heated together at about 250°C for a period of 10-12 hr in an inert atmosphere. The ring-opened caprolactam product, 6-aminohexanoic acid (Eq. 21.11),... 

Caprolactam (world production of which is about 5 million tons) is mostly produced from benzene through three intermediates cyclohexane, cyclohexanone and cyclohexanone oxime. Cyclohexanone is mainly produced by oxidation of cyclohexane with air, but a small part of it is obtained by hydrogenation of phenol. It can be also produced through selective hydrogenation of benzene to cyclohexene, subsequent hydration of cyclohexene and dehydrogenation of cyclohexanol. The route via cyclohexene has been commercialized by the Asahi Chemical Company in Japan for adipic acid manufacturing, but the process has not yet been applied for caprolactam production. 

Although many units based on phenol are still in operation, new plants use cyclohexane as the raw material In 1987,68 per cent of worldwide caprolactam production capacity... 

Caprolactam production a survey of current technology", Europ. Chem. News, 24-25(30 April 1976). Toluene rivals conventional caprolactam feedstocks . urop. Chem. News, 20-22 (25 June 1976). 

Alternatives to the use of urea in printing and some continuous reactive dyeing methods are ongoing. Use of a dicyandiamide in the dyebath has been shown to reduce the amount of urea required (Phillips, 1996). Caprolactam products can result in partial or complete substitution for urea in reactive dyeing and in printing of cotton fabrics (Sheth and Musale, 2004). 

Olevsky, V. M. 1992. New Results and Modern Technologies for Nitric Acid, Nitrogen Fertilizers and Caprolactam Production, Paper presented at the International Meeting on Chemical En eering and Biotechnologyr-ACHEMASIA 92. 

Potassium sulfate and ammonium sulfate solution obtained as a byproduct from caprolactam production are used industrially. In the feba phosphoric aad process (Figure 13.8), phosphate rock is reacted with a mbcture of sulfuric and nitric acids under conditions that form calcium sulfate in the hemihydrate form, which is re moved by fittiation 115]. In this process, part of the sulfuric add may be replaced by ammonium sulfate. 

The results reported have very high industrial applicability. The new process can be easily applied to all current CPL production technologies that are based on cyclohexanone oxime (90% of worldwide caprolactam production). 

---