Caprolactam Production Research And Technology Evaluation

With the demand of nylon6fibers and engineering plastics grows quickly in domestic, the raw material-caprolactam imports also increased rapidly.In order to expand domestic production of caprolactam, This paper conduct a detailed investigation of caprolactam and the analysis of the existing process technology.At the same time this paper point out the development direction of technology and finish the process’s investment benefit evaluation.The world caprolactam capacity is about5million tons in2006, of which Asia account for35.42%, respectively North America, Western Europe, Central and Eastern Europe, Latin America is about24.82%,21.7%,15.59%and2.47%. The plans of building new facilities and expansion mainly focused on China、Japan、South Korea and other Asia countrys in next few years. Consumption breakdown is as follows: nylon6fibers is about62.9%, nylon6films that used for engineering plastics and food packaging is about32.3%, Other is4.8%.China have four plants to produce caprolactam, three of their technology is import.At present China caprolactam capacity is about353,000tons annual, the consumption is about734,800tons annual, consumption structure is as follows:used to Fiber about81.9%, the other18.1%was used for non-fiber.Caprolactam is inadequate for domestic demands, In recent years more than60percent of the total consumption is imports. The major products imported from Russia, Japan, the Netherlands, Belgium and other places. Before2010, the capacity will increase415,000tons annual in domestic.According to the different raw materials, the industrialized technology lines of caprolactam produce mainly have three kinds in the world. They are phenol benzene and toluene. The proportion of the production is approximately19%,78%and3%.The main differences of benzene’s different process are the different preparation methods of cyclohexanone and hydroxylamine. And the price of raw materials will directly affect the cost. At the same time ammonium sulfate as the by-product is more and the economy of the route is pooer.China’s capacity of benzene rapidly growth in recent year.This will provide sufficient raw material for benzene-line. On the other hand this is a better way of a large number of benzene’s use. The caprolactam of benzene-line has good quality.DSM-HPO process, SINA toluene process and Toray Guangya nitrification process are the traditional methods. DSM-HPO has the competitive advantage.Technology’s development of Benzene-line mainly lies in the research of cyclohexanone, cyclohexanone oxime and Beckmann rearrangement.The way of produce cyclohexanone mainly includes cobalt salt, acid oxidation, no-catalytic oxidation, Bionic catalytic oxidation and cyclohexene hydration. Bionic catalytic oxidation method and Cyclohexene hydration method are friendly to environment. They have the development prospects in the future.Traditional methods that produce Cyclohexanone oxime divide into HPO-process、NO-process、HSO-process by the different way of hydroxylamine’s produce.HPO-process is the most important. The newly developed technology that is ammonia-oxime-process is better than HPO-process.The installation cost reduced18to25percent than the same size HPO-process. The cost of product reduced6percent than HPO-process.Traditional process of Beckmann rearrangement use concentrated sulfuric acid or Smoke sulfate as catalyst.which will produce large amounts of ammonium sulfate that impact the process’s economic benefits. Gas rearrangement is the newly development technology that use solid acid as catalyst. Beckmann rearrangement no longer produces ammonium sulfate.this method has the good prospects in the future.The first direction of development is to improve traditional technologies, in order to reduce the amount of ammonium sulfate or produce the higher value by-product. The second way is to develop green-technology, in order to reduce impact to environment. The final way is to use cheap raw materials or shorten the process.Building a100,000tons/year’s installations using the recommended technology, the investment is about661.86million yuan.the average annual revenue is1.30889billion yuan,after-tax profit is209.15million yuan,and after-tax internal rate of financial return is34.34percent that far exceeded the benchmark of12percent.this show building a new device will have good economic benefits.