สำนักราชบัณฑิตยสภา

The Journal of the Royal Institute of Thailand Vol. 27 No. 3 Jul.-Sept. 2002 Commercialization of the Worldûs First Oleflex Unit ˆˆÙ Commercialization of the Worldûs First Oleflex Unit * Purposive propylene production via catalytic dehydro- genation of propane on a commercial scale unit was attempted for the first time in early 1990 when the UOP-designed first Oleflex unit went on stream at NPC, Thailand. Prior to that time, propylene was simply a by-product of other processes, i.e. naphtha-based steam cracker and fluid catalytic cracker. The situation in Thailand at that time, with no naphtha-based steam cracker and only a small catalytic cracker in the country, called for a purposive propylene production route to satisfy the demand for propylene. The UOP propane dehydrogena- tion process was therefore chosen and the Thai Oleflex Unit became the first commercial scale propane dehydrogenation unit. Some problems were encountered during the initial stage of operation. With the joint effort between the UOP support team and NPC technical staff, the problems were resolved to the satisfaction of the owner. The solutions applied included changes and modifications of certain hardware, modification to certain operating conditions, and a change to new versions of catalyst with better performance. In addition, UOP’s com- mitment to improve the stability and selectivity of the Oleflex catalyst resulted in the availability of several new versions of catalyst over the years and NPC has enjoyed the benefits of these improvements. Over some 10 years of operation with over 3,200 days on-stream, NPC has operated on four versions of Oleflex catalyst and has noted improvement of each new version over the previous ones. Five batches of catalyst have been loaded on the unit. Regrettably, in spite of the technical success in operating the unit, the many changes in the eco- nomic picture and climate of the country and the region have resulted in the decline of the profitability of the unit. Although the return is well below the expectation, it is still economical to keep the unit in operation. The paper describes the various operating experiences and the performance data of the unit, including the catalyst performance. The catalyst life in gen- eral significantly exceeded expectation. The economic perfor- mance of the unit over the year is also included. Key words : commercialization, the World First Oleflex Unit Pramote Chaiyavech Associate Member, the Academy of Science The Royal Institute * Presented at the 223rd National Meeting of the American Chemical Society, Orlando, Florida, USA, April 8, 2002 ACS Award in Industrial Chemistry in Honor of Bipin V. Vora Session. Propylene has been and still is an important by-product of steam cracking and catalytic crack- ing operations. In general, propy- lene demand can be met from these two sources of supply, thanks to the increasing capacity of the two processes. Propylene price for chemical industry use usually fol- lows its value as alkylate feedstock, which is an alternative outlet of propylene in the oil industry. The price of gasoline thus has an im- portant influence on the propy- lene price in the market. As a re- sult, the propylene price has been kept low most of the time, espe- cially in the United States. For locations which are short of propylene, such as in the Far East, purposive propylene produc- tion via catalytic dehydrogenation of propane can become a viable alternative, subject to the existing economic conditions. This was the case for Thailand in 1985. The discovery of natural gas in the Gulf of Thailand provided the country with ethane and propane (E/P) while the demand for ethylene and propylene was rapidly increasing. A gas-based olefin plant was thus