Resid FCC-Design for Operating Flexibilty
Publication Date: 2012-May-07
The IP.com Prior Art Database
Page 01 of 16
Resid FCC --- Design For Operating
S.A. Kalota and C.R. Santner
The M.W. Kellogg Company
M. Mutoh, A. Kosuge, S. Kohno
Tohoku Oil Company, Ltd.
Over the years, the refining industry has experienced numerous changes in the market environment. Early processes were no more complex than crude distillation. However, today's demand for products has advanced refining technology into integrated complexes for heavy oil conversion. Residue Fluid Catalytic Cracking (RFCC) is quickly becoming one of the primary process technologies to meet today's market demands. This paper discusses the performance of a recently commissioned Resid FCC Unit which was specifically designed for this flexibility.
Increasinglycompetitive local, regional, nationalor global markets requirefrequent shifts in refined product distributions from heavy feedstock conversion units. This is necessary to maximize profitability and satisfy consumer demand. In rapidly changing markets, it may be necessary to operate for maximum gasoline yield during one period, then rapidly shift to maximum distillate yield. Today's properly designed RFCC has the flexibility to optimally achieve each of these desired performance goals.
THE TOHOI<U RESlD FCC
In 1990, MitsubishiOil Company made a decision to install a Resid FCC Unit in its affiliate Tohoku Oil Company's refineryto counter declining demand for heavy fuel oil in Japan. M.W.Kelloggwas selected to supply technology and basic engineering for the unit. Chiyoda Corporation carried out detailed engineering, procurement and construction.
The Resid FCC Unit, located in Sendai City, Japan, was commissioned in November 1992. As a result of extensive preparation and training by Tohoku, the initial startup of the unit occurred very smoothly and without any difficulties.
The unit was designed to process 25,000 B E Din two separate production modes; (1) maximum gasoline and (2) maximum middle distillate. To achieve these objectives, design operating conditions were optimized in conjunction with Kellogg/Mobil advanced technology. The unit design incorporated flexibility to maximize the yield for each case by varying riser outlet temperature, combined feed ratio, regenerator heat removal and catalyst activity without sacrificing yield performance. This paper summarizes the commercial performance data from the unit.
COMPANY CONFIDENTIAL --- NOT TO BE DUPLICATED
Page 02 of 16
Resid FCC --- Design For Operating Flexibility
Figure 1 shows a simplified process flow diagram of the Tohoku Oil RFCC. The unit incorporates the latest Orthoflow design with state-of-the-art MobiVKellogg technology including riser multi- point radial feed injection, closed cyclones, two stage stripping, spent catalyst and air distribution systems. The unit was designed, however, before ATOMAX feed nozzles were commercially available. Disengager product vapors are condensed and separated in a typical Main FractionatorNapor Recovery Unit configuration. Tr...