278102 Study of Deactivation and Coke Formation Over Zeolite Catalyst During JP8 Reforming
Study of deactivation and coke formation over zeolite catalyst during JP8 reforming
Sungtak Kim, John Bedenbaugh, Salim Shahriar, Jochen Lauterbach
JP-8 which is a widespread military fuel in NATO (North Atlantic Treaty Organization) and the U.S. military has been studied for more flexible and efficient application by extracting demanded fuel from it. However, JP-8 is a difficult fuel to be utilized as a flexible energy source via reformation due to a number of reasons. Zeolite catalysts have been used widely in refining and petrochemical processes such as cracking and isomerization because of their high activity, shape selectivity and high thermal stability. Therefore, in this work, catalytic reforming of non-desulfurized JP-8 into LPG like hydrocarbon fuel mixtures that are composed from C2 to C4 on a laboratory scale fixed bed reactor and coke characterization on zeolite catalyst were carried out in other to understand deactivation mechanism of zeolite catalysts and coke formation, which occurs in the pores and on the surface of zeolite catalysts and causes deactivation. Deactivation of the catalysts was monitored by GC-MS, and the amount and the chemical composition of carbonaceous deposits were studied by various analytical techniques, such as temperature programmed oxidation (TPO), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) pore volume measurement, and scanning electron microscopy (SEM). The results showed that activity and stability of the catalysts and coke formation on the zeolite catalysts depends on not only reaction parameters like temperature and time on stream and zeolite type, but also an addition of different type of metals, for example Pt or Gd, onto the zeolites. H/C mole ratio of the carbonaceous deposits combined with the other results revealed the nature of coke compound in each case. In addition, a structure change of the zeolite catalysts caused by carbonaceous deposits will be discussed as well.