Steam Reforming of Liquid Hydrocarbons

J.R. Rostrup-Nielsen, T.S. Christensen and I. Dybkjaer, Steam Reforming of Liquid Hydrocarbons , Stud. Surf. Sci. Catal., 113 81-95 (1998). 

Wang, L., Murta, K., Inaba, M. (2004). Development of novel highly active and sulphur-tolerant catalysts for steam reforming of liquid hydrocarbons to produce hydrogen. Appl. Catalysis A General 257,443-47. 

Rostrup-Nielsen JR, Christensen TS, Dybkjaer I (1998) Steam reforming of liquid hydrocarbons. Recent Advances in Basic and Applied Aspects of Industrial Catalysis 113 81... 

Table 2.17. Steam Reforming of Liquid Hydrocarbons over Some of the Most Recently Reported Catalyst Compositions... 

Noble metals and hybrid of noble metal- and base metal-supported catalysts have also been developed in order to minimize the carbon formation and sulfur tolerance in the steam reforming of liquid hydrocarbons. Idemitsu Co., Ltd. in Japan has reported Ru-based naphtha reforming catalyst (ISR-7G) for the steam reforming of kerosene,134 whose chemical composition is more or less similar to that of JP-8 jet fuel as described in Table 2.13. The catalyst exhibited stable activity over 12,000h with 100% kerosene conversion and stable outlet gas composition. The catalyst was expected to meet the target lifetime of about 40,000 h, which corresponds to 10 years on the presupposition that the fuel cell would be operated in daytime only. 

The mechanism of steam reforming of higher hydrocarbons discussed in Section 2.2.2.3 is also valid for the steam reforming of liquid hydrocarbons as well. As noted, the mechanism involves adsorption of the hydrocarbon on the catalyst surface followed by the formation of Ci species by the successive a-cleavage of the C-C bonds. The steps involved in the steam reforming of higher hydrocarbons are also given in Equations 2.29-2.37.120... 

Rostrup-Nielsen, I.R., Christensen, T.S., and Dybkjaer, I. Steam reforming of liquid hydrocarbons. Studies in Surface Science and Catalysis, 1998, 113, 81. 

Lu, Y., Chen, J., Liu, Y., Xue, Q., and He, M. Highly sulfur-tolerant Pt/Ceo.8Gd02OL9 catalyst for steam reforming of liquid hydrocarbons in fuel cell applications. Journal of Catalysis, 2008, 254... 

Zheng, J., Strohm, J J., and Song, C. Steam reforming of liquid hydrocarbon fuels for micro-fuel cells. Pre-reforming of model jet fuels over supported metal catalysts. Fuel Processing Technology, 2008, 89 (4), 440. 

The design of catalysts for steam reforming of liquid hydrocarbons is dictated mainly from the need to avoid carbon formation. As illustrated in the simplified mechanism (1) in Table 2, the hydrocarbons are adsorbed on the nickel surface, and the C -species, formed by successive a-cleavage of the carbon/carbon bonds, are dehydrogenated stepwise into adsorbed carbon atoms which may dissolve in the nickel crystal. When the concentration of carbon is above saturation, a carbon whisker will nucleate. These reactions compete with the reaction of the Ci-species with adsorbed oxygen atoms to gaseous products. The concentration of adsorbed oxygen depends on the steam adsorption (and CO2 -adsorption) on the catalyst. 

The positive impact of alkali and magnesia on carbon -free steam reforming of liquid hydrocarbons is well-known. It is explained (1,2) by enhanced steam adsorption and spillover to the nickel surface, as also reflected by negative reactions orders with respect to steam. 

Chen, Y., Xu, H., Wang, Y., Xiong, G. (2006). Hydrogen production from the steam reforming of liquid hydrocarbons in membrane reactor. Catalysis Today, 118, 136-143. 

Shi, Y, Khan, R. and Cross III, J.C. (2005) Steam reforming of liquid hydrocarbon fuels for fuel cell applications. Fuel Cell Seminar November 15-17, Palm Springs, California. 

Xie, C., et al., 2010. Sulfur poisoning of Ce02—Al203-supported mono- and bi-metaUic Ni and Rh catalysts in steam reforming of liquid hydrocarbons at low and high temperatures. Applied Catalysis A General 390 (1—2), 210—218. 

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