Naphtha reforming chemistry

KINPTR is an overall process model thus it simulates all important aspects of the process which affect performance. In order to lay a foundation for upcoming discussions related to KINPTR development, the important aspects of naphtha reforming—chemistry, catalysis, and reactor/hardware design—will be summarized. More extensive reviews are available in the literature (1-3). 

The overall chemistry of the steam-naphtha reforming process may be represented by the following equations ... 

Dehydrocyclisation of alkanes to aromatic compounds is one of the basic reactions of naphtha reforming, which is one of the most important industrial catalytic processes. IThe nature of the ring closure step is one of the main questions of understanding the chemistry of dehydrocyclisation. Sharan reviewed earlier work on tracer studies of this reaction.[ 1 An excellent discussion on the development of ideas and the role of [ C] isotope in elucidating reaction pathways has been published by Davis.Two basic ideas have competed in Scheme 2. One assumed stepwise dehydrogenation of open-chain alkanes then cyclisation as one of... 

Methanol Formaldehyde Ethylene Propylene oxide Phenol 1,4-Butanediol Tetrahydrofuran Ethylene glycol Adipic acid Isocyanates Styrene Methyl methacrylate Methyl formate Two-step, via CH4 steam reforming Three-step, via methanol Cracking of naphtha Co-product with t-butyl alcohol or styrene Co-product with acetone Reppe acetylene chemistry Multi-step Hydration of ethylene oxide Multi-step Phosgene chemistry Co-product with propylene oxide Two-step, via methacrolein Three-step, via methanol... 

But how ubiquitous actually are alkalis in the promotion of reactions catalyzed at metal surfaces An examination of recent authoritative sources [6,7] shows that the majority of medium-to large-scale processes do not employ alkali promoters, even when one includes nonmetallic (i.e., metal oxide) catalysts. In a number of cases (e.g., steam reforming of naphtha) it seems clear that the role of alkali is simply to reduce the acidity of the oxide support. There are famous cases, of course, where the presence of alkali species on the catalytically active metal surface is critically important to the chemistry. Notable are ethene epoxidation (Ag-Cs), ammonia synthesis (Fe-K), acetoxylation of ethene to vinyl acetate (Pd, Pd/Au-K), and Fischer-Tropsch synthesis (Fe, Co, Ru-K). The first three are major industrial... 

Dehydrogenation is a key reaction in the production of commodity chemicals such as butadiene, styrene and formaldehyde and in the catalytic reforming of petroleum naphtha [1-3], In the fine chemical industry, however, dehydrogenation is used less than the numerous hydrogenation reactions which are available. Dehydrogenation is usually an endothermic reaction which requires high temperatures. For such conditions the chemical stability of many fine chemicals is often insufficient. Most of the dehydrogenation reactions used in fine chemistry yield aromatic or heteroaromatic compounds and aldehydes or ketones. 

The chemistry of reforming naphtha is considerably more complex than methane. Reforming naphtha with the general formula C,n)H,2n+2) proceeds according to the following reactions ... 

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