Evaluation of the recyclable reaction pairs, alkyl-decalin /alkyl-naphthalene and alkyl-cyclohexane / alkyl-benzene with use ofcatalytic dehydrogeno-aromatization and aromatic hydrogenation

摘要

Catalytic dehydrogeno-aromatization of organic chemical hydride was proposed as the keytechnology for a hydrogen supply and storage system in combination with its counter process,catalytic aromatic hydrogenation. Both cyclohexane / benzene and decaline / naphthalenereaction pairs have already been developed. However, after the reactions, cyclohexane willbe converted to carcinogenic benzene, and decaline will be converted to solid naphthalene atroom temperature. For safety and easier operations, alkyl naphthalene and alkyl benzeneobtained from our oil refinery were hydrogenated to utilize as organic chemical hydrides.These aromatic compounds were easily hydrogenated at 200-240℃, 2MPa, LHSV=1hr -1 .Catalytic dehydrogenation reactions were also investigated at various reaction conditionsusing these organic chemical hydrides. The dehydrogenation temperature was about300-350℃ of catalyst temperature at 0.3MPa and the maximum hydrogen generation rate ismore than 58 liters per a mole of alkyl cyclohexane and more than 100 liters per a mole ofalkyl decaline, respectively. The estimated conversions are 90-100% at 350℃ of catalysttemperature, 0.3 MPa, LHSV=2hr -1 . For the stable operation, catalyst temperature wasinferentially preferable under 320℃ although the conversion was around 80-90%. Thestability test of dehydrogenation was performed at the 80% conversion condition and nodeactivation was found during 64 hours continuous run. Alkyl benzene / alkyl cyclohexanereaction pair was cyclically tested at 100% hydrogenation conversion and 80%dehydrogenation conversion. Finally, the alkyl benzene / alkyl cyclohexane reaction pairwas proved to be applicable for the cyclic use of a hydrogen supply and storage system.