Metal-ion pillared clays as hydrocracking catalysts (I): Catalyst preparation and assessment of performance at short contact times q S.D. Bodman a , W.R. McWhinnie a , V. Begon b , I. Suelves 1 , M.-J. Lazaro 1 , T.J. Morgan b , A.A. Herod a, * , R. Kandiyoti b a Department of Chemical Engineering and Applied Chemistry, Aston University, Aston Triangle, Birmingham B4 7ET, UK b Department of Chemical Engineering and Chemical Technology, Imperial College, University of London, London SW7 2BY, UK Received 30 April 2001; revised 25 September 2001; accepted 17 October 2001; available online 4 December 2001 Abstract A set of pillared clay catalysts based on montmorillonite (a natural clay) and laponite (a synthetic clay) have been prepared. The new catalysts have been pillared with tin, chromium and aluminium pillars as well as layered double hydroxides based on polyoxo-vanadate and -molybdate. The activities of these novel catalysts have been compared with that of a commercial supported NiMo/Al 2 O 3 catalyst and with sulphidedMo(CO) 6 duringshort(10min)contactruns.Acoalextractsamplewasreactedat440 8Cinamicrobombreactorinthepresenceof tetralinand19MPahydrogen.Productswerecomparedbysizeexclusionchromatography,usingNMPaseluent,andbyUV±¯uorescence. BoilingpointdistributionsofhydrocrackedproductsweredeterminedbyaTGAbasedmethod;`conversions'werede®nedasthedecreasein thefractionofmaterialwithboilingpoints .450 8Cduringthereaction.Previousworkat440 8Cand19MPaH 2 indicatesextensivethermal (pyrolytic) cracking during the ®rst 10 min; in the absence of catalyst recombination reactions rapidly take over. Results with several of the new catalysts did not show any improvement compared to the absence of catalyst with ,39% conversion. The highest conversion (,70%) was obtained with the Sn laponite pillared clay. The Cr montmorillonite catalyst, pre-calcined at 500 8C, gave the greatest overall shift to smaller molecular masses even though the observed conversion of .450 8C boiling material was relatively poor. q 2001 Elsevier Science Ltd. All rights reserved. Keywords: Catalytic; Hydrocracking; Coal liquids; Pillared clays 1. Introduction Coalliquefactionhascommandedconsiderablylessinter- estsincethereturnoflowoilpricesandevenseveralrecent high-price incursions have not altered general perceptions. The status of liquefaction as a strategic alternative is never- thelessmaintainedbylargeoilconsumercountriesÐifonly as a mental note. This paper describes the preparation and performance of several potentially powerful catalysts for hydrocracking heavy hydrocarbon mixtures derived from coal and from petroleum. Theinvestigationofmethodstoproduceliquidfuelsfrom coal has a long history. In most processes, a heavy hydro- carbon liquid is produced and subsequently re®ned. Direct, one-step liquefaction as well as two-step processes, where an extract is produced in the ®rst step and hydrogenated in thesecond,arewellknown[1].Processroutesbasedprimar- ily on Fisher±Tropsch catalysis have been used for produc- tion by SASOL in South Africa [1,2]. The coal extract sample used in the present study originated from the two- step process developed by British Coal at the Point of Ayr Coal Liquefaction Pilot Plant [3]; the next processing step forthisextractwouldhaveinvolvedbeingtakenthroughthe catalytichydrocracker.Thepresentworkattemptedtosimu- late the hydrocracking step with a range of catalysts as an initial screening study. 1.1. Sample-catalyst interactions As in all processes dealing with heavy hydrocarbon liquids, describing a precise sequence of events at/near catalyst surfaces is fairly dif®cult. When using a commer- cially produced supported NiMo/Al 2 O 3 or CoMo/Al 2 O 3 catalyst, it is known that initial carbon deposition on fresh catalyst surfaces is rapid and intense, and corresponds to a large fraction of the catalyst weight (,10±20%) [4±7]. Fuel 81 (2002) 449±459 0016-2361/02/$ - see front matter q 2001 Elsevier Science Ltd. All rights reserved. PII:S0016-2361(01)00193-4 www.fuel®rst.com * Corresponding author. Tel.: 144-207-5111 x55619; fax: 144-207- 594-5604. E-mail address: a.herod@ic.ac.uk (A.A. Herod). 1 Present address: Instituto de Carboquimica, (CSIC), Miguel Luesma Casta Ân, 4, 50015, Zaragoza, Spain. q Published ®rst on the web via Fuel®rst.comÐhttp://www.fuel®rst.com