Biomass and Bioenergy 22 (2002) 365–375 Production of chemicals from cellulose and biomass-derived compounds through catalytic sub-critical water oxidation in a monolith reactor Ben D. Schutt a , B. Serrano b , Ramon L. Cerro c , Martin A. Abraham a ; * a Department of Chemical and Environmental Engineering, The University of Toledo, 3055 Nitschke Hall Toledo OH, 43606, USA b Facultad de Ciencias Quimicas, Universidad Autonoma de Zacatecas, Carr. a Cd. Cuauhtemoc, Km 0.5, Guadalupe Zacatecas Mexico, 98600, Mexico c Chemical and Materials Engineering, University of Alabama in Huntsville, Huntsville, AL 35899, USA Received 27 March 2001; received in revised form 20 December 2001; accepted 20 December 2001 Abstract Selective conversion of cellulose to small organic molecules, including carboxylic acids, represents a potential route for upgrading biomass resources to value-added chemical precursors. However, since biomass resources such as cellulose are not soluble in water, the use of a catalyzed system requires a novel reactor design that facilitates slurry ow. As demonstrated herein, the monolith froth reactor is uniquely suited for the conversion of solid materials in a four-phase (solid catalyst, solid reactant, gaseous reactant, and aqueous solution) reaction system. Reactions were performed using a palladium catalyst and 1000 ppm (w) cellulose, and results were compared with previous experiments conducted over platinum. At 150 ◦ C, nearly 100% conversion of the cellulose was achieved in approximately 5 h, which compares favorably with results obtained using a platinum catalyst. The palladium catalyst gave a dierent distribution of intermediate products compared to platinum. For example, acetic acid and malic acid achieved yields of 40 and 80 ppm (w), respectively, using the palladium catalyst. The product selectivity was evaluated under pH control, through the addition of acetic or carbonic acid, and shown to have only a minor eect on the performance of the system. ? 2002 Elsevier Science Ltd. All rights reserved. Keywords: Cellulose; Monolith froth reactor; Supported palladium catalyst; Partial oxidation 1. Introduction The growing demand for application of renewable resources for industrial products has led to an interest in selective and clean processes for the conversion of carbohydrates. Carbohydrates derived from biomass ∗ Corresponding author. Tel.: +1-419-530-8092; fax: +1-419- 530-8086. E-mail addresses: beniser@prodigy.net.mx (B. Serrano), rlc@che.uah.edu (R.L. Cerro), mabraham@eng.utoledo.edu (M.A. Abraham). are appropriate starting materials for chemical manu- facture. Clean and ecient conversion methods must be developed. Biomass-derived molecules, however, are substantially dierent than raw materials derived from petroleum products. In particular, most carbo- hydrates are water soluble, thus “green” conversion techniques should involve aqueous phase chemistry. As a result, new conversion processes (including new catalysts and new three-phase contactors) must be de- veloped for commercial utilization of these resources. The conversion of biomass into chemicals re- quires several steps [1]. Conversion begins with the 0961-9534/02/$ - see front matter ? 2002 Elsevier Science Ltd. All rights reserved. PII:S0961-9534(02)00010-7