Isopropanol

Catalysis Today 158 (2010) 89–96

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Catalysis Today
journal homepage: www.elsevier.com/locate/cattod

Isopropanol decomposition on carbon based acid and basic catalysts
J. Bedia, J.M. Rosas, D. Vera, J. Rodríguez-Mirasol, T. Cordero ∗
Chemical Engineering Department, School of Industrial Engineering, University of Málaga, Campus de Teatinos s/n,29071 Málaga, Spain

a r t i c l e
Keywords: Isopropanol Dehydration Dehydrogenation Carbon catalyst

i n f o

a b s t r a c t
Chemical activation of biomass waste with different activating agents allows the preparation of activated carbons with a relatively highly porous development and different surface chemistry properties. Acidic and basic carbon based catalysts have been prepared bychemical activation of olive stone waste with H3 PO4 and H2 SO4 of acid character and Ca(OH)2 and Ba(OH)2 of basic character. The carbons have been tested as catalysts for the isopropanol decomposition reaction. The acidic carbons show higher steady state conversions than those corresponding to the basic carbons. The highest conversions were obtained using the carbon activated with phosphoric acidas catalyst. In the absence of oxygen acidic carbon based catalysts dehydrate isopropanol to propylene. In the case of the basic carbon catalysts, the carbon activated with Ba(OH)2 mainly dehydrogenates isopropanol to acetone, with low production of propylene. The carbon activated with Ca(OH)2 presents acid and basic surface sites and propylene and acetone are obtained on this catalyst. In thepresence of oxygen, the acidic carbons show higher conversion values and part of the isopropanol suffers oxidative dehydrogenation yielding acetone as well as propylene, although at high isopropanol steady state conversion values only propylene is obtained. © 2010 Elsevier B.V. All rights reserved.

1. Introduction Flash pyrolysis of biomass produces liquid oil (bio-oil) constituted mostly byoxygenated compounds, which are of great interest as fuel [1,2]. Like the biomass precursor, this bio-oil contains almost negligible amount of nitrogen, sulfur and metals. However, transformation of bio-oil is necessary to reach a quality similar to that of the conventional fuel. Studies have been conducted to improve the quality of bio-oil as fuel through catalytic processes with inorganic acid solids[3–5]. Gayubo et al. [4] studied the catalytic transformation of several model components of biomass pyrolysis oil, such as phenols and alcohols (1-propanol, isopropanol, 1 and 2-butanol, etc), over HZSM-5 zeolite obtaining mainly light olefins and aromatics. Nowadays, nearly 90% of acetone is coproduced with phenol by the cumene route. This technique is the preferred technology because of itslower cost. The main process for manufacturing cumene involves the reaction of propylene and benzene in the presence of phosphoric acid-based catalysts or, more recently, zeolite catalysts. The cumene is oxidized in the liquid phase to cumene hydroperoxide, which is then cleaved in the presence of sulfuric acid to phenol and acetone. About 0.62 tons of acetone is produced per ton of phenol obtained.The production of acetone from only cumene would require a balancing of the market with the

∗ Corresponding author. Tel.: +34 952132038; fax: +34 952132038. E-mail address: cordero@uma.es (T. Cordero). 0920-5861/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.cattod.2010.04.043

coproduct phenol from this process. Therefore, there is a needing of alternativeacetone production routes. In the isopropyl alcohol route, the alcohol is dehydrogenated to acetone over a metal, metal oxide or salt catalyst. Acetone could be obtained from isopropanol alcohol by either dehydrogenation or air oxidation. Propylene is a key building block for the petrochemical industry used for the production of polypropylene, acrylonitrile, propylene oxide, cumene, oxo-alcohols and...