Title: Fe/HY zeolite as an effective catalyst for levulinic acid production from glucose: Characterization and catalytic performance
Author: Nur Aainaa Syahirah Ramli Nor Aishah Saidina
Reference: APCATB 13525
To appear in: Applied Catalysis B: Environmental
Received date: 15-5-2014
Revised date: 22-7-2014
Accepted date: 19-8-2014
Please cite this article as: N.A.S. Ramli, N.A.S. Amin, Fe/HY zeolite as an effective catalyst for levulinic acid production from glucose: characterization and catalytic performance, Applied Catalysis B, Environmental (2014), http://dx.doi.org/10.1016/j.apcatb.2014.08.031
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Ac ce pte d M an us cri pt
Fe/HY zeolite as an effective catalyst for levulinic acid production from glucose: characterization and catalytic performance
Nur Aainaa Syahirah Ramli, *Nor Aishah Saidina Amin
Chemical Reaction Engineering Group (CREG), Energy Research Alliance,
Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor, Johor Bahru, Malaysia *Corresponding author. Tel: +6075535579; Fax: +6075588166
Email address: *firstname.lastname@example.org
Highlights 1. Fe/HY catalyst were characterized and tested for glucose conversion to levulinic acid 2. Catalyst acidity and porosity influenced the catalyst activity 3. Significant findings were found for 10% Fe/HY catalyst with 62% levulinic acid yield 4. The reusability of Fe/HY zeolite catalyst was tested for five successive trials 5. Test for leaching indicated low Fe ions in the reaction product
A series of Fe/HY zeolite catalysts with different FeCl3weight percent (5%, 10% and 15%) on
HY zeolite have been synthesized in this study. All the catalysts were characterized by XRD,
FESEM, N2 physisorption, FTIR, TGA, NH3-TPD and IR-pyridine. The performance of the
Fe/HY catalysts was tested in glucose to levulinic acid transformation. The amount and type of
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Ac ce pte d M an us cri pt acid sites together with surface area and porosity influenced the catalytic activity. The catalyst with a large surface area, high concentration of active acid sites and appropriate ratio of Brønsted to Lewis acids seemed suitable for levulinic acid production. However, catalyst with excess
Lewis acidity converted glucose into humins, but samples with high relative mesopority and low relative microporosity gave a decent levulinic acid yield. Among the catalysts tested, 10%
Fe/HY catalyst exhibited the highest catalytic performance with 62% yield at 180°C in 180 min.
The reused catalyst exhibited constant activity for five successive runs. The experimental results demonstrated the potential of Fe/HY catalyst for biomass conversion to levulinic acid under mild process conditions.
Keywords: Levulinic acid, Fe/HY zeolite catalyst, acidity, porosity, biomass conversion 1. Introduction
The depletion and price hike of fossil fuel resources have exacerbated the utilization of renewable sources such as biomass for the production of energy . Currently, extensive research are being carried out to investigate the conversion of biomass into biofuels and other chemical feedstocks [2, 3]. C6 sugars (e.g. glucose and fructose) have been used as feedstocks to produce 5-hydroxymethylfurfural (HMF) and levulinic acid. The formation of HMF, an intermediate product for levulinic acid production, is proposed to take place through the dehydration of a five-membered ring monosaccharide. Therefore, fructose can be easier converted to HMF and levulinic acid in aqueous solution.
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Levulinic acid is a versatile building block containing a ketone carbonyl group and an acidic carboxyl group. Levulinic acid can be used for the preparation of various high valueadded organic chemicals, polymers, resin, flavour substances and fuel additives with numerous potential industrial applications . Esterification of levulinic acid with alcohols produces levulinic esters for diesel additives . Levulinic acid can also undergo hydrogenation to produce γ-valerolactone (GVL), to be blended with gasoline as well as to serve as a precursor of polymers and fine chemicals . The first commercial-scale plant for the synthesis of levulinic acid from biomass was built in Caserta, Italy through a process developed by Biofine
Renewables [7, 8]. The Biofine process involves two different stages of acid-catalyzed hydrolysis for the optimum product yield and minimum product degradation and tar formation . The first stage is the fast production of HMF in only few seconds, while the production of levulinic acid in the second stage requires longer residence time.
Although glucose is less reactive in dehydration compared to fructose due to its comparatively stable nature, it is more preferable since glucose is less expensive. Initially, acids (H2SO4, HCl, formic acid) have been used as homogeneous catalysts for the production of levulinic acid from various feedstocks including fructose, glucose, cellulose and lignocellulosic biomass [9-11]. The homogeneous catalytic system is effective, but caused several problems such as equipment corrosion, environmental pollution and acid recycling. As an alternative, heterogeneous catalyst is introduced to overcome the problems associated with homogeneous catalytic system. Generally, solid acid catalysts used for the production of levulinic acid are reusable, with tolerable reduction in product yield until five to six runs [12, 13]. Consequently,