Abstract:
Concerns towards diminishing fossil resources compel the chemical industry to
explore alternatives for basic chemical productions. Carbohydrates derived
biomass are promising alternatives for sustainable supply of fuels and valuable
chemicals due to their abundant and relatively inexpensive properties.
Carbohydrate such as glucose is a compound from which various bio-based
chemicals can be derived. Among those chemicals, levulinic acid (LA) has
received significant attention as platform chemicals for synthesizing a broad
range of bio-based fuels. The conversion of carbohydrates to LA have been
conducted in water in the presence of various catalysts, including homogeneous
and heterogeneous catalysts. In this study, a new zeolite immobilized ionic liquid
(HY-IL) catalyst has been explored for catalytic conversion of glucose to LA. The
catalyst was prepared by immobilizing an acidic ionic liquid; 1,4 methylsulfonic
acid imidazolium tetrachloroaluminate ([MSIM][AlCl4]) into HY zeolite with weight
ratio 1:2 of ionic liquid to zeolite. The synthesized [MSIM][AlCl4] was
characterized using CHNS elemental analysis to validate the prepared
[MSIM][AlCl4]. Meanwhile, the parents HY zeolite and HY-IL were characterized
using N2 physisorption and temperature desorption of ammonia (NH3-TPD) to
determine their surface area and acidity, respectively. From the characterization
results, the prepared [MSIM][AlCl4] was validated, the surface area of HY-IL was decreased, while the acidity of HY-IL was increased compared to the parent HY
zeolite. The catalytic testing were conducted at 160 °C for 5 h using 0.4 g of
catalyst and 0.4 g of glucose. HY-IL gave the highest LA yield (21%) compared
to parent catalysts; [MSIM][AlCl4] (23%) and HY zeolite (traces). The high
catalytic performance of HY-IL was due to its high concentration of active acid
sites compared to HY zeolite. This study demonstrated the potential of zeolite immobilized ionic liquid as a catalyst for biomass transformation to platform
chemicals under mild process condition
