Conversion of Xylose to Furfural over Lignin-Based Activated Carbon-Supported Iron Catalysts

Abstract

In this study, conversion of xylose to furfural was studied using lignin-based activated carbon-supported iron catalysts. First, three activated carbon supports were prepared from hydrolysis lignin with different activation methods. The supports were modified with different metal precursors and metal concentrations into five iron catalysts. The prepared catalysts were studied in furfural production from xylose using different reaction temperatures and times. The best results were achieved with a 4 wt% iron-containing catalyst, 5Fe-ACs, which produced a 57% furfural yield, 92% xylose conversion and 65% reaction selectivity at 170 °C in 3 h. The amount of Fe in 5Fe-ACs was only 3.6 µmol and using this amount of homogeneous FeCl3 as a catalyst, reduced the furfural yield, xylose conversion and selectivity. Good catalytic activity of 5Fe-ACs could be associated with iron oxide and hydroxyl groups on the catalyst surface. Based on the recycling experiments, the prepared catalyst needs some improvements to increase its stability but it is a feasible alternative to homogeneous FeCl3.

Valorization of Waste Lignocellulose to Furfural by Sulfonated Biobased Heterogeneous Catalyst Using Ultrasonic-Treated Chestnut Shell Waste as Carrier

“…Processes 2021, 9, 2269 2 of 10 pectin [30], etc., have been discovered and utilized for furfural production. Very recently, biomass-based heterogeneous catalysts, including carbon, sucrose [31], miscanthus [32], and lignin [33], have gained considerable interest due to the utilization of available, inexpensive, and renewable biomass as a carrier. Carbon-based solid acid catalyst (SC-CCA) was synthesized by sulfonation of carbonaceous materials obtained by carbonization of sucrose with 4-BDS as a sulfonating agent.…”

Support–Activity Relationship in Heterogeneous Catalysis for Biomass Valorization and Fine-Chemicals Production

“…The most common activation methodologies are essentially two, namely: physical and chemical activation. The first one involves the treatment of the carbonized biomass at high temperatures (600-1000 • C), inert atmosphere in the presence of steam [43,[53][54][55][56]; chemical activation can instead be performed directly either on carbon precursors or on the carbonized biomass that during this process are treated in the presence of chemical species at elevated temperatures [50,57]. Before the process, raw materials are initially impregnated with an acid/oxidizing agent and further dehydrating chemicals, which activate pyrolytic degradation, improve the activated carbon yield, while causing changes in the thermal precursor's decomposition, giving rise to the formation of porous carbon materials [58,59].…”

“…This kind of activation is performed whenever the insertion of oxygenated groups (principally acids, alcohols, ethers and esters) on the surface of activated carbons is necessary [60,61]. The chemicals employed for this kind of treatment are principally strong inorganic acids, mainly H 3 PO 4 [43,53,55,56,[62][63][64][65], HNO 3 [54] or H 2 SO 4 [66]; however, alternative chemicals such as ZnCl 2 [54,56], KOH [56,65] or H 2 O 2 [65] can also be employed. Recently, alternative activation methodologies were also developed.…”

“…Conversely, chemical activation is responsible for the insertion of oxygenated groups that break the regularity of the conjugated structure, promoting debenzylation reactions. Rusanen and co-workers studied the effect that different activations of carbons have on the conversion of xylose into furfural, also bringing into play biomass valorization [54]. They compared Fe-based catalysts prepared using carbons activated either with steam, ZnCl 2 or HNO 3 , or with homogeneous FeCl 3 .…”

Editorial Catalysts: Special Issue on “Biomass Derived Heterogeneous and Homogeneous Catalysts”

“…Last, but not least, furfural is an intermediate step for the generation of many pharmaceutical and chemical products, mainly obtained from xylose in agricultural wastes. The use of lignin-based activated carbon-supported iron catalysts for that purpose was studied by Rusanen et al, being a feasible alternative for FeCl 3 , with furfural yields up to 57%, although their reusability should be improved [11].…”