Recovery of pentoses-containing olive stones for their conversion into furfural in the presence of solid acid catalysts

Functionalized Coal Fly Ash Is an Efficient Catalyst for Synthesizing Furfural from Xylose at a Low Catalyst Load

“…Various solid acid catalysts for producing furfural have been synthesized. These include Cr-deAl-Y [11], Sn-Beta [12], γ-Al 2 O 3 [13], Nb 2 O 5 [14], MSPFR [15], Cl 0.3 -SR [16], SO 4 2− /Sn-TRP [17], SO 4 2− /SnO 2 -Al 2 O 3 -CFA [9]. In contrast to other solid acid catalysts, coal fly ash (CFA) is a solid waste from coal-burning power plants, and there is great interest in developing CFA-based catalysts because CFA is very thermally stable, cheap, and possible to functionalize [18,19].…”

“…Modifying a catalyst, by loading it with metal ions that act as Lewis acid sites and sulfonating it to provide Brønsted acid sites, can typically improve catalytic performance [17]. Specifically, Al 3+ forms a well-activated metal center as an especially efficient Lewis acid site for facilitating xylose to produce furfural [13,26]. Sulfonation, using sulfamic acid as a sulfonating agent and NaNO 2 as a diazotizing agent, is a simple process that produces relatively little hazardous waste [27,28].…”