Production of Benzoic Acid through Catalytic Transformation of Renewable Lignocellulosic Biomass

Abstract

In the present work, we reported a novel route for the conversion of lignocellulosic biomass (sawdust) to a high-value chemical of benzoic acid under atmospheric pressure. The transformation involved the catalytic pyrolysis of sawdust into aromatics, the decomposition of heavier alkylaromatics to toluene, and the liquid-phase oxidation of toluene-rich aromatics to benzoic acid. The production of the desired benzoic acid from the sawdust-derived aromatics, with the benzoic acid selectivity of 85.1 C-mol% and nearly complete conversion of toluene, was achieved using the MnO 2 /NHPI catalyst at 100 • C for 5 h. The influence of adding methanol on the catalytic conversion of sawdust to the core intermediate of toluene was also investigated in detail.

Selective conversion of furans to p‐xylene with surface‐modified zeolites

“…HZSM‐5 zeolites (named as HZ) with Si/Al ratios of 25, 50 and 80 were supplied by Nankai University Catalyst Co., Ltd (Tianjin, China). La 2 O 3 ‐ and/or CeO 2 ‐modified HZSM‐5 zeolite catalysts were prepared by impregnation of HZSM‐5 with solutions of lanthanum and/or cerium nitrates respectively . These catalysts were denoted as x %La/HZ, y %Ce/HZ and x %La/ y %Ce/HZ, where x and y are the mass percentages of the corresponding metal oxides (modifiers) in the zeolite catalyst.…”

“…The acidities of the catalysts were measured by ammonia temperature‐programmed desorption (NH 3 ‐TPD) from 100 to 700 °C at a heating rate of 10 °C min −1 . To examine the external acidity of the modified zeolites, the catalytic cracking of TIPB was used as a surface probe reaction and performed in a continuous flow fixed bed reactor . To clearly show the differences in external acidity between the parent HZSM‐5 and the modified HZSM‐5 zeolites, the catalytic cracking reactions of TIPB were typically conducted at 350 °C and a weight hourly space velocity (WHSV) of 1.0 h −1 .…”

“…La 2 O 3 -and/or CeO 2 -modified HZSM-5 zeolite catalysts were prepared by impregnation of HZSM-5 with solutions of lanthanum and/or cerium nitrates respectively. 41,[49][50][51] These catalysts were denoted as x%La/HZ, y%Ce/HZ and x%La/y%Ce/HZ, where x and y are the mass percentages of the corresponding metal oxides (modifiers) in the zeolite catalyst. Typically, HZ was impregnated in the corresponding metal nitrate solution overnight, followed by rotary evaporation at 80 ∘ C for 6 h. The dried sample was calcined at 550 ∘ C for 5 h and crushed to 40-60 mesh before use.…”

“…To examine the external acidity of the modified zeolites, the catalytic cracking of TIPB was used as a surface probe reaction and performed in a continuous flow fixed bed reactor. [49][50][51] To clearly show the differences in external acidity between the parent HZSM-5 and the modified HZSM-5 zeolites, the catalytic cracking reactions of TIPB were typically conducted at 350 ∘ C and a weight hourly space velocity (WHSV) of 1.0 h −1 . 41 The main properties of the catalysts are summarized in Table 1.…”

“…The catalytic conversion of furanic compounds was carried out in a continuous flow fixed bed reactor as described in detail elsewhere. [49][50][51] Briefly, the catalysts were located in the middle of the reactor, and the reaction temperature was measured using a thermocouple inserted in the center of the catalyst bed. Nitrogen gas used as the carrier gas was switched to the reactor.…”