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

Abstract

BACKGROUND Owing to the growing consumption of oil and the negative environmental impacts, the production of p‐xylene (PX) from renewable biomass has gained significant attention recently. However, the major challenge for the production of PX from biomass or furans is how to improve the yield and selectivity of PX, along with reducing coke. RESULTS The para selectivity in the catalytic conversion of furans was greatly enhanced owing to the deactivation of external surface and the adjustment of pore entrance. Co‐catalytic conversion of furans and methanol significantly enhanced the production of PX by the Diels–Alder reactions between furans and olefins and the alkylation of benzene/toluene with methanol. The highest PX yield of 17.8 C‐mol% with a p‐xylene/xylene ratio of 94.5% was obtained by the co‐conversion of 2‐methylfuran with methanol over the 15%La/10%Ce/HZ catalyst. CONCLUSION This work proved that furans (2‐methylfuran, 2,5‐dimethylfuran, furfural and furan) were able to be selectively converted into a high‐value chemical (PX) over the 15%La/10%Ce/HZ catalyst. The transformation mainly involved four key reactions: the catalytic cracking of furans, the Diels–Alder reactions, the alkylation of aromatics and the isomerization of xylenes over the surface‐modified zeolite. © 2019 Society of Chemical Industry

Selective catalytic transformation of cellulose into bio-based cresol with CuCr2O4@MCM-41 catalyst

“…Methanol itself can also form aromatics through the aromatization reactions (Fig. 3), which is consistent with previous work (Zhu et al 2019). Previous studies showed the overall yield of aromatics increased for the co-catalytic conversion of furan/methanol (Zhu et al 2019;Zheng et al 2014) or biomass/methanol over HZSM-5 (Zhang et al 2012).…”

“…In order to analyze the catalyst's crystal phase, X-ray diffraction (XRD) spectra were gained by using an X'pert Pro-Philips diffractometer (Philips in Netherlands) (Zhu et al 2019). XRD patterns were obtained using the Cu K radiation (0.15406 nm) at 45 kV and 40 mA, which were scanned in the range of 5°\ 2h \ 80°.…”

“…The catalyst's acidity and characteristics were investigated by the ammonia temperature-programmed desorption analysis (NH 3 -TPD, scanning range: 100-700 °C heating rate: 10 °C min -1 ) (Zhu et al 2019).…”

Catalytic Fast Pyrolysis of Lignocellulosic Biomass to Benzene, Toluene, and Xylenes

“…Of course, not all furanics were equally converted. A comparison of 2,5-dimethylfuran (DMF), furan, and furfural revealed that electron-rich DMF quickly reacted while the electron-deficient furfural lagged behind: DMF > furan > furfural [94]. In addition to aromatics, CO 2 , CO, and other olefins were also made at 400-600 °C [38].…”

Value‐Added Products from Fruit and Vegetable Wastes: A Review

“…Some studies have indicated that a simultaneous saccharification and fermentation process is more advantageous in contrast to carrying out these steps separately, because the yields obtained are higher, only one tank is required, and the operation time is shorter. [ 88,261 ] The increase in yield is mainly due to the fact that glucose is rapidly transformed into bioethanol, avoiding its inhibitory effect on hydrolytic enzymes, which increases glucose yield and increases the availability of substrate for alcoholic fermentation. However, simultaneous saccharification and fermentation requires the optimization of parameters such as temperature, pH, and enzymatic concentrations, since the optimal temperature and pH, as well as the fermentation strains are different in the two processes.…”