Yanni Guo,Hanqiong Jia,Jiayao Qi,Binbin Fan,Bo Qin,Jinghong Ma,Yanze Du,Ruifeng Li
In the hydrocracking of 9, 10-dihydroanthracene, acid sites and their locations in the Y zeolites play crucial roles. Hydrogen transfer is the dominant reaction for the industrial Y zeolites with undeveloped mesopores whether at low or high temperatures. Those with developed mesopores exhibit enhanced ring-opening and cracking ability due to the improved molecular transport and accessibility of acid sites. Their ring-opening and cracking ability is crucially related to the amount of highly strong Brønsted acid sites in the high-silica Y zeolites. The reaction processes of 9, 10-dihydroanthracene hydrocracking over the industrial Y zeolites with different properties were expounded rationally.
The N-doped activated carbon (NAC) was prepared for bagasse (BAG) pyrolysis with 9,10-dihydroanthracene (DHA) to selectively improve production of individual 4-ethyl phenol (4-EP). Both pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale apparatus were employed to conduct catalytic fast pyrolysis (CFP) experiments. The effects of N-doping modification, pyrolysis temperature, DHA/BAG ratio and NAC/BAG ratio on yield and selectivity of 4-EP were comprehensively investigated. Results indicated that the NAC exhibited excellent catalytic abilities in improving 4-EP production. About 3.03 wt % of 4-EP was obtained over NAC in the absence of DHA, whereas the 4-EP yield over activated carbon was only 2.46 wt %, indicating an increment of 23.17 % via N-doping modification. The 4-EP yield reached the maximum of 4.75 wt % with a selectivity of 25.12 % at temperature of 350 °C with a DHA/BAG ratio of 7:20 and NAC/BAG ratio of 3:1, indicating 88.45 % of 4-VP (5.37 wt %) was converted into 4-EP. Result of lab-scale tests showed that 4-EP production attained the highest value (4.02 wt %) with a selectivity of 25.53 % at temperature of 350 °C with DHA/BAG and NAC/BAG ratios of 1:5 and 1.5:1, respectively. Finally, the possible mechanism on 4-EP formation from BAG pyrolysis with co-assist of NAC and DHA was inferred.