Finely regulating methanol concentration to control the alkylation depth in methanol aromatization for optimizing product distribution

Integration of Nano-Sized HZSM-5 with ZnZrOx as a Bifunctional Catalyst to Boost Benzene Alkylation with Carbon Dioxide and Hydrogen

“…A similar trend was also shown in ZZO-mHZ60 (Figure 8b), i.e., the most significant coke formation occurred in the first 8 h (1.78 wt %), and there was a slight rise to 3.03 and 3.48 wt %. Overall, the degree of coke deposition in the benzene alkylation reaction with CO 2 /H 2 is significantly less than that in the MTA 46,56 and benzene alkylation with methanol 4 due to the in situ consumption of CH 3 O* which depressed the methanol self-reaction, and the atmosphere rich in H 2 and H 2 O was conducive to the elimination of coke. The smaller size and the more moderate acid property in nHZ240 led to a better diffusion efficiency of coke precursors and fewer deep alkylation side reactions.…”

“…The smaller size and the more moderate acid property in nHZ240 led to a better diffusion efficiency of coke precursors and fewer deep alkylation side reactions. The GC-MS (Figure 8c) revealed more detailed information about the soluble coke species, and there were several oxygenated aromatics such as dimethyl-benzaldehyde, tert-butylphenol, and di-tert-butylphenol, indicating that the oxygenated aromatics were main coke precursors under an atmosphere of CO 2 , CO, and H 2 , quite different from the coking process of MTA 46,56 and benzene alkylation with the methanol reaction. 4 The oxygenated aromatics may be derived from the carbonylation reaction of aromatic spices and CO through the Gattermann−Koch reaction.…”

“…HZSM-5 samples were synthesized according to our previous reports. , Taking the sample with SiO 2 /Al 2 O 3 = 60 as an example, 108 g of tetrapropyl-ammonium hydroxide (TPAOH, 25 wt %) and 112.5 g of tetraethyl orthosilicate (TEOS, AR) were mixed and heated to 80 °C in a three-necked flask with continuous mechanical stirring and condensation reflux. Keeping stirring for 24 h, an alkali solution [3.6 g of sodium hydroxide (NaOH, AR) dissolved into 20.0 g of deionized water] and an aluminum salt solution [6.752 g aluminum nitrate nonahydrate (Al­(NO 3 ) 3 ·9H 2 O, AR) dissolved into 20.0 g of deionized water] were dropwise added into the flask by a peristaltic pump, successively.…”

Enhancing the Stability of Methanol-to-Olefins Reaction Catalyzed by SAPO-34 Zeolite in the Presence of CO2 and Oxygen-Vacancy-Rich ZnCeZrOx

“…In addition, the band at 1648 cm –1 attributed to the diene increased as the reaction proceeded . At the same time, dimethylcyclopentenyl cationic species (DMCP), the key intermediates of the formation of aromatics, were identified by the peak at 1510 cm –1 . The methyl group on the benzene ring exhibited a C–H stretching vibration band at 2835 and 2975 cm –1 , while the benzene ring skeleton C = C vibrations and C–H bending vibrations appeared at 1610, 1568, 1455, and 1375 cm –1 . − The intensity of these bands of SA in N 2 and CO 2 atmospheres increased as the reaction proceeded.…”

Influence of Mo modification on coaromatization coupling methanol with n-hexane over [Zn,Mo]/HZSM-5 catalysts

“…[8][9][10] It is well known that the aromatics selectivity over HZSM-5 is relatively lower in the MTA reaction, while metal modified HZSM-5 can improve it by modulating the acid properties as well as the B/L ratio. [11][12][13] HZSM-5 is usually modified with Zn species to enhance alkane dehydrogenation and olefin aromatization, thus improving the aromatics selectivity. 14,15 In previous reports, we have also found it.…”