Xin Su,Chunquan Liu,Jing Liu,Guanyi Chen,Beibei Yan,Jingang Yao,Zhanjun Cheng,Weiming Yi
Arundo donax, acknowledged for its elevated energy content, substantial biomass yield and rapid growth, stands as an alluring candidate for biofuel production. In this investigation, a molecular sieve-based catalyst was utilized to scrutinize the catalytic fast pyrolysis (CFP) of Arundo donax, aiming for the production of naphtha-range compounds. The study also encompassed the evaluation of pyrolysis product yields within a fixed-bed reactor. The systematic exploration included an assessment of the impacts arising from catalyst type, temperature, weight hourly space velocity (WHSV), and N 2 flow rate. The results demonstrated that at 500 °C, WHSV of 1 h −1 and N 2 flow rate of 300 ml/min, SAPO-11 exhibited a selectivity of 64.55% to naphtha-range compounds and 64.55% to isomerous naphtha-range compounds. This was in stark contrast to the control group, which contained no catalyst (with a selectivity of 41.40% and 3.19%, respectively), SAPO-41 (with a selectivity of 11.02% and 9.55%, respectively) and HZSM-5 (with a selectivity of 59.89% and 53.51%, respectively). Additionally, SAPO-11 yielded the highest bio-oil compared to other catalysts (SAPO-11 of 28.52 wt% > none of 19.48 wt% > HZSM-5 of 18.90 wt% > SAPO-41 of 13.11 wt%). The conclusions drawn from these findings imply that the synthesized SAPO-11 catalyst exhibited superior catalytic activity and isomerization proficiency in contrast to other catalysts (SAPO-41 and HZSM-5). Remarkably, under the specified conditions of SAPO-11 catalyst, temperature = 500 °C, WHSV = 1 h −1 and N 2 flow rate = 200 ml/min, the CFP process yielded a remarkable maximum absolute yield of the naphtha-range compound at 25.82 wt%, with an isomerized naphtha-range compound absolute yield of 25.35 wt%.
The high yields of coke and tar pitch relating to volatile reactions can cause plug in the product lines during low temperature pyrolysis of low-rank coals. To study the potential transformation of volatile into coke during its migration in the pyrolysis process, six distillates and their blends from the same coal tar were heated at 400–600 °C. The composition , radicals of six distillates and coke structure were characterized by GC × GC–MS, ESR and Raman techniques, respectively. The results show that the coke yields increase with temperature during thermal reaction for all six distillates. When light oil and pitch are blended, the interaction between the two distillates compresses the transformation of volatile into coke above 500 °C. This can be ascribed to that the reactive hydrogen radicals generated from light oil may weaken the bonding between large molecules. By contrast, other distillates (phenolic oil, naphthalic oil, wash oil and anthracene oil) promote coke formation, resulting in higher coke yields than expected. It is also observed that the highest extent of interaction occurs between phenolic oil and pitch, which may be related to the high content of oxygen containing compounds in phenolic oil and the high electron density of the compounds in pitch.
危险品化学品经营许可证（带存储）