MeMo/USY催化剂对神东煤热解产物的调控

Regulation of Shendong coal pyrolysis products based on MeMo/USY catalyst

以USY分子筛为载体,通过等体积浸渍MoO_3、Fe_2O_3、Co_3O_4、NiO四种过渡金属氧化物,制备了Mo/USY、FeMo/USY、CoMo/USY、NiMo/USY催化剂,并借助ICP、XRD、BET、NH_3-TPD、TG等手段对催化剂进行表征。使用粉-粒流化床进行神东煤的催化热解实验,考察了过渡金属氧化物对USY的改性作用及其对热解产物的影响。结果表明:不同催化剂作用下,半焦收率基本保持在65%左右;与SiO_2相比,USY分子筛使焦油中酚类化合物含量从36.95%减少到5.08%,萘类化合物含量从8.24%增加到72.76%;与USY相比,Mo/USY使气体、液体产物的收率分别降低了4.4个百分点、30.0个百分点,萘类含量减少了18.5个百分点;Fe_2O_3、Co_3O_4、NiO对Mo/USY的改性作用明显,降低了催化剂的积炭率,提高了CH4、C2、C3、CO_2的收率和气体总收率;FeMo/USY促进了产物的芳构化和萘类的生成;CoMo/USY促进了产物的芳构化反应,抑制了萘类的生成反应;NiMo/USY抑制了产物的芳构化反应、萘类的生成反应。

Four transition metal oxides, MoO3, Fe2O3, Co3O4, and NiO, were supported on USY molecular sieves by equal volume impregnation to prepare Mo/USY, FeMo/USY, CoMo/USY and NiMo/USY catalysts, and characterized by ICP, XRD, BET, NH3-TPD, TG. The pyrolysis experiments of Shendong coal were conducted in a powder-particle fluidized bed reactor. The results showed that the yield of the semi coke was basically around 65% with different catalysts. Compared with SiO2, the content of phenols was reduced from 36.95% to 5.08%, and the content of naphthalenes was increased from 8.24% to 72.76% in tar by USY molecular sieve. Compared with USY molecular sieve, gas product yield, liquid product yield, and content of naphthalenes was decreased by 4.4%, 30.0% and 18.5% by Mo / USY, respectively. The effects of Fe2O3, Co3O4 and NiO on the modification of Mo/USY were obvious, which reduced the carbon accumulation rate of the catalyst and increased the yield of CH4, C2, C3, CO2 and the total gas. The aromatization of the products and the formation of naphthalenes were enhanced by FeMo/ USY. The aromatization reaction of the product was enhanced, but the formation reaction of naphthalenes was inhibited by CoMo/USY. The aromatization reaction of the products and the formation reaction of naphthalenes were inhibited by NiMo/USY.