浆态床反应器中含氮合成气合成二甲醚的研究

The Study of Direct Synthesis of DME from Syngas Containing N_2 in Slurry-Bed Reactor

Cu ZnO Al2O3甲醇合成催化剂和HZSM 5分子筛通过机械混合制备了合成气直接合成二甲醚催化剂,并在浆态床反应器中进行了含氮合成气制二甲醚的研究,考察了各种工艺条件对二甲醚合成性能的影响。结果表明:转子转速、原料气空速、反应压力和温度均对催化剂的反应性能有影响。采用浆态床反应器合成二甲醚,可实现等温操作并可使反应热及时移出,从而避免催化剂床层形成热点,使催化剂失活减缓,但CO转化率和二甲醚选择性相对较低。采用浆态床反应器与固定床反应器集成技术,不仅可以解决催化剂床层形成热点问题,还可得到90%的CO转化率和75%的二甲醚选择性,并使催化剂保持高的稳定性,二甲醚收率为68%。

The mechanical mixing method was used to prepare the bifunctional catalyst for DME synthesis from Cu-based catalyst for methanol synthesis and HZSM-5 zeolite. The DME synthesis from syngas containing N_2 was studied in the slurry-bed reactor. The results indicated that the speed of rotator, space velocity of the feed gas, the pressure and temperature of the reaction would influence the reaction performance. Using slurry-bed reactor, reaction heat is easy to remove from catalyst bed, which would avoid hot-spot on catalyst bed, prevent catalyst from sintering and then keep catalyst stable, but much lower CO conversion was obtained due to the extra resistance of mass transfer through liquid phase. Using an integrated reactor of slurry-bed reactor connecting with fixed-bed reactor, not only high CO conversion of 90% and high DME selectivity of 75% were obtained, but also high catalyst stability was kept during DME synthesis.