Abstract

Processes of converting CO₂ to methanol and dimethyl ether (DME) in a flow-circulation mode where the converted gas is partially returned to the reactor are studied to address the issue of utilizing carbon dioxide emissions. Experimental data are presented on methanol synthesis (industrial catalyst MegaMax 507) and the direct synthesis of DME (MegaMax 507/industrial zeolite TsVM in a mass ratio of 1 : 1). In methanol synthesis from synthesis gas (composition, vol %: Н₂ 76.6, СО₂ 19.8, and N₂ 3.6), high СО₂ conversion of 84–99.6% is achieved at 240–260°С and a pressure of 5.3 MPa with low selectivity in regard to the side reaction (<4.7% synthesis of CO). The maximum specific productivity of methanol at 260°C is 1.24 kg (kg_cat h)⁻¹. Experiments performed under special conditions show that slight heating (up to 10°C) is observed at the inlet into the catalyst bed under methanol synthesis condition, thus indicating that the reactor is of polytropic type. In the synthesis of DME, the yield of DME per weight amount of a bifunctional catalyst lies within the range of 0.08–0.17 kg (kg_cat h)⁻¹, depending on the conditions of the reaction. In addition, the conversion of methanol in DME is no lower than 42%, СО₂ conversion lies in the range of 79–96%, and DME synthesis proceeds almost under isothermal conditions.

中文翻译：

---

流动循环模式下由CO 2和H 2合成甲醇和二甲醚。

摘要

为了解决利用二氧化碳排放的问题，研究了将CO ₂转化为甲醇和二甲醚（DME）的流动循环方法，其中转化后的气体部分返回反应器。给出了有关甲醇合成（工业催化剂MegaMax 507）和DME直接合成（MegaMax 507 /工业沸石TsVM的质量比为1：1）的实验数据。在从合成气合成甲醇（组合物，体积％：Н ₂ 76.6，СО ₂ 19.8，和N ₂ 3.6），高СО ₂在240-260°С和5.3 MPa的压力下，副反应选择性低（CO合成<4.7％），转化率为84-99.6％。260℃下甲醇的最大比生产率为1.24kg（kg _cat h）^-1。在特殊条件下进行的实验表明，在甲醇合成条件下，在催化剂床的入口处观察到轻微的加热（高达10℃），因此表明该反应器是多方型的。在DME的合成中，根据反应条件的不同，每单位重量的双功能催化剂的DME收率在0.08-0.17 kg（kg _cat h）^-1的范围内。另外，甲醇在DME的转化是不低于42％，СО ₂ 转化率在79％至96％之间，DME合成几乎在等温条件下进行。