Taking CO2 absorption by amine solutions in industrial-scale spray towers as the research object, a computational fluid dynamics (CFD) model is established to describe the gas-liquid two-phase flow, interphase heat and mass transfer, and chemical reaction process in industrial-scale spray scrubber, based on the Euler-Lagrange method. The reliability of the CFD model is validated by experimental data of CO2 absorption by monoethanolamine (MEA) solution. On this basis, the fundamental laws of heat and mass transfer and chemical reactions accompanying the CO2 absorption process, as well as the effects of the absorbents’ chemical composition, gas-liquid phase flow characteristics, and operating pressure on the efficiency of CO2 removal in a spray tower were investigated. The numerical results indicate that, the volume fraction of CO2 in flue gas decreases with the increase of scrubber height, while both the gas temperature and water vapor pressure firstly increase and then decrease with the increase of elevation. With the increase of CO2 load in lean solution from 0.1 to 0.4, the highest gas temperature in the scrubber declines from 70 ℃ to 54 ℃. The overall decarbonization efficiency for the spray scrubber significantly decreases when the load of lean solution is greater than 0.25. When the superficial gas velocity is greater than 2.5 m/s, the enhancement of increased mass transfer specific interface area on CO2 absorption is restricted ascribed to the declines of gas residence time and mass transfer coefficient. For the decrease of operating pressure in spray scrubber from 101 kPa to 70 kPa, the CO2 removal efficiency decreases by about 15.9 percentage points.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |