TRANSPORT PROCESS OF CO AND H_2 GASES IN LIQUID PHASE METHANOL SYNTHESIS AND REACTION RATE

摘要

In this study, transport process of CO and H_2 gases in liquid phase Methanol synthesis and the reaction rate of hydrogenolysis of methyl formate were studied to recover wasted or unused discharged heat from industrial sources for thermal energy demands of residential areas. The solubility and diffusivity of CO and H_2 gases in methanol and methyl formate were measured by the method of total pressure decrease due to absorption under pressures up to 1500 kPa and temperatures up to 140 °C. The diffusivities of the gases in the liquids were also measured by measuring the diameter and solution time of single gas bubbles in liquid for temperatures ranged from 25 to 90°C under a pressure of 500 kPa. It was obtained that the mole fraction solubilities are in the order of between 10~(-4) and 10~(-2). The Henry's law constants are about 250 MPa for CO in methanol and about 150 MPa for COin methyl formate, and about 630 MPa for H_2 in methanol or methyl formate at a temperature of 20°C. The solubilities show increases with the increase of temperature. The diffusion coefficients of CO in methanol are between 5 ×10~(-9) and 9.5 ×10~(-6) m~2/s for the temperature range from 25 to 90°C, and become higher as temperature increases. Correlations for solubilities and diffusivity at various temperatures were obtained based on the experimental data. The chemical reaction rate of methanol synthesis by hydrogenolysis of methyl formate was measured using a plate type of Raney copper catalyst in a reactor with rectangular channel under 20 atm and 130 °C. The initial reaction rate was about 0.2 mmol/(l · min), and the reaction rate decreased with reaction time.