Purification Of Yellow Phosphorus Tail Gas Synthesis Of Dimethyl Ether

The nature, applications, production, using prospect of dimethyl ether (DME) was Summaried in this paper, and the technological progress of single-step synthesis of dimethyl ether from syngas and syngas containing CO₂ was also presented detailedly. Synthesizing the green chemicals—dimethyl ether from yellow phosphorus tail gas containing CO and a little CO₂ emissioned from yellow phosphorus industries that is one of the pillar industries in Yunnan Province ,and gas from water-gas shift reaction researched in this paper possess economic, environmental and other multiple positive.The bifunctional catalysts preparation , inspection of their performance and technical conditions of the single-step synthesis dimethyl ether from the syngas (CO,H₂) containing CO₂ were comprehensively studied in this research paper, mainly including :(1) It being the fact that the complexity of single-step synthesis of DME from syngas and syngas containing CO₂, setting up a analysis system that the side-by-side double column was connected in series solved the problem which insert sample and sampling time after time in experiment on-line,and lay a foundation for analyzing reactional gas of synthesis of DME from yellow phosphorus tail gas .(2)This paper researches the performance of bifunctional catalysts prepared by two methanol synthesis catalysts(C301 , C207) and two methanol dehydration catalysts(γ-Al₂O₃, HZSM-5) in Temp=250℃,Stirring speed=1200r/min,m(methanol synthesis catalyst):m(methanol dehydration catalyst)=4, H2: CO=1.7² , achieving the conclusion that HZSM-5 as methanol dehydration catalyst leaded to byproduct increase and yield of DME decrease suddenly , and methanol synthesis catalyst C207 put up the better performance than C301 in the reaction system, moreover that can promote CO₂ concerned with dimethyl ether synthetic reactions. Therefore, C207-γ-Al₂O₃ was chosen as the bifunctional catalysts of the synthesis of dimethyl ether from syngas containing CO₂.(3)This paper also studied the effect of stirring speed on synthesis of dimethyl ether, operating conditions:H2:CO=2, Press=4.6MPa, Temp=250°C, m (C301) : m (Y-AI2O3) =4, geting the conclusion that when the rate exceeded 275r/min, CO conversion rates, selectivity of DME and CO2 was almost constant at a certain value, forming a stable system of three-phase. So, stirring speed 750r/min was made as the feasible stirring speed.(4) Optimizing technical conditions and effecting of CO2 content on intermittent system of the synthesis of DME from syngas containing CO2 with C207—Y-Al2O3as the bifunctional catalysts were studied in slurry reactor in this paper, resulting rule that total carbon conversion rates, selectivity and yield of DME follow as temperature, pressure, the mass of bifunctional catalysts and CO2 content (fixed the proportion of H2 and CO).Finally, operating conditions:Temp=250°C , Press=4.6MPa, the mass of bifunctional catalysts 10g(m(C207): m(Y-Al2O3)=4) was made as the best technical.(5)The thermodynamics data,the balance compose,total carbon conversion rate, selectivity of DME, yield of DME ,of main reaction of the single-step synthesis DME from syngas containing CO2 at different temperature(210-290°C)and different pressure(1.16⁴.60MPa) were calculated and analysed. The result have theoretics significance for practice application, which have good tally with experiment data.