The effect of plasma plasma energy density on C2H6 dehydrogenation reaction in H2 atmosphere

• Categories:Technical Support
• Author:Plasma cleaning machine-CRF plasma plasma equipment-plasma surface treatment machine manufacturer-chengfeng intelligent manufacturing
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• Time of issue:2022-01-21
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(Summary description)The effect of plasma plasma energy density on C2H6 dehydrogenation reaction in H2 atmosphere: The effect of H2 addition on the C2H6 dehydrogenation reaction when the plasma energy density was 860 kJ/mol: with the increase of H2 concentration, the conversion rate of C2H6, the yields of C2H2, C2H4 and CH4 all increased, which indicated that the addition of H2 It is beneficial to the conversion of C2H6 and the generation of C2H2, C2H4 and CH4. The possible reasons for the above results are: on the one hand, due to its good thermal conductivity, hydrogen can transfer a large amount of heat and act as a diluent gas in ethane plasma; When the electron collides with the H2 molecule inelastically, the H2 molecule absorbs energy to break the HH bond and generate an active hydrogen atom. Active hydrogen atoms can abstract hydrogen from C2H6 to generate C2H5 radicals, which themselves generate H2. Further hydrogen abstraction by active hydrogen atoms and radical recombination reactions lead to the formation of C2H4 and C2H2. At the same time, the inelastic collision of C2H6 itself with high-energy electrons is more likely to lead to the breakage of its C-C bond, resulting in the formation of the middle base, which lays the foundation for the formation of CH4. Therefore, compared with pure C2H6 dehydrogenation under plasma plasma, the conversion rate of C2H6, the yields of C2H2, C2H4 and CH4 increased significantly with the increase of H2 concentration. One advantage of the force of adding H2 to C2H6 is that it inhibits the formation of carbon deposits. The effect of plasma plasma energy density on C2H6 dehydrogenation reaction in H2 atmosphere is shown in Table 3-2. With the increase of plasma injection power, the conversion rate of C2H6 increases rapidly. This is because when the plasma energy density increases, the electron energy and electron density in the plasma increase, and the high-energy electrons inelastically collide with H2. The probability increases, so the probability of generating active species increases, resulting in an increase in the conversion rate of C2H6, and an increase in the concentration of various CHx and C2Hx free radicals required for other products, which promotes the increase in the production of C2H4 and C2H2. When the plasma energy density is 860kJ/mol, the ethane conversion rate can reach 59.2%, and the sum of the ethylene and acetylene yields can reach 37.9%. But at the same time, it should be noted that with the increase of plasma energy density, the selectivity to generate C2H4 and C2H2 gradually decreases, and more carbon deposits are generated on the reactor wall. In order to obtain higher energy efficiency, the appropriate plasma energy density should be selected, rather than the higher the energy density, the better. Table 3-2 Effect of plasma energy density on C2H6 reaction in H2 atmosphere Ed/(kJ/mol) XC2H6/% YCH4/% YC2H4/% YC2H2/% 320 37.6 2.6 3.7 10.6 640 45.2 6.1 8.7 21.2 860 59.2 7.0 9.2 28.7 1000 61.6 7.9 9.6 34.6 Note: The reaction conditions are C2H6/H2=2