The paper researches the effect of temperature on ammonia synthesis. The ammonia synthesis reaction N2(g)+3H2(g)=2NH3(g)is exothermic with a negative entropy change. ΔG0condition is fulfilled at lower temperatures up...The paper researches the effect of temperature on ammonia synthesis. The ammonia synthesis reaction N2(g)+3H2(g)=2NH3(g)is exothermic with a negative entropy change. ΔG0condition is fulfilled at lower temperatures up to 464 K. It is a constant equilibrium of the ammonia synthesis reaction K′p≫1at lower temperatures, which means that the NH3(g)) synthesis reaction is shifted in the direction of NH3(g) formation (higher production of ammonia). The downside of lowering the temperature is that more ammonia is obtained, but the reaction rate slows down. Above 464K, the free enthalpy of the NH3(g) synthesis reaction is greater than zero, so the reaction enters thermodynamically unfavorable conditions. By increasing the reaction temperature, the ammonia yield NH3(g) decreases in the equilibrium mixture. At 400 K, it is 0.5128 kmol/kmol (51.28%) and at 900 K, the synthesis process NH3(g) is practically complete.展开更多
文摘The paper researches the effect of temperature on ammonia synthesis. The ammonia synthesis reaction N2(g)+3H2(g)=2NH3(g)is exothermic with a negative entropy change. ΔG0condition is fulfilled at lower temperatures up to 464 K. It is a constant equilibrium of the ammonia synthesis reaction K′p≫1at lower temperatures, which means that the NH3(g)) synthesis reaction is shifted in the direction of NH3(g) formation (higher production of ammonia). The downside of lowering the temperature is that more ammonia is obtained, but the reaction rate slows down. Above 464K, the free enthalpy of the NH3(g) synthesis reaction is greater than zero, so the reaction enters thermodynamically unfavorable conditions. By increasing the reaction temperature, the ammonia yield NH3(g) decreases in the equilibrium mixture. At 400 K, it is 0.5128 kmol/kmol (51.28%) and at 900 K, the synthesis process NH3(g) is practically complete.
