The industrial methanation of carbon monoxide to produce synthetic natural gas (methane) is a key reversible reaction in energy technology:
CO(g)+3H2(g)⇌CH4(g)+H2O(g) \text{CO}(\text{g}) + 3\text{H}_2(\text{g}) \rightleftharpoons \text{CH}_4(\text{g}) + \text{H}_2\text{O}(\text{g}) CO(g)+3H2(g)⇌CH4(g)+H2O(g)The forward reaction is exothermic.
An engineering firm evaluated two distinct operating configurations, A A\,A and BBB, for a new pilot plant.
In both configurations, carbon monoxide is mixed with a stoichiometric excess of hydrogen. Configuration B B\,B employs a catalyst, a lower operating temperature, and a higher operating pressure than configuration AAA.
The parameters for each configuration are detailed below:
| Configuration | Pressure / atm | Temperature / °C | Catalyst |
|---|---|---|---|
| AAA | 5 | 450 | None |
| BBB | 35 | 280 | Nickel-based catalyst |
The firm decided to run the pilot plant using configuration B B\,B instead of configuration AAA.
Explain, by discussing the impacts of altering these operating conditions on both the rate of attainment of equilibrium and the equilibrium yield of methane, why configuration B B\,B was selected.
38 exam-style questions on Edexcel GCSE Chemistry 5.2 Reversible reactions and equilibria, covering 5.2.1 Reversible reactions and dynamic equilibrium, 5.2.2 The Haber process, and 5.2.3 Changing the position of a dynamic equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.