What is the heat of formation of methane produced by the pyrolysis of alcohol?
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What is the heat release when alcohol is pyrolyzed to produce 1 kmole of methane at 150°? This post was last edited by hw197358 on 2009-2-9 18:37.]
This can be calculated based on the energy gains and losses from the breaking and reforming of chemical bonds.
PROii simulation was used under the following conditions: 1. Reaction equation: Ethanol = Methane + Formaldehyde; 2. Raw material temperature: 30; 3. Reaction pressure: 10 kg of absolute pressure; 4. Reaction temperature: 150. The heat load obtained was 18,800 kcal/kmol.
The heat effect of forming 1 mole of a pure substance from the most stable elements at a certain temperature and pressure. It is now more commonly referred to as the enthalpy of formation, because the heat effect of this formation reaction is equal to the increase in the enthalpy of the system during that process. The enthalpy of formation under standard conditions (where all elements and the pure substances formed are in their standard states) is called the standard enthalpy of formation. In the current manual, it is referred to as the molar standard enthalpy of formation, abbreviated as standard enthalpy of formation, denoted by the symbol △fHθm, with the unit of kilojoules per mole (KJ/mol).
I’m sorry for everyone’s inconvenience; I made a mistake in my response. It should be that ethanol, through cracking reactions, produces methane, hydrogen, and carbon monoxide.
Standard molar enthalpy of formation of ethanol(g): -235.1 kJ/mol. Standard molar heat capacity at constant pressure of ethanol(g): 65.44 J/mol*K. Standard molar enthalpy of formation of methane(g): -74.81 kJ/mol. Standard molar heat capacity at constant pressure of ethane(g): 35.309 J/mol*K. Standard molar enthalpy of formation of hydrogen gas(g): 0 kJ/mol. Standard molar heat capacity at constant pressure of hydrogen gas(g): 28.824 J/mol*K. Standard molar enthalpy of formation of carbon monoxide(g): -110.525 kJ/mol. Standard molar heat capacity at constant pressure of carbon monoxide(g): 29.142 J/mol*K. Standard molar reaction enthalpy: 49.765 kJ/mol. Temperature difference for the reaction: 125 K. Heat released in the reaction: 53244.375 kJ. Amount of reactants: 1000 moles
Standard molar enthalpy of formation of methane (g) –74.81 kJ/mol
CH4(g) –74.9 kJ/mol–1 《Practical Handbook for Chemical Engineers–Perry’s Standard Charts and Formulas》