Acetylene production

Basics

• Acetylene is a Fuel Gas used mainly for Oxy-Acetylene Welding and Oxy-Acetylene Cutting
  • To an extent it can be used for lighting (Such as in Carbide Lamps ) or for Process Heating but outside of areas where Large Supplies+Reserves of it Exist due to using it for Welding/Cutting Elsewhere, it is Cheaper to use Propane , Methane (Either CNG or Bio-Methane / SNG etc (Or novel systems like Hydrogen , Inductive Heat Treatment , or P2X for Industrial Heating etc
• It is produced by reacting Calcium Carbide (CaC2) with Water.
  • Calcium carbide is generated by the carbothermic reduction of lime (CaO) at 2000C. Lime can be produced by reducing Limestone ( The Mineral Form of Calcium Carbonate ) in a furnace at 900C-1000C.
  • Once lime has been produced however, one does not need to continue to harvest more limestone to keep making acetylene. The reaction of calcium carbide with water produces acetylene and calcium hydroxide (Ca(OH)2). The hydroxide dissociates back into water and lime at 512C.
    • This process can even be utilized for Carbon Capture , re Regenerative Calcium Cycle
  • Carbon however, which is burned as acetylene, must be continually provided. Only the calcium is preserved; thus the closed loop is:

Calcium hydroxide + 512C -> Calcium oxide (lime) + water

Calcium oxide + Carbon + 2000C -> Calcium carbide + Carbon Monoxide

Calcium carbide + water (room temp) -> Acetylene + calcium hydroxide.

• • Carbon may be provided from Biomass (ie: Charcoal , Bio-Refinery Sustainably Sourced Petcoke , or Carbon Black etc).
  • It would be useful to know what effect the presence of hydrogen has on the reaction in order to determine if Wood Gas / Syngas, Biogas, and other easily attainable simple organic molecules could be used in place of pure carbon.

Internal Links

• Calcium Carbide
• Related Devices:
  • Open Source Acetylene Generator
    • Essentially a MASSIVELY scaled up Carbide Lamp used to provide enough gas for Cutting/Welding
      • Although it may be scalable to the size of an Atmospheric Storage Tank and used for Large Scale / Community Scale (RE User Eric’s Rant on Scaling of Processes/Systems )

External Links

• Halstead, P.E.; Moore, A.E. (1957). "The Thermal Dissociation Of Calcium Hydroxide". Journal of the Chemical Society 769: 3873. doi:10.1039/JR9570003873