Aspirin

Aspirin molecule

Aspirin is the brand name for Salicylic acid. Its production on Mars would be part of a larger chemical production system, and it can be used as a model for the complexity of the chemical industry that would be required for a Mars Settlement. The chemical formula of Salicylic acid is C₇H₆O₃.

In situ production

Aspirin could be synthesized from simple precursor molecules using the following synthesis path:

Chemical synthesis of Salicylic acid

Main production path

Methane (CH4) + Catalytic reforming -> mixture of aromatic hydrocarbons including Toluene and Benzene

Separation by distillation -> Toluene (C₇H₈)

Toluene + O₂ in a cobalt catalyzed reaction -> Benzoic acid (C₇H₆O₂)

Benzoic acid + molten Sodium benzoate(C₆H₅COONa) in a copper-catalyzed reaction -> Phenol (C₆H₅OH)

Phenol + Sodium hydroxide(NaOH) -> Sodium phenoxide (NaOC₆H₅)

Sodium phenoxide +CO₂ at 100 atm and 115 °C in a method known as the Kolbe-Schmitt reaction -> sodium salicylate (C₇H₅NaO₃₎

Sodium salicylate + acidification with sulfuric acid ->

Salicylic acid

Sodium benzoate production

Benzoic acid(C₇H₆O₂) + Sodium hydroxide (NaOH) -> sodium benzoate (C₆H₅COONa)

Sodium hydroxide production

Sodium hydroxide is also known as caustic soda.

Sodium hydroxide (NaOH) is produced by the electrolysis of sodium chloride(NaCl-table salt) using the Chloralkali process.

Alternate biological production

It may be more practical to produce aspirin from the bark of the willow tree, that contains the amino acid Phenylalanine. However, this requires the mastery of enzyme catalyzed processes.