Moon Miner
  

Lunar Chemistry

Lunar Chemistry 

2H2 + CO ==> CH3OH      ZnO-Cr2O3 catalyst used
                        methanol

CH3OH + CO => CH3COOH     50 atm rhodium catalyst 200° C.
                            acetic acid

CH3OH + HCl ==> CH3Cl + H2O
                       methyl chloride

3H2 + CO ==> CH4 + H2O   Ni catalyst used
                     methane

4H2 + 2CO ==> C2H4 + 2H2O
                       ethylene

5H2 + 2CO ==> C2H6 + 2H2O
                         ethane

6H2 + 3 CO ==> C3H6 + 3H2O
                        propylene

So what does it all mean?

Methanol can be used as a solvent and it can be converted to formaldehyde which is used to make resins and plastics.  In the commonly used formox process, methanol and oxygen react at ca. 250–400 °C in presence of iron oxide in combination with molybdenum and/or vanadium to produce formaldehyde according to the chemical equation:

2 CH3OH + O2 → 2 CH2O + 2 H2

                          formaldehyde

Methanol can be reacted with HCl to make methyl chloride which can be reacted with silicon at 300° C. in the presence of a copper catalyst to make dimethyldichlorosilane (CH3)2SiCl2 . This can then be reacted with water to make silicone polymers and HCl which can be recycled because chlorine is rare on the Moon. Silicones can make lubricant oils, greases, caulk, waxes, rubber.

(CH3)2SiCl2 reacts with water to form (CH3)2Si(OH)2 which then condenses to form silicone polymers

Methane is the most common component of natural gas. It's mostly useful as a fuel that has a much higher boiling point than LH2. It could be reacted with oxygen in fuel cells to make electricity for motors and waste heat that might be useful for warming pressurized cabins. The products are water and CO2. These would have to be recaptured and recycled on the Moon because they aren't that plentiful even if we do mine polar ices. On Mars where CO2 can be obtained by pumping down atmosphere this might not be as critical. Since CO and CO2 are very stable and decompose at very high temperatures, it is easier to combine them with hydrogen to make methane which can then be decomposed at 900 C. to get pure carbon and hydrogen that can be recycled.  Pure carbon can be used to make steel and be used for air and water filters.

Ethane is the second most common component of natural gas. Like methane, it won't be found underground on the Moon but there might be some in polar ices since it has been detected in comets. It's mostly used to make ethylene by steam cracking. On the Moon ethylene could be made by directly combining hydrogen and CO in the right proportions without making ethane first. Ethane can be used as a refrigerant in cryogenic systems and it can be used in heat pipes that run too cold for ammonia.

Ethylene and propylene are used to make polymers. Polyethylene and polypropylene are the two most common plastics in use today. Ethylene and propylene gases are compressed to high pressure in the presence of catalysts and polymerize. Plastics would not be discarded on the Moon or in space. They would be rigorously reused and recycled. Carbon, hydrogen, nitrogen and organic compounds from polar ice will be not be cheap enough for disposables; and why trash the Moon as we have trashed the oceans?


Methanol can also be converted to acetic acid which is used to make acetate salts like calcium acetate. Calcium acetate can be dry distilled to make acetone, another solvent that also makes nail polish remover, and calcium carbonate a.k.a. limestone. Limestone is not present on the Moon so it would have to be synthesized. It is useful as a flux in steel making and it can be used as a pH buffer in closed ecological life support systems. Acetone is also used for making numerous organic chemicals.  See:  https://en.wikipedia.org/wiki/Acetone  

Ca(CH3COO)2 → CaO(s) + CO2(g) + (CH3)2CO

calcium acetate                                      acetone

                                                                                   acetone         calcium carbonate (limestone)


Calcium acetate is made by reacting calcium metal, calcium hydroxide or calcium oxide with concentrated acetic acid. CaCO3 is calcium carbonate a.k.a. limestone. Dry distilliation is pictured below. Electric heat instead of fire would be used on the Moon of course.

Most acetone today is made by the cumene process.  Benzene and propylene are reacted to form cumene which then reacts with oxygen in the air to form acetone and phenol.  Phenol can be combined with formaldehyde to make Bakelite, a hard scratch resistant electrically and thermally insulating plastic that is seldom used today.  As described earlier, propylene can be made by combining carbon monoxide and hydrogen.  Benzene is common in crude oil on Earth but some might be found in lunar polar ices since benzene was detected in comet 67P/Churyumov-Gerasimenko by the Rosetta spacecraft along with toluene, butane, pentane, hexane and heptane. See:  https://ui.adsabs.harvard.edu/abs/2019A%26A...630A..31S/abstract 

Benzene is prepared from ethyne by the process of cyclic polymerization. In this process, ethyne is passed through a red hot iron tube at 873 K. The ethyne molecule then undergoes cyclic polymerization to form benzene. Ethyne is more commonly called acetylene. Acetylene or ethyne can be made by reacting calcium carbide with water (see below).  

from: https://byjus.com/chemistry/preparation-of-benzene/       

Benzene has many uses. See: https://en.wikipedia.org/wiki/Benzene 

                                                                                                      

CaC2 + 2H2O → Ca(OH)2 + C2H2
calcium carbide                   acetylene

Calcium carbide reacts with water to make acetylene. Acetylene is used for Oxv-Acetylene welding and cutting. Acetylene gas is unstable and must be dissolved in acetone under pressure.

Calcium carbide is produced industrially in an electric arc furnace from a mixture of lime and coke at approximately 2,200 °C (3,990 °F). This method has not changed since its invention in 1892:

CaO + 3 C → CaC2 + CO
                calcium carbide


Calcium is present on the Moon in the mineral anorthosite CaAl2Si2O8 which composes most of the lunar highlands regolith. Anorthosite can be melted, quenched with LOX and ground fine in rod and ball mills then leached with sulfuric acid H2SO4 to form a solution of highly soluble aluminum sulfate and a precipitate of silicic acid and barely soluble calcium sulfate. These can be dried out and separated electrostatically. The silica gel can be used as is, melted to make glass or roasted with sodium oxide to make sodium silicate. The calcium sulfate is plaster for walls and molds. Plaster can be applied between sheets of woven glass fiber or perhaps basalt fiber to make drywall also known as sheetrock. The CaSO4 can be roasted at about 1500° C. to form solid calcium oxide and gaseous oxides of sulfur. CaO could be electrolyzed in FFC cells to get calcium metal and oxygen.

Acetylene reacts with anhydrous hydrogen chloride gas over a mercuric chloride catalyst to give vinyl chloride:


C2H2 + HCl → CH2=CHCl
                        vinyl chloride


When heated to 500 °C at 15–30 atm (1.5 to 3 MPa) pressure, dichloroethane decomposes to produce vinyl chloride and anhydrous HCl.

ClCH2CH2Cl -----→ CH2=CHCl + HCl
dichloroethane        vinyl chloride

Due to the relatively low cost of dichloroethane compared to acetylene, most vinyl chloride has been produced via this technique since the late 1950s.  Nearly 20 million tons of 1,2-dichloroethane are produced in the United States, Western Europe, and Japan annually. Production is primarily achieved through the iron(III) chloride-catalysed reaction of ethylene and chlorine:


H2C=CH2 (g) + Cl2 (g) → ClCH2–CH2Cl (l)
ethylene                             dichloroethane

Vinyl chloride is polymerized to make PVC or "Vinyl" plastic which was once used to make LP records and furniture including car seats.  Polyvinyl chloride abbreviated: PVC) is the world's third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene. About 40 million tonnes are produced per year.

Many Uses for Lunar Ice
by Dave Dietzler

Lunar polar ices are probably of cometary origin and will contain more than water. Even so, water is very important.

Water for drinking, cooking, brewing, bathing, washing, mopping, flushing toilets, farming, aquaculture, dissolving sodium silicate for making sand molds, quenching hot metals, mixing cement for “indoor” purposes, chemical processes, lubricant, coolant, steam cleaning which doesn't pollute air in closed environments like ammonia water and chemical cleansers do.....

Water is a source of oxygen and hydrogen which can be used as rocket propellants and fuel cell reactants and of course oxygen for breathing. Hydrogen is also used to make chemicals.

Ammonia and several less abundant compounds in comets contain nitrogen for atmospheres and nitrate fertilizer. Some polymers like nylon and kevlar require nitrogen. Nitrate explosives for mining can be replaced with magnesium or aluminum powder and LOX explosives so nitrogen is not wasted.

Methane can be decomposed at 900 C. to get pure carbon for making steel and carbon filters. It can also be used as a fuel cell reactant with a much higher boiling point than LH2. Carbon monoxide, CO2 and hydrogen can be reacted to make methane. Since CO and CO2 are very stable molecules and have high decomposition temperatures it is easier to convert them to methane and decompose the CH4 to get pure carbon and recycle the hydrogen.

Methane, carbon monoxide, carbon dioxide and numerous other compounds like methanol, formaldehyde and ethane can be used to synthesize plastics including insulation for wiring, medicines, lubricants, rubber, hydraulic fluid, adhesives, varnish for electric motor coils, dyes, paints, etc.

Halogens have also been detected in comets. These can be used to make table salt, silicones, silane (SiH4), Teflon, refrigerants, medicines and possibly aluminum production.    

Teflon is needed for seals and gaskets in cryogenic equipment and fluorine filled devices like gas centrifuges.

Also PVC (Polyvinyl Chloride or just "Vinyl") requires chlorine and uranium refining and enrichment requires fluorine to makes UF6 gas that goes into gas centrifuges..

Table salt has many uses. It even cleans coffee pots.  When you mix lye with fat to make soap, you then add salt to separate the lye soap into cake soap and glycerin....

There are also sulfur compounds in comets that could be used for sulfuric acid, polymers and sulfur cement.

Lunar polar ice could be indispensable for space industrialization and settlement.