Methane

Methane

Phase Change Information
Specific Heat	20.4 J/mol*K
Latent Heat	1000 J/mol
Min Condensation Pressure	6.3 kPa at 81.6 K
Max Liquid Temperature	6000 kPa at 195 K
Freezes at	81.6 K
Liquid Volume	40 L/kmol
Molar Mass	16 g/mol

Description

Methane is a combustible fuel. It is refined from Ice (Volatiles) - Stationpedia

Methane or CH₄ is a combustible gas in the presence of Oxygen and the breathing gas of the Zrilian species. The main source of Methane on most planets is in the form of Ice (Volatiles) that can be mined on the surface. Methane will autoignite at 300 Celsius or above in the presence of Oxygen, and autoignite at 50 Celsius or above in the presence of Nitrous Oxide.

Composition

Its combustion generates Pollutants, which are also formed through the evaporation of Liquid Sodium Chloride. With the fact it's also toxic to humans and plants, it is possible it's not actually methane but a close relative of it.

Possible compound: CH₃Cl (Chloromethane)

Usage

See also: Fuel

Different ratios of Methane and Oxygen will produce different temperatures and pressures during combustion. Combustion will create a large amount of Heat, pressure, and Carbon Dioxide. This reaction is useful inside a Furnace for smelting ores and creating alloys, but can be catastrophic when inside a Canister or a room.

These are the combustion reactions of methane:

2x + 1x = 6x + 3x + 572 kJ (Autoignites at 573.15 K (300.0 °C))

1x + 1x = 2x + 2x + 572 kJ (Autoignites at 323.15 K (50.0 °C))

3x + 2x = 6x + 3x + 1x + 1716 kJ (Autoignites at 423.15 K (150.0 °C))

Since both reactions results in same amount of heat, but the one with Nitrous Oxide results with less moles, it produces much more heat per amount of matter (2.25 times more heat energy per mole of reaction products). Also, Nitrogen has lower heat capacity than pollutant, which results in even higher temperature.

The reaction rate by default (for example: in atmosphere) depends on temperature as clamp01(1 / (0.002 * (T_C + 273.0)^1.6 + 0.05) / 5 for oxygen as an oxidizer, and clamp01(1 / (0.0025 * (T_C + 273.0)^1.01 + 0.05) / 5 for nitrous oxide or ozone. Thus, the maximum default reaction rate is 0.2 and is valid at temperatures below 211C when without nitrous oxide and 107C when enough nitrous oxide is present (>~5%). After that reaction rate decreases logarithmically. At temperatures above 460C, nitrous enriched fuel combusts faster (at approx. 2x rate) than oxygen only. At higher temperatures, the difference is even greater, thus making the reaction more efficient and violent. Some devices (like Combustor or Gas Fuel Generator) increases rate of reaction (to 0.9 i.e. 90% in both cases).

If a combusting gas mix contains Volatiles, NOS, and O2, they all will react proportionally at same rate, according to aforementioned reactions (i.e. at 90% reaction rate and ideally balanced mix, each component will decrease by 90% from it's original amount). When mix is unbalanced and have either excess of volatiles or oxidizers, then proportions decrease accordingly, i.e. with excess of volatiles, only the amount of volatiles corresponding to amount of oxidizers (2 per Oxygen, 1 per Nitrous Oxide) will decrease proportionally; with excess of oxidizers, similarly, only the amount of oxidizers corresponding to the amount of volatiles is decreased at reaction rate, i.e. oxygen reacts at half the rate of nitrous oxide.

Volatiles have a specific heat of 20.4 Joule / mol.

Notes

• The Specific heat of 20.4 Joule / mol is in-between the specific heat of Hydrogen and Methane.
• The actual Autoignition temperature of Chloromethane in Oxygen is 625 °C (1,157 °F; 898 K), the game grossly underestimated the iginition temperature by about 1.56 times.
• Concentrations of methane aboute 1% in atmosphere are lethal to plants, keep attention on that designing a greenhouse, because the Portable Composter Advanced Composter will release Volatiles during the process.
• Enthalpy of Methane (CH₄) combustion is precisely 286 kJ/mol (multiplied by 2 when using Nitrous Oxide or Ozone as oxidizers).
• As far as rocketry is concerned, Methane have a mass of 62.5 mol/kg.
• Given the above, Volatiles have a molar mass of 16, suggesting it really is methane (CH₄).

Sources

Volatiles can be collected from the following sources:

Source	Amount
Biomass	8 mol
Ice (Volatiles)	20 mol
Ore (Cobalt)	1 mol

Can be also obtainable by trading.

References

Gases and Liquids
Elements	Compounds	Mixtures	Other
		Fuel (66.6% H2 + 33.3% O2) Superfuel (50% H2 + 50% N2O) Air (75% N2 + 25% O2)	Atmosphere Coolant