Isobutane Gas Properties

Isobutane is a flammable hydrocarbon with distinct physical and chemical properties. It is widely used in the refrigeration, fuel and chemical industries.

Difference Between Isobutane and n-Butane

Isobutane is an isomer of n-butane that’s converted in an isomerization process. Both have the chemical formula of C₄H₁₀, but the arrangement of the carbon and hydrogen atoms is different. They also have different physical properties.

Key Properties of Isobutane

Here are some of the key properties of isobutane:

Chemical and Physical Properties of Isobutane
Property	Value
Isobutane Molar Mass	58.12 g/mol
Isobutane Boiling Point	-11.75 °C
Isobutane Melting Point	-159.61 °C
Liquid Density at Boiling Point	593.821 kg/m3
Vapor Pressure	310.9 kPa at 21 °C
Solubility in Water	Slight
Solubility in Common Solvents	Soluble in chloroform, ether and ethanol
Odor	Light natural gas odor

Isobutane Reactivity and Stability

Since isobutane is flammable, it is reactive to nitrous oxides, halogens and acetylene. It is incompatible with strong oxidizing agents such as:

• Nitrates
• Chlorine
• Perchlorates
• Fluorine
• Nickel carbonyl with oxygen

Isobutane gas is stable in its recommended storage conditions.

Flammability of Isobutane

Isobutane gas is extremely flammable, with a limit of flammability between 1.8 and 8.4% by volume. Mixing isobutane with air can be explosive, and if isobutane containers are exposed to intense heat or fire, they may rupture.

With complete combustion, isobutane flammability results in carbon dioxide, water and heat. With incomplete combustion from an insufficient oxygen-to-isobutane ratio, carbon monoxide is created, which can be dangerous.

Industrial and Common Uses

Isobutane is used in the following applications:

• Chemical intermediate: Isobutane is a chemical intermediate in manufacturing various goods.
• Calibration gas: Isobutane is a common component in calibration gases.
• Refrigeration: Pure isobutane is used for refrigeration in place of ozone-depleting halocarbons.
• Plastics: Isobutane is used in manufacturing propylene oxide to make polyurethane plastics.
• Solvent: Isobutane is used as a blended solvent for cannabis or botanical extraction.
• Laboratory research: Isobutane is used as a reagent gas, reference point for calorimetric measurements and more.

Safety and Hazards

Since isobutane vapor is heavier than air, it can displace oxygen and act as an asphyxiant in high concentrations. In its liquid form, isobutane can cause frostbite if it touches skin. Exposure to isobutane can cause symptoms such as:

• Nausea
• Lightheadedness
• Dizziness
• Headache
• Unconsciousness

Isobutane is shipped as a liquefied gas under vapor pressure.

Partner With Meritus Gas Partners for Your Isobutane Needs

Meritus Gas Partners supplies pure isobutane gas and related expertise to a variety of businesses. Contact us for supply and technical support, or find a partner near you today.