Qualities of Natural Gas

Although the gas industry has relied on various gases during the close to 200 years of its history, only substances produced by the gasification or degassing of coal, natural gas, and propane- and butane-based liquid gases have been used to an important extent.

• Fuel gases produced by the gasification or degassing of coal have an average calorific value. In the Czech Republic, they are known as coke gas and city gas. While the most important constituents of these gases are methane, hydrogen, and carbon monoxide, they also contain nitrogen, carbon dioxide, and higher hydrocarbons. Due to high carbon monoxide content, these gases are toxic. Their calorific value ranges between 17 - 20 MJ/m3.
• Fuel gases with high methane content have excellent heating characteristics. In the Czech Republic, they include natural gas (carbon- and oil-based) and biogases. While their prevalent constituent is methane, they can contain higher hydrocarbons and inert gases. Their calorific value depends on methane content and ranges from some 20 MJ/m3 (biogases, carbon-based natural gas with high content of inert gases) up to 40 MJ/m3 (the calorific value may be even higher if the hydrocarbon content is higher).
• Fuel gases based on propane and butane have a very high calorific value. In the Czech Republic, these gases are used in a pure form or in a mixture known as propane-butane. Unlike the previously mentioned gases, propane- and butane-based fuel gases are distributed in liquid state. Their calorific value depends on the ratio of propane and butane in the mixture, and ranges between 101.7 (pure propane) and 133.9 MJ/m3 (pure butane) or 50 MJ/kg of mixture of these gases (they are sold per weight).