Fuel Gases

Tap into Heat Energy - with Our Full Range of Fuel Gases in Different Supply Modes

The term fuel gases refers to gases that can be burned to generate a flame and/or heat. They include acetylene, hydrogen, natural gas, propane and propylene.

Most fuel gases are composed in whole or in part of hydrocarbons (methane, acetylene, propane and propylene), hydrogen, carbon monoxide and oil vapors. Each fuel gas has a different ratio of carbon to hydrogen atoms, which means that different amounts of oxygen are needed to burn the gas efficiently.

This ratio of fuel to oxidant and the molecular structure affect the temperature of the flame, as well as the flammability and explosive limits.

Fuel gases can be stored either as a compressed gas or as a liquid, depending on the gas type and on the amount of product required. Some gases such as acetylene have to be stored in a very specific way, in this case in a cylinder filled with a porous mass soaked in acetone.

Visit your local site to find which fuel gases from Linde are available in your region.

What Are Fuel Gases Used for?

Fuel gases are used across an extremely broad application spectrum. Many metal fabrication steps, including cutting and welding, flame heating processes and heat treatment, rely on fuel gases. Most metal heating applications require rapid and concentrated heat input into a given area. An oxy-fuel gas flame provides the hottest flame and heat intensity for these use cases. The oxidant can be supplied from oxygen cylinders or a bulk source. Lower-temperature applications that can be heated slowly over a longer period of time can use alternative air-fuel gas systems. Here the air is provided from cylinders, a compressed air supply source, or air induced into the torch by the action of higher-pressure fuel gas. Our experts have many decades of experience in the use of fuel gases for welding, cutting and other metal fabrication applications. Not only do we supply the full range of compressed fuel gases in cylinders, we can also help you optimize the flame temperature and oxygen jet, and advise on the appropriate safety precautions. In addition, we offer the full range of welding and cutting equipment.

Fuel gases are also commonly used as a source of power and energy for transportation, with the potential to reduce the environmental impact - and emissions in particular - of a growing number of road vehicles. Natural gas and liquefied natural gas are seen by many industry experts as an increasingly valuable bridge towards a lower-carbon, renewable-rich landscape. With a new wave of LNG projects currently in the pipeline, our gas processing, liquefaction and storage expertise is proving an invaluable asset. Hydrogen too is helping to power the transition to a greener economy - reaching beyond cars and trucks to innovative rail and maritime applications. As a global leader in the production, processing, storage and distribution of hydrogen, we have the largest liquid hydrogen capacity and distribution network in the world.

Looking beyond metal fabrication and transportation, fuel gases are also at the heart of many industrial processes. Industries such as steel, non-ferrous metals, glass, concrete, and pulp and paper rely on the high temperatures and rapid heating capabilities of fuel gases - often enriched with oxygen - to provide combustion and process heating in furnaces, kilns, boilers, reactors and similar. The benefits of an oxygen-enriched environment include higher temperatures, enhanced combustion efficiency and the reduction or elimination of harmful emissions. 

What's the Difference Between Individual Fuel Gases?

Natural gas and hydrogen are suited to transportation options. The choice for metal fabrication and combustion applications is wider, depending on the specific application and heating requirements. Because each fuel gas has a different ratio of carbon atoms to hydrogen atoms, different amounts of oxygen are needed to burn the fuel gas efficiently. This ratio of fuel to oxidant affects the temperature of the flame, the flammability and explosive limits. Some of the differentiating features and benefits of fuel gases - especially for heat treatment, flame and melting applications - are summarized in the following.

• Acetylene is lighter than air and gives the highest flame temperature of all the fuel gases along with high heat distribution in the inner cone. It also uses the least amount of oxygen to give complete combustion. Because it produces relatively low levels of carbon dioxide (CO2) and water vapor, it is ideal for lower-preheat applications before welding. It is also easier for operators to set an accurate and consistent flame condition with acetylene. This precise flame focus makes it suitable for heating a small area of metal quickly - for bending and hardening selective zones, for instance. Even when used with air, it gives a high-temperature flame with very sharp focus, making it popular for applications such as heating with automatic brazing systems.
• Hydrogen is lighter than air and burns with an invisible flame. It uses less oxygen than all other fuel gases. It is also the only fuel gas that doesn’t contain any carbon atoms, so it produces no carbon compounds. Consequently, it delivers a clean, almost invisible flame as it burns in oxygen or air to form water vapor. The cleanliness of the flame makes hydrogen very suitable for heating applications where any contamination on the workpiece would cause a problem.
• Natural gas is predominantly composed of methane. It is considered a cost-effective fuel gas alternative for many applications. It produces a low flame temperature and a wide primary flame. It heats slower than other fuel gases but can be very useful for heating a large area over a long period of time.
• Propane is heavier than air with most of its energy concentrated in the outer or secondary envelope of the flame. Propane thus gives a high heat output and less focused flame. It will heat a large area of metal fairly quickly, making it more suitable for general heating tasks such as heat treatment and higher-temperature preheating of larger areas before welding. When used with air, propane produces a large "bushy" flame that is suitable for general area heating only.
• Like propane, propylene is heavier than air. It has both a high primary and secondary flame temperature. This means that although it is similar to propane, it has a higher heat output and higher heat distribution in the inner cone. It also has a higher vapor pressure, making it suitable for high-pressure applications.

Key Properties of Fuel Gases at a Glance