When we talk about gas internal combustion engines, most people immediately think of natural gas. However, many other types of gases can be used in internal combustion engines, not just natural gas. In this article, we will explore the different types of gases frequently used in gas internal combustion engines, including natural gas, biogas, coalbed methane, and industrial coal gas. Let's dive in and learn more!
Natural gas is the most common combustible gas used in internal combustion engines. Its primary component is methane (CH₄), which typically accounts for over 85% of its composition. Natural gas provides the optimal fuel conditions for gas-powered generators, and when selecting a unit, there’s no need to overthink the composition or calorific value.
Key types of natural gas include:
Natural Gas: Typically refers to the pipeline natural gas delivered through municipal pipelines, mainly composed of CH₄ with small amounts of ethane (C₂H₆) and higher molecular compounds. Its calorific value is approximately 8000–8500 kcal/Nm³.
CNG (Compressed Natural Gas): Essentially the same as natural gas, but compressed for transportation via tank trucks.
LNG (Liquefied Natural Gas): A more advanced form of CNG, where gas is further pressurized and cooled to become liquid, with the same chemical composition as natural gas.
Shale Gas and Methane Hydrate: Emerging new sources of energy, with higher CH₄ content than conventional natural gas. These are unconventional natural gases, with challenges in extraction and transportation. Future breakthroughs could unlock their potential for widespread use.
Wellhead Gas: Also known as associated gas, this gas is extracted alongside oil from oil fields. Its composition is more complex, typically containing 50%-80% CH₄, 20%-40% ethane (C₂H₆), 5%-10% inert gases like N₂ and CO₂, and small amounts of H₂S.
Biogas is produced by the anaerobic digestion of organic matter. Depending on the feedstock, biogas can be classified into different types:
Biogas: Derived from organic waste such as manure, food waste, straw, and industrial waste from alcohol, slaughterhouses, and paper mills. Biogas typically contains 55%-60% CH₄, with traces of H₂S. Organic materials like corn silage, rice straw, and leaves can also be used as feedstock for biogas production.
Landfill Gas: Produced by the anaerobic decomposition of waste in landfills, containing 55%-60% CH₄ and a certain amount of H₂S.
Sewage Treatment Gas: Produced during the anaerobic fermentation of sewage sludge in wastewater treatment plants, generating biogas that can be utilized for power generation.
Coalbed methane (CBM) is a gas that occurs naturally within coal seams and is primarily composed of CH₄:
Coalbed Methane (CBM): Typically extracted by dewatering the coal seams before mining. It has a high purity, with CH₄ content ranging from 95%-99%.
High-Concentration Gas: This refers to coalbed methane with CH₄ content between 30%-60%. It is relatively pure, with the remaining components mainly being air (N₂ + O₂).
Low-Concentration Gas: This type of coalbed methane contains less than 30% CH₄, with the remainder being air. CH₄ content usually ranges from 5%-20%.
Industrial coal gas is rich in CO and H₂, and is commonly used in steel production and other industrial processes:
Ferromanganese Furnace Gas: Typically containing 50%-85% CO, 2%-14% H₂, and smaller amounts of CH₄, N₂, O₂, and H₂O. The calorific value is approximately 1680-2760 kcal/Nm³.
Coke Oven Gas: A byproduct of coking coal for steelmaking, coke oven gas contains 25%-30% CH₄, 50%-60% H₂, and 5%-10% CO, with a low calorific value of 4000-4500 kcal/Nm³. Due to its high H₂ content, coke oven gas is not suitable for most generator units, though Liyu offers specially designed models capable of stable operation at reduced power.
Blast Furnace Gas: Produced during iron smelting in a blast furnace, it contains 26%-30% CO, 1%-3% H₂, 6%-12% CO₂, and 55%-60% N₂. Its calorific value is very low (800-1000 kcal/Nm³) and the gas contains high dust content.
Basic Oxygen Furnace Gas: A byproduct from steelmaking in a basic oxygen furnace, this gas has a high CO content (65%-80%), with 2%-3% H₂ and the rest being CO₂, N₂, O₂, etc., and a calorific value of 1500-2000 kcal/Nm³.
For nearly 29 years, Liyu has been deeply involved in the field of gas internal combustion engines. We continually adapt to the rapidly changing gas market, developing engines that efficiently convert a variety of combustible gases—such as natural gas, coalbed methane, biogas, and industrial coal gas—into valuable green electricity. This process reduces greenhouse gas emissions, lowers costs, and improves energy efficiency, helping customers achieve both economic and environmental benefits.
The gas internal combustion engine industry is at a golden opportunity period. Liyu will continue to follow the latest trends in global energy technology, expand the application scope of our engine products, and uphold our customer-centric service philosophy to provide high-quality products and services.
