What Is an Example of a Synthetic Gas?

An example of a synthetic gas is synthesis gas—commonly called syngas—which is a man-made mixture primarily of hydrogen (H2) and carbon monoxide (CO). Produced by reforming natural gas or gasifying coal and biomass, syngas is a foundational feedstock for fuels, chemicals, and power generation.

Defining Synthetic Gas and Syngas

Synthetic gas refers to any combustible gas manufactured from solid or liquid feedstocks rather than extracted directly from natural reservoirs. Syngas is the most prominent example: an engineered blend typically dominated by H2 and CO, with variable amounts of carbon dioxide (CO2), methane (CH4), steam (H2O vapor), and nitrogen (N2) depending on the production method.

The following list outlines the common components found in syngas and why they matter to downstream uses.

• Hydrogen (H2): Crucial for ammonia, methanol, and hydroprocessing; often targeted for separation as pure hydrogen.
• Carbon monoxide (CO): Key reactant for Fischer–Tropsch synthesis and methanol production; influences process selectivity.
• Carbon dioxide (CO2): Byproduct that can be removed or utilized; its share depends on process conditions and reforming routes.
• Methane (CH4): Residual methane may remain from reforming; often minimized for chemical synthesis efficiency.
• Nitrogen (N2): Introduced in air-blown gasification; dilutes heating value and affects combustion or synthesis steps.

Taken together, these constituents determine the H2:CO ratio, heating value, and the suitability of the gas for specific industrial applications.

How Syngas Is Produced

Steam Methane Reforming (SMR)

SMR reacts methane (from natural gas) with steam over a nickel catalyst at high temperatures to produce H2 and CO, followed by a water-gas shift step that converts CO and steam to additional H2 and CO2. SMR is widely used in refineries and chemical plants due to its maturity and efficiency.

Coal or Biomass Gasification

Gasifiers convert solid feedstocks (coal, municipal solid waste, agricultural residues, or woody biomass) into syngas by reacting them with oxygen or air and steam under controlled conditions. Air-blown systems yield lower heating-value syngas with nitrogen dilution, while oxygen-blown designs produce a richer, cleaner synthesis gas.

Partial Oxidation (POX)

In POX, heavy hydrocarbons or resid oils are partially burned with oxygen to form syngas. This fast, non-catalytic process is robust for challenging feedstocks but typically has a lower H2:CO ratio, often requiring downstream adjustment via the water-gas shift.

Autothermal Reforming (ATR)

ATR blends catalytic reforming with partial oxidation in a single reactor, using oxygen and steam to balance heat within the unit. It is increasingly deployed in large-scale hydrogen and blue-ammonia projects where integrated CO2 capture is planned.

What Syngas Is Used For

The following list summarizes the principal industrial uses of syngas and how the gas composition affects each pathway.

• Ammonia and fertilizers: Syngas is shifted to maximize hydrogen for the Haber–Bosch process.
• Methanol and derivatives: A tuned H2:CO ratio enables efficient conversion to methanol, a building block for formaldehyde, acetic acid, and fuels.
• Fischer–Tropsch liquids: Syngas is catalytically converted into synthetic diesel, jet fuel, and waxes.
• Hydrogen production: Syngas serves as an intermediate; hydrogen is purified via pressure swing adsorption or membranes.
• Power generation and heat: Syngas can be burned in gas turbines, engines, or boilers, including in integrated gasification combined cycle (IGCC) plants.
• Synthetic natural gas (SNG): Further methanation converts syngas to pipeline-quality methane.

These applications make syngas a pivotal bridge between diverse feedstocks and high-value energy carriers and chemicals across the global economy.

Other Examples of Synthetic Gas

Beyond syngas, several historic and modern manufactured gases illustrate the breadth of synthetic gas technologies.

• Water gas: Produced by reacting steam with hot coke to yield a CO- and H2-rich gas; historically enriched to make “carbureted water gas.”
• Producer gas: Formed by blowing air through hot coal or coke, yielding a low-heating-value mix of CO, H2, N2, and CO2.
• Town gas (coal gas): A manufactured gas once widely used for lighting and cooking, containing H2, CO, methane, and other hydrocarbons.
• Synthetic natural gas (SNG): Methane produced from coal or biomass-derived syngas via methanation, intended as a substitute for fossil natural gas.

While their compositions and uses differ, each of these gases is created through industrial processing rather than extracted as-is from natural deposits.

Environmental and Safety Notes

The next list highlights key considerations associated with synthetic gases in modern energy systems.

• Carbon intensity: Conventional syngas production emits CO2; pairing with carbon capture and storage (CCS) can significantly reduce emissions in “blue” hydrogen, ammonia, or fuels projects.
• Feedstock choice: Biomass or waste-based gasification can lower net lifecycle emissions when sustainably sourced.
• Toxicity and safety: Carbon monoxide is highly toxic; stringent monitoring, ventilation, and detection are essential in handling syngas.
• Infrastructure integration: Upgrading and purification steps (desulfurization, CO2 removal, moisture control) are critical for reliable downstream performance.

Addressing these factors is central to scaling synthetic gas pathways in cleaner, safer, and more efficient ways.

Summary

Synthesis gas (syngas)—a manufactured mixture primarily of hydrogen and carbon monoxide—is the leading example of a synthetic gas. Produced via reforming or gasification, it underpins ammonia, methanol, synthetic fuels, hydrogen production, and power generation. Related manufactured gases include water gas, producer gas, town gas, and synthetic natural gas, each tailored to specific applications and infrastructure needs.