science

Substitute natural gas

Substitute natural gas is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Substitute natural gas rather than just read about it. In short: Substitute natural gas (SNG), or synthetic natural gas, is a fuel gas (predominantly methane, CH4) that can be produced from fossil fuels such as lignite coal, oil shale, or from biofuels (when it is named bio-SNG) or using electricity with power-to-gas systems. SNG in the form of liquefied natural gas (LNG) or compressed natural gas (CNG) can be used in road, rail, air and marine transport vehicles as a substitute…

Key takeaways

Substitute natural gas belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Substitute natural gas to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Substitute natural gas from memory before moving on to harder problems.

Reference excerpt

Substitute natural gas (SNG), or synthetic natural gas, is a fuel gas (predominantly methane, CH4) that can be produced from fossil fuels such as lignite coal, oil shale, or from biofuels (when it is named bio-SNG) or using electricity with power-to-gas systems. SNG in the form of liquefied natural gas (LNG) or compressed natural gas (CNG) can be used in road, rail, air and marine transport vehicles as a substitute for costly fuels like diesel and petrol. The carbon footprint of SNG derived from coal is comparable to that of petroleum products. Bio-SNG has a much smaller carbon footprint compared to petroleum products. Liquefied petroleum gas (LPG) can also be produced by synthesising SNG with partial reverse hydrogenation at high pressure and low temperature. LPG is more easily transportable than SNG, more suitable as fuel in two-wheeler or smaller horsepower vehicles and engines, and also fetches higher price in international markets due to short supply. Renewable electrical energy can also be used to create SNG (methane) via for example electrolysis of water or via a proton-exchange membrane fuel cell (PEMFC) in reverse to create hydrogen, which is then reacted with CO2 from for example, CSS/U Utilisation in the Sabatier reaction.

CO2 + 4H2 → CH4 + 2H2O

Distribution It is advantageous to distribute SNG and bio-SNG together with natural gas in a gas grid. In this way, the production of renewable gas can be phased in at the same rate as the production capacity is increased. The gas market and infrastructure the natural gas has contributed is a condition for large scale introduction of renewable biomethane produced through anaerobic digestion (biogas) or gasification and methanation bio-SNG.

Projects

The Great Plains Synfuels Plant injects approximately 4.1 million m3/day of SNG from lignite coal into the United States national gas grid. The production process of SNG at the Great Plains plant involves gasification, gas cleaning, shift, and methanation. China is constructing nearly 30 nos massive SNG production plants from coal / lignite with aggregate annual capacity of 120 billion standard cubic meters of SNG. SNG can be produced from low rank coal/lignite using hydrogen. When hydrogen is used in place of oxygen/air, the gasification process is called hydrogasification.

See also Landfill gas Renewable natural gas Oil shale gas Power to gas

References

External links SGC Rapport 187 Substitute natural gas from biomass gasification SGC-rapport on gasification and methanation

Worked examples

Example 1 — a first encounter with Substitute natural gas

Start with the simplest possible case. Write down what Substitute natural gas claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Substitute natural gas before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Substitute natural gas ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Substitute natural gas

In research: Substitute natural gas appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Substitute natural gas in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Substitute natural gas is common in secondary-school and first-year university syllabi. It links to neighbouring topics Natural gas, Synthetic fuel technologies, so understanding it makes those chapters shorter.
In everyday life: Look for Substitute natural gas outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Substitute natural gas in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Substitute natural gas means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Substitute natural gas out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Substitute natural gas in simple terms?

Why does Substitute natural gas matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Substitute natural gas?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Substitute natural gas.