Wondering why camping gas is stored as a liquid? Well, wonder no more. For, we have the answers to the questions posed by the inquisitive chemistry enthusiast in you!
If you’re a seasoned camper or BBQ enthusiast, or if you’ve been using propane and butane canisters for any purpose whatsoever, you’ll know that all these fuels, which are often collectively called “Camping Gas” are stored as liquids.
Be it a 20 – lb refillable propane tank or a 1 – lb disposable canister of isobutane – all these fuels have one thing in common – their storage.
If you’re new to the concepts of camping gas, and are curious about knowing more about the varieties available in the market and the right fit for your outdoor needs, we recommend you check out our previous articles –
In these articles we discuss everything – from the pros and cons of propane and butane, to setting up and maintaining your very own camping stove from scratch.
Now, coming at the question in hand – why are these so-called camping gases stored in the liquid form?
Let us put our lab coats on, and dive deep into the curious chemistry behind camping gases. Let’s begin!
#1 What Is The Difference Between Liquefaction And Compression?
Before discussing anything complex, it is only logical to look at the very processes that convert propane, butane, or for that matter any gas into liquids.
If you recall your high school chemistry lessons, you’ll note that two terms often appear in tandem with each other – liquefaction and compression.
What are these terms? Are they same, interchangeable words for some identical process, or are they two entirely different processes?
The short answer is – neither.
The long answer is – both liquefaction and compression are different, but not entirely independent of each other.
Compression is when we apply higher and higher pressure on a gas.
Liquefaction is when we cool and pressurise a gas until it becomes liquid.
So, as you might note – liquefaction involves compression.
#2 Liquefaction In Detail
Liquefaction is a widely used process across industries to liquify many commercially and industrially important gases like propane, butane, isobutane, carbon dioxide, hydrogen etc.
Before we look at the steps involved in the process of liquification, it is important to know the meaning of two terms –
1. Critical Temperature
This is the temperature for a gas below which it can get converted into liquid state. Above this temperature, no matter how much pressure you apply, the gas will not get converted to liquid. Thus, in liquefaction, it is important to reach the critical temperature of the gas being liquified.
2. Critical Pressure
What could this be? Well, you guessed it right – critical pressure, on the same lines of critical temperature, is the pressure below which a gas can be converted to liquid.
It is interesting to note that every substance has a unique set of critical temperature and pressure values – in other words, the parameters critical temperature and critical pressure are characteristic properties of material.
Steps Involved In The Process –
1. The gas to be liquified is compressed. The pressure on it is increased, while simultaneously reducing the temperature.
2. This is continued until the critical temperature and critical pressure values are reached.
Beyond these points, the gas gets converted into liquid. It is then stored in high pressure vessels or transported via high-pressure underground pipelines.
#3 Why Liquefy Camping Gas?
Before answering this question, let us recall quickly what camping gas is –
Camping gas includes propane, butane, and isobutane. These gases are part of the loosely defined family of hydrocarbons called Liquified Petroleum Gas or LPG.
Common Properties –
1. High volatility
2. High flammability
These 2 properties – volatility and flammability – are known to be extremely high in all gases that come under the loosely defined LPG family.
These hydrocarbons vaporize at standard temperature and pressure (STP) i.e. 32 degrees Fahrenheit temperature and 1 atmospheric pressure (atm).
Liquefaction is necessary especially because of the following reasons –
1. Risks involved.
Storing any of the camping gas varieties in gaseous form is very risky, when compared to storing in liquid form.
- In gaseous form, the camping gas vaporizes quickly and very easily on contact of very little surface heat.
- These vapours make them an explosive risk, as the vapours of all of camping gas varieties are highly flammable.
- This vaporization of camping gas on application of very little surface heat can be considered the courtesy of the high volatility of the camping gas variants.
2. Space occupied by gases is very large.
As an example, if you consider propane – the volume of propane in the gaseous form happens to be 270 times higher than the volume of liquid propane.
This means that storing camping gas in the gaseous form is not only highly risky, but also very bulky; on the other hand, storing camping gas as liquid is relatively safer and compact in storage.
3. Ease of transport and carrying.
Since the volume occupied by liquified gases is much less than the volume occupied by gaseous form, the transport of camping gases becomes easier when liquified.
Frequently Asked Questions
Now that you’ve understood the basics of the chemistry behind camping gases, this must have answered your queries about why camping gas is stored in liquid form and not in the gaseous form.
Remember to not slosh around the liquid within the canisters, keep them upright and always store them in cool and dry places away from direct sunlight.
Another important thing to note in the concluding remarks is about the correct way of using camping gases –
- Use camping gas in an area with appropriate ventilation.
- Do not leave camping gas near ignition sources.
- Always remember to switch off all the valves on the camping gas canisters and stove.
- Regularly check for leaks in the hose and connecting points.
Now, you’re good to go. Happy camping!