Natural gas guide
For both private and commercial use, we utilise raw materials that our planet provides us with. A typical example of such resources is natural gas, which has recently become an important focus of media reports, as it continues to be an essential part of our security of supply.
But what exactly is natural gas? What are the valuable, but possibly also questionable properties of natural gas? And how can this substance be extracted? Are there specific regulations on how to safely explore, transport and use the substance? We at Compur Monitors have compiled this detailed guide for interested parties. If you have any further questions, we will of course be happy to provide you with competent and specific advice.
- Historical facts about natural gas
- Physical and chemical properties of natural gas
- Types of natural gas
- Education: How natural gas is produced
- Deposits of natural gas
- Extraction and production of natural gas
- Fields of application for natural gas
- Environmental impact of natural gas
- Natural gas and safety aspects
- The detection of natural gas
Historical facts about natural gas
Good to know: Even though many people believe that the formation of natural gas is a constant process, the formation processes surrounding natural gas deposits on our planet are already complete. The natural gas we use today was formed millions of years ago. It is estimated to be between 15 million and 600 million years old. So today we are consuming ancient raw materials whose deposits are also limited.
Even though natural gas is millions of years old, the period in which it has been used commercially by humans is comparatively short. The first wells for the extraction of natural gas are said to have been drilled in the third century BC. Chinese workers planned to use natural gas as a source of energy, for example to fire salt pans. The start of commercial natural gas extraction by America, traditionally an established gas-producing country, was in the 19th century. The first natural gas companies and pipelines were established.
Germany did not start using natural gas as a fossil fuel until the early 1960s.
Physical and chemical properties of natural gas
Natural gas: a valuable mixture beneath the earth’s surface
If you take a closer look at natural gas, the name says it all. This is because the two components of the term natural gas already indicate what kind of substance it is. On the one hand, natural gas is a substance that is stored under the earth’s surface. This can be either the soil of the mainland or the seabed. Natural gas and crude oil have this type of deposit in common. This is not surprising, as the formation of natural gas and crude oil is actually based on very similar processes.
The second component of the term natural gas, i.e. gas, already describes the physical state of this valuable substance: natural gas is in a gaseous state. However, anyone who thinks that the natural gas found underground is a single homogeneous substance is mistaken. In fact, natural gas is a mixture of gases, as the next chapter of our natural gas guide describes.
The mixture of natural gas
Classification of natural gas:
Natural gas is classed as a natural gas. It is a representative of hydrocarbons and therefore an organic gas. The compressed gas has colourless and odourless properties.
Chemical properties of natural gas:
Natural gas consists of mixtures that can vary greatly. The respective composition of a natural gas deposit depends in particular on the site where it was found and which formation processes actually took place there in prehistoric times.
However, all natural gas deposits have one thing in common: the main component of the chemical composition is the same, namely methane. This member of the chemical group of substances known as alkanes typically makes up between 70 and 99 per cent of the respective natural gas mixture. Methane therefore also determines the properties of the natural gas in particular.
However, natural gas also contains other components. Varying proportions of butane, ethane and ethene, pentanes and propane characterise the specific properties of this mixture, which always has a high hydrocarbon content.
Natural gas also contains other accompanying substances. Hydrogen sulphide is a typical component of natural gas. Organic sulphur compounds (mercaptans) are also typical. The stronger the natural gas smells, the higher the content of these sulphur-containing substances. The sulphur present is removed by desulphurisation, e.g. in a Claus plant. Nitrogen and carbon dioxide are also typical components of natural gas.
Even noble gases are components of raw gas, i.e. natural gas extracted directly from the earth. Helium in particular is an important representative of such noble gases. These noble gases are also known as inert gases. In general, the higher the proportion of isolable noble gases such as helium, the higher the quality of the natural gas mixture.
Physico-chemical properties of natural gas:
Characteristic properties of natural gas are a boiling point between -195 and -155 °C, a density between 0.7 and 1.0 kg/m³ and an ignition temperature between 575 and 640 °C. The LEL is 4.4 %. The LEL is 4.4 %. The water solubility of natural gas is comparatively low. Users should pay particular attention to the high flammability of natural gas. Contact between natural gas and chlorine and chlorine dioxide, nitrogen oxides and nitrogen trifluoride, difluorine dioxide and difluorine oxide, but especially liquid oxygen, can lead to dangerous reactions. This also applies to contact between natural gas and oxidising agents, e.g. bromine pentafluoride, chlorine trifluoride and iodine heptafluoride.
Types of natural gas
Dry and wet natural gas: learn the difference
Because natural gas is a gaseous mixture, it may initially come as a surprise that a distinction is made between dry and wet natural gas. Nevertheless, experts make this distinction because natural gas, as a naturally occurring mixture, can have very different compositions.
Wet natural gas has a particularly high proportion of hydrocarbons, such as ethane or propane. These can be easily converted from a gaseous to a liquid state under pressure. This is why such mixtures are also referred to as wet natural gas. Even if natural gas has a high proportion of water vapour, it is called wet natural gas.
Dry natural gas has far fewer liquefiable elements such as water vapour and higher alkanes.
Education: How natural gas is produced
Natural gas is produced underground. The key basic conditions for its formation are found in this enclosed space underground. On the one hand, the pressure of heavy rock and earth and, on the other hand, the isolation of air are the basis for its formation. These processes also support high temperatures far underground and the existence of microorganisms. The formation of crude oil follows the same mechanisms.
Deposits of natural gas
Our entire planet has gas deposits, regardless of the continent in question. However, calculations show that our planet’s natural gas deposits could soon be exhausted. Estimates predict this will happen within a few decades. Alternative energy sources are therefore the be-all and end-all.
The countries with the highest production volumes are: United States of America, Russia, Iran, People’s Republic of China, Qatar and Canada. Underground storage facilities are the tried and tested means of storing processed natural gas in order to compensate for load fluctuations and peaks in demand.
Various processes are important for producing safe and environmentally friendly natural gas. The high sulphur content of the natural gas, as well as the carbon oxide present in the gas, must be removed by gas scrubbing and desulphurisation. Some of these substances have environmentally toxic properties. Drying is particularly important for the safe and efficient production of universally usable gas. We distinguish between natural gas drying by removing water, natural gas drying as absorption drying by using glycol, which also removes water, and drying of natural gas by developed molecular sieves.
The methods of cleaning and drying gas are used in particular to produce a natural gas that offers a consistently good calorific value and that does not damage valuable fittings of pipelines or other equipment with hard particles or condensation.
Extraction and production of natural gas
In principle, we distinguish between two forms of natural gas extraction. Because natural gas and crude oil often occur together, they can also be extracted together. In this case, the natural gas is of course a welcome by-product of the actual extraction of crude oil deposits from the earth. Or, of course, natural gas fields from which the valuable gas mixture is extracted directly. Special measures are required once the gaseous raw material has been extracted.
The purpose of these methods is to make it easier and cheaper to transport natural gas by changing its aggregate state. This is realised using different methods.
Pressurised containers compress the natural gas, for example. Such natural gas is then referred to as CNG, compressed natural gas. The liquefaction of natural gas also serves to reduce its volume. This liquefaction is achieved either by compression or by cooling. Specialists then refer to the respective gas as LNG, or liquefied natural gas. Using special processes, natural gas can be converted into liquid hydrocarbons and used as a raw material for other organic compounds.
All these processes make it possible, among other things, to transport the natural gas not only through pipelines. One particular advantage of compressed natural gas and the associated reduction in volume is that it can be transported in tankers
Fields of application for natural gas
As a fossil fuel, natural gas offers attractive supply options in a wide range of applications. The classic use of natural gas is, of course, in the heating of buildings. However, natural gas is also well suited to commercial manufacturing processes that require thermal energy. Typical examples are ovens in bakeries, industrial plants in cement or glass works, the generation of electricity or production processes in heavy industry. But of course, natural gas has also proven itself as a fuel. This applies to both shipping and motor vehicle traffic. Refineries also use natural gas as an easy-to-handle energy source. Gas-fired power plants that run on natural gas are particularly flexible when it comes to covering peak demand.
Environmental impact of natural gas
Despite being a fossil fuel, natural gas is considered a relatively clean option because it causes comparatively little carbon dioxide contamination in our shared environment. Conventional heating oil, for example, emits a quarter more CO2 than natural gas. Natural gas also scores highly in terms of extraction. This is because the joint extraction of crude oil and natural gas causes fewer emissions and energy consumption. However, this does not apply if fracking, a rather new method of extraction that is notorious for being environmentally unfriendly, is used.
Natural gas itself is a non-toxic gas. It is also not considered a substance hazardous to water.
Natural gas and safety aspects
Natural gas is considered to be a particularly flammable substance. Air and natural gas together can cause dangerous explosions. That is why safety strategies regarding the tightly closed natural gas container are essential. High concentrations of natural gas displace oxygen. This is something that safety experts must also take into account – for example, if there has been a natural gas leak. Danger of suffocation!
The above-mentioned interactions between natural gas and, for example, chlorine and fluorine, but also oxidising agents, must be professionally and thoroughly assessed by safety experts.
Comprehensive safety measures must be taken into account when using natural gas. These affect different areas of a company. This natural gas guide is also intended to present essential aspects of safe natural gas handling.
Gas cylinders – correct handling
A key aspect of the safe storage and use of natural gas concerns gas cylinders and tanks as classic containers. Both the safety personnel of companies that use natural gas and the responsible employees must of course be fully aware of all regulations. Gas containers must be stored away from work areas and protected from mechanical impact and heat. Their valves must be handled with care and opened slowly if necessary. After use, close them carefully and securely. Avoid transferring gas between containers at all costs!
Proper storage of gas containers
A large part of the technical protective measures relating to gas cylinders concerns their storage – always outside of work areas. The containers must be upright, impact-resistant and absolutely leak-proof. Gas cylinders and similar gas containers must not block escape routes. The room should have cool temperatures, definitely less than 50 degrees Celsius, and be free from sunlight. Valves should be additionally secured with protective cages or caps. Consistent monitoring is also an essential protective measure. The prevention or early detection of leaks and escaping natural gas must be implemented by those responsible. This also applies to electrical charging or unfavourable heating. If a leak is suspected, sprinkling with cool water is an effective measure to prevent possible explosions.
Regulations relating to the storage of gas cylinders also include so-called co-storage conditions. In order to prevent explosions and fires, this primarily concerns oxidising gases and flammable substances. Companies must also ensure a large distance between gas containers, oxidising materials and sources of ignition or heat.
The strict ban on storing natural gas and other hazardous substances together applies, for example, to explosive and flammable substances and mixtures, oxidising substances, toxic, radioactive, corrosive and other substances that are hazardous to health, as well as foodstuffs and animal feed.
The storage and use of natural gas also requires technical and personnel protection measures. Fire extinguishing equipment must be provided for fire prevention and firefighting reasons. Fire safety officers and employee training are essential to prevent hazards from escaping natural gas. Such training must be refreshed annually – due to the importance of a well-functioning protection concept regarding the storage and use of natural gas, but also to maintain vigilance regarding the dangers of natural gas.
Because natural gas and air can form an explosive mixture, the formation of an explosive mixture must be strictly prevented. All types of ignition sources – such as naked flames and sparks, heaters or electrical appliances – must be banned from the vicinity of gas cylinders and other gas containers. It goes without saying that smoking and welding are also strictly prohibited.
Pressurised gas cylinders may only be used by trained and authorised persons. The company’s risk analysis describes in detail the potential dangers of using natural gas and draws up an escape and rescue plan, which also describes the escape routes and their labelling. Flame-retardant clothing and safety shoes serve as personal protection against the hazardous effects of natural gas. If gas escapes from the containers despite all safety precautions, the alarm plan comes into force.
Release of natural gas
If natural gas escapes, there is a risk of explosion. An important criterion for explosion and fire prevention is the exclusion of ignition sources. Clearing contaminated areas and neighbouring areas is a mandatory measure. Warnings must be followed. Persons must not enter the endangered area without the correct protective equipment. The next steps are for safety personnel to prevent further gas leaks and monitor the current concentration of the released natural gas.
If fires are caused by the release of natural gas, sprayed water or dry powder are suitable extinguishing agents. Still intact gas containers should also be cooled down with water jets and ideally removed from the hazardous area. After notifying the fire brigade, emergency services should ideally receive information about existing closed, open or damaged gas cylinders immediately.
Disposal of natural gas containers
According to the AVV, the Waste Catalogue Ordinance, natural gas is considered hazardous. The user is therefore obliged to dispose of it properly. Normally, empty pressurised gas cylinders must be returned to the respective supplier. To avoid confusion between full and empty gas cylinders, the containers must be labelled accordingly. Explosion hazard zone II applies around gas transfer stations.
Regulations relating to the use of natural gas
Numerous regulations address the correct handling of natural gas. Typical examples are: Waste Catalogue Ordinance (AVV), workplace labelling according to the ASR, DGUV (regulations of the accident insurance institutions), various provisions of the TRGS – technical regulations for hazardous substances -, EH-GHS classification and labelling, Hazardous Incident Ordinance and many other provisions affect the natural gas sector. And, of course, a strategically clever safety concept can also better cover insurance issues. Indispensable for the development and implementation of comprehensive security concepts: training employees and appointing security experts by the company.
The detection of natural gas
A good natural gas guide should of course also provide valuable information regarding the detection of any natural gas leaks. There are excellent measuring devices that can be used to detect various occurrences of natural gas leaks. These serve as valuable support in terms of safety – because a leak of the typically colourless and odourless natural gas would otherwise not be detectable.
Modern measuring devices – including those from the well-stocked Compur Monitors range – detect leaked natural gas using highly specific, reliable measurement technology. This is easy to use and provides clarity. Ex measurements are therefore an important addition to safety precautions relating to natural gas hazards. Compur Moniotrs offers a comprehensive range of customisable options for the safe measurement of any gas leaks. Relevant categories include stationary gas detectors and, of course, portable detectors. Multi-gas detectors and discontinuous gas detectors complete the portfolio. Depending on the device, immediate gas warnings as well as leak detection can be realised. Simple application means that measurement results can also be read by non-experts.
The be-all and end-all of an efficient and successfully functioning protection concept for the useful, but also not harmless, product natural gas is the needs-based selection of a professional and – in particular – precisely fitting measuring device. The team at the specialist Compur Monitors provides interested parties with detailed and specific advice.
Dr. Josef von Stackelberg
Managing Director COMPUR MONITORS GmbH & Co. KG
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