The Nigerian National Gas Policy (2017) stated that only 5% of Nigerian households use liquefied petroleum gas (LPG) as their household cooking fuel. Furthermore, a survey conducted in Lagos revealed that 70% of Lagosians used kerosene as primary cooking fuel. About 90% of respondents who did not use LPG were willing to switch to LPG but were dissuaded because of the cost and perceived safety issues. There exists a perception amongst non-users, as well as users, of LPG that using cooking gas is dangerous, and this can be attributed to news reports describing explosions caused by gas. While LPG, as other hydrocarbons, always need to be handled safely, however, the fear and resentment associated with the perceived volatility of LPG is oftentimes misplaced and this article will explain why.
 

Gases; Ready to Burn
A glance into the combustion of (most) solid fuels shows that solids undergo pyrolysis, first of all, giving off gases which then burn. Pyrolysis is the process by which a solid undergoes thermal degradation into smaller volatile molecules, without interacting with oxygen or any other oxidants (Stauffer et al, 2008). Wood, for example, begins pyrolysis and gives off up chemicals, including methane and methanol, which begin to burn. The combustion of these gases keeps the process going. Like wood, most materials need to be in a gaseous state in order to be ignited
Combustible substances in the gaseous state have a low mass and therefore require lesser amount of energy for ignition. Combustion (burning) is a chemical reaction and gases, which are substances with free molecules moving freely in all directions, react faster than liquids and solids. This is why the gaseous state can be referred to as the ready to burn state. The question to answer now is: since gases are generally more combustible than liquids and solids, how is Liquefied Petroleum Gas safe to use household cooking?

Gas – not LPG – explosions
Whenever the news of a gas explosion is reported, it always tends to point out LPG as the culprit, yet many times this is not the case. It seems there is a bias which makes the mind think of LPG whenever ‘gas’ (especially related to its flammability) is mentioned but LPG is not the only flammable substance used in society today. Consider acetylene gas, a highly flammable colourless gas with a distinct odour. Acetylene has a number of uses including welding and has the hottest flame temperature compared to natural gas and propane. A number of recent gas explosions reveal this fact. For instance, a fatal accident occurred in Sabon Tasha area of Kaduna state, and the phrase ‘gas explosion’ was used without specifying what type of gas was involved. It was later discovered that the explosion was caused by acetylene. The more recent Abule Ado explosion in Lagos was also thought to have been caused by LPG whereas it was caused by excess pipeline pressure. It is, therefore, necessary to know the specifics of the gas rather than link all reports of ‘gas’ to LPG.
 

LPG Safety Features
LPG, as well as a plethora of other ‘domestic’ substances, is potentially hazardous from the point of production till final use. To understand the safety procedures involved in using LPG, it is necessary to understand what can cause LPG related-accidents. It is also necessary to understand how LPG behaves. The behaviour of LPG is predictable; hence potential hazards can be minimized using proper principles and equipment.
Pure LPG is colourless and odourless, which is why a distinctive odour is added (using ethyl mercaptan) to it during processing for safety reasons. This odour indicates the presence of LPG, allowing even the smallest leak to be detected. Every uncontrolled leak is a hazardous event and calls for immediate attention. Here is a list of some potential hazards involved in using LPG:

1. The principal potential hazard in using LPG is fire and explosion. This might occur due to its flammability or due to high pressure (or a combination of both) leading to Boiling Liquid Expansion Vapor Explosion (BLEVE). The BLEVE occurs when a pressurized liquid in a container ruptures due to high temperature and pressure.
2. LPG is heavier than air, therefore it will most likely flow on the ground when poured out, making such leaks a bit harder to detect.
3. Another hazard is the inadequate dispersion of the products of LPG combustion, such as carbon dioxide. Carbon monoxide might be produced and reach dangerous levels. The inhaling of these substances is very dangerous.

The High-Pressure Gas Safety Institute of Japan classifies LPG accidents based on four categories:

1. Leakage.
2. Leakage and explosion.
3. Leakage and fire (i.e. excluding explosion).
4. Carbon monoxide poisoning or asphyxiation.

 
The above categorization shows that the major challenge to be handled is leakage, followed by inadequate ventilation which prevents the combustion product from dispersing. These can be handled largely by a proper selection of equipment.

1. LPG Storage Tanks (or Cylinders): LPG is a pressurized fluid, hence it needs to be stored in a container that can withstand the pressure. These containers are made of steel, aluminium or composite with varying levels of thickness. The LPG tanks are designed in a cylinder-spherical manner to prevent gas pressure build-ups in corners, these could lead to explosions. The tanks are also designed with excess capacity because of thermal expansion of the liquid. This liquid expansion is the reason why LPG tanks are not to be filled above 80% of their water capacity, although this degree depends on operating conditions.

To this end, it is necessary to be intentional about the integrity of LPG tanks and cylinders used. LPG cylinders have a 15-year life span after which it is not advisable to continue using them. Cylinders are expected to go through certification processes every five years to ascertain if they are still fit for operation.

2. Odour: Occasionally the seal on the domestic LPG cylinder fails causing LPG to escape into the environment. The danger in this escape is that the LPG will return to its gaseous state, which is over 250 times the liquid volume, once in atmospheric conditions. The odour given off by LPG helps with identifying a leakage, which is succeeded by taking the appropriate action, such as shutting off supply or changing part of the equipment.

Some other things to note include:

• LPG is best stored in an open, well-ventilated area to prevent leaked gas from collecting in a corner of the building. The Department for Petroleum Resources (DPR) has recommended spacing for gas tanks.
• Burners used must be properly maintained to avoid a fault that would lead to incomplete combustion.

Government Regulations
The Nigerian government has been pushing for the increased consumption of LPG in Nigeria due to many benefits that the product portent. The growing industry will attract many businesses, with some willing to take short cuts, thereby putting lives at risk. Others do not know the necessary safety requirements – they are only concerned with sales. To this end, the government (DPR, Standards Organization of Nigeria (SON), Customs, and other agencies) are working together to ensure that the necessary guidelines adhere.
Some examples of government intervention and policy measures include:

1. The SON’s certify LPG tanks and cylinders, to ensure they are safe to use.
2. The DPR sets gas plant construction guidelines. The DPR has regular patrols to ensure compliance.

 
The last point is the awareness of stakeholders, especially retail shops and the end-users. Considering Indonesia, as the adoption of LPG increased, so did the frequency of accidents. These accidents were mostly because the end-users had inadequate knowledge of how to use LPG. The government then made product quality improvements, improvements of inspection of the distribution chain, and organized over 5,000 socialization events across the country to teach safe usage of LPG. These resulted in a significant drop in the frequency of LPG related accidents within one year. The chart below shows the importance of educating the relevant stakeholders on the necessary safety measures; it cannot be over-emphasized.
 
Figure 1. Indonesian LPG Accident Trend

Source: WLPGA, Kerosene to LPG Conversion Programme in Indonesia.
 
LPG is potentially hazardous until it is properly handled. It is necessary for stakeholders to produce and purchase standard equipment, decommission expired or faulty equipment, regularly maintain their equipment, be able to recognize the smell of LPG, etc. These will ensure accidents are minimized. To the question of whether one should be scared of LPG; the answer is no – know the rules, follow the rules, and you will be safe.
 
 
KiakiaGas Limited is a leading Gas business in Lagos,Nigeria with expertise in LPG retailing, New Gas Market development, Building of Gas Plants and Gas strategy advisory.
If you need a partner with hands-on local expertise in the Nigerian Gas space or any of our bespoke solutions/services, write us at gaspreneur@kiakiagas.com or call/Whatsapp: +2348085269328