Rethinking Nigeria’s Energy Transition: The Risks of CNG Vehicles And The Case For Biofuels

By: Hon. Femi Adebisi JP

As Nigeria grapples with the escalating prices of petrol and diesel, the federal government’s recent resolution to transition to compressed natural gas (CNG) vehicles has ignited discussions across the nation. While the intention is commendable, the lack of sufficient infrastructure for CNG dispensing and conversion raises critical safety and operational concerns. Furthermore, Malaysia’s announcement to ban CNG vehicles by January 1, 2025, due to safety risks, amplifies the urgency for Nigeria to reconsider its energy transition strategy.

CNG vehicles are often touted as a cleaner alternative to traditional petrol and diesel vehicles. However, they come with significant technical risks that must not be overlooked.

1. High-Pressure Storage Risks

– Pressure Hazards: CNG is stored at pressures typically around 3,600 psi (25 MPa). This high pressure poses a significant risk of catastrophic failure if the storage tank or associated components (like valves and fittings) are compromised.

– Scientific Basis: The failure of pressure vessels is governed by the principles of material science and fluid mechanics. According to the American Society of Mechanical Engineers (ASME) standards, materials must withstand specific stress levels to prevent failure. A failure can result from fatigue, corrosion, or manufacturing defects.

2. Leakage and Explosion Risks

– Methane Leakage: Methane, the primary component of CNG, is a potent greenhouse gas (GHG) with a global warming potential over 25 times that of CO₂ over 100 years. Even minor leaks can have significant environmental impacts.

– Research Findings: Studies, such as those published in the journal Environmental Science & Technology, indicate that fugitive methane emissions occur during extraction, processing, and distribution. The detection and quantification of these leaks are critical to minimizing their impact.

3. Combustion Risks

– Flammability: Methane is highly flammable, and its lower explosive limit (LEL) is approximately 5% by volume in air. An accumulation of gas in confined spaces can lead to explosions if ignited.

– Scientific Analysis: The National Fire Protection Association (NFPA) outlines the risks associated with flammable gases. The risk of ignition increases with factors such as temperature, pressure, and the presence of ignition sources.

4. Material Compatibility and Degradation

– Corrosion and Material Fatigue: CNG systems must use materials that can resist the corrosive impacts of natural gas and the effects of high pressure. Inadequate materials can lead to leaks and failures.

– Material Science Research: Studies indicate that certain metals, including carbon steel, can suffer from stress corrosion cracking when exposed to high-pressure natural gas. Research published in Corrosion Science highlights the importance of choosing appropriate materials for CNG applications.

5. Limited Refueling Infrastructure

– Infrastructure Risks: The CNG refueling infrastructure is not as developed as gasoline or electric vehicle charging networks. Limited availability can lead to operational challenges and increased reliance on potentially substandard refueling stations.

– Operational Studies: Research from the U.S. Department of Energy emphasizes the need for widespread, reliable refueling infrastructure to support the safe operation of CNG vehicles.

6. Performance Limitations

– Engine Performance Variability: CNG vehicles may experience performance issues, including reduced power output compared to gasoline engines due to the lower energy content of CNG.

– Combustion Efficiency Studies: Research published in journals like the Journal of Energy Resources Technology has shown that while CNG burns cleaner, the stoichiometric air-fuel ratio is different from gasoline, affecting engine efficiency and output.

7. Risk of Overfilling

– Overpressure Situations: During refueling, failure to monitor and control pressure can lead to overfilling of the storage tank, resulting in excessive pressure that may exceed the design limits.

– Regulatory Standards: The Occupational Safety and Health Administration (OSHA) provides guidelines for safe refueling practices to mitigate these risks.

Given the technical and scientific evidence-based risks associated with CNG vehicles and the failure to provide necessary infrastructure, the Nigerian government must pivot towards a more sustainable energy transition. Alternatives such as electric vehicles (EVs) and biofuels, particularly ethanol, present viable pathways.

Both compressed natural gas (CNG) and liquefied natural gas (LNG) offer distinct advantages and serve different purposes within the energy landscape. CNG is ideal for local use and transportation, while LNG is better suited for long-distance transport and large-scale applications. Understanding their characteristics and advantages helps in making informed decisions about energy choices and infrastructure investments.

Compressed Natural Gas (CNG) is natural gas that has been compressed to less than 1% of its volume at standard atmospheric pressure. It is stored in high-pressure cylinders and is primarily used as a fuel for vehicles and in some power generation applications.

Liquefied Natural Gas (LNG) is natural gas that has been cooled to a liquid state at around -162°C (-260°F). This process reduces its volume to about 1/600th of its gaseous state, making it easier to store and transport, especially over long distances where pipelines are not feasible.

Here is an overview of how they work:

Compressed Natural Gas (CNG):

– Storage and Dispensing: CNG is stored in cylindrical tanks made of steel or composite materials at high pressures (typically around 3,600 psi). The gas is dispensed to vehicles through special refueling stations equipped with compressors.

– Vehicle Operation: CNG vehicles use either dedicated CNG engines or modified gasoline engines that can run on natural gas. The gas is injected into the engine’s combustion chamber, where it mixes with air and is ignited to produce power.

Liquefied Natural Gas (LNG):

– Production and Transportation: LNG is produced by cooling natural gas to its liquid form, which is then stored in specialized insulated tanks. LNG can be transported over long distances in cryogenic tankers.

– Re-gasification: Upon reaching its destination, LNG is re-gasified at re-gasification terminals, where it is converted back to gas before being distributed through pipelines for use in electricity generation, heating, and industrial applications.

 

Comparative Advantages:

1. Volume and Storage Efficiency:

– CNG: More practical for local distribution and vehicle use due to its ability to be stored in high-pressure tanks. However, its storage requires significant space and infrastructure.

– LNG: Extremely efficient for long-distance transportation due to its reduced volume. A smaller quantity can be transported compared to CNG, making it ideal for international shipping and remote locations.

2. Transport Flexibility:

– CNG: Best suited for short-distance travel and local distribution, often requiring dedicated refueling infrastructure.

– LNG: Capable of being transported across oceans, making it a suitable choice for countries without extensive pipeline networks.

3. Environmental Impact:

– Both CNG and LNG are cleaner alternatives to coal and oil, producing lower emissions of carbon dioxide (CO₂), particulate matter, and sulfur dioxide (SO₂). However, their environmental benefits can be offset by methane leaks during extraction and transportation.

– CNG: Burns cleanly in vehicles, producing fewer pollutants compared to gasoline and diesel.

– LNG: When used for power generation, it can significantly reduce emissions compared to coal-fired plants.

4. Cost:

– CNG: Typically cheaper than gasoline or diesel in regions with established natural gas infrastructure. However, the cost can vary based on local supply and demand.

– LNG: Price competitiveness can depend on global market conditions. LNG can be more economical for large-scale power generation, especially where pipeline gas is not available.

5. Infrastructure and Accessibility:

– CNG: Requires a network of high-pressure refueling stations, which can be a barrier to widespread adoption in some areas like Nigeria.

– LNG: Needs specialized infrastructure for liquefaction and re-gasification, making it more suitable for large-scale industrial applications and international trade.

On the other hand, Electronic vehicle EV technology has advanced rapidly, offering a cleaner and more sustainable alternative to fossil fuels. With the global push for renewable energy sources, Nigeria could benefit from investing in EV infrastructure. The transition to EVs can significantly reduce urban air pollution and greenhouse gas emissions, especially when powered by renewable energy sources.

Another energy consideration is biofuel from Ethanol, derived from agricultural products like sugarcane, corn, and cassava, which presents a promising alternative. Brazil has successfully integrated ethanol into its fuel mix, with approximately 92% of new vehicles running on ethanol produced from sugarcane. This model demonstrates the potential for Nigeria to harness its agricultural resources to produce biofuels.

By investing in biofuel production, Nigeria could empower millions of farmers, creating jobs and stimulating rural economies. The availability of raw materials like sugarcane and cassava positions Nigeria favorably in the biofuel market.

Ethanol is a renewable fuel that emits significantly lower levels of greenhouse gases compared to gasoline. This aligns with global efforts to combat climate change and reduce reliance on fossil fuels.

– Energy Independence: Developing a robust biofuel industry can reduce Nigeria’s dependence on imported fossil fuels, enhancing energy security and stabilizing fuel prices.

Looking at the future, Elon Musk has just released a new innovative hydrogen Water Engine (WE), which may make nonsense of the entire fossil fuels and battery-powered car industries.

Musk made this surprise announcement through a post on X, which used to be called Twitter. He shared that Tesla is shifting its focus from battery power to hydrogen power. This change comes after Tesla faced challenges with their 4,680 battery cells, leading them to rethink their energy strategy. As the news spread, the world waited with bated breath, wondering how this shift would reshape the future of energy, not just for Tesla, but for the entire automotive industry.

The water engine is not just another option; it’s a major innovation that could completely transform the automotive industry and beyond. With this, Tesla hopes to lead the way to a more sustainable future, staying true to Musk’s commitment to technological progress and environmental care.

Overall, while CNG can serve as a transitional fuel, it should not be the ultimate destination for Nigeria’s energy strategy. Instead, it could function as a bridge while the country invests in the infrastructure and technologies necessary for a sustainable transition to EVs and biofuels. This approach not only addresses immediate fuel price challenges but also positions Nigeria as a leader in renewable energy within the region.

In light of the technical risks associated with CNG vehicles and the pressing need for a sustainable energy transition, the Nigerian government must rethink its strategy. By investing in electric vehicles, leveraging on the large deposit of lithium in Nigeria, and ethanol, derivable from Sugarcane, Corn, and Cassava, Nigeria can create a cleaner, safer, and more economically viable future. The time to act is now, ensuring that the country harnesses its agricultural potential and technological advancements to secure a sustainable energy landscape for generations to come.