Natural gas: A bridge to energy

Introduction

Natural gas is often considered a “bridge fuel” to clean energy, serving as a transitional energy source as the world moves toward more sustainable and renewable energy systems.

This gas produces significantly less carbon dioxide (CO₂) emissions per unit of energy when burned compared to coal or oil. For example: it emits approximately 50% less CO₂ than coal and 30% less than oil for the same amount of energy produced. This makes it a cleaner alternative for power generation while expanding alternative energy capacity. Renewable energy sources such as solar and wind are intermittent, as their availability depends on weather conditions.

This article discusses the role of natural gas, emphasizing its impact through concepts such as blue hydrogen, methane emissions, carbon capture, sustainable electricity generation, liquefied natural gas (LNG), emissions, and use as backup power.

Natural gas: More efficient and abundant

Natural gas combustion is very efficient, allowing it to generate more energy per unit compared to coal or oil. Natural gas-fired power plants can quickly ramp up or down to fill gaps in the power supply, providing reliable backup and stabilizes the grid.

It also works in combined cycle power plants, where waste heat is reused to produce electricity, further improving efficiency.

Its abundance facilitates its widespread use as a transition fuel. Advances in extraction technologies, such as hydraulic fracturing and horizontal drilling, have made gas more accessible and affordable.

Natural gas in the contemporary energy landscape

Natural gas has positioned itself as a key player in the energy transition, providing an intermediate solution between traditional fossil fuels and renewable energies. Its versatility and efficiency make it a strategic resource to ensure a balanced transition to a sustainable energy future.

Natural gas currently plays a central role in shaping the energy matrices of many countries because it guarantees a continuous and reliable supply. This fossil resource, composed mainly of methane, burns more efficiently and with lower carbon dioxide emissions than coal and oil. In addition, its versatility allows its use in multiple applications, from electricity generation to its implementation in advanced industrial processes and as a vehicle fuel. The existing infrastructure for its transportation and storage also reinforces its importance in modern energy systems.

Properties and technical benefits of natural gas in the energy transition

Natural gas, due to its technical characteristics, is positioned as a key component to achieve a balanced energy transition. Among its main benefits are the following:

• Reduced emission profile: Its combustion generates lower amounts of carbon dioxide and pollutants such as sulfur oxide and nitrogen oxide, which contributes to mitigate atmospheric pollution.
• High thermal efficiency: Its use in combined cycle turbines allows reaching efficiency levels above 60%, optimizing the use of the resource.
• Multidimensional applicability: From cogeneration of energy in industrial facilities to residential use, natural gas offers diversified solutions that complement energy stability.
• Compatibility with hybrid technologies: Its ability to integrate with intermittent renewable sources, such as solar or wind, makes it a fundamental resource for guaranteeing the balance of electricity grids.

Technological innovations to maximize the potential of natural gas

The implementation of emerging technologies has made it possible to optimize the use of natural gas, minimizing its environmental impacts and maximizing its efficiency. The following innovations stand out:

• Blue hydrogen production: Through methane reforming with carbon capture and storage (CCS), hydrogen generation is achieved with significantly reduced emissions.
• Advanced emissions monitoring: The use of smart sensors and predictive analytics systems enables detection and mitigation of methane leaks at the extraction, transportation and distribution stages.
• Advanced catalysts: New developments in catalyst chemistry enable the reduction of greenhouse gas emissions in the combustion and chemical conversion processes.
• Liquefaction and regasification technologies: Advances in Liquefied Natural Gas (LNG) have optimized its transportation over long distances, improving efficiency and reducing logistics costs.

The role of natural gas in modern energy systems

Natural gas represents a fundamental component in the energy transition due to its versatility and lower environmental impact compared to other fossil fuels. Its role in modern systems includes being a reliable backup for intermittent renewable sources, such as solar and wind, ensuring stability in the power grid.

Combined cycle power generation

Combined cycles represent a highly efficient technology for electricity production using natural gas as the main fuel. This system integrates a gas turbine that generates electricity and uses the exhaust gases to heat water, producing steam that feeds an additional steam turbine. This scheme maximizes thermal efficiency, reaching values above 60%, significantly higher than conventional methods.

The modular design of combined cycles facilitates their implementation in plants of different capacities, from industrial facilities to large power plants. This combined cycle technology generates electricity using a single energy source (natural gas). In the first, natural gas is injected into the combustor together with combustion air that has been previously filtered and compressed in the internal compressor of the gas turbine. In the combustor the combustion process takes place at high pressure, generating the energy of the combustion gases when they expand, turning the main shaft of the gas turbine. Coupled to the generator, the turbine transforms the mechanical energy into electrical energy.

Advanced technologies, such as carbon capture and storage (CCS)

Carbon capture and storage (CCS) is a significant technology in the mitigation of CO₂ emissions from industrial and power generation sources. This process consists of three stages: capture of carbon dioxide at the point of emission, transport of the compressed gas to a suitable site, and storage in safe geological formations, such as saline aquifers or depleted hydrocarbon reservoirs.

CCS significantly reduces the carbon footprint of fossil fuel-dependent energy systems, transforming them into more sustainable options in the short and medium term. In addition, its integration with combined cycle power plants or other industrial processes enhances the efficiency of these facilities while moving towards a low-carbon energy transition.

Natural gas and its role in the production of blue hydrogen

Natural gas is used in the production of blue hydrogen, facilitating a transition to a hydrogen-based economy. it represents an energy vector that balances the use of fossil resources with a substantial reduction in emissions. Through steam reforming, methane gas reacts to generate hydrogen and carbon dioxide, the latter of which is captured and stored using CCS technologies, reducing the environmental impact of the process.

Blue hydrogen, derived from natural gas with carbon capture and storage (CCS) technologies, represents a significant advance in the production of low-carbon fuels. In this process, methane from natural gas undergoes methane steam reforming to produce hydrogen, while the associated carbon dioxide is captured and stored.

Currently, Shell, through the Shell Blue Hydrogen Project, a comprehensive product line that enables hydrogen production, transforms low-value streams such as bottom-of-barrel residues, asphaltenes and heavy oils into synthesis gas. This approach enables the monetization of these resources through their use in refineries, power generation and other industrial applications. In addition, the project incorporates advanced carbon capture technologies, allowing the chemical and refining industries to diversify their supply and reduce carbon emissions in their operations.

For more information on this process, I invite you to watch the following video. Source: Shell.

Environmental impacts and challenges associated with the use of natural gas

Although natural gas is considered a cleaner alternative to other fossil fuels, its exploitation and use present significant challenges that must be addressed with technical and regulatory rigor:

• Impacts of fracking: Unconventional extraction technologies, such as hydraulic fracturing, raise concerns about aquifer contamination, emission of volatile organic compounds and associated seismic risk.
• Persistent methane emissions: As a major component of natural gas, methane has a significantly higher global warming potential than carbon dioxide, underscoring the need to reduce leakage throughout the value chain.
• Environmental and social regulations: The development of strict standards and continuous monitoring mechanisms is essential to ensure that natural gas operations are environmentally sustainable and socially responsible.

The role of natural gas in the integration of renewable energies

Natural gas contributes to direct power generation, and plays a critical role in the stability of hybrid energy systems. Its ability to respond quickly and flexibly to fluctuations in intermittent renewable energy generation, such as wind and solar, makes it an indispensable component of modern power grids. Furthermore, its use in combination with energy storage technologies, such as lithium batteries, improves system resilience and ensures continuous supply in conditions of high demand or low renewable generation.

This compound represents a strategic ally in the transition to sustainable energy systems, to complement renewable energies, such as solar and wind, which are inherently intermittent due to the variability in weather conditions and daily cycles. This represents a significant challenge to ensure a continuous and reliable supply of energy. In this context, natural gas acts as an efficient, flexible and less polluting backup solution compared to other traditional fossil fuels.

Operational flexibility and rapid response

One of the most outstanding features of natural gas in its application within hybrid systems is its ability to respond immediately to changes in energy demand. Generating plants using gas turbines are able to rapidly increase or decrease their power output to balance fluctuations in renewable sources. This is particularly critical during periods of low solar generation, such as on cloudy days or at night, or when wind speeds are not high enough to activate wind turbines.

This operational flexibility ensures that power grids can maintain supply stability without resorting to more polluting energy sources, such as coal, which have slower response times and generate higher greenhouse gas emissions.

Complementarity with energy storage technologies

This resource also plays an essential role when integrated with energy storage systems, such as lithium batteries and other advanced technologies. During periods when renewable generation exceeds demand, the surplus can be stored and then used when renewable sources are not sufficient to meet energy needs. However, current storage capacity is not sufficient to cover all periods of intermittency, especially during extended blackouts. This gas can be stored and used in the existing natural gas grid, providing a long-term energy storage solution.

In these cases, it becomes a bridging energy source, ensuring a continuous supply while storage technologies evolve to offer larger and more efficient capacities. This hybrid approach improves the resilience of power systems, and optimizes the use of renewable resources by reducing reliance on more polluting fossil fuels.

Reducing emissions in power generation

Although natural gas remains a fossil resource, its use in power generation produces significantly less carbon dioxide and other air pollutants compared to coal or oil. This characteristic makes it a cleaner option to support renewable generation in the transition to a decarbonized energy system. In addition, innovations in Carbon Capture and Storage (CCS) technologies applied to natural gas plants are further reducing associated emissions, positioning it as an essential resource in sustainable energy systems.

Towards a more balanced and sustainable energy model

In the context of the energy transition, natural gas appears as a considerable resource to ensure a balance between environmental sustainability goals and current energy needs. Its integration with renewable sources increases supply reliability, and reduces global emissions by minimizing dependence on more polluting fossil fuels.

As renewable and storage technologies continue to advance, the role of natural gas may evolve into a more strategic use, focusing on emergency situations or as a supplement in times of high energy demand. Collaboration between technology, government and industry sectors will be critical to maximize its contribution to a cleaner, more resilient and sustainable energy system.

Natural gas facilitates the incorporation of renewable energies on a large scale, while acting as a catalyst to accelerate the transition to a decarbonized economy.

Conclusions

Natural gas is a strategic resource in the transition to a cleaner, more efficient and reliable energy system. Optimal utilization depends on the adoption of advanced technological solutions and the implementation of regulatory policies that promote sustainability. Although it faces challenges, it acts as a bridge between traditional fossil fuels and renewable energies, and is key to moving towards a decarbonized and resilient energy economy. Cooperation between industry sectors, governments and the scientific community is essential to maximize benefits, mitigate negative impacts and ensure a sustainable energy future for generations to come.

Natural gas occupies a central place in the energy transition, as it is a cleaner and more efficient source compared to other fossil fuels. Its use contributes to the reduction of greenhouse gas emissions and facilitates the integration of renewable energies by guaranteeing a reliable and flexible source of energy, making it an indispensable resource for moving towards balanced and sustainable energy systems.

The development and implementation of technologies such as carbon capture, blue hydrogen, methane emissions reduction, and intelligent monitoring of transportation and storage systems reinforce the role of natural gas in the energy transition. These innovations improve efficiency and reduce environmental impacts, promoting a comprehensive approach that combines technological advances with sustainability-oriented strategies.

References

1. Oil and gas production handbook; Edition 3.0 Oslo, August 2013
2. Oil and Gas: Processing and Production Technologies- Oliver Haghi.
3. Nontechnical Guide to Petroleum Geology, Exploration, Drilling & Production, 4th edition – Norman J. Hyne, Ph.D.