Methane, a potent gas, has been gaining prominence as an alternative fuel source. While the adverse impacts of methane are widely recognized, it is also worth exploring the direct societal benefits that arise from its capture and utilization. Methane offers many economic, environmental, and social benefits when used efficiently. Capturing methane emissions and converting them into electricity or other useful forms of energy reduces the total amount of gases released into our atmosphere.
Improving Air Quality
From an environmental standpoint, utilizing captured methane also reduces air pollution. This reduction is a key point because, in many industrialized regions, methane emissions are responsible for a significant portion of air pollution, particularly ground-level ozone, or smog.
When exposed to UV radiation from sunlight, methane reacts with other gases and volatile organic compounds (VOCs) commonly found in landfills to produce ozone. When it forms at ground level, it can form smog, causing severe health effects for people, animals, trees, crops, and even surface waterways when it forms acid rain.
Although methane is not directly toxic, its interaction with other compounds plays a significant role in creating harmful air pollution. Therefore, reducing emissions levels, especially in urban areas, becomes a crucial public health priority due to the resulting health impacts.
A Source of Renewable Fuel
Due to its relatively high energy density, methane has the potential to be an economically viable renewable fuel source. The term "high energy density" refers to the amount of energy that can be extracted from a given volume or mass of fuel. Methane, a primary component of natural gas, contains significant potential energy that can be converted into useful power. This attribute makes methane a practical and efficient fuel source, especially compared to other renewable energy sources. Its high energy density generates more power from a smaller amount of fuel, creating economic and environmental advantages when methane is captured and used for energy production.
Methane-based power can be harnessed by direct capture from biogas generation or by burning it in a gas turbine or combined-cycle power plant. Gas turbines are known for their superior efficiency ratings compared to other combustion engines. This efficiency makes them a more environmentally friendly option, and methane fuels are already being developed and utilized to power vehicles such as cars, buses, and ships.
The Social Benefits of Methane Capture and Use
As part of a series of broad initiatives to develop and transition to renewable energy sources, the social benefits of methane capture and use are innumerable. Reduced pressure on natural ecosystems and improved human health are evident from rising air and water quality as we pivot from fossil fuels. The potential breadth and scope of benefits to global populations and local communities defy description.
With that in mind, let's briefly glance at a few examples of how a focused and vigorous methane capture and use could benefit us all.
Methane and the Energy Sector
- Effective capture and utilization of methane emissions can reduce the need for costly energy imports in many countries, freeing up resources that can be used to address other areas of concern.
- Direct access to local sources of affordable energy can spur local development and provide a secondary stream of revenue for farmers and ranchers.
- Using energy from recovered methane can help curtail the use of wood, coal, and oil, all of which produce higher levels of pollutants.
- Development of a wider variety of vehicles powered by compressed natural gas or compressed biogas can lower the cost of transportation for goods and people and reduce air pollution.
- Since methane is more energy-dense than other forms of fuel, fewer gases are produced when combusted, particularly carbon dioxide, sulfur oxide, and nitrogen oxides.
Methane, Fertilizers, and the Circular Economy
The circular economy concept revolves around minimizing waste and maximizing resource efficiency by recycling, reusing, and repurposing materials and energy. Its primary objective is to assign value and purpose to all materials typically considered "waste." When applied to methane, this circular approach recognizes the value of all methane, including that produced by "cow burps" and landfill gas. Methane emissions must be captured from various sources before they are released into the atmosphere to minimize waste. Moreover, efficiency dictates that this captured methane should be utilized for beneficial purposes.
In practical terms, let's focus on biogas produced through the anaerobic digestion of organic waste. This process generates methane and yields ammonia, a vital nitrogen fertilizer component. In a circular economy, both products are collected and utilized. The biogas is treated and combined with other elements to create a wide range of nitrogen-based fertilizers, directly supporting plant growth.
Instead of allowing biogas to escape unnoticed into the atmosphere, the circular economy calls for a closed-loop approach, where resources and energy are valued and preserved within a cycle of use. Through this example of capturing and utilizing methane, we can contribute to the sustainable production of agricultural inputs, thus maintaining a circular economy model.
Food out of Thin Air: Converting Carbon Dioxide to Proteins
At first blush, it sounds like a scene from Star Trek, but the future has indeed arrived. (Actually, it arrived a few decades ago). Carbon dioxide is now being utilized as a substrate in producing high-quality single-cell proteins (SCP) containing essential nutrients like a wide spectrum of important amino acids, carbohydrates, lipids, minerals, nucleic acids, and vitamins. These proteins have already been substituted (successfully!) for more expensive protein sources like fish and soybean products.
When methane is burned in the air, it produces carbon dioxide, water, and heat. If even that CO2 can be valorized as a basis for sustainable food production, this could close the circular economy loop by generating products like high-value food for fish, livestock, and humans from what might have been a troublesome waste product.
