Background
Methane, a potent greenhouse gas, constitutes most natural gas and is emitted from various sources such as agriculture, wetlands, and fossil fuel industries. Despite its potential as an energy source, methane’s low boiling point and flammability pose significant challenges for its compression and transport, leading to its frequent flaring and substantial CO2 emissions. Converting methane into methanol (a liquid at ambient conditions) is a promising solution to mitigate these emissions while producing a valuable fuel. However, traditional methods for this conversion involve a two-step process that is inefficient and environmentally detrimental.
Current approaches to methane-to-methanol conversion face critical issues. The conventional two-step process, which includes the production of syngas, operates at high pressures and temperatures, resulting in a high carbon footprint and limiting its applicability to areas where methane is emitted.
Direct methane to methanol (DMtM) conversion in a single step offers a promising alternative but is hindered by a fundamental selectivity-conversion trade-off. As methane conversion increases, methanol selectivity decreases due to methanol’s high reactivity in oxidizing environments, leading to its overoxidation into CO and CO2. Additionally, both traditional thermal catalysis and nonthermal plasma methods struggle with this selectivity-conversion limit, constraining the maximum achievable methanol yield and making the process less efficient and scalable.
Technology overview
The technology described involves a novel method for converting methane (CH4) to methanol (MeOH) using targeted vibrational excitations and plasma environments. This approach addresses the challenges of methane’s low boiling point, flammability, and the environmental impact of its flaring, which contributes significantly to global CO2 emissions.
Traditional methods of methane conversion to methanol involve high temperatures and pressures, leading to suboptimal yields and unwanted byproducts like CO and CO2. The new method leverages vibrational excitations to selectively activate methane molecules and drive their conversion to methanol at near room temperature and atmospheric pressure using electrical energy. This process bypasses the need for syngas production and operates under mild conditions, making it more environmentally friendly and energy-efficient.
What differentiates this technology is its ability to overcome the selectivity-conversion limit that has historically constrained the direct methane-to-methanol (DMtM) conversion processes. By controlling the vibrational excitation pathways, the technology minimizes the production of undesired byproducts and enhances methanol yield. The integration of phase extraction within the reactor allows for the active removal of methanol, preventing its overoxidation and enabling higher selectivity at increased methane conversions.
This method achieves record methanol yields (>20%) and energy efficiency (>12%) by utilizing renewable electrical energy, making it a scalable and sustainable alternative to conventional methane utilization processes. The technology’s ability to operate at mild conditions without relying on catalysts or industrial process heating further underscores its potential for distributed methane conversion applications.
Benefits
- Reduces methane emissions and global CO2 levels by converting methane to methanol
- Utilizes electrical energy for methane conversion, resulting in a low carbon footprint
- Operates at near room temperature and atmospheric pressure, making it suitable for distributed scales
- Bypasses the production and composition constraints of syngas in conventional methods
- Achieves high methanol yield (>20%) and energy efficiency (>12%)
- Eliminates the need for catalysts or industrial process heating
- Enables scalable utilization of methane with targeted vibrational excitations
- Facilitates active product removal, overcoming the selectivity-conversion limit
- Offers operational simplicity, transportability, and ease of setup for remote locations
- Potentially achieves near-zero carbon intensity by using renewable electrical energy
Applications
- Natural gas utilization
- Methanol production
- Greenhouse gas reduction
- Renewable energy storage
- Distributed fuel conversion
Patent
PCT application serial number US2024/048648, “Tailoring Non-Equilibrium Pathways for the Selective Formation of Intermediate Compounds.” https://worldwide.espacenet.com/patent/search?q=pn%3DWO2025072511A1
