Transforming Coal into “Green” Fuel

Supplying 25% of the world’s energy demand with abundant and widespread reserves, while being relatively inexpensive, coal is viewed as a “transitional” fuel source during a time when humanity is striving to reduce dependence on oil and gas and gradually shift towards sustainable, environmentally friendly fuels such as solar and wind energy.

Given the ongoing volatility in oil and gas prices and the unstable supply, coal is expected to play a key role in meeting the world’s energy needs over the next 20 years. To ensure energy security, not only top energy-consuming countries like the United States, China, and India, but also many other countries are actively researching and developing technologies to convert coal—often criticized for its environmental pollution—into clean energy alternatives to gasoline and diesel. Leading this trend is China, the world’s largest producer and consumer of coal today.

Clean coal technologies aim to reduce environmental pollution in power plants.

According to China’s national science and technology development plan released in February this year, over the next 15 years, the world’s fourth-largest economy will prioritize the development of technologies to convert coal—its most abundant resource—into various forms of clean fuel. One of these technologies involves capturing carbon dioxide (CO₂) generated during coal combustion to achieve near-zero CO₂ emissions.

Currently, China is accelerating the development of dimethyl ether (DME), a gas transformed from coal, as a primary alternative to diesel fuel. Under normal temperature and pressure conditions, DME can be compressed into a liquid form and used as a substitute for diesel with relatively eco-friendly CO₂ emissions. Chinese researchers have also developed vehicles powered by DME. However, the current challenge is to find ways to reduce the production costs of DME and limit water usage in the conversion process (3 tons of water are needed to produce 1 ton of DME).

Experts predict that China could develop coal gasification technology independently within the next five years, with production costs expected to be 50% lower than the global market price at that time. Chinese companies are also actively participating in research and pilot projects for clean coal technology. Notably, the Shanxi Luan Group is implementing a project to liquefy coal to extract oil in Shanxi Province—one of China’s coal “granaries.” Meanwhile, China Huaneng Group, the largest coal-fired power producer on the mainland, is collaborating with domestic and international partners to construct and operate the world’s first coal-fired power plant that emits no CO₂.

China has the third-largest coal reserves in the world, and over 60% of its energy is generated from coal. It is estimated that by 2020, global coal demand will rise to 7.6 billion tons per year, up from the current 5.3 billion tons. Of this, China’s consumption alone is expected to be around 3 billion tons.

With approximately 95% of its energy reserves being coal, while oil and gas account for only 2% and 3%, respectively, the U.S. has recently launched the “Vision 21” initiative—developing technologies for coal-powered energy plants aimed at reducing CO₂ emissions to near zero. Recently, American scientists announced that they have successfully improved technology to convert coal into “green diesel.” The technique for converting coal and other carbon sources into liquid fuel has been in existence since the 1920s. Today, most large transport vehicles in South Africa—one of the countries with significant coal reserves—run on diesel produced using this technology. A team of chemists from the University of North Carolina has enhanced the coal-to-diesel conversion process to be more “green” by using special catalysts to rearrange carbon atoms in coal to form higher energy efficiency molecules before transforming them into diesel.

Compared to oil and gas, coal presents several superior advantages, such as its widespread distribution across countries with recoverable reserves in approximately 70 nations. With current extraction rates, global coal reserves are estimated to meet humanity’s consumption needs for another 200 years. In contrast, over 68% of oil reserves and 67% of gas reserves are primarily concentrated in the Middle East and Russia. With the current consumption trend showing no signs of decline, it is estimated that crude oil and gas reserves will be depleted within 45-65 years.

Coal currently supplies about 25% of the global basic energy demand and generates 40% of the world’s electricity. China is the largest producer and consumer of coal globally, while the United States has the largest coal reserves on the planet, followed by India, China, Australia, Russia, Ukraine, Finland, South Africa, and Canada…

DIEP MAI