World energy consumption is growing. Reliable forecasts say total energy consumption will increase by around 60% in the next 20 years, and coal will still be the major source of power generation globally.
According the International Energy Agency, in 30 years’ time the volume of the international coal trade will increase by almost 1.5 times compared to current levels and trade flows will continue to move towards Asia. Continuous improvement in geological exploration and mining methods mean new coal resources continue to be found.
During underground mining, highly concentrated methane (CH4) can be captured and removed through the use of extraction systems. Where practical, this gas is used to generate electricity or heat mining facilities.
High-rank coals are high in carbon and low in ash and moisture. This means that, when burned, less fuel is required to vaporise moisture and less heat is lost to the ash. Furthermore, washing coal prior to combustion helps not only to reduce the coal’s ash content by more than 50%, but also the sulphur content. Therefore, the higher the quality of coal, the fewer emissions there are for the same amount of electricity produced.
Increasing the efficiency of coal plants also leads to fewer CO2 emissions without affecting the power output. A one percentage point improvement in the efficiency of a conventional pulverised coal combustion plant results in a
Currently, most coal-fired power plants operate under sub-critical steam conditions and have an average efficiency of 35%. New technologies enable coal-fired plants to work at supercritical and ultra-supercritical temperatures, with an efficiency increase of 40% or 50% and above at ultra-supercritical plants. Increasing the efficiency of all coal-fired power plants from 33% to 40% would cut CO2 emissions by an amount equal to expanding the world’s current solar power capacity by 195 times.
Another research trend is coal gasification, which combines power generation with coal chemistry products. Coal gasification allows the production of chemical products such as methanol, polyethylene, diesel, ammonia and more. While coal gasification is more expensive today than the traditional use of oil and natural gas, significant progress has been made in decreasing coal gasification CAPEX
China is the global leader in coal gasification technologies. In 2017 the first plant producing ethanol from coal was launched, supported by the Chinese Academy of Science. The gasoline with 10% ethanol could effectively reduce about 1/3 pollutant emission. IEA forecasts that Chinese coal-to-liquid fuel capacity might grow from 2.5 million tonnes in 2015 to over 20 million tonnes by 2020.