Biomass energy has great potential to achieve carbon peak and carbon neutrality in China

As mentioned earlier, the total capacity of China's large-capacity super (super) critical parameter and sub-critical parameter units has 873 million kilowatts, and the total assets of these units and their supporting facilities and transmission and distribution systems are as high as 10 trillion yuan. This huge asset is the wealth accumulated by the long struggle of the country and the people. Most of these units have not been in service for a long time, and when they are "young" and "young and strong", they must not be easily retired in the name of "low-carbon transformation", causing irreparable huge losses. If the power production capacity of the above coal power system is replaced with a new production, energy storage (there is no mature technology at present) and unstable wind and solar power generation system, the high investment and operating costs will be imagined.

Third, biomass and coal coupling power generation is coal power

Biomass power generation and wind power, solar power and other renewable energy power, are (nearly) zero-carbon emissions of electricity production, but also has wind power and solar power do not have the advantages: that is, in nature, the annual regeneration of agricultural and forest residual resources is relatively stable; Fuel can be transported and stored for balanced use throughout the year. It is an advanced technology to realize biomass power generation in the world by using large and efficient coal-fired units to burn biomass fuel for power generation. It is not only more efficient than the existing biomass direct combustion power generation (generally for small and medium power plants), but also can significantly reduce the carbon emissions of coal power units, improve the flexibility of coal-biomass coupled power generation, and strengthen the sustainability of coal power production, which is a practical and feasible path for coal power to low carbon.

The international use of biomass co-firing technology in large coal-fired power plants stems from the Kyoto Protocol to the United Nations Framework Convention on Climate Change adopted in Kyoto, Japan, in December 1997. The protocol aims to curb global climate change by limiting carbon dioxide emissions in developed countries. Since then, developed countries, especially EU countries, have begun to take various measures in regulations, policies and technologies to reduce carbon emissions from coal power. One of the most important technologies is the use of coal and biomass coupled mixed combustion power generation. After the biomass mixed combustion technology gradually matures, it has been well promoted and applied.

Fourth, Britain and Denmark shut down coal power

Take Denmark, for example. In 2017, modern bioenergy already accounted for nearly seven in 10 (69%) of renewable energy. Its most important contribution is to replace coal with biomass fuel, especially biomass pellet fuel, in the field of cogeneration. Due to the technical solution to the problem that mixed stalks rich in potassium and chlorine are easy to produce boiler coking, in 1992, the midkraft power plant with a power of 78,000 kilowatts used straw and coal to generate electricity, which reached 50%:50% ratio, and digested 70,000 tons of straw annually. In 1999, Denmark has achieved the goal of using 1.2 million tons of straw (accounting for nearly 30% of the national annual output of 3.5 million tons of straw) and 200,000 tons of wood slicing and coal mixed combustion power generation (insufficient raw material imports). Denmark's Energy Information Agency (EnergiNet) estimates that biomass already accounts for more than a quarter of the country's electricity consumption; It is expected that as more biomass (including biogas) cogeneration projects come on stream, this figure will increase to 57% by 2026. In the United Kingdom, driven by strong incentive policies, coal-to-biomass coupled power generation has been strongly developed since the end of the last century. After more than 20 years of practice in coal power plants with biomass coupling and coal-fired power generation, all large coal-fired power plants in the UK have finally been transformed into biomass combined combustion. The most typical is the largest Drax power plant in the UK. The power plant has a total of six 660,000 kilowatt coal-fired units. Starting from the transformation of 5% biomass in a unit in 2003, the biomass ratio has been continuously increased until all coal power units have been transformed into biomass mixed combustion, and finally in 2018, four 660,000 kW coal power units have achieved 100% combustion of biomass pellet fuel. Become the world's largest biomass fuel thermal power plant. At the same time, the plant has solved the supply problem of 10 million tons of biomass pellet fuel per year through two domestic and foreign markets. Therefore, according to their experience, the coal-biomass co-combustion power generation of large coal-fired units is technically very mature, which shows a good way for China's coal power industry to learn from international experience to achieve low-carbon transformation. And the special advantage of China's large coal-fired units is that it can make coal-biomass mixed combustion power generation. One of its advantages is that China's coal-fired units in the world's highest power supply efficiency and the lowest power supply coal consumption, the second has a deep peak load regulation technology, so that the unit load regulation range of 100%-20%, the third is soot, SO2, NOX and other conventional air pollutants can achieve ultra-low emissions.