能源科技

在“双碳”目标下，国家逐步压减煤炭高碳能源减污降碳的新形势对煤炭产品质量、生产模式及煤炭清洁高效利用提出新要求，煤炭生产利用产业链不仅要减少污染物排放，而且要减少CO₂排放量，因此，清洁燃煤电厂厂用动力煤除了灰分、硫份等指标外，H/C原子比是评价动力煤性质的重要指标，由于褐煤等低变质程度煤H/C原子比高，在获得同样热量的情况下，CO₂排放量少，有助于燃煤电厂减少CO₂排放。初步测算，若燃烧褐煤达到天然气的CO₂排放水平，脱除42%的CO₂即可。在未来清洁燃煤电厂中，褐煤等低变质程度煤将是“双碳”目标下的优质动力煤，但由于褐煤水分含量高、发热量低的特性限制了其能源效率的提高，因此，应建设“利用电厂的余热对褐煤进行干燥脱水提质加工的煤电一体化”新模式，提高褐煤品质和发电效率，降低煤炭生产利用成本，为燃煤电厂实施CO₂捕集封存拓展足够的成本空间，使清洁燃煤电厂污染物和CO₂排放达到或低于天然气电厂水平，实现低碳化，充分发挥清洁煤电在“双碳”目标下的“兜底”和能源安全保障作用，使清洁煤电成为碳中和后我国清洁能源中不可缺少的组成部分。

Under “carbon peaking and carbon neutrality” strategy,the state’s new situation of gradually reducing coal and high-carbon energy,reducing pollution and carbon puts forward new requirements for coal product quality,production mode,and clean and efficient utilization of coal.The industrial chain of coal production and utilization should not only reduce pollutant emissions,but also reduce CO₂ emission.Therefore,in addition to ash content and sulfur content,H/C atomic ratio is an important indicator to evaluate the properties of thermal coal used in clean coal-fired power plants.Due to the high H/C atomic ratio of lignite and other low metamorphic coal,the CO₂ emission is less under the condition of obtaining the same heat,which is conducive to the reduction of CO₂ emission in coal-fired power plants.It is preliminarily estimated that if the combustion of lignite reaches the CO₂ emission level of natural gas,about 42% of CO₂ can be removed.In the future clean coal-fired power plants,lignite and other low-metamorphic coal will be highquality thermal coal under the“carbon peaking and carbon neutrality”strategy.However,the improvement of its energy efficiency is limited due to its high moisture content and low calorific value.Therefore,a new model of“coal power integration of drying,dehydration and quality improvement of lignite by using the waste heat of power plant”should be built to improve lignite quality,improve lignite power generation efficiency,expand sufficient cost space for CO₂ capture and storage in coal-fired power plants to make the pollutant and CO₂ emission of clean coal-fired power plants reach or be lower than that of natural gas power plants,realizing low carbonization,and give full play to the“general protection”and energy security role of clean coal power under the“carbon peaking and carbon neutrality”strategy,and make clean coal power an indispensable part of China’s clean energy after“carbon neutrality”.