Three general carbon emission reduction technologies

namely energy saving

CO_2 capture and storage(CCS)

and nature gas replacement technology

are introduced and the development situation is presented.Moreover

three representative techniques are chosen to compare the mitigation performance and techno-economic performance.The results show that

the next generation coal-fired power plants with main steam temperature of 700 ℃ and double-reheat cycle can reduce the energy consumption by enhancing the net efficiency

thus to realize CO_2 emission reduction

but the investment cost is huge.The post-CCS technique based on chemical absorption can reduce the CO_2 emission sharply

but the unit efficiency decreases by 6~9% points.Through clean energy replacement

the CO_2 emission of nature gas combined cycle power plant without CO_2 capture is only 45% of that in coal-fired power plant.Its cost of electricity(COE)and the cost of CO_2avoided(COA)is the lowest among these three techniques.In addition

with a certain extend increase of nature gas price(around 20%)

the nature gas combined cycle power plant still presents good economic performance.The results show the nature gas replacement is a potential technique aiming to achieve large mitigation in near and medium-term.