By-production,emissions and abatement costeclimate benefit of HFC-23 in China's HCFC-22 plants

After the Kigali Amendment(KA)came into effect,HCFC-22 plants are obliged to limit HFC-23 emissions.Therefore,the study of costeffective mitigation pathways for HFC-23 is important for the sustainable implementation of KA in China and other HCFC-22 producing countries.This study constructed an inventory of HFC-23 by-production,emissions,and abatement for HCFC-22 plants in China from 2006 to 2020,and predicted the costs and climate benefits of HFC-23 abatement in China's compliance with the KA between 2021 and 2060.Results showed that HFC-23 emissions from HCFC-22 plants in China contributed about 60%of the growth in global atmospheric mole fraction of HFC-23 observed by Advanced Global Atmospheric Gases Experiment(AGAGE)from 2007 to 2020.Furthermore,China's cumulative HFC-23 abatement was about 109 kt(1613 Mt CO_(2)-eq)from 2006 to 2019,accounting for 53%of total by-production,which allowed the global atmospheric mole fraction and radiative forcing of HFC-23 in 2020 to avoid an uplift of 9.2×10^(-9)and i.7 mW m^(-2),respectively,contributing to climate change mitigation.Under the baseline of the Kigali Amendment,less emission(LE),and resource utilization(RU)scenarios,the cumulative HFC-23 abatement from 2021 to 2060 would be 683±29 kt(10,107±431 Mt CO_(2)-eq),694±29 kt(10,277±427 Mt CO_(2)-eq),and 702±29 kt(10,385±426 Mt CO_(2)-eq),respectively.The cumulative net abatement costs for the KA,LE,and RU scenarios would be(5.0±0.2)billion,(2.9±0.2)billion,and(-2.7±0.2)billion CNY(2021 prices),respectively.In the future,applying resource utilization technology to reduce HFC-23 emissions can achieve both climate and economic benefits.

Scenario analysis of hydrofluorocarbons emission reduction in China's mobile air-conditioning sector

With the Kigali Amendment(KA)coming into effect in China,the control of hydrofuorocarbons(HFCs)emissions has become more imperative.The mobile air-conditioning(MAC)sector is one of the important HFCs consumer sectors,and therefore studying its feasible mitigation paths and costs is of great significance to Chinas successful implementation of KA.This study used the bottom-up method with updated emission factors to re-evaluate the emission inventory of HFCs from the MAC sector in China from 2005 to 2020.The average annual growth rate of HFCs consumption in the MAC sector is 9.8%,and HFCs emissions have increased from 5.8(5.3-6.2)kt in 2005 to 22.2(20.6-23.8)kt in 2020,with an average annual growth rate of 8.8%.Using the Gompertz model combined with the Weibull function of vehicle survival rate,the ownership and new registrations of internal combustion engine vehicles(ICEVs)and electric vehicles(EVs)in China are predicted.The ownership of ICEVs and EVs is projected to be 310 million and 91 million in 2030,respectively and 2 million and 641 million in 2060,respectively.HFCs emissions in the MAC sector would reach 59.8(55.3-64.3)kt(80.093.0 Mt CO_(2-eq))in 2060 if without any control measure.To implement the KA,the cumulative of 1.6 Gt CO_(2-eq) emissions would be reduced.Under the other two accelerated mitigation scenarios,the MAC sector's HFCs will reach their emissions peak in 2028 and 2025 and achieve zero emissions in 2050 and 2046,respectively.Under the accelerated mitigation with recovery scenario,the cumulative emissions are only 15.0%of the business as usual(BAU)scenario.Using HFO-1234yf as the substitute,the unit abatement cost of the MAC sector is 27.3-37.4 USD _(t)^(-1)CO_(2-eq).