HFC-134a is the most important alternative to CFC-12 used in the mobile air-conditioner sector in China. The consumption of HFC-134a has been increasing rapidly in recent years. It becomes the most consumed HFC in the sector. Selecting 2005 as the base line year, future consumption and emission amounts of HFC-134a are estimated through an analysis of a combined scenario: 1) replacement by non-HFC-134a blends, 2) good practice in servicing, 3) technology promotion, and 4) government policies on control of HFC-134a emissions. The analysis shows that HFC-134a consumption and emissions will continue to increase in the next 10 years. The projected HFC-134a consumption will approach 20,150 t and 34,875 t in 2010 and 2015 respectively, while the estimated emission amounts will reach 16,065 t and 30,186 t (i.e., 21 Mt CO2 -eq and 39 Mt CO2 -eq emissions) correspondingly. Compared with the business-as-usual scenario, the expected emission reductions in 2010 and 2015 will range between 6.7 Mt CO2 -eq and 13.0 Mt CO2 -eq.
mobile air-conditioner ; HFC-134a ; emission reduction
The ODP (ozone depletion potential) is used in the Montreal Protocol for Protection Ozone as a criterion to define ozone depleting substances (hereafter ODS). The most important principle for selective substitutes or alternatives is to reduce the ozone depletion. Consequently CFCs (Chlorohalocarbons) with high ODP have been prohibited to use. HFCs (Hydrofluorocarbons) were once regarded as the perfect substitutes for their zero-ODP values. However, in the Kyoto Protocol, HFCs were listed as one of the six gas categories with high values in global warming potential (GWP). They are therefore restricted in the Kyoto Protocol, and are no longer regarded as permanent substitutes for ODS.
HFC-134a (CH2FCF3), one of the most important HFCs consumed in China and developed countries [ IPCC and TEAP , 2005 ], plays a leading role as refrigerant used in mobile air-conditioner (hereafter MAC). Nowadays, all cars and trucks are using HFC-134a as refrigerant, while large and middle size buses partly use HFC-134a and blends. Although HFC-134a has zero-ODP value, it is already being regulated in some developed countries [ EPCEU , 2006b ] for its relatively high GWP value of 1,300 [ IPCC and TEAP , 2005 ]. The total greenhouse gases (GHGs) emissions in China have already reached 6.1 Gt CO2 -eq [ NDRC , 2007 ], and will continue increasing along with the economic development. China will face great difficulties to control GHGs emissions in the future.
The total halocarbon radiative forcing is about 0.34 W m- 2 [ IPCC , 2007 ]. Among the controlled halocarbons in the Tokyo Protocol, HFC-134a is the major HFC in use [ MEPC , 2003 ]. The application in mobile air-conditioning is the principal consumption sector. Therefore, the estimation of future consumptions and emissions of HFC-134a used in MAC in China is of great importance. China needs to respond to the international actions on accelerated phase-out of HFC-134a, to control the GHGs emissions, and to increase the implementation of substitutes.
With the support of the Ministry of Environmental Protection of China, Peking University (PKU) carried out some projects, such as Strategy for CFCs Phase-out in Refrigeration Servicing Sector in China, and Research on Control Strategy of Fluorinated Greenhouse Gases Emission in China. Except indicated sources, the data and emissions factors mentioned in this paper are all derived from PKU investigations from relevant enterprises and industry associations.
The Chinese automobile industry started in the 1950s. China has already become one of the largest countries of automobile production in the world [ CATRC and CAAM , 2003 ]. The gross production of automobiles (including cars, buses and trucks) was about 0.22 million units in 1980, and increased dramatically from 0.51 million units in 1990 up to 2 million units in 2000 [ NBSC , 2007 ]. After joining the WTO, production in 2002, 2003 and 2004 exceeded 3 million units, 4 million units and 5 million units respectively. The increasing rate of gross production of automobiles was much higher than that of GDP over the same period. Although there was an obvious decline in the increasing rate after 2003, the gross production in 2006 reached 7.28 million units with an increasing rate of 27.6%, indicating another boom in automobile production in China.
The rapid increase in production and marketing of automobiles in China mainly depends on the rising demand in cars. The proportion of cars in automobile production increased from 48.5% in 2005 to 53.2% in 2006, to more than half of the total automobiles [ NBSC , 2007 ]. In the marketing of automobiles, consumption of cars increased dramatically and has become the leading contributor to the automobile market in China.
With the increasing demand in air-conditioned automobiles, the annual production and total number of registered air-conditioned automobiles has increased significantly, especially cars and buses. According to Strategy for CFCs Phase-out in Refrigeration Servicing Sector in China [MEPC , 2003 ], the production and total number of registered air-conditioned automobiles increased at an average annual rate of 29% and 22% respectively from 1991 to 1994. In 1994, 1.34 million automobiles were produced, among which 0.28 million units were equipped with MAC systems. The production and total number of registered air-conditioned automobiles from 1995 to 2002 are listed in Table 1 [ MEPC , 2003 ]. In the aforementioned Sector Plan, HFC-134a is chosen to be the only substitute for CFC-12 in new cars and trucks produced in China.
|Total number based on CFC-12||159||193||233||259||277||291||292||276|
|Production based on CFC-12||37||36||40||27||20||16||10||0|
|Total number based on HFC-134a||6||16||32||62||113||179||261||367|
|Production based on HFC-134a||5||10||16||31||51||67||87||140|
Before 1994, CFC-12 was widely used as refrigerant for MAC, except a small quantity used in MAC system which adopted foreign technology. In 1994, China started to phase out CFC-12 use in MAC by the requirement of the Montreal Protocol. At the end of 2001, China banned the use of CFC-12 as refrigerant in new productions of MAC, but CFC-12 is still consumed in servicing till now. While the manufacturers began to use HFC-134a as refrigerant for MAC more and more, the consumption of HFC-134a increased gradually from 1,358 t in 1995 to 6,618 t in 2003 [ MEPC , 2003 ]. Currently, HFC-134a and CFC-12 are the major refrigerants used in MAC in China. Besides these two, other blends (e.g. MP52 and MTL-1) are used in MAC systems of buses [ She , 2001 ].
In 2001, China Automobile Industrial Association, together with the Ministry of Environmental Protection of China, conducted a survey on refrigerant servicing in the MAC sector. Based on the survey, there is no recycling conducted during servicing, and the recharging amount of refrigerant is about 30% of the initial fill amount in general MAC systems [ MEPC , 2003 ]. Consumptions of refrigerants for first-fill of new MAC and for servicing from 1995 to 2002 are shown in Table 2 .
|First-fill amount of CFC-12 in new MAC||609||544||592||443||377||230||130||0|
|Servicing amount of CFC-12||749||984||1,205||1,406||1,554||1,680||1,685||1,560|
|Total consumption of CFC-12||1,358||1,528||1,797||1,849||1,931||1,910||1,815||1,560|
|First-fill amount of HFC-134a in new MAC||71||152||240||461||765||999||1,233||2,450|
|Servicing amount of HFC-134a||30||83||150||465||565||900||1,300||1,700|
|Total consumption of HFC-134a||101||235||390||926||1,330||1,899||2,533||4,150|
According to the historical data of production, import and export of automobiles in China Statistical Yearbook 2007 [NBSC , 2007 ], the portion of import decreases gradually and is less than 5% of the production. Based on this, the servicing consumptions and emissions due to imported automobiles are neglected. Although the export of automobiles increased in recent years, all the first-fills of HFC-134a in new MAC occur in China. The consumption of HFC-134a for export is included in the estimation which is based on the total production. Hence, the estimation of HFC-134a consumption and emissions is based on the total production of automobiles in China.
The demand of HFC-134a in MAC mainly includes the first-fill for new MAC and the recharge in servicing processes of existing units. While in estimating the emissions of HFC-134a in the MAC sub-sector, we followed the bottom-up estimation method recommended by IPCC Good Practice Guidance [ IPCC , 2000 ]. The emissions mainly include initial emissions, operational emissions (including accidental emissions and servicing emissions), and end-of-life emissions. Specific parameters for the different types in estimation are given in Table 3 .
|Type||First-fill (kg unit - 1 ) a||Lifetimes (year) a||Emission during life (%)||End-of-life emission (%)|
|Initial b||Operational a||Recovery efficiency b||Initial charge remaining b|
a. Data source: [ MEPC , 2003 ]
b. Data source: [ IPCC , 2000 ]
Production and marketing of automobiles in China increased fast in recent years. According to the statistical data of the National Bureau of Statistics of China [ NBSC , 2008 ], the production of automobiles in 2007 was reported to be 8.88 million units. Based on the increasing trends in the period of 1995–2005, a diminishing rate of growth is adopted to forecast the future demand of automobiles in China, which is assumed to be 10% in 2010 and 7% in 2015 respectively in this study.
Along with the development of MAC technologies in China, there is no doubt that HFC-134a will dominate the refrigerant market for MAC. The European Union plans from 2011 onwards to prompt substitutes with GWP values less than 150 [ EPCEU , 2006a ], and this may affect the refrigerant market in China. Following this, it is difficult to estimate the specific portion shared by HFC-134a, blends, CO2 , and other refrigerants in the future. In order to forecast the consumption and emissions of HFC-134a, a BAU scenario (business-as-usual) is assumed where all MACs before 2005 will use HFC-134a as refrigerant without recycling. According to the assumption, the estimated total number of registered air-conditioned automobiles with HFC-134a and production, as well as the corresponding consumption and emissions is shown in Table 4 . In 2005, the total consumption of HFC-134a was 10,139 t and the emissions added to 7,321 t.
|Year||Type||Total number (10,000 units)||Production (10,000 units)||First-fill amount for new MAC (t)||Servicing amount (t)||Total consumption (t)||Emissions (t)|
Note: It is assumed that the leakage and servicing is at the same level as of 2001.
The consumption of HFC-134a for first-fill and servicing in the future will be affected by several factors, such as the containment of HFCs by IPCC and TEAP , the emissions control management of fluorocarbons by the European Union [ EPCEU , 2006a ], and the requirement on resource-conserving, energy-saving and emissions-reduction in China [ CCCPC , 2006 ]. In order to analyze the consumption and emissions more reasonably, a combined scenario which contains the following four measures is taken into consideration (Table 5 ).
|BAU scenario||30% of the registered MAC needs servicing every year|
|Measures||Replacement by non-HFC-134a blends||Half of the new buses use non-HFC-134a blends as refrigerants after 2005|
|Good practices in serving||Good practices reduce 3% of the servicing amount under basis case after 2007|
|Technology promotion Government policies on control of HFC-134a emissions||The leakage rate would reduce 2% for new MAC produced after 2010 Recycling, recovering and reuse would reduce 3% of the servicing consumption under base case after 2010|
There are many applications of non-HFC-134a blends used as refrigerants in China, especially in bus air-conditioning systems. It is assumed that in the future non-HFC-134a blends will be used in new bus air-conditioning systems, due to higher energy efficiency. Regarding this, the scenario implies that after 2005 50% of new air-conditioned buses will adopt non-HFC-134a blends.
Along with the improved knowledge of the service workers, the consumption of HFC-134a will be reduced through good practices in servicing processes. It is assumed that by good practices compared to the BAU scenario 3% of the servicing consumption will be reduced after 2007.
Along with the technology development, the leakage rate of refrigerants will be reduced in the future. Consequently, the servicing consumption of HFC-134a will be reduced. It is assumed that the leakage rate after 2010 will be reduced by 2% for newly produced MACs.
For meeting the requirement of environmental protection and the Kyoto Protocol, China government may issue policies to require recycling, recovering and reuse of HFC-134a. It is assumed that after 2010 recycling, recovering and reuse will lead to a 3% reduction in the servicing consumption.
Selecting 2005 as the basis year, the estimated consumption and emissions of HFC-134a of the combined scenario are given in Table 6 . In the following ten years, the consumption and emissions of HFC-134a in China are estimated to increase. However if taken into consideration the replacement by non-HFC-134a blends, technology improvement of MAC, good practice in servicing, and issuance of governmental policies on recycling/recovery/reuse of HFC-134a, the consumption of HFC-134a in 2010 and 2015 is estimated to be 20,150 t and 34,875 t respectively. Emissions of HFC-134a in the years range at 16,065 t and 30,186 t respectively, and are identical to 21 Mt CO2 -eq and 39 Mt CO2 -eq.
|Year||Type||Replacement by blends, good practice, technology improvement, and government policy|
|First-fill amount for new MAC||Servicing amount||Total consumption||Emission|
Considering non-HFC-134a blends, technology promotion, good practice in serving and government policies on control of HFC-134a emissions, the emissions of HFC-134a from MAC systems are projected to be around 21 Mt CO2 -eq in 2010 and 39 Mt CO2 -eq in 2015. An emission reduction of 6.7 Mt CO2 -eq (2010) and 13 Mt CO2 -eq (2015) is estimated in comparison with the BAU scenario (business-as-usual current policy and no recovery management).
The bottom-up approach is used to estimate emissions of HFC-134a from MAC systems, and the uncertainties are mainly sourced from choice of activity data and emission factors [ IPCC , 2000 ]. For the lack of relevant studies in China, the default emission factors given in the IPCC Good Practice Guidance [ IPCC , 2000 ] were used to calculate most scenarios. The annual increasing rate of automobile production is much higher than that of GDP. The chosen lineal diminishing rate of growth which is assumed for the GDP may also result in an underestimation of consumption of automobiles, which further would cause an underestimation of HFC-134a consumption and emissions considerably.
This study was supported by the Research on Control Strategy of Fluorinated Greenhouse Gases Emission in China.