4.1 Sector overview
In 2008, New Zealand’s industrial processes sector produced 4,292.0 Gg of carbon dioxide equivalent (CO2‑e), contributing 5.7 per cent of New Zealand’s total greenhouse gas emissions. Emissions from industrial processes had increased by 906.2 Gg CO2-e (26.8 per cent) above the 1990 level of 3,385.8 Gg CO2-e (Figure 4.1.1). The largest source of industrial process emissions are from the metal production category (CO2 and perfluorocarbons (PFCs)) contributing 48.5 per cent of emissions in 2008.
Figure 4.1.1 New Zealand’s industrial processes sector emissions from 1990 to 2008
|Gg CO2 equivalent|
Figure 4.1.2 Change in New Zealand’s industrial processes sector emissions from 1990 to 2008
|1990 Gg CO2 equivalent||2008 Gg CO2 equivalent|
|Consumption of Halocarbons and SF6(2)||12.3||829.5|
Notes: The per cent change for other production and the production of halocarbons and sulphur hexafluoride (SF6) is not occurring (NO) within New Zealand. The per cent change for the consumption of halocarbons and SF6 is not applicable (NA) as within New Zealand there was no production of hydrofluorocarbons (HFCs) in 1990.
The emissions reported in the industrial processes sector are from the chemical transformation of materials from one substance to another. Although fuel is also often combusted in the manufacturing process, emissions arising from combustion are reported in the energy sector. Carbon dioxide emissions related to energy production, for example, refining crude oil and the production of synthetic petrol from natural gas, are also reported within the energy sector.
New Zealand has a relatively small number of plants emitting non-energy related greenhouse gases from industrial processes. However, there are six industrial processes in New Zealand that emit significant quantities of CO2. These are the:
- reduction of ironsand in steel production
- oxidation of anodes in aluminium production
- calcination of limestone for use in cement production
- calcination of limestone for lime
- production of ammonia for use in the production of urea
- production of hydrogen.
Changes in emissions between 2007 and 2008
Between 2007 and 2008, emissions from the industrial processes sector decreased by 344.6 Gg CO2-e (7.4 per cent). The largest decrease of 183.3 Gg CO2-e (8.1 per cent) was due to a reduction in emissions from steel and aluminium production.
Between 2007 and 2008, emissions from the consumption of halocarbons and sulphur hexafluoride (SF6) category decreased by 105.3 Gg CO2-e (11.3 per cent.) This was largely due to a reduction in annual sales of new refrigerant (including halocarbons imported in bulk and in equipment, excluding exports). There was also a reduction in the amount of HFC-134a sold to the mobile air conditioning industry.
4.1.1 Methodological issues
Emissions of CO2 from industrial processes are compiled by the Ministry of Economic Development from information collected through industry surveys. The results are reported in New Zealand Energy Greenhouse Gas Emissions 1990–2008 (Ministry of Economic Development, 2009).
Most of the activity data for the non-CO2 gases is collated via an industry survey. Between 1990 and 2008, the only known methane (CH4) emissions from the industrial processes sector came from methanol production. Emissions of hydrofluorocarbons (HFCs) and PFCs are estimated using the Intergovernmental Panel on Climate Change (IPCC) Tier 2 approach. Sulphur hexafluoride emissions from large users are assessed via the Tier 3a approach (IPCC, 2000).
The number of companies in New Zealand producing CO2 from industrial processes is small and the emissions of CO2 supplied by the companies are considered to be accurate to 5 per cent (Ministry of Economic Development, 2006). The uncertainty surrounding estimates of non-CO2 emissions is greater than for CO2 emissions and varies depending on the particular gas and category. Uncertainty of non-CO2 emissions is discussed under each category.
4.2 Mineral products (CRF 2A)
In 2008, the mineral products category accounted for 802.6 Gg CO2-e (18.6 per cent) of total emissions from the industrial processes sector. Emissions in this category have increased by 252.0 Gg CO2-e (45.8 per cent) from the 1990 level of 550.6 Gg CO2-e. There are no known emissions of CH4 or nitrous oxide (N2O) from the mineral products category.
This category includes emissions produced from the production of cement and lime, soda ash production and use, asphalt roofing, limestone and dolomite use, road paving with asphalt, and glass production. In 2008, cement production accounted for 634.2 Gg CO2-e (79.0 per cent) of emissions from the mineral products category. In the same year, lime production accounted for 119.1 Gg CO2-e (14.8 per cent). Only the emissions related to the calcination process for lime and cement production are included in this category. The emissions from the combustion of coal, used to provide heat for the calcination process, are reported in the energy sector.
4.2.2 Methodological issues
In 2008, CO2 emissions from cement production were a key category in the level assessment (Table 1.5.1). In 2008, there were two cement production companies operating in New Zealand, Holcim New Zealand Ltd and Golden Bay Cement Ltd. Both companies produce general purpose and portland cement. Holcim New Zealand Ltd also produces general, blended cement. From 1995 to 1998 inclusive, another smaller cement company, Lee Cement Ltd, was also operating.
Due to commercial sensitivity, individual company estimates have remained confidential and the data has been indexed as shown in Figure 4.2.1. Consequently, only total process emissions are reported and the implied emission factors are not included in the common reporting format tables.
Carbon dioxide is emitted during the production of clinker, an intermediate product of cement production. Clinker is formed when limestone is calcined (heated) within kilns to produce lime and CO2. The emissions from the combustion of fuel to heat the kilns are reported in the energy sector.
Estimates of CO2 emissions from cement production are calculated by the companies using the Cement CO2 Protocol (World Business Council for Sustainable Development, 2005). The amount of clinker produced by each cement plant is multiplied by a plant-specific clinker emission factor. The emission factors are based on the calcium oxide (CaO) and magnesium oxide (MgO) content of the clinker produced. The inclusion of MgO results in the emission factors being slightly higher than the IPCC default of 0.50 t CO2/t cement.
The cement companies supply their emission data to the Ministry of Economic Development during an annual survey. The IPCC (2000) default cement-kiln dust correction factor, 1.02, is included in Holcim New Zealand Ltd’s CO2 emissions calculation. Cement-kiln dust is a mix of calcined and uncalcined raw materials and clinker. Golden Bay Cement Ltd has not included a correction factor as it operates a dry process with no cement-kiln dust lost to the system.
Figure 4.2.1 shows the trends in New Zealand clinker and cement production, imported clinker and the implied emission factor for clinker and cement for the 1990–2008 time series. In general, the figure shows clinker and cement production increasing over the time series 1990–2008. Relatively, over the same time series, cement production has increased more than clinker production. The cement-implied emission factor decreased between 2000 and 2004 with increasing amounts of imported clinker. Meanwhile, the implied emission factor for clinker remained relatively unchanged.
A change in national standards for cement production in 1995, permitting mineral additions to cement of up to 5 per cent by weight (Cement and Concrete Association of New Zealand, 1995), has also resulted in less CO2 emissions per tonne of cement produced. The increase in clinker production from 2006 to 2007 is due to one of New Zealand’s cement companies running at full production in 2007.
Sulphur dioxide (SO2) is emitted in small quantities from the cement-making process. The amount of SO2 is determined by the sulphur content of the limestone. Seventy-five to 95 per cent of the SO2 will be absorbed by the alkaline clinker product (IPCC, 1996). The emission factor for SO2, used by New Zealand, is calculated using information from a sulphur mass-balance study on one company’s dry kiln process. The mass-balance study enabled the proportion of sulphur, originating in the fuel and the sulphur in the raw clinker material as sodium and potassium salts, to be determined. The average emission factor was calculated as 0.64 kg SO2/t clinker and was weighted to take into account the relative activity of the two cement companies. This submission continues to use this emission factor as it is still considered to accurately reflect the New Zealand situation.
Figure 4.2.1 New Zealand’s cement production data including clinker production, clinker imports and cement and clinker-implied emission factor (indexed) from 1990 to 2008
|Clinker Production||Clinker IEF||Clinker imported||Cement Production||Cement IEF|
In 2008, lime production in New Zealand was not a key category. There are three companies (McDonalds Ltd, Websters Hydrated Lime Ltd and Perrys Group Ltd) producing burnt lime in New Zealand. All three companies produce high-calcium lime, and two companies produce hydrated lime.
Emissions from lime production occur when the limestone (CaCO3) is heated within the kilns to produce CaO and CO2. The emissions from the combustion of fuel are reported within the energy sector.
Carbon dioxide and SO2 emission data from lime production are supplied to the Ministry of Economic Development by the lime production companies. Emissions are calculated by multiplying lime activity data by an emission factor (IPCC, 2000). Given the limited data availability before 2002, a single New Zealand-specific emission factor based on the typical levels of impurities in the lime produced in New Zealand was applied for
1990–2002. Since 2002, plant-specific emission factors have been used. In alignment with good practice, a correction factor is applied to the hydraulic lime produced. There has been little change in the implied emission factor varying from 0.72 t CO2/t lime to 0.73 t CO2/t lime from 1990 to 2008.
The SO2 emissions from lime production vary depending on the processing technology and the input materials. An average emission factor for SO2 was calculated as 0.5 kg SO2/t lime. The emission factor was weighted to take SO2 measurements at the various lime plants into account (CRL Energy, 2006). This submission has continued to use the 2005 emission factor.
Limestone and dolomite use
Limestone and dolomite can be used in pulp and paper processing and mining. However, the majority of limestone quarried in New Zealand is calcinated to produce lime or cement. Emissions from the use of limestone for these activities are reported under the lime and cement production categories as specified in the IPCC guidelines (IPCC, 1996). Ground limestone used in the liming of agricultural soils is reported in the land use, land-use change and forestry sector.
Small amounts of limestone are used in the production of iron and steel by the company, New Zealand Steel Ltd. In the iron production process, the coal is blended with limestone to achieve the required primary concentrate specifications. New Zealand has separated emissions arising from limestone, coke and electrodes used in the iron and steel-making process from the remaining process CO2 emissions, and reported these emissions under the limestone and dolomite use subcategory (2A.3). This data could not be disaggregated any further (ie, reporting only limestone emissions from iron and steel production under 2.A.3). Emissions from limestone/coke/electrode use make up 1–2 per cent of total iron and steel process emissions.
This subcategory also includes emissions from the use of soda ash and from glass production. These emissions are included here because of confidentiality concerns.
Soda ash production and use
There is no soda ash production in New Zealand. A survey of the industrial processes sector estimated CO2 emissions resulting from the use of soda ash in glass production in 2005 (CRL Energy, 2006). The glass manufacturer provided information on the amount of imported soda ash used in 2005. The manufacturer also provided approximate proportions of recycled glass over the previous 10 years to enable CO2 emissions from soda ash to be estimated from 1996 to 2005. This is because the amount of soda ash used is in fixed proportion to the production of new (rather than recycled) glass. Linear extrapolation was used to estimate activity data from 1990 to 1995. Updated activity data for subsequent years was provided by the glass manufacturer through an external consultant. The IPCC default emission factor of 415 kg CO2/t of soda ash was applied to the soda ash activity data to calculate the CO2 emissions.
The activity data and resulting CO2 emissions are considered confidential by the glass manufacturer. Consequently, the emissions resulting from the use of soda ash are reported under the limestone and dolomite use subcategory.
There is one company manufacturing asphalt roofing in New Zealand, Bitumen Supply Ltd. Default emission factors of 0.05 kg non-methane volatile organic compound (NMVOC) per tonne of product and 0.0095 kg carbon monoxide (CO) per tonne of product respectively were used to calculate NMVOC and CO emissions (IPCC, 1996). A survey of indirect greenhouse gases was last conducted for the 2005 calendar year. In the absence of updated data, activity data for 2005 has been used for 2006–2008.
Road paving with asphalt
There are three main bitumen production companies operating within New Zealand. Data on bitumen production and emission rates is provided by these companies. Estimates of national consumption of bitumen for road paving are confirmed by the New Zealand Bitumen Contractors’ Association.
In New Zealand, solvents are rarely added to asphalt. This means that asphalt paving is not considered a significant source of emissions. New Zealand uses a wet “cut-back” bitumen method rather than bitumen emulsions that are common in other countries.
The revised 1996 IPCC guidelines (IPCC, 1996) make no reference to cut-back bitumen but do provide default emission factors for the low rates of SO2, oxides of nitrogen (NOx), CO and NMVOC emissions that arise from an asphalt plant. The IPCC default road-surface emissions factor of 320 kg NMVOC/t of asphalt paved is not considered applicable to New Zealand. There is no possibility of this level of NMVOC emissions because the bitumen content of asphalt in New Zealand is only 6 per cent.
For the 2004 inventory submission, the New Zealand Bitumen Contractors’ Association provided a method (Box 4.1) for calculating total NMVOC emissions from the use of solvents in the roading industry. The industrial processes survey for the 2005 calendar year (CRL Energy, 2006) showed that the fraction by weight of bitumen used to produce chip-seal has been changing over recent years as methods of laying bitumen have improved. From 1990 to 2001, the fraction by weight of bitumen used to produce chip-seal was 0.80. From 2002 to 2003, it was 0.65 and, from 2004, the fraction was 0.60. The NMVOC emissions were updated to reflect this changing fraction.
In the absence of updated data, activity data for 2005 was extrapolated for 2006–2008.
Box 4.1 New Zealand’s calculation of NMVOC emissions from road-paving asphalt
NMVOC emitted = A x B x C x D
A = The amount of bitumen used for road paving
B = The fraction by weight of bitumen used to produce chip-seal (0.80)
C = Solvent added to the bitumen as a fraction of the chip-seal (0.04)
D = The fraction of solvent emitted (0.75)
There is one major glass manufacturer in New Zealand, O-I New Zealand. Production data is considered confidential by O-I New Zealand, consequently emissions are reported under the limestone and dolomite use subcategory. Estimates of CO2 from soda ash use were obtained from the industrial processes survey (CRL Energy, 2009) and are reported with limestone and dolomite use (2.A.3) because of confidentiality concerns.
Non-methane volatile organic compounds may be emitted from the manufacture of glass and suggest a default emissions factor of 4.5 kg NMVOC/t of glass output (IPCC, 1996). It has been assumed that the IPCC default emission factor for NMVOCs was based on total glass production that includes recycled glass input.
Due to confidentiality concerns, the NMVOCs and SO2 emissions are now reported under the limestone and dolomite use subcategory as confidential.
Oxides of nitrogen and CO emissions are assumed to be associated with fuel use and are reported under the energy sector.
4.2.3 Uncertainties and time-series consistency
Uncertainties in CO2 emissions are assessed as ±5 per cent (section 4.1.2). Uncertainties in non-CO2 emissions (Table 4.2.1) have been assessed by a contractor from the questionnaires and correspondence with industry sources (CRL Energy, 2006).
Table 4.2.1 Uncertainty in New Zealand’s non-CO2 emissions from the mineral products category
|Mineral product||Uncertainty in activity data (%)||Uncertainty in emission factors (%)|
|Asphalt roofing||±30 (+50 for 1990–2000)||±40|
|Road paving with asphalt||±10||±15 (chip-seal fraction and solvent emission fraction) to ±25 (solvent dilution)|
|Glass||0||NMVOC: ±50 |
4.2.4 Source-specific QA/QC and verification
In 2008, CO2 emissions from cement production were a key category (level and trend assessment). In the preparation of this inventory, the data for these emissions underwent IPCC Tier 1 quality checks. The estimates for lime production were also subject to IPCC Tier 1 quality checks.
4.2.5 Source-specific recalculations
The plant-specific cement-kiln dust correction factor applied by Holcim New Zealand was not able to be verified in time for the 2010 submission. Consequently, the IPCC (2000) default factor of 1.02 has been applied to the whole time series for that company.
One company had provided incorrect data for the 2007 calendar year for the 2009 submission and this has subsequently been corrected for the 2010 submission.
Limestone and dolomite use
Emissions from soda ash are now included in this subcategory because of confidentiality concerns for the glass manufacturer.
4.2.6 Source-specific planned improvements
There are no planned improvements for this source.
4.3 Chemical industry (CRF 2B)
The chemical industry category reports emissions from the production of chemicals. The major chemical processes occurring in New Zealand that fall into this category are the production of ammonia and urea, methanol, hydrogen, superphosphate fertiliser and formaldehyde. There is no production of nitric acid, adipic acid, carbide, carbon black, ethylene, dichloroethylene, styrene, coke or caprolactam in New Zealand.
In 2008, emissions from the chemical industry category comprised 578.3 Gg CO2-e (13.4 per cent) of total emissions from the industrial processes sector. Emissions have increased by 148.0 Gg CO2-e (34.4 per cent) from the 1990 level of 430.2 Gg CO2-e. In 2008, CO2 emissions from ammonia production accounted for 331.6 Gg CO2-e (57.3 per cent) of emissions in the chemical industry category. In 2008, ammonia production was a qualitative key category (Table 1.5.1). Hydrogen production contributed the remaining 246.7 Gg CO2-e (42.7 per cent) of emissions from the chemical industry in 2008.
Emissions from methanol production should be included in this category, however, because of confidentiality concerns, methanol emissions are reported in the energy sector.
4.3.2 Methodological issues
Ammonia is manufactured in New Zealand by the catalytic steam reforming of natural gas. Liquid ammonia and CO2 are reacted together to produce urea. The total amount of natural gas supplied to the plant is provided to the Ministry of Economic Development by Balance Agri-Nutrients Ltd which operates the ammonia production plant.
Only 20 per cent of the carbon is assumed to be sequestered in the urea product and this is eventually released after it is applied to the land. The remaining 80 per cent is assumed to be combusted and these emissions are consequently reported in the energy sector. Emissions of CO2 are calculated by multiplying the quantities of gas (from different gas fields) by their respective emission factors. The proportion of gas from each of these fields used in ammonia production changes on an annual basis. This explains the fluctuation in the CO2 implied emission factor over the 1990–2008 time series.
Non-carbon dioxide emissions are considered by industry experts to arise from fuel combustion rather than from the process of making ammonia and are therefore covered in the energy sector.
Formaldehyde is produced at five plants (owned by two different companies) in New Zealand. Non-methane volatile organic compound emissions are calculated from company-supplied activity data and a New Zealand-specific emission factor of 1.5 kg NMVOC/t of product. Emissions of CO and CH4 are not reported under this subcategory as these emissions relate to fuel combustion and are consequently reported in the energy sector.
Emissions estimated from the production of methanol are reported under the energy sector (see section 3.3.2) because of confidentiality concerns.
The production of sulphuric acid during the manufacture of superphosphate fertiliser produces indirect emissions of SO2. In New Zealand, there are two companies, Balance Agri-Nutrients and Ravensdown, producing superphosphate. Each company owns two production plants. Three plants produce sulphuric acid. One plant imports the sulphuric acid.
Activity data supplied in 2005 has been used for 2006–2008. Plant-specific emission factors used in previous years were applied to the 2008 data. No reference is made to superphosphate production in the IPCC guidelines (IPCC, 1996). For sulphuric acid the IPCC guidelines recommend a default emission factor of 17.5 kg SO2 (range of 1 to 25) per tonne of sulphuric acid. However, New Zealand industry experts have recommended that this is a factor of 2 to 10 times too high for the New Zealand industry. Consequently, emission estimates are based on emission factors supplied by industry. In 2008, the combined implied emission factor is 1.5 kg SO2.
Emissions of CO2 from hydrogen production are supplied directly to the Ministry of Economic Development by the two production companies. The majority of hydrogen produced in New Zealand is made by the New Zealand Refining Company as a feedstock at the Marsden Point refinery. Another company, Degussa Peroxide Ltd, produces a small amount of hydrogen that is converted to hydrogen peroxide. The hydrogen is produced from CH4 and steam. Carbon dioxide is a by-product of the reaction and is vented to the atmosphere. Company-specific emission factors are used to determine the CO2 emissions from the production of hydrogen. In 2008, the implied emission factor was 6.1 tonnes of CO2 per tonne of hydrogen produced.
4.3.3 Uncertainties and time-series consistency
Uncertainties in CO2 emissions are assessed as ±5 per cent (section 4.1.2). Uncertainties in non-CO2 emissions are assessed from the questionnaires and correspondence with industry sources (CRL Energy, 2006). These are documented in Table 4.3.1.
|Chemical industry||Uncertainty in activity data (%)||Uncertainty in emission factors (%)|
|Methanol||±0||±50 (NOx and CO) |
|Fertiliser||±10 sulphuric acid |
|±15 sulphuric acid |
±25 to ±60 superphosphate (varies per plant)
4.3.4 Source-specific QA/QC and verification
New Zealand has specified CO2 from ammonia production as a qualitative key category due to the large increase in nitrogenous fertiliser use observed in the agriculture sector since 1990. The ammonia produced in New Zealand is used in the production of urea fertiliser. In the preparation of this inventory, the data for these emissions underwent IPCC Tier 1 quality checks.
4.3.5 Source-specific recalculations
The accuracy and comparability of the ammonia emissions estimates has improved for the whole time series due to using daily emissions factor data for the three main gas fields in New Zealand to derive a weighted average emission factor.
Methanol and hydrogen
The accuracy of the methanol CH4 and the hydrogen CO2 emission estimates has improved since the 2009 submission. Corrections were made to errors identified by the Ministry of Economic Developing during the improvements made to its database during 2009. All methanol emission estimates are now reported in the energy sector because of confidentiality concerns.
4.3.6 Source-specific planned improvements
There are no planned improvements for this source.
4.4 Metal production (CRF 2C)
The metal production category reports CO2 emissions from the production of iron and steel, ferroalloys, aluminium and magnesium. The major metal production activities occurring in New Zealand are the production of steel (from ironsand and scrap steel) and aluminium. A small amount of SF6 was used in a magnesium foundry until 1998. New Zealand has no production of coke, sinter or ferroalloys. In 2008, perfluorocarbon emissions from the aluminium production subcategory were a key category in the trend analysis.
In 2008, emissions from the metal production category were 2,081.7 Gg CO2-e (48.2 per cent) of emissions from the industrial processes sector. Emissions from this category decreased 310.9 Gg CO2-e (13.0 per cent) from the 1990 level of 2,392.6 Gg CO2-e. Carbon dioxide emissions accounted for 98.2 per cent of emissions in this category with another 1.8 per cent from PFCs. In 2008, the level of CO2 emissions increased by 285.3 Gg CO2-e (16.2 per cent) above the 1990 level. Perfluorocarbon emissions have decreased from the 629.9 Gg CO2-e in 1990 to 36.5 Gg CO2-e in 2008, a decrease of 593.4 Gg CO2-e (94.2 per cent). This decrease is due to improvements made by the aluminium smelter. These improvements are discussed further in the following section.
4.4.2 Methodological issues
Iron and steel
There are two steel producers in New Zealand. New Zealand Steel Ltd produces iron using the “alternative iron-making” process (Ure, 2000) from titanomagnetite ironsand. The iron is then processed into steel. Pacific Steel Ltd operates an electric arc furnace to process scrap metal into steel.
The majority of the CO2 emissions from the iron and steel subcategory are produced through the production of iron from titanomagnetite ironsand. The CO2 emissions arise from the use of coal as a reducing agent and the consumption of other carbon-bearing materials such as electrodes. The carbon content of the ironsand is negligible with iron, in the form of magnetite, the predominant chemical in the sand (Ure, 2000), and has therefore not been counted.
Sub-bituminous coal and limestone in the multi-hearth furnaces are heated and dried together with the ironsand. This iron mixture is then fed into the reduction kilns, where it is converted to 80 per cent metallic iron. Melters then convert this into molten iron. The iron, at a temperature around 1480°C, is transferred to the Vanadium Recovery Unit, where vanadium-rich slag is recovered for export and further processing into a steel strengthening additive. The molten pig iron is then converted to steel in a Klockner Oxygen Blown Maxhutte oxygen steel-making furnace. Further refining occurs at the ladle treatment station, where ferroalloys are added to bring the steel composition up to its required specification. The molten steel from the ladle treatment station is then transferred to the continuous caster, where it is cast into slabs.
The IPCC Tier 2 approach is used for calculating CO2 emissions from the iron and steel plant operated by New Zealand Steel Ltd. Emissions from pig iron and steel production are not estimated separately as all of the pig iron is transformed into steel. A plant-specific emission factor is applied to the sub-bituminous coal used as a reducing agent. The emission factor is calculated based on the specific characteristics of the coal used.
Care has been taken not to double-count coal use for iron and steel making. New Zealand energy statistics for coal are disaggregated into coal used in steel making and coal used in other industries and sectors. The coal used in the iron-making process acts both as a reductant and an energy source. However, all of the coal is first fed into the reduction kilns and, consequently, all CO2 emissions associated with coal use are reported in the industrial processes sector, regardless of the end use (IPCC, 2000).
All emissions from limestone use at New Zealand Steel Ltd are reported in the limestone use subcategory.
Emissions from Pacific Steel’s production of steel arise from the combustion of the carbon charge to the electric arc furnace. Reported emissions exclude the minor carbon component of the additives that are subsequently added to the ladle, as the emissions are generally a contaminant of the vanadium, manganese or silicon additives and are acknowledged as contributing a negligible amount to the final carbon content of the billet steel.
Due to limited process data at Pacific Steel, emissions between 1990 and 1999 are calculated using a default emission factor (IPCC, 1996) based on production volume. Emissions from 2000 onwards are reported using the IPCC Tier 2 method. Pacific Steel provides this data directly to the Ministry of Economic Development.
The non-CO2 emission factors for the indirect greenhouse gases (CO, SO2 and NOx) for both steel plants are based on measurements in conjunction with mass balance (for SO2) and technical reviews (CRL Energy, 2006).
There is one aluminium smelter in New Zealand, Rio Tinto Alcan Ltd (NZAS). The smelter produces aluminium from raw material using the centre worked prebaked technology. In 2008, aluminium emissions were 542.5 Gg CO2-e, a decrease of 536.4 Gg CO2-e (49.7 per cent) from the 1990 level of 1,078.9 Gg CO2-e. In 2008, both CO2 and PFC emissions from aluminium production were key categories for New Zealand (level and trend respectively).
Aluminium production is a source for CO2 and PFC emissions. Carbon dioxide is emitted during the oxidation of the carbon anodes. The PFCs are emitted from the cells during anode effects. An anode effect occurs when the aluminium oxide concentration in the reduction cell electrolyte is low. The emissions from combustion of various fuels used in the aluminium production process, such as heavy fuel oil, liquefied petroleum gas, petrol and diesel, are included in the energy sector. The indirect emissions are reported at the end of this section.
NZAS calculates the process CO2 emissions using the International Aluminium Institute (2006) Tier 3 method. This method breaks the prebake anode process into three stages (baked anode consumption, pitch volatiles consumption and packing coke consumption).
Estimates of CO2 and PFC emissions were supplied by NZAS to the Ministry of the Environment. The PFC emissions from aluminium smelting are calculated using the IPCC/International Aluminium Institute (2006) Tier 2 methodology summarised below:
Perfluorocarbon emissions (t CO2-e) = Hot metal production × slope factor × anode effect duration (min/cell-day) × global warming potential.
The smelter captures every anode effect, both count and duration, through its process-control software. All monitoring data is logged and stored electronically to provide the anode effect minutes per cell day value. This is then multiplied by the tonnes of hot metal, the slope factor and the global warming potential to provide an estimate of tetrafluoromethane (CF4) and hexafluoroethane (C2F6) emissions. The slope values of 0.143 for CF4 and 0.0173 for C2F6 are applied because they are specific to the centre worked prebaked technology and are sourced from the International Aluminium Institute (2006).
Anode effect durations were not recorded in 1990, 1991 and 1992. Consequently, the Tier 1 method (IPCC 2000) has been applied, with the following defaults: 0.31 kg CF4/t of aluminium and 0.04 kg C2F6/t of aluminium. The estimates for 1991 are based on the reduction cell operating conditions being similar to those in 1990.
To derive the value for 1992, the Tier 2 (International Aluminium Institute, 2006) method has been applied using the mid-point value for the extrapolated anode effect duration from the 1991 Tier 1 default PFC emission rate and the 1993 anode effect duration. The reported estimate for 1992 is considered to better reflect to PFC emissions than the IPCC default value.
The smelter advises that there are no plans to directly measure PFC emissions. A smelter-specific long-term relationship between measured emissions and operating parameters is not likely to be established in the near future.
NZAS adds soda ash to the reduction cells to maintain the electrolyte chemical composition. This results in CO2 emissions as a by-product. NZAS has assumed that all of the carbon content of the soda ash is released as carbon dioxide. The emissions are estimated using the Tier 3 International Aluminium Institute (2006) method.
As Figure 4.4.1 indicates, the implied emission factors for emissions from aluminium production have fluctuated over the time series. These fluctuations are identified and explained in Table 4.4.1.
Figure 4.4.1 New Zealand’s implied emission factors for aluminium production from 1990 to 2008
CO2 implied emission factor
|2009 Submission||2010 Submission|
CF4 implied emission factor
|2009 Submission||2010 Submission|
C2F6 implied emission factor
|2009 Submission||2010 Submission|
|Variation in emissions||Reason for variation|
|Increase in CO2 and PFC emissions in 1996.||Commissioning of the Line 4 cells.|
|Decrease in CO2 emissions in 1995.||Good anode performance compared with 1994 and 1996.|
|Decrease in CO2 emissions in 1998.||Good anode performance.|
|Decrease in CO2 emissions in 2001, 2003 and 2006.||Less cells operating from reduced aluminium production due to reduced electricity supply.|
|Good anode performance contributed in 2001.|
|Increase in CO2 emissions in 1995.||All cells operating, including introduction of additional cells.|
|Increasing aluminium production rate from the cells.|
|Decrease in PFC emissions in 1995.||Reduced anode frequencies.|
|The implementation of the change control strategy to all reduction cells.|
|Repairs made to cells exerting higher frequencies.|
|PFC emissions remained high in 1997.||Instability over the whole plant as the operating parameters were tuned for the material coming from the newly commissioned dry scrubbing equipment (removes the fluoride and particulate from the main stack discharge).|
|Decrease in PFC emissions in 1998.||Cell operating parameter control from the introduction of modified software. This software has improved the detection of an anode effect onset and will initiate actions to prevent the anode effect from occurring.|
|PFCs remain relatively static in 2001, 2003 and 2006.||Increased emissions from restarting the cells.|
Aluminium production also produces indirect emissions. The most significant are CO emissions from the anode preparation. There is also a small amount of CO emitted during the electrolysis reaction in the cells. For estimates of indirect greenhouse gases, plant-specific emission factors were used for CO and SO2. Sulphur dioxide emissions are calculated from the input sulphur levels and direct monitoring. An industry supplied value of 110 kg CO/t (IPCC range 135–400 kg CO/t) was based on measurements and comparison with Australian CO emission factors. The IPCC default emission factor was used for NOx emissions.
Other metal production
Small amounts of SF6 were used as a cover gas in a magnesium foundry to prevent oxidation of molten magnesium from 1990–1999. The company has since changed to zinc technology so SF6 is no longer used and emitted.
The only other metals produced in New Zealand are gold and silver. Companies operating in New Zealand confirm they do not emit indirect gases (NOx, CO and SO2) with one using the Cyanisorb recovery process to ensure everything is kept under negative pressure to ensure no gas escapes to the atmosphere. Gold and silver production processes are listed in IPCC (1996) as sources of non-CO2 emissions. However, no details or emission factors are provided and no published information on emission factors has been identified. Consequently, no estimation of emissions from this source has been included.
4.4.3 Uncertainties and time-series consistency
Uncertainty in CO2 emissions is assessed as ±5 per cent as discussed in section 4.1.2. Uncertainties in non-CO2 emissions are assessed by the contractor from the questionnaires and correspondence with industry sources (CRL Energy, 2006). These are documented in Table 4.4.2.
|Metal product||Uncertainty in activity data (%)||Uncertainty in emission factors (%)|
|Iron and steel||0||±20–30 (CO) |
|Aluminium||0||±5 (SO2) |
1 There is no independent means of assessing the calculations of PFC emissions from the smelter. Given the broad range of possible emission factors indicated in the IPCC (2000) Table 3.10, and in the absence of measurement data and precision measures, the total uncertainty is assessed to be ±30 per cent (CRL Energy, 2006).
4.4.4 Source-specific QA/QC and verification
Carbon dioxide emissions from the iron and steel production and PFC emissions from aluminium production (trend assessment) were key categories in 2008. In the preparation of this inventory, the data for these subcategories underwent IPCC Tier 1 quality checks. Given the recalculations for CO2 emissions from aluminium production, this subcategory was also subject to IPCC quality checks.
4.4.5 Source-specific recalculations
The accuracy, completeness and consistency of the emission estimates for steel production have improved for 2000–2007. After significant research and discussion, an agreement was reached in 2009 between the inventory team and Pacific Steel over the scope and boundary of the emission source. Industrial processes CO2 emissions from Pacific Steel are now only estimated from the oxidation of the electric arc furnace process. The minor carbon components of the additives that are subsequently added to the ladle are excluded. This exclusion is because the associated emissions are generally a contaminant of the vanadium, manganese or silicon additives and are acknowledged as contributing to the final carbon content of the billet steel.
All other CO2 emissions from the steel-making process at Pacific Steel are estimated in the energy sector. This includes emissions from electricity, natural gas, diesel and liquefied petroleum gas.
Aluminium – CO2
The accuracy, completeness and consistency of the entire time series have improved largely because of the following reasons:
- actual plant data has been provided for 1991 and 1992, replacing previously interpolated estimates
- estimates of soda ash have been included for the first time
- 1990–2001 now calculates CO2 emitted from pitch volatile and packing coke combustion in the Carbon Baking Furnaces separately. This is consistent with the International Aluminium Institute (2006) method. Previously, a factor was applied to the net carbon consumption (tonnes baked anode carbon per tonnes aluminium) to account for the other anode consumption derived sources of CO2
- 1996–1998 now estimates CO2 from pitch volatile combustion. During these years, a new furnace was commissioned and another decommissioned, providing for greater uncertainty for the required inputs to the calculation using the International Aluminium Institute (2006) method
- 2002–2007 includes improved input data following a review by NZAS of the inputs involved in the calculation. This includes packing coke consumption and the sulphur content of the baked anodes.
Aluminium – PFCs
The accuracy and consistency of the entire time series have improved because of the following reasons:
- the estimates for 1991 and 1992 were previously interpolated. This did not account for the reduction in production due to power shortage. The estimate for 1991 is now estimated using the Tier 1 IPCC (2000) method with default emission factors. The estimate assumes reduction cell operating conditions are similar to those in 1990
- the estimate for 1992 is now derived using the Tier 2 (International Aluminium Institute, 2006) method with the mid-point value for the extrapolated anode effect duration from the 1991 Tier 1 default emission rate and the 1993 plant specific anode effect duration
- the influence of the extended voltage operation during new cell start up has been eliminated to provide consistency with the International Aluminium Institute (2006) method
- other improvements are due to correcting database errors at NZAS.
4.4.6 Source-specific planned improvements
There are no planned improvements for this source.
4.5 Other production (CRF 2D)
The other production category includes emissions from the production of pulp and paper, and food and drink. In 2008, emissions from this category totalled 7.5 Gg NMVOC. This was an increase of 1.5 Gg NMVOC from the 1990 level of 5.9 Gg CO2-e.
4.5.2 Methodological issues
Pulp and paper
There are a variety of pulping processes in New Zealand. These include:
- chemical (Kraft)
- chemical thermomechanical
Pulp production in New Zealand is evenly split between mechanical pulp production and chemical production. Estimates of emissions from the chemical pulping process are calculated from production figures obtained from the Ministry of Agriculture and Forestry. Emission estimates from all chemical pulping processes have been calculated from the industry-supplied emission factors for the Kraft process. In the absence of better information, the NMVOC emission factor applied to the chemical pulping processes is also applied to the thermomechanical pulp processes (CRL Energy, 2006). Emissions of CO and NOx from these processes are related to fuel combustion and not reported under industrial processes.
Food and drink
Emissions of NMVOCs are produced during the fermentation of cereals and fruits in the manufacture of alcoholic beverages. These emissions are also produced during all processes in the food chain that follow after the slaughtering of animals or harvesting of crops. Estimates of indirect greenhouse gas emissions for the period 1990–2005 have been calculated using New Zealand production figures from Statistics New Zealand and relevant industry groups with default IPCC emission factors (IPCC, 1996). No New Zealand-specific emission factors could be identified. Subsequent NMVOC estimates from food and drink have been estimated using linear extrapolation as no industry survey was conducted. In 2008, NMVOC emissions were estimated to be 6.7 Gg, an increase of 1.5 Gg from the 1990 level of 5.2 Gg.
4.5.3 Uncertainties and time-series consistency
Uncertainties in non-CO2 emissions are assessed by the contractor from the questionnaires and correspondence with industry sources (CRL Energy, 2006). These are documented in Table 4.5.1.
|Product||Uncertainty in activity data (%)||Uncertainty in emission factors (%)|
|Pulp and paper||5||±50 (chemical pulp) |
±70 (thermal pulp)
|Food – alcoholic beverages||±5 (beer) |
|±80 (beer and wine) |
|Food – food production||±5–20 (varies with food type)||±80 (IPCC factors)|
4.5.4 Source-specific QA/QC and verification
Other production was not a key category and no specific quality-assurance or quality-control activities were performed. Where possible, activity data is cross referenced between companies and industry associations to verify the data.
4.5.5 Source-specific recalculations
There were no recalculations for this source.
4.5.6 Source-specific planned improvements
There are no planned improvements for this source.
4.6 Production of halocarbons and SF6 (CRF 2E)
New Zealand does not manufacture halocarbons and SF6. Emissions from consumption are reported under section 4.7
4.7 Consumption of halocarbons and SF6 (CRF 2F)
In 2008, emissions from the consumption of hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs) totalled 814.9 Gg CO2-e (19.0 per cent) of emissions from the industrial processes sector. There was no consumption of HFCs or PFCs in 1990. The first consumption of HFCs in New Zealand was reported in 1992 and the first consumption of PFCs in 1995. In 2008, emissions from the consumption of HFCs and PFCs from refrigeration and air conditioning were identified as a key category (level and trend assessment).
Hydrofluorocarbons and PFCs are used in a wide range of equipment and products from refrigeration systems to aerosols. No HFCs or PFCs are manufactured within New Zealand. Perfluorocarbons are produced from the aluminium-smelting process (as discussed in section 4.4.2).
The use of synthetic gases, especially HFCs, has increased since the mid-1990s when chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) began to be phased out under the Montreal Protocol. In New Zealand, the Ozone Layer Protection Act 1996 sets out a programme for phasing out the use of ozone-depleting substances by 2015. According to the 1996 IPCC guidelines, emissions of HFCs and PFCs are separated into seven subcategories:
- mobile air conditioning
- stationary refrigeration and air conditioning
- fire protection
In 2008, sulphur hexafluoride (SF6) emissions were 14.5 Gg CO2-e, this is an increase of 2.2 Gg CO2-e (17.9 per cent) from the 1990 level of 12.3 Gg CO2-e. The majority of SF6 emissions are from the use in electrical equipment.
The emissions inventory for SF6 is broken down into two subcategories: electrical equipment and “other”. In New Zealand, one electricity company accounts for 75–80 per cent of total SF6 used in electrical equipment.
4.7.2 Methodological issues
Activity data on the bulk imports and end use of HFCs and PFCs in New Zealand was collected through an annual survey of HFC and PFC importers and distributors. This data has been used to estimate the proportion of bulk chemicals used in each sub-source category. The total quantity of bulk chemical HFCs imported each year was compared with import data supplied by Statistics New Zealand. Imports of HFCs in products and bulk imports of PFCs and SF6 are more difficult to determine as import tariff codes are not specific enough to identify these chemicals.
New Zealand uses the IPCC Tier 2 approach to calculate emissions from the consumption of HFCs and PFCs (IPCC, 2000). The Tier 2 approach accounts for the time lag between consumption and emissions of the chemicals. A summary of the methodologies and emission factors used in emission estimates are included in Table 4.7.1.
Potential emissions for HFCs and PFCs are included for completeness as required by the Climate Change Convention reporting guidelines (UNFCCC, 2006). Potential emissions for HFCs and PFCs have been calculated using the IPCC Tier 1b approach. Incomplete data is available on imports into New Zealand of HFC and PFC gases contained in equipment. Models have been developed to provide a complete data set (CRL Energy, 2009).
|HFC source||Calculation method||Emission factor|
|Aerosols (including metered does inhalers)||IPCC (2006a) equation 7.6||IPCC default factor of 50 per cent of the initial charge per year|
|Foam||IPCC (2006a)||IPCC default factor of 10 per cent initial charge in first year and 4.5 per cent annual loss of initial charge over an assumed 20-year lifetime|
|Mobile air conditioning||IPCC (2000a) equation 3.44||Top-down approach |
First fill: 0.5 per cent
|Stationary refrigeration/ air conditioning||IPCC (2006a) equation 7.9||N/A|
|Fire protection||IPCC (2006a)||Top-down approach using emission rate of 1.5 per cent|
|SF6 source||Calculation method||Emission factor|
|Electrical equipment||IPCC (2000) equation 3.17||Tier 3 approach based on overall consumption and disposal. Company-specific emission factors measured annually and averaging 1 per cent for the main utility (representing 75 per cent of total holdings) and an equipment manufacturer. |
This was supplemented by data from other utilities and users using the IPCC default emission factor of 2 per cent (Tier 2b approach)
|Other applications||IPCC (2000) equation 3.22||No emission factor required as 100 per cent is emitted within two years|
Aerosols and metered dose inhalers
New Zealand reports HFC-134a emissions from metered dose inhalers and other aerosols separately. Emissions from aerosols contributed 32.0 Gg CO2-e in 2008, an increase of 30.4 Gg CO2-e from the 1996 level of 1.6 Gg CO2-e. Aerosols were not widely used in New Zealand until 1994, and therefore emissions from aerosols are estimated from 1996 – the initial charge is expected to be emitted within the first two years of sale. In 2008, emissions from metered dose inhalers contributed 51.3 Gg CO2-e, an increase of 50.8 Gg CO2-e from the 1995 level of 0.5 Gg CO2-e. The consumption of HFCs in metered dose inhalers is not known to have occurred in New Zealand before 1995.
Activity data on aerosol usage was provided by Arandee Ltd, the only New Zealand aerosol manufacturer using HFCs, and the Aerosol Association of Australia/New Zealand. Arandee Ltd also provided activity data on annual HFC use, domestic and export sales, and product loading emission rates.
Data on the total number of doses contained in metered dose inhalers used from 1999 to 2008 is provided by Pharmac, New Zealand’s government pharmaceutical purchasing agency. The weighted average quantity of propellant per dose is calculated from information supplied by industry. Activity data from 1995 to 1998 is based upon expert opinion (CRL Energy, 2009).
Due to insufficient information at a sub-application level, a Tier 1a method (IPCC, 2006a), is used to calculate HFC-134a emissions from aerosol use in New Zealand. This is a mass-balance approach, based on import and sales data. The approach accounts for the lag from time of sale to time of use. The only sub-application that does have sufficient data is metered dose inhalers. Consequently, a Tier 2a method has been applied. The default emission factor of 50 per cent of the initial charge per year (IPCC, 2006a) is applied to the sales of aerosol and metered dose inhalers.
The significant increase in emissions over the time series from both aerosols and metered dose inhalers can be attributed to HFC-134a being used as a substitute propellant for HCFCs and CFCs, as discussed in section 4.7.1.
A survey of distributors of solvent products and solvent recycling firms did not identify any use of HFCs or PFCs as solvents in New Zealand (CRL Energy, 2009).
In New Zealand, only emissions from closed-cell foam (hard foam) are known to have occurred between 2000 and 2008. In 2008, emissions from the use of HFC-134a in hard foam blowing were 0.10 Gg CO2-e. This is an increase of 0.1 Gg CO2-e (80.0 per cent) from the 2000 level of 0.07 Gg CO2-e.
The HFC-245fa/365mfc mixture is only known to have been used in New Zealand in foam blowing from 2004 to 2008. These emissions are estimated to have increased from 0.1 tonne in 2004 to 0.6 tonne in 2008. However, a global warming potential for this mixture has not been agreed by the IPCC and the Climate Change Convention. This mixture is reported in the common reporting format tables “Information on additional greenhouse gases”, as recommended by the in-country review team (UNFCCC, 2007).
For 2008, activity data was provided by the sole supplier of HFCs for foam blowing (CRL Energy, 2009). Fisher and Paykel provided information on foam containing HFCs imported. It is unlikely that any HFC is used for insulation foam in exported equipment. However, there is insufficient information to be certain of this.
The IPCC (2006a) Tier 2 method is used to calculate emissions from foam blowing. The recommended default emission factor of 10 per cent of the initial charge in the first year and 4.5 per cent annual loss of the initial charge over an assumed 20-year lifetime is applied.
Stationary refrigeration/air conditioning
Emissions from the use of HFCs and PFCs in stationary refrigeration and air conditioning were 574.3 Gg CO2‑e in 2008. This is an increase from the 1992 level of 1.3 Gg CO2-e. In 2008, stationary refrigeration and air conditioning made up 69.2 per cent of the emissions from the halocarbon and SF6 consumption category. The category has been identified as a key category (level and trend). In 1992, only HFC-134a was used, while in 2008 HFCs -32, -23, -152a, -134a, -125, -143a and PFC-218 (C3F8) were consumed. There was no use of HFCs and PFCs before 1992.
The increase in emissions from 1992 to 2008 is due to HFCs and PFCs used as replacement refrigerants for CFCs and HCFCs in refrigeration and air-conditioning equipment (section 4.7.1).
New Zealand uses a top-down Tier 2b approach (Box 4.2) and New Zealand-specific data to obtain actual emissions from stationary refrigeration and air conditioning.
Box 4.2 Equation 7.9 (IPCC, 2006a)
Emissions = (annual sales of new refrigerant) – (total charge of new equipment) + (original total charge of retiring equipment) – (amount of intentional destruction)
To estimate HFCs and PFCs emissions, all refrigeration equipment is split into two groups: factory-charged equipment and all other equipment that is charged with refrigerant on site. This is because some information is available on the quantities of factory-charged imported refrigeration and air-conditioning equipment and on the amount of bulk HFC refrigerant used in that equipment.
The amount of new refrigerant used to charge all other equipment (charged on site after assembly) is assumed to be the amount of HFC refrigerant sold each year minus that used to manufacture factory-charged equipment and that used to top up all non-factory-charged equipment.
Factory-charged equipment consists of all equipment charged in factories (both in New Zealand and overseas), including all household refrigerators and freezers and all factory-charged, self-contained refrigerated equipment used in the retail food and beverage industry. All household air conditioners and most medium-sized, commercial air conditioners are also factory charged, although some extra refrigerant may be added by the installer for piping.
It is estimated there are about 2.2 refrigerators and freezers per household in New Zealand. This calculation included schools, factories, offices and hotels (Roke, 2006). Imported appliances account for around half of new sales each year, with the remainder manufactured locally. New Zealand also exports a significant number of factory-charged refrigerators and freezers.
Commercial refrigeration includes central rack systems used in supermarkets, self-contained refrigeration equipment chillers used for commercial building air conditioning and process cooling applications, rooftop air conditioners, transport refrigeration systems, and cool stores. In many instances, these types of systems are assembled and charged on site, although most imported units may already be pre-charged. Self-contained commercial equipment is pre-charged and includes some frozen food display cases, reach-in refrigerators and freezers, beverage merchandisers and vending machines.
The report on HFC and PFC emissions in New Zealand (CRL Energy, 2009) provides detailed information on the assumptions that have been used to build models of refrigerant consumption and banks for the domestic and commercial refrigeration categories, dairy farms, industrial and commercial cool stores, transport refrigeration and stationary air conditioning.
Mobile air conditioning
In 2008, HFC-134a emissions from mobile air conditioning were 155.9 Gg CO2-e, an increase over the 1994 level of 4.6 Gg CO2-e. Emissions from mobile air conditioning made up 18.9 per cent of total emissions from the halocarbon and SF6 consumption category in 2008. There was no use of HFCs as refrigerants for mobile air conditioning in New Zealand before 1994. This increase can largely be attributed to pre-installed, air-conditioning units in a large number of second-hand vehicles imported from Japan, as well as reflecting the global trend of increasing use of air conditioning in new vehicles.
The automotive industry has used HFC-134a as the refrigerant for mobile air conditioning in new vehicles since 1994. HFC-134a is imported into New Zealand for use in the mobile air-conditioning industry through bulk chemical importers/distributors and within the air-conditioning systems of imported vehicles. Industry sources report that air-conditioning systems were retrofitted (with ‘aftermarket’ units) to new trucks and buses and to second-hand cars. Refrigerated transport is included in the stationary refrigeration/air-conditioning subcategory.
New Zealand has used a Tier 2b method, mass-balance approach (Box 4.3). This approach does not require emission factors (except for the minor first-fill component) as it is based on chemical sales and not equipment leak rates.
Box 4.3 Equation 3.44 (IPCC, 2000)
Emissions = First-fill emissions + operation emissions + disposal emissions – intentional destruction
First-fill emissions are calculated from vehicle fleet numbers provided by the New Zealand Transport Registry Centre. Assumptions are made on the percentage of mobile air-conditioning installations. Operation and disposal data are obtained from a survey of the industry and data from Land Transport New Zealand.
Detailed information on the assumptions that have been used in the calculation of emissions from mobile air conditioning can be found in the report on HFC emissions in New Zealand (CRL Energy, 2009).
In 2008, HFC-227ea emissions from fire protection were 1.4 Gg CO2-e, an increase over the 1994 level of 0.1 Gg CO2-e. There was no use of HFCs in fire protection systems before 1994 in New Zealand. The increase was due to HFCs used as substitutes to halons in portable and fixed fire protection equipment.
Within the New Zealand fire protection industry, the two main supply companies are identified as using relatively small amounts of HFC-227ea. The systems installed have very low leak rates, with most emissions occurring during routine servicing and accidental discharges.
A simplified version of the Tier 2b method, mass-balance approach (IPCC, 2006a) has been used to estimate emissions. A New Zealand-specific annual emission rate of 1.5 per cent has been applied to the total amount of HFC installed. This rate is based on industry experience. Due to limited data, it has been assumed that HFC from any retirements was totally recovered for use in other systems.
In 2008, SF6 emissions from electrical equipment were 11.7 Gg CO2-e, an increase over the 1990 level of 9.5 Gg CO2-e.
The high dielectric strength of SF6 makes it an effective insulant in electrical equipment. It is also very effective as an arc-extinguishing agent, preventing dangerous over-voltages once a current has been interrupted.
Actual emissions are calculated using the IPCC (2000) Tier 3a approach for the utility responsible for 75 per cent of the total SF6 held in electrical switchgear equipment. This data is supplemented by data from other utilities. The additional data enables a Tier 2b approach to be taken for the rest of the industry (CRL Energy, 2009).
Activity and emissions data is provided by the two importers of SF6 and New Zealand’s main users of SF6, the electricity transmission, generation and distribution companies (CRL Energy, 2009).
The IPCC (2000) Tier 1 method (equation 3.18) is used to calculate potential emissions of SF6 (including estimates for SF6 other applications). This is based on total annual imports of SF6 into New Zealand. Potential SF6 emissions are usually two-to-three times greater than actual emissions in a given year. However, in 2005, potential emissions were less than actual emissions because there was less SF6 imported compared with previous years. Import data from 2006 to 2008 shows potential SF6 emissions are again greater than actual emissions.
Other SF6 applications
Emissions from other SF6 applications in 1990 and 2008 were 2.9 Gg CO2-e. In New Zealand, other applications include medical uses for eye surgery, tracer gas studies, magnesium casting, plumbing services, tyre manufacture and industrial machinery equipment. A Tier 2 method (IPCC, 2000) is applied and no emission factor is used as 100 per cent is assumed to be emitted over a short period of time.
Activity data for 2008 was provided by one main supplier for eye surgery, scientific use, plumbing, tyre manufacture and industry. Scientific use was also discussed with the National Institute of Water and Atmospheric Research and GNS Science.
4.7.3 Uncertainties and time-series consistency
The uncertainty in estimates of actual emissions from the use of HFCs and PFCs varied with each application and is described in Table 4.7.2. For many sources, there is no statistical measure of uncertainty but a quantitative assessment is provided from expert opinion.
|HFC source||Uncertainty estimates (%)|
|Aerosols||Combined uncertainty ±49|
|Metered dose inhalers||Combined uncertainty ±10|
|Foam||Combined uncertainty ±64|
|Stationary refrigeration/air conditioning||Combined uncertainty ±34|
|Mobile air conditioning||Combined uncertainty ±31|
|Fire protection||Combined uncertainty ±32|
|Electrical equipment||Combined uncertainty ±26|
4.7.4 Source-specific QA/QC and verification
In the preparation of this inventory, the data for the consumption of halocarbons and SF6 underwent Tier 1 quality checks. During data collection and calculation, activity data provided by industry was verified against national totals where possible and unreturned questionnaires and anomalous data were followed up and verified to ensure an accurate record of activity data.
4.7.5 Source-specific recalculations
The accuracy of emission estimates from halocarbon consumption has improved largely due to revised supply assumptions for the stationary refrigeration and air conditioning and mobile air-conditioning categories.
The most significant improvement is the revised assumption shift to reduced supply of HFC-134a for the mobile air-conditioning category compared with the stationary refrigeration and air-conditioning category. This is due to a significant reduction in supply of HFC-134a in 2008, showing that previous assumptions were significantly overestimated. Even with an assumption shift that mobile air conditioning HFC-134a supply (for leakage) was 5 per cent of the vehicle refrigerant bank in 2008 (instead of the previous 6.5 per cent). The 2008 estimates were so atypical compared with previous years that a further temporary reduction to 3.3 per cent was assumed for that year. This was necessary to avoid negative emissions from the stationary refrigeration and air-conditioning category.
Estimates now include improved household and commercial export and import data from Statistics New Zealand for equipment containing HFCs in the stationary refrigeration and air-conditioning category.
Improved assumptions for the cool store sector have resulted in a 50 per cent reduction in the estimates of the HFC refrigerant bank and annual additions. A detailed estimate of Canterbury stocks, together with reassessments of the previous surveys of Bay of Plenty, Hawke’s Bay and Nelson led to the conclusion that Canterbury would be more typical (than those other three regions previously used) for pro rata estimates of all other regions. To build up a bank of 120 tonne (80 per cent R404A/20 per cent R134A), annual additions have been assumed of 5 tonne in 1999, 10 tonne in 2000 to 2003 and 15 tonne for 2004 onwards. This represented a 20 tonne annual decrease in HFC chemicals used to charge new equipment in recent years so calculated operation emissions have increased accordingly.
New information for the sales data for air-conditioning equipment has improved the understanding of sales and import data. Consequently, the model has been expanded to reflect the format for the household and commercial refrigeration sectors (with separate imports, exports and New Zealand manufacture estimates). Examples of the effects of the changed assumptions for imports, exports and New Zealand manufacture are that the estimates of HFCs imported in air-conditioning equipment in 2006 and 2007 have increased 4 per cent to 96 tonne and 16 per cent to 122 tonne respectively (compared with previous estimates).
Other changes to the commercial refrigeration sector were relatively minor. It was learned from equipment suppliers that the small number of refrigerated rail units had been included in refrigerated truck figures and that refrigerated shipping is likely to have been even smaller than the small quantities assumed previously. Consequently, new installations were assumed to have totalled 0.3 tonne R404A from 1997 to 2002 and 0.5 tonne from 2003 (rather than 0.5 tonne and 1.0 tonne respectively). Minor calculation errors were discovered and corrected for the proportion of R134A versus R404A versus R22 for the dairy farm sector from 1998 to 2003. To illustrate the size of the errors, the HFC-125 emission estimates were reduced by 0.4 tonne, 0.4 tonne, 0.3 tonne, 0.4 tonne, 0.3 tonne and 0.1 tonne respectively for 1998 to 2003.
The previous assumption that, on average, one-third of the refrigerant in retired commercial refrigeration equipment would be collected for recycling has been revised, as any reused or recycled refrigerant would simply replace bulk chemicals used for new equipment or for replacing leakage. Consistent with the mass-balance methodology, the total charge is now assumed to be lost on retirement as it is in other sectors and the only correction made to that assumption is captured in the refrigerant amounts collected for destruction. The result of this change is that the HFC amount retired from stationary refrigeration and air-conditioning equipment in 2007 was 4.7 tonnes rather than the previous estimate of 3.7 tonnes (a 0.6 tonne increase for 2006, 0.2 tonne for 2005 and negligible in earlier years).
Due to a review of the consistency of the approach for reporting exported bulk chemicals, it is now assumed that all HFC destruction occurs in Australia and is consequently reported under exported gases.
As explained for the stationary refrigeration and air-conditioning category above, the most significant improvement made to the mobile air-conditioning category is revised assumptions for the supply split of HFC-134a for the mobile air-conditioning and stationary refrigeration and air-conditioning sectors. Previous assumptions of mobile air-conditioning supply were overestimated. Even with an assumption shift that mobile air-conditioning HFC supply (for leakage) is now 5 per cent of the vehicle refrigerant bank (instead of the previous 6.5 per cent) the 2008 estimates are so atypical that a temporary reduction to 3.3 per cent has been assumed for that year. This translates to 60 tonnes of supply for 2008 instead of 90 tonnes for the 5 per cent assumption or 119 tonnes under the assumptions used for the last two studies.
Improved statistics from the New Zealand Transport Agency on the age distribution of deregistered vehicles and the consequent emissions assumed from scrapping those vehicles containing HFC mobile air-conditioning systems has improved the accuracy of the estimates from the mobile air-conditioning category. Due to the anomalies in the age distribution, the scrap rate was increased 14 per cent in 2005, 9 per cent in 2006 and only 1 per cent in 2007. Also minor errors (<1 per cent increases) in the calculation of mobile air-conditioning emissions for 2006 and 2007 were corrected.
Previous estimates of foam blowing emissions have been made more comprehensive by considering the three components separately. HFC-134a was reported to be used for foam blowing (0.5 tonne per year) from 2000–2003, so the total HFC-134a emissions (assuming 4.5 per cent annual loss) were about 0.1 tonne per year (and will be assumed to continue for about 15 years). Then HFC-245fa/365mfc was reported to be used from 2004 to 2008. Consequently, HFC-245fa and HFC-365mfc manufacturing emissions (assuming 4.5 per cent annual loss) have each steadily increased from about 0.05 tonne in 2004 to 0.36 tonne in 2008. An assessment of additional foam emissions from United States of America and Mexico refrigerator imports of 0.03 tonne of HFC-245fa emissions in 2004, rising to 0.10 tonne emissions in 2008 have been included for the first time.
Pharmac has amended its figures for total inhaler doses and for HFC doses for 1999–2007 compared with the estimates. The consequent relative increases in HFC-134a emissions compared with the 2008 survey ranged from 1 per cent to 4 per cent.
The accuracy of the entire time series of SF6 emission estimates has improved because of the following reasons.
- A minor level of equipment manufacturing emissions was separated from operation emissions for 2001 to 2008. There was no information available to estimate any manufacturing emissions before 2001.
- Responses from major electrical users showed that their previous holdings were overestimated so there has been a slight reduction (<0.2 per cent) in assessed emissions for the last few years in line with those revisions.
- Potential SF6 emissions have increased for 2002 because of new information that SF6 was handled within New Zealand, rather than sent overseas for destruction.
There has been a review of the notation keys for consumption of halocarbons and SF6. The notation key NO (‘not occurring’) has been applied in the common report format tables to HFC-23 and HFC-152a where exports of the minor gases for destruction are greater than negligible imports.
4.7.6 Source-specific planned improvements
For the 2011 submission, some estimates will be provided where no data has been available for manufacturing emissions (where the notation NE (‘not estimated’) has been applied). The estimates for refrigeration and air conditioning will be reported under domestic, commercial, transport and industrial processes in future inventory submissions.
4.8 Other production (CRF 2G)
Particleboard and medium-density fibreboard activity data is obtained from the Ministry of Agriculture and Forestry. The NMVOC emission factors for particleboard and medium-density fibreboard are derived from two major manufacturers (CRL, 2006). An assumption was made that the industry-supplied NMVOC emission factors are applicable to all particleboard and fibreboard production in New Zealand. There is no information in the IPCC guidelines (1996) for this category.
Estimates of NMVOC emissions from panel products in 2008 were 1.2 Gg. This is an increase of 0.3 Gg over the 1990 level of 0.9 Gg.