Naphtha storage fraction & GHG emissions in the Korean - - PowerPoint PPT Presentation
Naphtha storage fraction & GHG emissions in the Korean petrochemical sector th IAEE European Conference 2017 15 th September 2017, Hofburg Congress Center, Vienna, Austria 6 Hi-chun Park Department of Economics, Inha University, Korea
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th IAEE European Conference 2017
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th September 2017, Hofburg Congress Center, Vienna, Austria
Hi-chun Park Department of Economics, Inha University, Korea Martin K Patel Institute of Environmental Sciences and Forel Institute University of Geneva, Switzerland
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Demonstrates for a Korean case study how to estimate the naphtha storage fraction and CO2 emissions from naphtha use in the petrochemical industry
Carbon contained in non-energy is partly converted into CO2 emissions during use and is partly stored in products unless these are incinerated
Important to know carbon storage factors as to estimate carbon emissions related to non-energy use
IPCC default storage fraction for naphtha is 75%(Vol. 3: Energy, p. 1.28, IPCC 1996 Guidelines for National GHG emissions)
Korea has been a large consumer of naphtha as feedstock for petrochemicals. The petrochemical industry processed naphtha in the amount of 39 Mt (million tonnes) to produce various chemicals in 2015 (IEA, 2016).
Park (2005) estimated the naphtha storage fraction for the year 2000 in Korea at 87% by using a NEAT model
A study commissioned by the Korean government (Ecosian, 2015) came to a naphtha storage fraction of 77%
This study is designed to estimate the Korean naphtha storage fraction for the 2011 to 2015 period as to revise the fraction to be used for the estimation of the annual GHG inventories by the Korean government
IPCC allows countries to revise their fractions: “Whenever possible, countries should substitute assumptions that represent more accurately the practices within their countries and provide documentation for these assumptions.” (IPCC guidelines: Vol. 3, Energy, p. 1.27,)
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Non-energy use:
100% stored: bitumen, carbon black, synthetic resins & fibers etc
0% stored (wholly converted into CO2): petroleum coke, pitch, ethanol etc
Partly stored: benzene, ethylene, toluene etc
Carbon storage & release related to non-energy use
Carbon storage: Estorage = ∑i { QNEUi * EFi * Pi } (1) Carbon release: Erelease = ∑i { QNEUi * EFi * (1 - Pi )} (2) where QNEUi means non-energy use (in Joule); Efi is carbon emission factor (in t CO2/GJ); Pi is carbon storage fraction
Non-energy use, carbon emission factors and storage fractions have to be known as to estimate carbon emissions related to non-energy use
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[Table 1] Carbon emission factors % storage fractions by energy source
Emission factor Emission factor (Korea) Storage fraction Storage fraction 1996 IPCC 2012∼2013 IPCC Korea [t C/TJ] [t C/TJ] [%] [%] Naphtha 20.0 19.2 0.75 1) 0.75 Lubricants 20.0 19.9 0.50 0.50 Bitumen 22.0 21.6 1.00 1.00 Tar 25.6
0.75 Natural gas 15.3 15.3 0.33 0.33 Diesel 19.9 20.2 0.50 0.50 Butane 17.2 18.1 0.80 0.80 Propane 17.2 17.6 0.80 0.80 Coal / Peat 26.4 26.2 0.75 0.75 Cokes (Petcok) 27.5 27.2 0.75 0.75 Solvent / Light producrs 19.9 20.0 0.80
19.6 19.6 0.80
19.6
Notes: 1) Vol. 2, Energy, p. 1.37: 80%; Vol. 3, Energy, p. 1.28: 75%.
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Marland and Rotty(1984), Marland and Marland(2003) estimated 80% as naphtha storage fraction for the 1950∼1982 period. CO2 emissions comprise of combustion, waste incineration and autonomous product oxidation and the naphtha storage fraction is the rate of carbon stored to the global naphtha consumption
Although the IPCC naphtha default storage fraction originates from the study of Marland and Rotty study, IPCC excludes waste incineration and autonomous product
storage fractions based on energy statistics which do not contain information on petrochemical trade, they are unable to estimate consumption based CO2 emissions.
Following OECD countries used their own naphtha storage fractions in preparing their National Inventory Report (NIR) submitted to UNFCCC (2014) 100% : Belgium, Finland, France 80% : Spain, Turkey 78% : Netherlands 75% : Germany, Japan, GB 70% : USA 64% : Italy
UNFCCC seems to accept NIR without any verification
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Park (2005) estimated the naphtha storage fraction by applying the so-called Non- Energy use Emission Accounting Tables (NEAT) model for the year 2000.
NEAT model distinguishes products between ODU (Oxidized during use) and NODU (Not oxidized during use); This distinction is similar to IPCC’s short-lived and long-lived products, respectively.
According to the study, the Korean petrochemical industry produces NODU products (48.1 Mt CO2 ) and ODU products (10.4 Mt CO2). ODU products in the amount of 2.8 Mt CO2 (about 4.7% of the total) were net exported.
The naphtha storage fraction was 82.2% (= 48.1/58.5) on the production basis.
Consumption basis naphtha fraction increases to 87% as the net export amount of 2.8 Mt CO2 can be considered as stored.
Net exports Storage Release NODU ODU Sum ODU ( A ) ( B ) (C = A + B) ( H ) (A + H) ( E ) [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] 2000 48.076 10.395 58.471 2.771 50.847 7.624 82.2% 17.8% 100.0% 4.7% 87.0% 13.0% Notes: NODU means not oxidized during use or long-lived products according to the IPCC terminolo ODU means oxidized during use or short-lived products according to the IPCC terminology.
Consumption basis estimates Production basis estimates
Production
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Ecosian tried to estimate the naphtha storage fraction jointly with the Korea Association of Petrochemical Industries and the Korea Petroleum Industry Association in a study commissioned by the GHG Inventory & Research Center of Korea (GIR). However, it estimated the share of non-energy in the naphtha use in the industry rather than the naphtha fraction.
The object of the estimation were reports submitted by six NCC (naphtha cracking centers) to get refunded import duties on naphtha which were 16 won per liter. These reports contained steam cracking material flows. Four refineries which operated BTX plants were omitted.
Naphtha storage fraction =
The study estimated the share of non-energy use at 79 to 81% for the 2007 to 2011 period, instead of estimating the naphtha storage fraction.
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NCC operations use only 58% of naphtha in Korea
BTX operations are different from those of NCC.
Recycled input is not supplied input from the refineries
Non-energy use in the petrochemical industry
Gross deliveries (100%) : Feedstock use, process heat, backflows to the refineries
Feedstock (non energy) use : Chemicals + feedstock type byproducts (15.532 Mt: 73.5%)
(Feedstock use according to ECOSIAN : 25.707 Mt)
Process heat : 4.283 ton (20.3%)
Backflows to the refinery : Fuel type byproducts (1.209 ton: 5.7%)
The object of the estimation not clear
The report tried to estimate the naphtha storage fraction but tried to estimate the share of feedstock in the naphtha input. Moreover, recycled input of feedstock type byproducts was falsely considered as the part of the net naphtha input to the petrochemical processes. Thus, the result did not lead to corrected values for the naphtha storage fraction.
Naphtha balances in six steam crackers in Korea (2011)
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Material flow 29,990 8,862 Feedstock Fuel Own use 21,138 type type Output Main Ethylene 6,877 products Propylene 3,340 etc. Sub total 14,389 1,101 5,996 5 7,863 14,964 Byproducts Hydrogen 35 CH4 49 etc. Sub total 11,053 168 1,143 1,209 279 9,568 12,388 4,284 285 4,568 3) The amounts of main products and byprocucts are different from those of their totals due to stock changes. 2) The amounts of non-energy use (petrochemicals), exports, process heat use and own use are exempted from paying import duties of won 16 per liter. Thus, only the amounts of sales (1.493 Mt) of "Fuel type" (1.209 Mt) and "Others" (0.284) are not refunded. The refunding ratio is calculated as 0.929 [= 1 - (1.493/21.138) * 1.0053]. The factor 1.0053 is the amount of raw material required to convert into one unit of the product. Material balance table used by 6 operators for refunding import duties on naphtha Sales Total Input Gross input Exports Others Recycled Gross deliveries (Net input) Fuel (Process heat) LOSS Fuel & LOSS Source: Ecosian, 2012. Note: 1) The term gross deliveroes means deliveries from refineries to NCC crackers who name it as "net input".
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Park’s study, according to which the naphtha storage fraction for Korea should be substantially higher than the IPCC’s default fraction, caused the Korean government to commission another study. Again, Ecosian was given the project for such estimation.
Ecosian executed the estimation in 3 steps as follows:
as short-lived (ODU) products]
Ecosian multiplied all three ratios (83.9% * 97% * 94%)each other to estimate the naphtha storage fraction in Korea at 77% (rounded up to 77%).
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Only NCC plants (54.3% of the naphtha input) are considered.
Adequate description of the production structure of the chemicals is missing.
Association of Petrochemical Industries are considered
(It does not describe the production structure)
trice
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Inconsistency between input and output
four refineries
Redundant estimation of NCC and downstream plants
with fuel type byproducts of naphtha
emissions belonging to industrial processes
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Inadequate estimation of the naphtha storage fraction
fraction as the storage fractions of final products are 100% whereas such of intermediates are partly lower than 100%.
not relevant to estimate the naphtha storage fraction
several intermediates are classified as products.
fraction.
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NEU-CO2 group developed a bottom-up spread sheet model named as NEAT 2.0 (Non-Energy use Emission Accounting Tables model version 2.0) financed by the EU
and bottom-up Sectoral Approach (SA) of IPCC (Patel, 2001; Park, 2002, 2005; Neelis et al., 2003).
NEAT model estimates CO2 emissions by subtracting from the total carbon input the share which is stored in products in the carbon flow path from basic chemicals to final
processes, solvent and other product use and waste as to verify IPCC-SA.
As being a material flow analysis NEAT model is able to estimate accurately CO2 emissions and storage.
As NEAT model considers exports and imports of chemicals it is able to estimate CO2 emissions on national boundary principle (consumption basis) which matches the purpose of emission accounting.
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ODU and NODU products correspond to short-lived and long-lived products of IPCC, respectively.
ODU (Oxidized during use) products: e.g. petroleum coke, pitch, ethanol etc. (storage rate : 0%)
NODU (Not oxidized during use) products: e.g. bitumen, synthetic resins, fibers, rubbers unless incinerated (storage rate : 100%)
Chemicals which are used both ODU and NODU products : benzene, ethylene, toluene (storage rate more than 0% and less than 100%)
Information on consumption (usage) pattern between ODU and NODU are found in Chauvel & Lefebvre (1989), Weissermel & Arpe (1998), Korea Petrochemical Statistics (Korea Petrochemical Industry Association, 2015) ; As there are certain uncertainties
release values are given.
Total consumption: consumption which originates directly from statistics because it is not used for the production of other NEAT core products
Other purposes : basic chemicals and intermediates which are required to produce
materials balance of the NEAT model.
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Case 1 Case 2 Case 3 Case 3: Consumption basis estimation for countries with net imports of ODU chemicals. ODU consumption ODU production ODU net imports Green color: Carbon storage; Violet color: Carbon release. Case 1: Production basis estimation. Case 2: Consumption basis estimation for countries with net exports of ODU chemicals. NODU production NODU production NODU production ODU production ODU net exports
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MIN RELEASE MAX RELEASE
NODU 2) ODU 2) ODU 2) ODU 2) [%] [%] [%] [%]
PRODUCTS
Acrylonitrile-Butadiene-Styrene (ABS) total 100 Butadiene Rubber (BR) total 100 Ethylene-Propylene-Diene-Monomer (E total 100 Epoxy resin total 100 Melamineformaldehyde resin total 100 Phenolic resin total 100 Polyacetales total 100 Polyacrylates total 100 Polyacrylonitrile total 100 Polyamide total 100 Polycarbonate total 100 Polyethylene (PE) total 100 Polyethyleneterephthalate (PET) total 100 Polypropylene (PP) total 100 Polystyrene (PS) total 100 Polyurethane (PUR) total 100 Polyvinylacetate total 100 Polyvinylchloride PVC total 100 Styrene-Acrylonitrile (SAN) total 100 Saturated polyester total 100 Styrene-Butadiene Rubber (SBR) total 100 Unsaturated polyester/alkyd resin total 100 Urea formaldehyde resin (UF) total 100
3) MTBE ends up as a antiknocking agent in the fuel pool and the emissions are thus taken into account
Compound 1) Total consumption
MEAN
1) Ammonia does not contain any embodied carbon and it is therefore not listed in this table. However, 2) ODU = Oxidised During Use, NODU = Not-Oxidised During Use
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Naphtha is processed in NCC (steam cracking) and BTX (catalytic reforming) plants to basic chemicals such as ethylene, propylene, butadiene, benzene, toluene, xylene etc.
Basic + basic chemicals ⇒ intermediate : ethylbenzene (75% benzene + 25% ethylene); cumene (65% benzene + 35% propylene; ⇒ products: EPDM (60% ethylene + 40% propylene) etc.
Basic chemical + intermediate ⇒ polyvinylacetate (51% ethylene + 49% acetic acid) etc.
Intermediate + intermediate: SAN(48% acrylonitrile + 52% styrene) etc.
Styrene road (NEAT approach)
Polystyrene 100% (1.0) 67% Ethylene 25% 31% SBR Butadiene (0.5) 100% (1.0) (1.0) Ethylbenzene Styrene 29% (1.0) (1.0) 52% 19% Benzene ABS Acrylonitrile (0.5) 75% (1.0) (1.0) 52% 48% 100% SAN Propylene Notes: (1.0) (0.6) 1) Figures in percentages are shares of inputs for the production. 2) Figures in brackets are storage fractions. Storage fractions for basic chemicals are for 'other uses' only. 3) Green: basic chemicals; Violet: intermediates; Yellow: products. (1.0)
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Introducing a carbon balance to calculate carbon use (consumption) by product.
Carbon balance developed based on C-Stroeme(Patel et al. 1999) and expert’s advices.
Carbon balance consists of upper balance (69 * 69) and lower balance(69 * 69).
Rows of upper balance [input rates (propotion) of other products to produce a product); columns (input rates of a product to produce other products]
Rows of lower balance (inputs of other products to produce a product); columns (input of a product to produce other products)
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Primary flow path of ethylene, propylene, benzene , CO
Year 2015 in Mt CO2
Aniline Cyclohexane Polyethylene 0.940 0.295 15.084 Polypropylene Acetic acid Benzene 12.616 0.647 10.913 Cumene Ethylbenzene TDI 1.444 2.699 Octanol 0.298 Acrylonitrile Ethylenedichloride 0.357 1.636 0.947 CO Octanol EPDM 0.928 1.071 Ethylene 0.404 Propylene i-Propanol 26.019 Epoxy resin 19.594 0.231 0.261 Bisphenol A EPDM Polyvinylacetate 0.269 0.017 Acetic acid Acrylic acid Net exports Ethylene oxide 1.032 1.359 1.470 Ethylene Epoxy resin Phenolic resin 26.019 0.155 0.038 CO Propylene oxide VCM 0.928 0.706 1.361 Basic chemicals Intermediates Phenolic resin Other purposes Products Other purposes/ 0.296 1.731 net exports
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Example of a carbon balance calculation for chemical products in NEAT
[Mt CO2 / yr] p-Xylene 14.50 p-Xylene derivatives Specific consumption Annual production Absolute consumption [Mt CO2 / Mt CO2 ] [Mt CO2 / yr] [Mt CO2 / Mt CO2 ] ( A ) ( B ) ( A * B ) Terephtalic acid (TPA)
1)
1.00 14.06 14.06 Dimethyl terephtalate (DMT)
2)
0.80 0.17 0.14 Sum of p-Xylene use 14.20 Other use of p-Xylene 0.30 Source : Neelis et al., 2003. Notes: 1) Stoichometric factors. In the production of TPA(8 carbon atoms), all carbon atoms come from p-Xylene. 2) In the production of DMT (10 carbon atoms), 8 carbin atoms come from p-Xylene and 2 atoms from methanol. Hence, the specific consumption is 0.8 for p-xylene and 0.2 for methanol.
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5.1 Korean petrochemical industry
3 petrochemical complexes in Ulsan, Yechun and Daesan operate NCC(Naphtha cracking center) plants to produce olefins and aromatics (BTX) with pyrolysis gasoline, PG). 4 refineries operate aromatics plants.
6 crackers : Daehan Chemicals, Lotte Chemicals, Yechum NCC, Hanwha Total, LG Chemicals, SK Chemicals
4 refineries: S-Oil, Hyundai Oil Bank, GS Caltex, SK
World ethylene production capacity industries (2014): USA (28.332 Mt), China (19.241Mt), Saudi Arabia (15.790 Mt), Korea (8.500 Mt)
[Table] Demand for petrochemicals in Korea Source: Korea Petrochemical Industry Association, 2015.
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Non-energy use of naphtha (IEA statistics): TPES – External backflows –Process heat (Internal backflows)
Non-energy use of naphtha in 2013 = 30.947 Mtoe ( 67.9% of TPES)
PRODUCT Naphtha FLOW Production 0.0 Imports 25253.7 Exports
International marine bunkers 0.0 International aviation bunkers 0.0 Stock changes
Total primary energy supply TPES A 20369.0 Transfers 1218.6 Statistical differences 363.2 Transformation processes 16557.5 Oil refineries B 25206.2 Petrochemical plants D
Total final consumption TFC C 38508.3 Total supply of naphtha A + B 45575.2 100% TFC of naphtha C 38508.3 Naphtha backflows A + B - C 7066.9 15.5% Process heat (naphtha) D 7561.1 16.6% Non-energy use of naphtha C - D 30947.2 67.9% Source: IEA, Energy Balances of OECD Countries, 2015. Note : Backflows = TPES - non-energy use - process heat = A + B - (C-D) - D = A + B - C
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Production data : 69 basic chemicals, intermediates and products needed
Association
Trade data : Korea International Trade Association, KITA.net
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5.3 Estimation of storage fraction, an example for 2015
In the case of ethylene:
100%)
Ethylenedichloride (NODU: 0%), Ethylene oxide (NODU: 29%), Acetic acid (NODU: 35%)
Year 2015 in Mt CO2
Polyethylene 15.084 Acetic acid 0.647 Ethylbenzene 2.699 Ethylenedichloride 0.947 EPDM Ethylene 0.404 26.019 Epoxy resin 0.261 Polyvinylacetate 0.017 Net exports Ethylene oxide 1.359 1.470 Phenolic resin 0.038 VCM 1.361 Other purposes 1.731 Styrene road (NEAT approach)
Polystyrene 100% (1.0) 67% Ethylene 25% 31% SBR Butadiene (0.5) 100% (1.0) (1.0) Ethylbenzene Styrene 29% (1.0) (1.0) 52% 19% Benzene ABS Acrylonitrile (0.5) 75% (1.0) (1.0) 52% 48% 100% SAN Propylene Notes: (1.0) (0.6) 1) Figures in percentages are shares of inputs for the production. 2) Figures in brackets are storage fractions. Storage fractions for basic chemicals are for 'other uses' only. 3) Green: basic chemicals; Violet: intermediates; Yellow: products. (1.0)
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` Gross Gross Ethylene Carbon Carbon carbon storage carbon release content storage release ( A ) ( B ) ( C ) ( = A * C ) (= B * C ) INTERMEDIATES Ethanol
0.258 1
0.258 Ethylbenzene 1.241 0.25 0.307 Ethylenedichloride 0.003 0.036 1 0.003 0.036 Ethylene glycol 0.375 0.269 0.72 0.270 0.194 Styrene 1.947 0.25 0.481 Vinylchloride monomer VCM 0.250 0.419 0.40 0.100 0.168 FINAL PRODUCTS ABS 5.364 0.16 0.849 EPDM 0.673 0.60 0.404 Epoxy resin 1.177 0.22 0.261 Polyethylene PE 15.328 0.98 15.084 Polyethyleneterephthalate PET 3.629 0.33 1.198 Polystyrene PS 3.456 0.25 0.855 Polyvinylacetate 0.033 0.51 0.017 Polyvinylchloride PVC 2.124 0.75 1.599 SAN 0.649 0.13 0.083 SBR 1.609 0.08 0.123 TOTAL 21.377 0.659 Share of storage and release 0.97 0.03 Notes: a) Gross carbon storage: production of NODU chemicals + net exports of ODU chemicals. b) Gross carbon release: use for the production of other chemicals * ODU share. c) Ethylene content: ethylene share in intermediates and final chemicals.
Storage Release Sub-total
21.377 0.659 22.036
0.866 0.866 1.732
1.359 1.359
production and sum of above amounts 0.865 0.027 0.892 Total 24.467 1.552 26.019 Share 94.04% 5.96% 100%
Carbon storage & release from the use of ethylene, 2015 (Mt CO2)
Naphtha storage fraction estimated with the NEAT method on consumption principle, for the year 2015
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Stored Released Production Stored Released % % [Mt CO2] [Mt CO2] [Mt CO2] Acetylene 100.0 0.496 0.496 0.000 Benzene 99.55 0.45 20.793 20.699 0.094 Butadiene 100 3.917 3.917 0.000 Other C4 21.10 78.90 2.721 0.574 2.147 CO-Source 93.66 6.34 0.928 0.869 0.059 Ethylene 94.04 5.96 26.019 24.467 1.551 Propylene 97.96 2.04 22.137 21.685 0.451 Toluene 21.56 78.44 5.531 1.193 4.338
90.97 9.03 1.192 1.084 0.108 m-xylene 9.17 90.83 0.621 0.057 0.564 p-xylene 98.33 1.67 30.101 29.599 0.502 Sum 114.455 104.641 9.814 in % 100.0 91.4 8.6
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Storage Release NODU ODU Sum NODU ODU Sum NODU ODU ( A ) ( B ) (C = A + B) ( D ) ( E ) (F = D + E) ( G ) ( H ) (A + H) ( E ) [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] 78.422 10.615 89.037 35.417 5.550 40.966 43.004 5.065 83.487 5.550 88.1% 11.9% 100.0% 5.7% 93.8% 6.2% 87.802 13.779 101.582 35.676 6.909 42.584 52.127 6.871 94.673 6.909 86.4% 13.6% 100.0% 6.8% 93.2% 6.8% 88.055 13.460 101.515 40.005 7.000 47.005 48.050 6.460 94.515 7.000 86.7% 13.3% 100.0% 6.4% 93.1% 6.9% 93.022 16.300 109.322 40.099 9.606 49.705 52.923 6.694 99.716 9.606 85.1% 14.9% 100.0% 6.1% 91.2% 8.8% 97.149 17.305 114.455 40.996 9.810 50.806 56.153 7.495 104.644 9.810 84.9% 15.1% 100.0% 6.5% 91.4% 8.6% Average 86.2% 13.8% 100.0% 6.3% 92.5% 7.5% Notes: NODU means not oxidized during use or long-lived products according to the IPCC terminology. 2014 2015 ODU means oxidized during use or short-lived products according to the IPCC terminology. Production Consumption Net exports 2011 2012 2013
Production basis estimates Consumption basis estimates
Storage fraction by basic chemical estimated with a simplified NEAT method for the 2013 to 2015 period
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Storage fraction by basic chemical 2013 2014 2015 Average Acetylene 100.0 100.0 100.0 100.0 Benzene 98.57 98.93 99.55 99.02 Butadiene 100.0 100.0 100.0 100.0 Other C4 10.0 17.1 21.1 16.1 CO-Source 95.87 92.07 93.66 93.87 Ethylene 93.74 94.64 94.04 94.14 Propylene 96.69 97.33 97.96 97.33 Toluene 61.76 39.94 21.56 41.09
98.75 91.66 90.97 93.79 m-xylene 3.65 15.52 9.17 9.45 p-xylene 97.21 99.43 98.33 98.33 Naphtha storage fraction 93.17 91.21 91.43 91.94
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Storage Release NODU ODU Sum NODU ODU ( A ) ( B ) (C = A + B) ( D ) ( E ) (A + E) (B - E ) [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] [Mt CO2] Mean 97.149 17.305 114.455 56.153 7.495 104.644 9.810 Release 84.9% 15.1% 100.0% 6.5% 91.4% 8.6% Maximum 97.149 21.481 118.631 52.994 10.654 107.803 10.828 Release 81.9% 18.1% 100.0% 9.0% 90.9% 9.1% Minimum 97.149 13.755 110.905 58.057 5.591 102.740 8.165 Release 87.6% 12.4% 100.0% 5.0% 92.6% 7.4% Production basis estimates Consumption basis estimates Production Net exports
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This study shows that the IPCC default naphtha storage fraction of 75% underestimates the Korean storage fraction. The IPCC default storage fraction does not reflect a country’s production and trade structure. It is desirable to estimate CO2 emissions on the consumption basis (national boundary principle).
Korea’s carbon emissions estimated with the IPCC default naphtha fraction of 75% is likely to have resulted in an overestimation of 17.1 Mt CO2 (15% of the emissions related to the use of naphtha in 2015) or 2.7% of the country’s total carbon emissions (about 630 Mt CO2).
A naphtha storage fraction of 90% is proposed as appropriate default fraction for the Korean petrochemical industry. The Korean government is recommended to account for this finding in their national emission accounting. A revision of the naphtha storage fraction is allowed by the IPCC guidelines.
This study provides a method to estimate storage fractions from non-energy use for the IPCC Guidelines for National GHG Inventories.