CGE Greenhouse Gas Inventory Handson Training Workshop Energy

CGE Greenhouse Gas Inventory Hands-on Training Workshop Energy Sector 1 A. 1

Our goal 2

Our goal To gain knowledge, comprehension, or mastery through experience or study. Pronunciation: shuey si 3

Outline of course n Fuel combustion n n n References Basic emission processes Methodologies Relationships with other sources and sectors Uncertainty Quality control and completeness 4

Outline of course (continued) n Fugitives n n References Coal mining and handling Oil and natural gas systems Data issues 5

Survey says…? Audience poll… n Who has prepared a national inventory for your country? n Who has worked on the Energy Sector? n Please share… n n Problems you have faced in preparing estimates for the Energy Sector Your plans for the future to improve your inventory 6

Reference materials n n UNFCCC (COP decisions, reporting guidelines, etc. ) IPCC n n n Revised 1996 IPCC Guidelines IPCC Good Practice Guidance Emission Factor Database (EFDB) IPCC Working Group I Assessment Reports n Use “old” Second Assessment Report (SAR) Global Warming Potential (GWP) values for reporting International Energy Agency 7

IPCC guidance n n Fundamental methods laid out in 1996 Revised Guidelines IPCC good practice guidance clarifies some issues (e. g. international bunker fuels) and provides some updated factors… …but no major changes made for fuel combustion! 2006 IPCC Guidelines will provide new information on Non-Energy Use, new Tier 2 method for oil systems fugitives, guidance on abandoned coal mines 8

Key Category Analysis n n n Level assessment based on share of total national emissions for each source category Trend assessment based on contribution of category to changes in emission trends Qualitative criteria 9

Key Category Analysis n n Idea of key sources based on a measure of which sources contribute to uncertainty in inventory Most if not all source categories in the Energy Sector will be Key Source Categories Analysis only as good as original emissions data You probably already know your key categories 10

Energy Sector – Fuel Combustion Emissions 1 A. 11

Stationary sources n Energy Industries n n Manufacturing Industries and Construction n n n n Extraction, production and transformation Electricity generation, petroleum refining Autoproduction of electricity Iron and steel production Non-ferrous metal production Chemical manufacturing Pulp, paper and print Food processing, beverages and tobacco Commercial/Institutional Residential Agriculture/Forestry/Fisheries 12

Autoproducers 13

Mobile sources n n Civil Aviation Road Transportation n n Cars Light duty trucks Heavy duty trucks and buses Motorcycles n Railways Navigation n International Bunker Fuels are reported separately n 14

Carbon dioxide (CO 2) emissions n n Methodology is mass-balance-based Oxidation of the carbon in fuels during combustion In perfect combustion conditions, total carbon content of fuels would be converted to CO 2 Real combustion processes result in small amounts of partially oxidized and unoxidized carbon 15

Carbon flow for a typical combustion process n n Most carbon is emitted as CO 2 immediately Small fraction emitted as non-CO 2 gases n n n CH 4, CO, non-methane volatile organic compounds (NMVOCs) Ultimately oxidizes to CO 2 in the atmosphere Integrated into overall calculation of CO 2 emissions Each carbon atom has two atmospheric lifetimes Remaining part of the fuel carbon is unburnt n n Assumed to remain as solid (ash and soot) Account by using oxidation factors 16

Non-CO 2 emissions n Direct greenhouse gases n n n Methane (CH 4) Nitrous oxide (N 2 O) Precursors and SO 2 n n Nitrogen oxides (NOx) Carbon monoxide (CO) Non-methane volatile organic compounds (NMVOCs) Sulfur dioxide (SO 2) 17

Require detailed process information n n n Combustion conditions Size and vintage of the combustion technology Maintenance Operational practices Emission controls Fuel characteristics 18

Methane (CH 4) n Emissions a function of: n n n methane content of the fuel hydrocarbons passing unburnt through engine type post-combustion controls Depends on temperature in boiler/kiln/stove Highest emissions in residential applications (e. g. small stoves, open biomass burning, charcoal production) 19

Nitrous oxide (N 2 O) n n Lower combustion temperatures tend to lead to higher N 2 O emissions Emission controls (catalysts) on vehicles can increase the rate of N 2 O generation, depending on: n n n driving practices (i. e. number of cold starts) type and age of the catalyst Significant emissions for countries with a high penetration of vehicles with catalysts http: //unfccc. int/resource/docs/2004/sbsta/inf 03. pdf 20

Methods for estimating CO 2 n Reference Approach (Tier 1) n n Sectoral Approach (Tier 1) n n Estimates based on national energy balance (production + imports - exports) by fuel type without information on activities Performed quickly if basic energy balance sheet is available Way of cross-checking emission estimates of CO 2 with the Sectoral Approach Estimates based on fuel consumption data by sectoral activity Bottom-Up Approaches (Tier 2 or 3) n More detailed activity and fuel data 21

Fundamental equation 22

Six basic steps 1. 2. 3. 4. 5. 6. Collect fuel consumption data Convert fuel data to a common energy unit Select carbon content factors for each fossil fuel/product type and estimate the total carbon content of fuels consumed Subtract the amount of carbon stored in products for long periods of time Multiply by an oxidation factor Convert carbon to full molecular weight of CO 2 and sum across all fuels 23

1. Consumption data n Reference Approach n n Sectoral Approach n n Estimate apparent consumption of fuels within the country Collect actual consumption statistics by fuel type and economic sector Tier 2 or 3 n Collect actual fuel consumption statistics by fuel type, economic sector and combustion technology type 24

Data collection issues n IPCC sectoral approach can still be used even if energy data are not collected using same sector categories n n n Focus on completeness and use judgement or proxy data to allocate to various subsectors Biomass combustion not needed for CO 2 estimation, but reported for information purposes Informal sector fuel use is important issue if not captured in energy statistics n Household kerosene use can be approximated based on expert judgement or proxy data 25

2. Common energy unit n n n Convert fuel data to a common energy unit Production and consumption of solid and liquid fuels in tonnes Gaseous fuels in cubic meters Original units converted into energy units using calorific values (i. e. heating values) Reference approach: use different calorific values for production, imports and exports Calorific values used should be reported 26

3. Estimate total carbon content of fuels consumed Natural gas n n n Depends on composition (methane, propane, butane and heavier hydrocarbons) Natural gas flared at the production site will usually be “wet’’ – its carbon content factor will be different Typical: 15 to 17 tonnes C/TJ Oil n n n Lower carbon content for light refined petroleum products such as gasoline Higher for heavier products such as residual fuel oil Typical for crude oil is 20 tonnes C/TJ Coal n n Depend on coal's rank and composition of hydrogen, sulfur, ash, oxygen and nitrogen Typical ranges from 25 to 28 tonnes C/TJ 27

4. Subtract non-energy uses Oil refineries: asphalt and bitumen for road construction, naphthas, lubricants and plastics n Natural gas: for ammonia production n Liquid petroleum gas (LPG): solvents and synthetic rubber n Coking: metals industry Attempt to use country-specific data instead of IPCC default carbon storage factors. n 28

5. Oxidation factor n n Multiply by an oxidation factor to account for the small amount of unoxidized carbon that is left in ash or soot. Amount of carbon remaining unoxidized should be low for oil and natural gas combustion… …but can be larger and more variable for coal combustion When national oxidation factors are not available, use IPCC default factors 29

Oxidation factor values Natural gas n n n Less than 1% left unburnt Remains as soot in the burner, stack or environment IPCC default oxidation factor = 99. 5% Higher for flares in the oil and gas industry Closer to 100% for efficient turbines Oil n n n 1. 5 ± 1 per cent left unburnt IPCC default oxidation factor = 99% Recent research has shown 100% in autos 30

Oxidation factor values (cont. ) Coal n n n Range from 0. 6% to 6. 6% unburnt Primarily in the form of bottom and fly ash IPCC default oxidation factor = 98% Biomass n n n Can range widely, especially for open combustion For closed combustion (e. g. boiler), the range is from 1% to 10% No IPCC default 31

6. Convert to full molecular weight and sum n n Convert carbon to full molecular weight of CO 2 and add across all fuels To express the results as CO 2, multiply the quantity of carbon oxidized by the molecular weight ratio of CO 2 to C (44: 12) 32

International bunker fuels n n CO 2 emissions arising from fuels used in ships or aircraft for international transport, not to be included in the national total Fuels delivered to and consumed by international bunkers should be subtracted from the fuel supply to the country Bunker fuel emissions should be mentioned in a separate table as a memo item See IPCC decision trees on marine and aviation transport emission allocation 33

Biomass fuels n n n CO 2 emissions from biomass fuels should not be included in national emission totals from fuel combustion Reported for information only… n household fuelwood n ethanol & biodiesel for transport Account for mixed fuels (e. g. ethanol blends) Net CO 2 emissions implicitly accounted for under the Land Use Change and Forestry Sector Non-CO 2 emissions from biomass combustion should be estimated and reported under the Energy Sector! 34

Methods for non-CO 2 emissions Tier 1 n Multiply fuel consumed by an average emission factor n Does not require detailed activity data n Rely on widely available fuel supply data that assume an average combustion technology is used Tiers 2/3 n Multiply fuel consumed by detailed fuel type and technologyspecific emission factors n Tier 2 methods use data that are disaggregated according to technology types n Tier 3 methods estimate emissions according to activity types (km traveled or tonne-km carried) and specific fuel efficiency or fuel rates Use most disaggregated technology-specific and country-specific emission factors available 35

Fundamental equation Emissions = Σ(Emission Factorabc • Fuel Consumptionabc) Where, a = fuel type b = sector activity c = technology type including emissions controls 36

Stationary combustion n Default emission factors for CH 4, N 2 O, NOx, CO and NMVOCs by major technology and fuel type are presented in the IPCC Guidelines Most notable: CH 4 emissions from open burning and biomass combustion Charcoal production is likely to produce methane emissions at a rate that is several orders of magnitude greater than from other combustion processes 37

Mobile combustion n Major transport activity (road, air, rail and ships) Most notable: N 2 O emissions from road transportation, affected by the type of emission control technologies Non-Annex I Parties should focus their efforts on collecting data on the number of vehicles with catalytic emissions control devices that operate in their country 38

Mobile combustion (cont. ) n Road transport activity data n n Assume vast majority of motor gasoline used for transport Check data with equipment counts or vehicle sales/import/export data Base assumptions of vehicle type and emission control technology on vehicle vintage data (i. e. model year of sale) and assumed activity level (i. e. vkt/vehicle) Consider national emission standards, leaded gasoline prevalence, and compliance with standards 39

Relationships with other sources and sectors n Industrial Processes Sector n n n Non-energy fossil fuel feedstocks data, if available, may not be reliable Petrochemical “feedstocks” may actually be used for energy Coal purchased by iron and steel industry may be used to make coke Focus on petrochemical industry and metal production (e. g. iron and steel) Conservative estimate: Assume plastics, asphalt, and some lubricants stored Subtract carbon content from these products 40

Relationships with other sources and sectors (cont. ) n Waste Sector n n n Land-Use Change and Forestry Sector n n Combustion of wastes for energy purposes included in Energy Sector Incineration of plastics Biomass carbon implicitly accounted for Autoproduction of electricity Fuel use for military purposes Mobile sources in agriculture 41

Quality control and completeness checks n n n n n All gases (CO 2, CH 4 and N 2 O) All source and sub-source categories All national territories addressed Bunker fuels and military operations All fossil-fuel-fired electric power stations Blast furnaces and coke production Waste combustion with energy recovery Black market fuels Non-metered fuel use for pipelines by compressor stations 42

Uncertainty n n Uncertainty in carbon content and calorific values for fuels is related to the variability in fuel composition and frequency of actual measurements. Likely to be small for all countries. For most non-Annex I Parties the uncertainty in activity data (i. e. fuel consumption data) will be the dominant issue! n n n Effort should focus on collection of fuel consumption data Country-specific carbon content factors are unlikely to improve CO 2 estimates significantly It is important to document the likely causes of uncertainty and discuss steps taken to reduce uncertainties. 43

IPCC software and reporting tables n n n Software to aid in preparation of greenhouse gas inventories Provides IPCC default (i. e. Tier 1) methods National factors can be used where available 44