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5. Terms and codes used in RAINS-EMCO

The definitions in this part are alphabetically ordered.

Animal types and agricultural sectors

In EMCO-Ammonia, emissions are calculated for a number of different animal types and some other sectors. The following table provides a list of animal types distinguished in RAINS and their abbreviations.

The definitions follow the standard conventions of the FAO (Food & Agricultural Organization). 'Other cattle' is calculated from total cattle (where appropriate including buffaloes) minus the dairy cows. 'Other poultry' equals total poultry (chicken, ducks, turkeys) minus laying hens. The category 'sheep' includes goats. Horses include mules and asses, 'Other Anthropogenic Sources' includes human respiration.

Table 5a: Animal types and sectors in EMCO Ammonia:

Regions & countries
used in RAINS Europe 7.2

An area source is considered as a geographical region containing a number of emitters. A region can be a sub-division of a country and may include one or more administrative districts or provinces within the country. A region may contain many different types of emission sources.

Table 5b: Countries distinguished in the RAINS Europe implementation

Table 5c: Regions for the RAINS Europe implementation

Control strategy
and control technology

To reduce emissions of sulfur dioxide, nitrogen oxides or ammonia from various sources, a number of control technologies (or emission abatement measures) are considered in RAINS. Examples of 'control technologies' are flue gas desulfurization, use of low-sulfur fuels, catalytic converters, stable adaptations, etc..

Detailed descriptions of control technologies considered in RAINS are provided in

• Control technologies for SO2
• Control technologies for NOx
• Control technologies for NH3

When exploring the impacts of the application of control technologies on actual emission levels, the user must construct control strategies and apply them for selected countries to particular energy pathways in order to construct an emission abatement scenario.

Control strategies are packages of emission control measures applied to the different emission source categories in a country. Control strategies are country-independent, and are expressed as percentages (of, e.g., fuel input to the entire sector), to which a given control measure is to be applied. In other words, control strategies can be considered as general descriptions of legislative packages for emission control, specifying for each individual emission category in a country the type, the timing and the extent of required emission control. Note, however, that a control strategy in RAINS is just the instruction of when, how and how much to reduce emissions; it is independent from a country and does therefore not directly result in an concrete emission reduction.

The actual fate of emissions is determined by the emission abatement scenario, which combines for individual regions energy pathways and control strategies.

Control strategies can be edited using the RAINS-EMCO strategy editor. Control strategies can be saved into files.

Control technologies for SO2

The national potentials and costs of emission reductions are estimated based on a detailed data base of the most common emission control techniques. For a given energy scenario, reduction options for SO2 emissions considered in RAINS are the use of low sulfur fuel, fuel desulfurization, combustion modification (e.g., lime stone injection processes and fluidized bed combustion) and flue gas desulfurization (e.g., wet limestone scrubbing processes). Structural changes, such as fuel substitution and energy conservation can also be evaluated, although only in interaction with an appropriate energy model.

The databases on emission control costs have been constructed based on the actual operating experience of various emission control options documented in a number of national studies (e.g., Schärer, 1993) as well as in reports of international organizations (e.g., OECD, 1993; Takeshita, 1995; Rentz et al., 1987). Country-specific information has been extracted from relevant national and international statistics (UN/ECE, 1996).

The basic input data for SO2 control technologies used in RAINS have been reviewed in the process of the negotiations for the Second Sulfur Protocol of the Convention on Long-range Transboundary Air Pollution and have been recently updated to take into account latest operating experience.

Table 5d: Control technologies for sulfur dioxide

Control technologies for NOx

RAINS distinguishes control options for stationary and mobile emission sources. The databases on emission control costs for stationary sources have been constructed based on the actual operating experience of various emission control options documented in a number of national studies (e.g., Schärer, 1993) as well as in reports of international organizations (e.g., OECD, 1993; Takeshita, 1995; Rentz et al., 1987). Country-specific information has been extracted from relevant national and international statistics (UN/ECE, 1996).

Options for mobile sources have been prepared on the basis of available literature (i.a., Gorißen, 1992, HSMO, 1994, McArragher et al., 1994, Rodt et al., 1995, UN/ECE, 1994a, UN/ECE, 1994b). They include the most important control measures analyzed by the European Auto/Oil Program (European Commission, 1996, Touche-Ross&Co., 1995).

The basic input data for NOx control technologies used in RAINS have been reviewed by countries in the preparation process for the Second NOx Protocol of the Convention on Long-range Transboundary Air Pollution in January 1997. Comments received from the national experts are incorporated in the distribution version.

Table 5e: Control technologies for nitrogen oxide

Control technologies for NH3

For each of the major sources of ammonia emissions (livestock farming, fertilizer use, and chemical industry), RAINS considers a number of emission control options (Klaassen, 1991b; UN/ECE, 1996; EEA,1996; Menzi et al., 1996).

Ammonia emissions from livestock occur at four stages, i.e., in the stable, during storage of manure, its application and during the grazing period. At every stage emissions can be controlled by applying various techniques. Obviously RAINS cannot distinguish all of the several hundred available control options, but considers groups of techniques with similar technical and economic characteristics. The major categories considered in RAINS are

• low nitrogen feed (dietary changes), e.g., multi-phase feeding for pigs and poultry, use of synthetic amino acids (pigs and poultry), and the replacement of grass and grass silage by maize for dairy cattle;
• biofiltration (air purification), i.e., by treatment of ventilated air, applicable mostly for pigs and poultry, using biological scrubbers to convert the ammonia into nitrate or biological beds where ammonia is absorbed by organic matter;
• stable adaptation by improved design and construction of the floor (applicable for cattle, pigs and poultry), flushing the floor, climate control (for pigs and poultry), or wet and dry manure systems for poultry;
• covered outdoor storage of manure (low efficiency options with floating foils or polystyrene, and high efficiency options using tension caps, concrete, corrugated iron or polyester);
• low ammonia application techniques, distinguishing high efficiency (immediate incorporation, deep and shallow injection of manure) and medium to low efficiency techniques, including slit injection, trailing shoe, slurry dilution, band spreading, sprinkling (spray boom system).

Ammonia emissions from the chemical industry can be reduced by introducing stripping and absorption techniques (Tangena, 1985; Technica, 1984).

The basic input data for NNH3 control technologies used in RAINS have been reviewed by countries in the preparation process for the Second NOx Protocol of the Convention on Long-range Transboundary Air Pollution in January 1997. Comments received from the national experts are incorporated in the distribution version.

Table 5f: Control technologies for ammonia:

Cost curve

The cost curve provides the minimum costs of achieving the emission reductions for each abatement level, using the optimal cost-abatement combination.

Cost curves are compiled by ranking the available emission abatement technologies (options), according to their cost-effectiveness and potential for emission reductions determined by combinations of fuel properties and abatement (or control) technologies, for various emission sources in the region.

The RAINS cost curves display for the the selected scenario, region and year the maximum emission of a pollutant under study in kilotons. The table includes columns listing fuel, economic sector, control technology (F-S-T), unit costs( in ECU/ton pollutant removed), marginal costs (in ECU/ton pollutant removed), actual amount of pollutant removed, remaining emissions ( i.e., maximum emission less cumulative emissions removed), total cumulative control costs, installed capacity of control equipment, and investment required for installation of control equipment.

The current implementation of RAINS displays cost curves that begin with the emission level calculated for the selected scenario. Thus all abatement technologies assumed in the scenario are taken into account while calculating the initial emission level. The cost curves include only controls on capacities that have remained uncontrolled in a given scenario. The costs of control measures already included in the selected scenario can be located in the appropriate table (Costs/Totals/Region totals). Abatement measures assumed in a given scenario might not be cost-optimal. To obtain a cost curve that ranks all possible control measures according to their cost-efficiency, the cost curve has to be generated for the "no control" control strategy. Such a strategy assumes that all emission sources are uncontrolled in the future years (i.e., 1995, 2000, 2005 and 2010). Further, it ignores the future-year effects of controls already installed in the base year (1990). Cost curves for the base year (1990) should be generated only for those scenarios, that do not include the effects of the base year controls.

Economic sectors

A sector is defined as a group of similar emission sources, which consumes energy (fuel) and releases emissions of sulfur dioxide and/or nitrogen dioxide. The sectors in RAINS are defined basically on the basis of economic activities, in order to link emission forecasting with available projections of economic activities.

The economic sectors distinguish

• fuel conversion (CON),
• centralized power plants and district heating (PP),
• domestic, commercial and agricultural use (DOM),
• transportation (TRA),
• industrial (IN), and
• non-energy use - feedstocks (NONEN).

The fuel conversion sector includes refineries, coke and briquettes production plants, coal gasification plants etc, but does not include the power stations and district heating plants. Energy consumption for fuel conversion as recorded under combustion in the conversion process (CON_COMB) includes only the energy consumed in the fuel conversion process and not the energy content of input material and final fuel products. The losses during transmission and distribution of the final product are reported under (CON_LOSS), encompassing the own-use of electricity and heat by the fuel conversion sector, and own-use of electricity and heat by the industrial auto producers of electricity and heat. Furthermore, also the own-use of electricity and heat by power plants and district heating plants as well as losses during the distribution of electricity and district heat are included in this category.

For industrial energy use, the RAINS database distinguishes energy combustion in industrial boilers for the auto-production of electricity and heat (IN_BO) and fuel consumption in industrial furnaces and for direct production processes (IN_OC). The NONEN category includes the consumption of lubricants, heavy oil fractions like asphalt for road construction and fuel used as chemical feedstock.

The transport sector is divided into road (TRA_RD) transport and other transport (off-road, rail, inland and coastal water transportation - TRA_OTHER). Air transport is not included because of its relatively low share in emissions to the atmospheric surface layer.

If necessary, sectors are further disaggregated. The main reason for distinguishing parts of sectors is the fact that emission factors and the applicability and effectiveness of control technologies are not always uniform for the entire sectors. Thus, a distinction has been made between the new power plants (PP_NEW) and existing power plants (PP_EX). Existing power plants refer to all sources which came on-line before 1990.

The Table 7e below list the codes used for economic sectors used in RAINS Europe.

Table 5g: Economic sectors

Emission abatement scenario

An Emission Abatement Scenario defines for each individual region a combination of an energy pathway - or in case of Ammonia agricultural activity - and an emission control strategy. In RAINS, emission abatement scenarios are created using the reduction scenario editor.

Emission factor / Removal efficiency / Cost coefficient

In order to speed up the calculation, the RAINS model generates internal files where interim results such as emission factors, removal efficiencies and cost coefficients are stored. These factors are the outcome of more complex calculation routines, taking into account factors such as heat values of fuels, sulfur content, sulfur retained in ash, applied control technology used, interest rate, electricity price, etc.).

Emission factors are given in thousand tons SO2/NOx emitted per PJ of fuel used; removal efficiencies are expressed as the percentage of emissions removed using a particular control technology; cost co-efficients (stored as EEC in EMIVEC.DBF) are reported in million ECU per PJ of fuel input to which a measure is applied.

Emission vector

Next to the calculation of emissions resulting from energy use and application of control strategies, RAINS-EMCO allows you also define and analyze emission scenarios simply by specifying emission totals for a particular region for a given year. Such sets of national (regional) emission totals are called emission vectors.

Emission vectors can be edited. Go to the Scenario editor, choose in the combo box at the left bottom 'emission vector', and click on the 'edit' button. Then you can change individual emission numbers. Emission vectors are stored in dBase files with the extensions *.sem, *.nem, *.aem.

Energy pathway

Energy pathways, which are an exogeneous input to RAINS, describe the sectoral use of the different fuel types over time. In order to calculate emission scenarios in RAINS, assumptions about the combination of energy pathways and emission control strategies have to be made.

Energy pathways are country-specific, and some of them may be available for a subset of countries only. RAINS is distributed with a number of energy pathways.

For the time being, energy scenarios cannot be created or modified within RAINS. Editing of energy scenarios is, however, possible with commercially available database management tools (e.g., FoxPro). If required, detailed instructions on the data format used can be obtained from IIASA.

Fuels

RAINS distinguishes a number of fuel types with different emission-related properties.

The main category of fuels include solid fuel, broken down into brown coal (BC), hard coal (HC), derived coal (DC) and other solids (OS). Liquid fuel is divided into heavy fuel oil (HF), medium distillate (MD), i.e., light fuel oil and diesel oil, light fractions (LF), i.e., gasoline. To compute emissions of nitrogen oxides, the consumption of natural gas (GAS) is also included. In order to complete the energy balances, also renewables (REN), hydro power (HYD), nuclear power (NUC), electricity (ELE) and heat (HT) are included in the RAINS databases.

Optionally, solid fuels can be further distinguished along differences in combustion and emission characteristics. It was decided not to introduce general definitions for the different grades, but leave the specification up to the specific situation, taking into account national characteristics as well as data availability.

Table 5h: Fuel types used in RAINS Europe:

Marginal costs, unit costs

Marginal costs and unit costs are terms crucial for the understanding of the cost calculations performed in RAINS.

For a given abatement option, unit costs refer to the cost of abatement related to a unit of reduced emissions. Such unit costs are technology- and country-specific and can be easily calculated by dividing the total costs for a particular measure by the total volume of emissions reduced.

The situation becomes a little bit more complicated when consideringmarginal costs. Marginal costs refer to the costs for removing the last unit of emissions. This distinction becomes relevant when more than one control options (with different removal potential and unit costs) are available for the same emission source (sector). When constructing cost curves, i.e., curves showing the least costs of achieving given emission reductions, the available abatement measures must be ranked along their marginal costs. This means that a more expensive option should be ranked based on their additional reduction in emissions (on top of the reductions achieved by the cheaper option), taking into account the additional costs for the second option.

One example for the calculation process for marginal abatement cost:

Assume a fuel type "F" is used in sector "S", and control technologies applicable to this fuel-sector combination ("F-S") are "CT1", "CT2" and "CT3". The total amount of pollutant emitted by this "F-S" fuel-sector combination, is 4 kt. Assume the technology "CT1" reduces emissions by 50% (i.e., 2 kt), "CT2" reduces emissions by 70% (2.8 kt), and "CT3" reduces sulfur dioxide emissions by 80% (3.2 kt). Further, assume the unit costs (ECU/ton) to reduce emissions using the three control technologies "CT1", "CT2" and "CT3" are ECU 700, ECU 814 and ECU 1025, respectively. Then the marginal costs for the first fuel-sector-control technology type "F-S-CT1" is equal to the unit cost, i.e., 700 ECU/ton. If the "CT2" type control technology is later applied to the same fuel-sector combination, then the marginal cost for fuel-sector-control technology type "F-S-CT2" is ( 814 ECU/ton * 2.8 kt) minus ( 700 ECU/ton * 2.0 kt) divided by extra amount of pollutant removed (0.8 kt) which is equal to 1099 ECU/ton. The marginal cost for the "F-S-CT3" combination is 2502 ECU/ton.

Process emission factors

vers. 1

Process emission factors are used to estimate emissions from those processes where emissions can not be directly linked to energy consumption.

The most important industrial processes that generate process emissions are: oil refineries (IN_PR_REF), coke plants (IN_PR_COKE), sinter plants (IN_PR_SINT), pig iron - blast furnaces (IN_PR_PIGI), non-ferrous metal smelters (IN_PR_NFME), sulfuric acid plants (IN_PR_SUAC), nitric acid plants (IN_PR_NIAC), cement and lime plants (IN_PR_CELI), and pulp mills (IN_PR_PULP).

For majority of those processes the process emission factor is defined as the difference between actual emissions per ton of activity and hypothetical emissions that would have been generated if the fuel used in the activity has been combusted. An exception is cement and lime where total emissions per ton of product are used to calculate the emissions. This is because retention of sulfur in ash during cement and lime production is so high (more than 80 percent), that it would have been necessary to use negative process emission factors. To avoid computational difficulties caused by negative emission factors, total emissions are included in the process emission factor. In order to avoid double accounting, fuel consumption by cement and lime industry is subtracted from total industrial fuel ues before performing emissions calculations (see Fuel consumption in cement & lime industry).
The emission factors are given in kg of pollutant per ton of activity of process causing process emissions.

vers. 2

The process emission factor is defined as the difference between actual emissions per ton of activity and hypothetical emissions that would have been generated if the fuel used in the activity was combusted. Thus, the process emission factor is positiv if emissions are greater than the amount that would be generated by fuel combustion alone, and negative if emissions are less than the amount that would be generated by fuel combustion alone.

Processes in EMCO-Ammonia

Ammonia emissions from livestock occur during four phases:

• during the production of manure in the stable (including the storage of manure);
• storage outside;
• when manure is applied on arable land or grassland;
• during the meadow period.

This distinction is important because it determines the extent to which abatement measures geared at one of these processes influence total emissions.

Table 5i: Processes in the EMCO-Ammonia module

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