1. Introduction

Pakistan as a signatory to the Malé Declaration on Control and Prevention of Air Pollution and Its Likely Transboundary Effects for South Asia is required to develop a baseline report on the status of air pollution and the measures taken to monitor, study and control its impacts in the country.This report includes preparation of a database, in a specified format, on the sources of air pollution in the country and on the estimated emissions of pollutants.The latter requirement amounts to developing an emissions inventory for Pakistan.

To provide a reliable and comprehensive estimate of emissions from all significant sources, a thorough exercise was undertaken to develop a National Emissions Inventory for Pakistan.The inventory is in Microsoft Excel®.Given in the following directory “sasia/baseline/Pakistan/inventry”.An effort was made to make the spreadsheets as self-contained as possible by providing within them all the information required to understand the numerical calculations.

This document provides general explanatory notes on the sources of data, emission factors, and methodology used to develop the inventory.

1.1 General Scheme of the Inventory

In the most general sense, the emissions estimates are based on the following simple relationship:

Total emissions of a particular pollutant = 

Where Ai is the magnitude of activity in sector i and EFi is the emission factor of the particular pollutant for the sector i.Examples of activity are fuel consumption (mtoe/yr), industrial production (tonnes/yr) or distance traveled by vehicles (km/yr).The typical emission factors corresponding to these activities are tonnes/mtoe, tonnes/tonnes of production and gm/km.The summation sign indicates that the total emissions for a particular pollutant will be the sum over all activities that result in emissions of that pollutant.

This relationship has been used throughout this inventory.

1.2 Pollutants

Based on the Malé Declaration reporting requirements, emissions in this inventory are estimated for the following pollutants:

aOxides of Nitrogen (NOX)

aSulfur Dioxide (SO2)

aParticulate Matter (PM), and

aAmmonia (NH3).

1.3 Sources of Emissions

The sources of emissions, or the activities mentioned in the previous section, included in the inventory are:

aCombustion of fossil fuels in industrial, residential, commercial, agricultural, transportation, government and power generation sectors

aCombustion of biofuels in industrial, residential and commercial sectors

aProduction of cement, fertilizer, sulfuric acid, paper and petroleum products

aAnimal husbandry and fertilizer application.

1.4 Sources of Data

The basic activity data used in the inventory is obtained from yearbooks, surveys, census reports and annual reports published by different government agencies.All of these are periodically published and publicly accessible.These were the only sources used to obtain data to ensure that the inventory can be updated every year once the source publications are available.The main sources are:

1.Pakistan Energy Yearbook.Prepared by the Hydrocarbon Development Institute of Pakistan.

2.Economic Survey. Published annually by the Economic Adviser’s Wing, Finance Division, Government of Pakistan.

3.Pakistan Railways Yearbook.Published by Pakistan Railways.

4.Agricultural Statistics of Pakistan. Published by the Ministry of Food, Agriculture and Livestock, Government of Pakistan.

5.Pakistan Census of Livestock.Published by Agricultural Census Organization.

6.Various publications of the National Transport Research Center.

1.5 Emission Factors

All emission factors used in the inventory are based on research and compilation undertaken in the US and the European countries.No research in this area has been conducted in Pakistan.Similarly, emissions and production data required to develop local emission factors is not available.However, wherever sufficient information is available the emission factors proposed by western sources are modified to suit local conditions.

The following are the main sources of emission factors used in this inventory:

aCompilation of Air Pollution Emission Factors (Stationary Sources), AP-42.Research Triangle Park: US Environmental Protection Agency, 1985

aRevised 1996 IPCC Guidelines for National Greenhouse Gas Inventories: Reference Manual, 1996

aLong-Range Energy Alternative Planning System.Boston: Stockholm Environment Institute, 1995

aEnvironmental Manual for Power Development. Darmstadt: Oeko-Institut, 1995.

1.6 Spatial Coverage

The emissions inventory covers the whole of Pakistan.Due to the lack of data, no regional inventories have been developed.

1.7 Temporal Coverage

The emissions inventories have been developed for eleven years (1980, 1985, and 1991-1998).

1.8 Uncertainties

Uncertainties are the amounts by which the calculated values are likely to differ from the true values.The causes of uncertainties could be:

aUncertainty in the basic activity data.This could be due to reporting, measurement or data collection errors

aDiffering interpretations of activity data

aVariations in conditions (fuel properties, operating conditions, vehicle characteristics, etc.) for which segregated data is not available

aApplicability of emission factors.Emission factors are ‘averaged’ values based on related assumptions to represent characteristics of a given population of sources.Most of the emission factors are developed in the US and European countries, and are therefore, applicable to these countries, strictly.In many cases, it can be argued that the emission factors are equally applicable to the conditions in Pakistan as well.However, the differences in climatic and operating conditions are likely to introduce uncertainties for which no estimates are available.

aUse of composite emission factors.Composite emission factors are developed on the basis of weighted averaged values to represent characteristics of a given population of sources.The key assumption in developing such composite emission factors is that the population distribution remains unchanged during the period of study.However, a change in the population distribution would introduce uncertainties in the estimated emissions inventory.

aInherent uncertainty in the scientific understanding of the basic processes leading to emissions.

Due to lack of information in the source data, uncertainties are not estimated in the inventory.

1.9 Organization of the Inventory

The emissions inventory is organized in six MS Excel files as follows:

 
H0BL1MAL-Energy.xls
Contains the consumption data of fuels segregated by type of fuels and sectors; properties of fuels; and conversion units.
H0BL2MAL-Mobile.xls
Estimates nitrogen oxides, particulate matter and sulfur dioxide emissions from mobile sources based on the fleet size and composition.
H0BL3MAL-StationaryCombustion.xls
Estimates nitrogen oxides, particulate matter and sulfur dioxide emissions from all stationary fuel combustion processes.
H0BL4MAL-IndustrialProcess.xls
Estimates nitrogen oxides, particulate matter and sulfur dioxide emissions from industrial production processes excluding fuel combustion.
H0BL5MAL-Ammonia.xls
Estimates ammonia emissions from all sources.
H0BL6MAL-Summary.xls
Collates and summarizes the results.

1.10 Inventory and the Database

The databases required to be developed as part of the Malé Declaration reporting requirement are an integral part of the emissions inventory.The worksheets containing data in the Malé Declaration database format are named as Table 1.1, Table 1.2 (a), etc.

2. Energy Consumption and Fuels

This section explains the source data and compilation of energy demand and supply for Pakistan.The statistics are included in the MS Excel File H0BL1MAL_Energy.xls.Unless otherwise stated, the worksheets referred to throughout this section are a part of this file.A list of worksheets in the file and their contents are provided in the worksheet table of contents (TOC).

2.1 Energy Flow Scheme

A simplified schematic diagram of energy flow is shown in the worksheet Flow Diagram.Imported fuels include petroleum products, crude oil, liquefied petroleum gas (LPG), and coal.Coal is imported only to produce coke at the Pakistan Steel Mills, Karachi.High speed diesel and furnace oil are the two main petroleum products that are imported.These two fuels comprise more than 95 percent of the total petroleum imports. More than 60 percent of the crude oil processed by the four refineries in the country is imported.

Primary fossil fuels produced indigenously include natural gas, oil, and coal.About 35 percent of the electricity is produced by hydropower plants.Nuclear power plants contribute less than 0.5 percent.Locally produced coal is used only at two power plants and in the brick kiln industry.In the Flow Diagram, fuel for power generation is shown to come directly from refineries, gas production companies, and coal production companies.In reality, the route is much more complex.Petroleum products are supplied to power plants by petroleum marketing companies and are also imported directly.Similarly, natural gas is supplied by transmission and distribution companies.However, for the sake of simplicity, these routes are not shown in the diagram.

The last stage of the energy flow, distribution of fuels from the distribution companies to the end-users, is shown through various letters instead of lines.Fuels used for thermal power generation include furnace oil, diesel coal, and natural gas.Small quantities of gasoline, kerosene, and light diesel oil are also consumed in the power generation industry.Exhibit A.1 on the following page summarizes the energy utilization in the industrial, domestic, and transportation sectors.

The database of energy consumption by year is included in the worksheet Table 1.1.A key to the database is provided in the worksheet Energy Diagram Key.The key provides a correspondence between the database and the energy flow diagram.The reference numbers of cells shown in red in the key also appear on the energy flow diagram at the appropriate position in the energy chain.One sector, shown as ‘Other’ in the energy flow diagram and the database, is explained later in Section 2.2.


Exhibit A.1: Utilization of Energy in the Industry, Domestic, and Transportation Sectors
 
Fuel
Industry
Domestic
Transportation
Residential
Commercial
Agriculture
Coal
aBrick Kilns

aSteel Mills

aCooking
Gasoline
aRoad Transportation
Kerosene
aLighting

aCooking

aSpace Heating

Diesel
aBoilers and Furnaces
aFarm Machinery
aRoad Transportation

aRailway

Light Diesel Oil
aEngines for Water Wells
Furnace Oil
aBoilers and Furnaces
aRailway
LPG
aCooking
aCooking
aRoad Transportation
Natural Gas
aBoilers and Furnaces

aFeedstock for Fertilizer

aCooking

aSpace Heating

aWater Heating

aCooking

aSpace Heating

aWater Heating

aRoad Transportation (CNG)
Biomass
aBagasse in Sugar Mills for Boilers

aFuelwood in Brick Kilns

aCooking

aSpace Heating

aWater Heating

aCooking
Electricity
aLighting

aMotors and Equipment

aLighting

aAppliances

aLighting

aAppliances

aElectric Pumps for Water Wells
aRail

2.2 Source of Energy Data

All modern fuel (fossil, hydel, and nuclear) consumption, supply, and production data has been obtained from various editions of the Pakistan Energy Yearbook, prepared by the Hydrocarbon Development Institute of Pakistan.In this report, the term ‘Yearbook,’ unless otherwise mentioned, refers to the Pakistan Energy Yearbook.

The Pakistan Energy Yearbook gives fuel consumption and production data in both metric tonnes and Pakistan tonnes of oil equivalent (toe).The latter unit has been defined by the Ministry of Petroleum and Natural Resources for use in Pakistan and is equal to 41.895 MMBtu (Million British Thermal Units).To avoid any confusion, the abbreviation ‘Ptoe’ is used throughout this document for Pakistan tonne of oil equivalent, whereas ‘toe’ refers to the international tonne of oil equivalent (equal to 41.686 MJ or 39.683 MMBtu).

Since it is a Malé Declaration reporting requirement that the energy consumption database be developed in terms of MMtoe, an intermediate worksheet Table 1.1 (Source Units) has been used for data entry.This worksheet contains data as it appears in the sources, ie, in the units used in the source data table.To minimize errors in data entry, the source data is not manipulated before it is entered in the database.The gray-shaded cells in the worksheet Table 1.1 (Source Units) contain numbers in exactly the same form as they appear in the source data.In cases where it is required that, for example, two numbers from the source be added before making an entry in a cell of the worksheet, the numbers are entered as a formula in the cell.Thus, all manipulation on the source data is done within the worksheet.The beige colored cells contain such formulas.

The methodology for data extraction and the rationale behind it is explained below:

1.The Pakistan Energy Yearbooks reports figures on the fiscal year basis.In Pakistan, the fiscal year starts on July 1st and ends on June 30th of the following calendar year.In this database, the figures shown for a particular year cover the first six months of that year and the last six months of the previous year.Thus, the data shown for 1980 corresponds to the fiscal year 1979-1980.

2.In general, each edition of the Yearbook gives data for the previous 6 years.For example, Pakistan Energy Yearbook, 1999 contains data from 1993-94 to 1998-99.In some cases, the figures for previous years are revised in the later editions.Wherever such changes have taken place, it has been assumed that the figures in the later editions are more accurate and they are used in the database.Thus, for example, the 1993-94 data is taken from the 1999 Yearbook and not the 1994 Yearbook.

3.The Yearbook gives the consumption figures for motor spirit and high octane blending components (HOBC).The consumption figures for Methyle Tertiary Butyle Ether (MTBE) are lumped with motor spirit in the yearbook.The gasoline consumption shown in the database includes, motor spirit, MTBE, and HOBC.Since these fuels have different calorific values, the total energy value of the fuels consumed, expressed in Ptoe, is extracted from the Yearbook rather than the tonnage.

4.Consumption figures for aviation fuels such as JP-1 and JP-4 are not given separately in the Yearbook.Again, for the reasons discussed in the previous point, the total energy value of aviation fuel consumption, expressed in Ptoe, is extracted from the Yearbook and not the tonnage.

5.The Yearbook does not contain the sectoral breakdown of LPG consumption figures.Only the total supply, ie, production and import, is given, which is assumed to be equal to consumption.The sectoral breakdown given in the database is based on the study reported in ENAR, 1992.According to this study, LPG consumption in the residential, commercial, and transportation sectors is 60 percent, 20 percent, and 15 percent of the total consumption, respectively.About 5 percent is consumed in other sectors.

6.Diesel consumption in tractors used in the agriculture sector is included in the transportation sector consumption in the Yearbook.

7.Figures for the energy consumed during crude oil processing are not separately available.It is assumed that this consumption is equal to the difference between the energy value of crude oil supplied to the refineries and the energy value of the products.This difference is expressed as follows:

Where,

ER =Energy consumed in crude oil processing (in Ptoe)

EI =Quantity of imported crude oil processed (in Ptoe)

EL =Quantity of local crude oil processed (in Ptoe)

EP =Quantity of total petroleum products (in Ptoe)

WN =Weight of non-energy petroleum products

HN =Equivalent heat content of non-energy products.IPCC, 1996 recommends a value of 40.19 GJ/tonne (0.90924 Ptoe/tonne).A value of 0.91 Ptoe/tonne has been used in the database.

8.In the above formula, the values for ER, EI, EL, EP and WN have been obtained directly from the Yearbook.However, for the first four years (1980, 1985, 1990 and 1991), the quantities of imported and local crude oil processed by the refineries are not given separately in the Yearbook.Only the total weight of crude processed is available.Thus, the total energy value of the processed crude is not known.To calculate this the following procedure is adopted: 

For 1992-1998, 37.5 percent of crude processed in the all refineries was local, whereas, the remaining 62.5 percent was imported.It is assumed that this ratio was the same before 1992.Further, it is known that the energy value of imported crude is 1.0338 times the energy values of the local crude oil (the calorific values of different fuels are discussed later).Thus, the energy value of the crude processed in the refineries (ER+EL) was set equal to:

WC * (0.375 + 0.625 * 1.0338)

where, WC is the total weight of the crude processed in the refineries (in metric tonnes).

9.In the Yearbook, industrial consumption of natural gas is given separately for the cement, fertilizer, and ‘general’ industries.The fertilizer industry uses natural gas as both fuel and feedstock.However, separate consumption figures for these are available only after 1997.For years prior to 1997, the Yearbook recommends that feedstock consumption be assumed as 60 percent of the total natural gas consumption in the fertilizer industry.Thus, for years before 1997, the industrial natural gas consumption is the sum of the consumption in the cement and general industries and 40 percent of the fertilizer industry’s consumption, as given in the Yearbook.The feedstock consumption in the fertilizer industry is shown under the column ‘Other.’

10.Natural gas consumption at the gas processing plants has been obtained directly from the ‘Primary Energy Balance Sheet’ of the Pakistan Energy Yearbooks.The number represents the difference in energy value of the gas supplied to the processing plant and that supplied by the processing plant to the transmission companies and consumers.The numbers in the balance sheet are given in Ptoe.The volume of equivalent gas is obtained using the calorific value of 980 Btu/cf.The gas processing plant consumption for 1980 and 1985 is not available.

11.Non-energy oils include lubrication oil, solvent oil, turpentine, asphalt, grease, wax, process oil, and carbon oil.The production data for these oils for 1980, 1985, 1990 and 1991 is not available.

12.The electricity consumption figure is based on the electricity supplied to the consumers by public utilities.Electricity produced by captive power plants is not included.

13.Apart from sectoral electricity consumption, the electricity produced by hydel and nuclear power plants is also shown.The electricity produced by these two sources, after deduction of transmission and distribution losses (approximately 26 percent), is already included in the total electricity consumption figures.The production figure for hydel and nuclear energy is shown under the ‘Other’ column only for convenience of presentation and does not imply consumption in this sector.

14.The last column “Other Uses” includes the following:

cConsumption of petroleum products, including non-energy oils, directly by the government agencies

cBulk supply of electricity, and electricity used for street lighting