This is part IV of a blog series - A Primer on 2006 IPCC Guidelines for Emission Inventories.

Introduction

Industrial activities are the backbone of a country’s economy. At the same time, they also contribute to a significant amount of GHG emissions. Industrial activities imply chemical or physical transformation of materials. A few examples of this would be manufacturing of cement from limestone, use of blast furnaces in the metal industry or use of fossil fuels for non-energy purposes. In addition to this, certain products use greenhouse gases as an integral part of its activity. For example, N2O is used as a propellant in aerosol products, Hydrofluorocarbons (HFCs) are used in the refrigeration and lubrication industry, sulphur hexafluoride (SF6) is used in electrical equipment or even running shoes. Usage of such chemicals in industrial processes causes the release of these greenhouse gases. It is important to measure these emissions as well. It is important to highlight that in most cases, there is a significant delay in the manufacturing of such products and the release of the emissions. The delay may range from a few weeks to even a few years in some cases.. 

Sectoral Classification 

The IPCC classifies the sector into eight categories. 

Challenges with emission counting 

Emissions from the IPPU sector can often be confused with emissions from the energy sector. This is especially the case when fossil fuels are involved. It is almost impossible to differentiate between the use of fossil fuels for fuel combustion and industrial processes. In order to simplify the calculation, IPCC has formulated a rule, 

‘Combustion emissions from fuels obtained directly or indirectly from the feedstock for an IPPU process will normally be allocated to the part of the source category in which the process occurs. These source categories are normally 2B and 2C. However, if the derived fuels are transferred for combustion in another source category, the emissions should be reported in the appropriate part of Energy Sector source categories (normally 1A1 or 1A2).’

What this means is that whenever any fossil fuel is used for the purpose of energy generation, it should be calculated under the energy sector. However, if the fossil fuel is used for any other non-energy uses, then the resulting emissions from the process should be calculated under the IPPU sector. The non-energy uses can be as follows;

1. Feedstock: as a raw material for any industrial activity like chemical industry

2. Reductant: carbon can be used a reducing agent especially in the metal industry (electrolysis)

3. Non-energy product: certain by-products of the refining industry are used as chemical intermediates. For example, bitumen for roads, paraffin wax, or lubricants & greases. 

Quality control (QC)

In order to ensure that emissions are neither double counted or omitted, IPCC provides two quality checks. It is essential to check that all sources of non-energy fuel consumption are allocated in the correct sub-category (Quality control (QC) of documenting allocation) and that all the sources are counted singularly (QC of completeness). QC of completeness is done by energy balance based on national energy statistics. 

Other gases

Apart from carbon dioxide, gases like hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) are also calculated to be included in the inventory. There are two methods suggested for calculating emissions from these gases; (1) mass balance approach (2) emission factor approach. The mass balance method records the amount of material which is added and/or consumed and calculates the changes in the stock. The consumption of material during the production process is used in determining the emissions. The emission factor approach, on the other hand, determines the emissions associated with a production activity by multiplying it with an emission factor. 

Depending on the national circumstances and data availability, any approach may be chosen. The mass balance method is fairly accurate and has the advantage of reflecting actual emissions from that particular place. However, there are two drawbacks. One, the accuracy of the measurement of mass and density affects the emissions and second, at certain times, emissions are calculated after they occur. The emission factor approach, on the other hand, is dependent on the accuracy of the emission factor, which, in some cases, does not even exist. It is therefore important for any country to select the method based on the data availability and quality.

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