Determination of South African carbon dioxide emission factors for selected solid fuels

Abstract

South Africa’s National Climate Change Response Policy requires accurate reporting of greenhouse gas (GHG) emissions. To achieve this, the South African Department of Forestry, Fisheries and the Environment initiated a process to develop country-specific emission factors (referred to as Tier 2 factors by the Intergovernmental Panel on Climate Change (IPCC)) for fuels produced or used locally, which are more accurate than those currently used (Tier 1). In this work, we report on the development of such county-specific emission factors for the solid fuels most commonly produced and used in South Africa, based on the analysis of 107 samples. The samples received were classified into types based on the IPCC fuel classification method, which has some differences from that used in South Africa. The CO2 emission factor for sub-bituminous coal, mainly used for power generation and in the liquid fuels/chemical sectors of South Africa, was found to be 97 807 kg CO2/TJ. For ‘other bituminous coal’, the CO2 emission factor was found to be 101 171 kg CO2/TJ. These emission factors are higher than the IPCC default (also referred to as Tier 1) factors, which have been in use in South Africa to date. As solid fossil fuel use is a major contributor to South Africa’s GHG emissions, this implies higher than previously estimated CO2 emissions from this sector as well as a higher contribution to global emissions.

SIGNIFICANCE: • South African Tier 2 carbon dioxide emission factors for solid fuel use are reported for the first time, as required by South Africa’s commitments under the United Nations Framework Convention on Climate Change and the Paris Climate Agreement. • The Tier 2 carbon dioxide emission factors were derived from the analysis of over 100 South African solid fuel samples. • Emission factors for the fuels used in the largest amounts are higher than the default Tier 1 factors previously used, leading to an increase in reported emissions for a similar fuel use. • The main user of coal in South Africa, the power generation sector, uses sub-bituminous coal based on the IPCC classification system, which includes volatile matter as a classification criterion. • Using the same IPCC criteria, the majority of samples from other South African industrial and commercial users are classified as ‘other bituminous coal’.