Energy gases and related carbon emissions in China

• Compositions, NCVs, resource distributions and productions of energy gases are studied.
• Chinese-specific carbon contents by gas type and by consuming sector are calculated.
• They are all lower with narrower confidence intervals compared to IPCC’s values.
• Development prospects and carbon emissions are evaluated for main utilization sectors.
• Policy suggestions are given to promote the development of gas energy.

With increasing energy demand and environmental problems in China, energy gases, such as natural gas(NG), coalbed methane(CBM) and coke-oven gas(COG) are alternatives of coal with great potential due to abundant reserves and remarkable environmental superiority for carbon reduction. Based on a large number of sampling data derived from comprehensive field investigations, energy gases used in China are researched on their compositions, net calorific values(NCVs), resources distributions and annual productions firstly in this paper, and then the Chinese-specific carbon contents by gas type and consuming sector are calculated to establish basic data for accurate estimation of carbon emissions. Results show that Chinese-specific carbon contents for NG, CBM and COG are 15.19 kg/GJ [15.15–15.37 kg/GJ], 15.13 kg/GJ [14.72–15.39 kg/GJ] and 11.41 kg/GJ [9.95–12.34 kg/GJ], respectively. Compared to IPCC, both carbon contents of NG and CBM are in close proximity to the default value, while COG has an obviously lower carbon content. Little difference exists among carbon contents of NG utilized in four main sectors including industry, power generation, households and vehicles, while a relatively obvious difference exists among those of COG. Carbon emissions would be greatly reduced by increasing the share of gas consumption in each sector. The market circumstances, application technologies, development bottlenecks as well as emission reduction potentials are studied respectively for the four utilization sectors with bright prospects. Finally, effective policy recommendations are given on the development of energy gases for the purpose of achieving a win-win of economy and environment.