Feasibility study on merging biogas into the natural gas pipe-network in China

Biogas is one of the options to improve the current serious energy and environment situation in China. However, biogas application is limited in China due to instabilities in quantity and quality of biomass. These instabilities are largely influenced by the local environment and climate. Merging non-upgraded biogas into the natural gas (NG) distributing system can (i) increase utilisation, (ii) reduce carbon intensity of gas pipe network and (iii) promote renewable energy usages. However, merging biogas into the gas pipe network comes with lots of challenges. This paper investigates the approaches of merging biogas into the NG distributing system. The interchangeabilities between the mixed bionatural gas and the China's 12T standard gas are evaluated based on several indices. This study results indicate that the maximal mixing volume ratio of non-upgraded biogas to the typical piped natural gas is 14.7% when the Wobbe number and combustion potential are used as determining indices.