Spatio-temporal estimation of landfill gas energy potential: A case study in China

Abstract

Municipal solid waste (MSW) landfills are among the largest anthropogenic sources of methane. However, there are also potential sources of landfill gas (LFG), which can be used to produce energy products, meaning that the recycling of LFG has gained global attention. Scientific evaluation of spatio-temporal LFG recycling potential is necessary to accelerate the promotion of LFG utilization. However, for a big country with uneven regional development level like China, the amount of LFG that can be recycled and utilized is difficult to determine, and there has been limited research that considers variation in regional characteristics, landfill sites and technologies. Therefore, this research first used sub-regional parameter sets that embodied the MSW characteristics of different regions to calculate LFG generation in China from 1990 to 2020. Next, this research estimated the LFG recovery potential for different regions in 2020 based on analysis of LFG collection and utilization technology, including technical parameters and application in different landfill sizes. The results showed that LFG generation in China will reach peak value around 2019 (3.49 billion N m3 of methane), and decrease quickly after that. The quantity of LFG with the utilization condition in 2020 will be 3.30 billion N m3, which could produce 7.39 billion kW h of electricity or 1.70 billion N m3 of bio natural gas. This could substitute 85.5% of electricity consumption or 25.3% of natural gas consumption in the transportation sector in 2014 (8.63 billion kW h and 6.74 billion N m3 respectively). Moreover, the findings show that the peak in LFG generation and a massive closure period of Chinese landfills will coincide. This will provide an opportunity to promote LFG utilization during the closed field management of landfills. Overall, LFG recycling presents a strong opportunity, and is in urgent need of promotion policies.