Current status and prospects of waste/agricultural methane emission control and resource utilization

After carbon dioxide, methane is the world's second largest greenhouse gas, with high warming potential and short lifespan, mainly from coal, oil and gas production, agriculture and waste treatment. The United Nations Environment Programme (UNEP) estimates that without tangible emission reduction measures, global anthropogenic methane emissions will increase by 20 million tonnes per year by 2030 to 50 million tonnes per year from current levels, compared to 2020 Annual emissions increase by 5%~13%.

Part 1 Current status

1. Methane emissions and resource utilization in agriculture (livestock and poultry manure)

In 2014, China's methane emissions from agricultural activities were 22.245 million tons, of which animal intestines, rice planting, animal manure management, and agricultural waste field incineration accounted for 44.3%, 40.1%, and 14.2%, respectively 1.4%. The comprehensive utilization of biogas using livestock and poultry manure and crop straw as raw materials has formed a certain scale. The biogas project uses livestock and poultry manure, crop straw and other organic wastes as the main raw materials (livestock and poultry manure accounts for more than ninety percent, followed by crop straw and other organic wastes). According to the data of the "2023 China Biomass Energy Industry Development Yearbook", the annual installed capacity and power generation capacity of biogas projects for power generation continued to rise from 2016 to 2022, with an installed capacity of 1.22 GW and an annual power generation capacity of 40 GW in 2022 100 million kWh, 3.3 billion kWh of on-grid electricity.

2. Methane emissions and resource utilization of waste treatment (garbage and sewage)

Compared with the energy sector and the agricultural sector, the total amount and proportion of waste disposal emissions are relatively small, but in recent years, as emissions continue to increase, the proportion of methane emissions has gradually increased. Methane-containing gas produced by domestic waste landfills and food waste fermentation is the key object of methane emission control and resource utilization of waste treatment. Methane from landfills can be recycled in a variety of ways, and power generation is still the mainstay. Methane production from anaerobic fermentation of waste can be generated by electricity, gas sales and organic fertilizers. According to the public data of a landfill methane collection and utilization, in 2022, its landfill gas power generation, heat sales and carbon trading revenue accounted for 94.3%, 1.1% and 1.5% of the company's total operating income, respectively.

Part 2 Opportunities and challenges

1. Methane emissions and resource utilization in agriculture (livestock and poultry manure)

In recent years, driven by the background of carbon peaking and carbon neutrality, the comprehensive utilization of biogas using livestock and poultry manure and crop straw as raw materials has broad prospects and has been supported by policies. However, methane emission control and resource utilization of agricultural activities face the following challenges:

First, the management system of livestock and poultry manure and straw collection, storage and transfer is not perfect, and the price fluctuates greatly;

Second, there is a lack of core technology for independent innovation, some technologies and equipment rely on imports, and the process technology needs to be improved;

Third, the project income is low, and only a few projects are running well under the strong subsidy and support policies of local governments, and the enthusiasm of social capital participation is not high.

2. Methane emissions and resource utilization of waste treatment (garbage and sewage)

The international community is highly concerned about methane emission control in waste treatment, and the methane emission satellite monitoring program of relevant international organizations has gradually covered methane leakage in landfills, and methane emission control and resource utilization in landfills will receive more and more attention. In addition, with the increasing number of landfill gas treatment projects, enterprises in the industry have gradually accumulated experience in project construction and daily operation, and the technical level has gradually improved, and the development space of the industry will be further expanded. However, methane emissions and resource utilization of waste treatment (garbage and sewage) face the following challenges:

First, the technical and economic cost of methane collection and purification of waste treatment is relatively high;

Second, under the guidance of the "zero landfill" policy of new domestic waste, the amount of new landfill has declined, and the gas production of existing landfills has shown a trend of "high before and then low", which weakens the prospect of resource utilization in the industry.