April 30, 2026

 

Pig-producing facility in China converts animal waste to high-value fertiliser and green energy

 

 

A large-scale pig farm on the outskirts of Shanghai, China, is proving that industrial agriculture doesn't have to be a burden on the environment.

 

The Songlin Ecological Agricultural Zone operates a "closed-loop" system that transforms animal waste into high-value fertiliser and green energy.

 

Located in Jinshan district, the facility raises approximately 80,000 hogs a year. While traditional farms of this size often struggle with the environmental impact of manure, Songlin has managed a 100% conversion rate of waste into resources.

 

Through a comprehensive recycling process, the system processes approximately 100,000 metric tonnes of pig waste annually, producing 3.65 million cubic meters of biogas. The resulting biogas slurry is used to fertilise farmland spanning 867 hectares nearby, saving ¥2 million (US$$290,000) in fertiliser costs.

 

Industry experts have praised this approach as a replicable and scalable model for zero-waste city development.

 

Fu Juanlin, general manager of the agricultural zone, said that what was once a troublesome pollutant has become a valuable resource through this system.

 

"The animal excrement and urine from the pigsties flow through pipes directly to anaerobic tanks, maintaining a closed-loop system that prevents any ground or atmospheric pollution, achieving zero emission of the pollutants," he said.

 

In the vegetable area of the agricultural zone, diluted biogas slurry, which comes from the anaerobic fermentation of pig waste, is sprayed on tomatoes and lettuce.

 

"We've created this complete 'pig waste-biogas-vegetable' cycle. The biogas slurry serves as high-quality organic fertilisers, and the carbon dioxide produced during biogas purification acts as an additional gaseous fertiliser, enhancing vegetable yield while thoroughly solving the waste pollution problem," said Fu, adding that the gaseous fertiliser can increase vegetable yields by around 20%.

 

The surplus biogas from this agricultural park is purified into biomethane gas, and is the first project in Shanghai where biomethane gas is integrated into the city's urban gas pipeline network.

 

"We have revolutionised the traditional use of biogas, truly converting agricultural waste into green energy," said Lu Qiang, deputy general manager of Shanghai Shenji Energy and Environmental Technology Co, partner of the agricultural zone for the biomethane gas project.

 

- China Daily