China’s Fourth-Generation Grain Silos Begin Operations

China has taken a major step forward in modernizing its national grain reserve system. On July 24, approximately 1,000 tons of soybeans were loaded into the first batch of domestically-produced 9,000-ton grain membrane silos at the Sinograin Changsha Direct Depot in Hunan Province, marking the first grain-loading and pressure-testing operation since construction completion, according to Xinhua News.

These silos represent China’s fourth-generation grain storage facility type, entering a new phase of practical application. Each silo stands 33.6 meters high—equivalent to an 11-story building—with a storage capacity of 9,000 tons and a diameter of 24 meters. Five such silos now stand at the Changsha depot, providing a combined storage capacity of 45,000 tons.

A ‘Sandwich’ Design for Superior Performance

Unlike the first three generations of granaries, the fourth-generation grain membrane silo features a distinctive three-layer “sandwich” integrated structure, explained Jin Yuyang, warehouse keeper at the Sinograin Changsha Direct Depot. The outer layer consists of high-molecular PVDF membrane material that is waterproof, flame-retardant, and resistant to heat radiation. A middle polyurethane insulation layer provides thermal protection, while an inner reinforced concrete structural layer bears the weight of the grain pile.

This design delivers remarkable performance gains. Wang Yaowu, deputy general manager of the Changsha depot, noted that the silos’ airtightness exceeds national high-standard grain warehouse requirements by more than six times, while thermal insulation performance is approximately three times that of traditional granaries. The enhanced airtightness means nitrogen gas conditioning—used to create a nearly oxygen-free environment that prevents pests and preserves grain quality—requires significantly less energy, with a single inflation maintaining conditions for extended periods.

Smart Technology at Scale

Each silo is equipped with a “smart nervous system” comprising 27 temperature-measuring cables with 14 sensors per cable, totaling 378 sensors per silo. These sensors monitor grain temperature in real-time, transmitting data to an intelligent control center that displays conditions on large screens in the depot’s control room.

The intelligent system extends beyond temperature monitoring. Xiong Xixi, another deputy general manager at the Changsha depot, described how the system automatically maintains optimal storage conditions: “If nitrogen concentration falls below the preset value, electric valves will open, nitrogen generation units will start to replenish nitrogen, maintaining the nitrogen concentration inside the silo to ensure the most suitable safe grain storage environment is always maintained.”

The combination of superior insulation and smart control systems keeps grain pile average temperatures below 15 degrees Celsius, achieving low-temperature storage that slows grain deterioration and inhibits mold growth.

Significant Energy and Cost Savings

According to People’s Daily, the membrane silos deliver substantial operational efficiencies. Compared to traditional silos, grain cooler electricity costs are reduced by 4.33%, air conditioning electricity costs by 50%, and gas conditioning usage by 16.79%. Overall operation and maintenance costs are expected to be reduced by more than 30%.

Construction itself is also more efficient. Jin Feng, project manager at China Coal Construction Group’s 68th Company, told Hubei Daily that the insulation and reinforced concrete layers are all constructed inside the inflated membrane, making the process completely unaffected by adverse weather. Traditional construction required over a hundred workers; now only 18 are needed, and the construction period is shortened by a quarter compared to previous-generation shallow round silos.

100% Domestic Innovation

The grain membrane silo was 100% independently developed by a joint team from Sinograin Chengdu Storage Research Institute and China Coal Construction Group, overcoming more than 20 key technical bottlenecks and achieving one world-first technology. Wang Yue, director of the Engineering Design Center at Sinograin Chengdu Storage Research Institute, explained that the team focused on five key technologies addressing critical pain points in grain storage, including high-airtightness sealing, all-climate adaptability, and efficient insulation and temperature control.

Xiang Yi, a registered structural designer at the institute, recalled the early skepticism in an interview with China News Service: “Regarding whether the grain membrane silo is reliable and stable, there were indeed differing opinions at the start of the project. Some worried about structural instability, others worried about grain spoilage accidents. But the R&D team remained true to their original intention and saw it through to the end.”

The project’s significance was recognized nationally when it was listed among the “2022 Top Ten Super Projects of Central SOEs,” alongside the China Space Station and the Baihetan Hydropower Station. In June 2026, the National Food and Strategic Reserves Administration further recognized the grain membrane silo among 132 outstanding scientific and technological achievements from the “14th Five-Year Plan” period.

Broader Transformation of China’s Grain Storage

The membrane silo deployment is part of a wider transformation of China’s grain storage infrastructure. According to Xinhuanet, during the “14th Five-Year Plan” period, China’s standard grain warehouse capacity exceeded 730 million tons, with 220 million tons of capacity having low-temperature or quasi-low-temperature storage capability. Nitrogen gas conditioning storage exceeded 55 million tons, and the comprehensive loss rate during storage cycles has been controlled within 1%.

The storage goals are shifting from “not losing a single grain” to “preserving every grain’s freshness,” according to the National Grain and Strategic Reserves Administration Science Research Institute. A “Five-in-One” green grain storage technology system is being promoted, encompassing warehouse performance improvement, efficient and environmentally friendly loading and unloading, intelligent monitoring and early warning, green comprehensive management, and efficiency evaluation.

Expanding Across the Country

Grain membrane silos are now being promoted and built in five locations across China: Chengdu (Sichuan), Changsha (Hunan), Suzhou (Jiangsu), Changchun (Jilin), and Huaibei (Anhui). Changchun is building China’s first 10,000-ton-class grain membrane silo, marking a key step from single-point breakthroughs to broader nationwide adoption.

Wang Yue acknowledged that adoption is still in its early stages: “Currently, the overall construction scale of grain membrane silos is still small, and the adoption rate is not high. As construction accelerates, warehouse keepers gain more experience, and storage processes are further optimized, grain membrane silos are expected to be rolled out more widely across the country, contributing to technology-based and green grain storage, and adding to food security.”

As China’s grain production continues to grow—surpassing 1.4 trillion jin (700 million tons) for the first time in 2024—the need for smarter, greener storage solutions becomes increasingly critical. The grain membrane silo represents a significant technological leap in ensuring that the nation’s harvest is not only stored securely but preserved with the quality and freshness that modern food security demands.