High-Solids Biogas Plant in Liaoning, China – Powered by PLUG FLOW Technology

Arciplug®’s biogas plant in Liaoning, China is designed to process cow manure efficiently using advanced PLUG FLOW technology. The facility demonstrates the system’s ability to handle high-solids agricultural waste streams while maintaining excellent biogas yield, stable operation, and high-quality fertilizer output.

Arciplug® PLUG FLOW technology can process cow manure with dry matter content from 15% up to 40%, directly and without the need for additional water. This makes the plant particularly suitable for high-solids manure, such as manure from beef cattle farms, where the manure can be collected without urine. The solid, structural composition of this raw material allows direct use in the digester – no dilution, no pre-treatment.

By contrast, cow slurry from dairy farms, which contains urine and has a much lower dry matter content (around 7%), is too fluid for direct use in PLUG FLOW systems. However, it can still be utilized after mechanical dewatering (e.g., screw press) to reach the required 15% minimum solids—expanding Arciplug®’s applicability across various farm types.

Although the Liaoning plant was designed for cow manure, maize straw was also considered as a potential co-substrate during the project planning phase. This highlights a key advantage of Arciplug® PLUG FLOW technology: its ability to process a wide range of organic feedstocks, including fibrous or contaminated materials that are often unsuitable for traditional digestion systems.

Whether operating with mono-substrates like cow dung or more complex mixtures such as manure and straw, the system ensures stable digestion, high methane yields, and minimal operational disruption. This flexibility allows operators to adapt to feedstock availability and reduce dependency on a single waste stream.

How anaerobic digestion works in Arciplug® systems

Anaerobic digestion is a biological process that converts waste into renewable energy.
In Arciplug® systems, bacteria break down biodegradable cow manure in the absence of oxygen, producing biogas and a nutrient-rich digestate. This process significantly reduces odors and pathogens typically associated with manure storage. The remaining digestate retains all the valuable nutrients found in raw manure, making it a high-quality organic fertilizer suitable for use on crops while closing the nutrient cycle.

Why cow manure works exceptionally well in PLUG FLOW digestion
Cow manure is well-suited for mono-digestion, thanks to its balanced carbon-to-nitrogen ratio, high organic content, and the natural presence of fermentation bacteria. The fibrous material in the manure has already been partially broken down in the cow’s digestive system, which accelerates microbial activity in the digester. Combined with a low presence of inhibitors and good buffering capacity, this makes cow manure a technically stable and economically attractive substrate.

While high lignin and nitrogen levels in cow manure can pose challenges in traditional systems—especially under thermophilic conditions due to free ammonia accumulation—Arciplug®’s PLUG FLOW technology effectively overcomes these limitations. The system maintains a stable microbial environment, tolerates varying ammonia concentrations, and delivers superior methane yields—up to 220 Nm³ CH₄/VS-ton—with lower energy consumption and higher process efficiency than conventional CSTR systems.

Moreover, Arciplug®’s technology is resilient to common inhibitors such as antibiotics, which often hinder microbial activity in traditional digesters. This ensures uninterrupted gas production and long-term operational stability, even with manure from antibiotic-treated herds.

High-value fertilizer from digested cow manure

Thanks to controlled anaerobic digestion, the resulting digestate is both hygienic and agronomically valuable. Odor emissions are significantly reduced, pathogens are eliminated, and nitrogen is converted into a plant-available, water-soluble form. The digestate can be applied as either solid or liquid fertilizer, improving crop uptake and reducing nutrient loss to the surrounding environment.

Compact and efficient gas storage on top of the digester

A unique feature of this facility is the gas storage unit installed directly on top of the reactor—a rare and technically advanced solution that enables efficient gas management within a compact site layout.

A climate-smart solution for agriculture

Cattle farms are the single largest source of agricultural greenhouse gas emissions, with one cow producing up to 100–120 kg (220 pounds) of methane annually.
Emissions from cattle production originate from cow bedding (methane), manure handling (methane, nitrous oxide), feed production (CO₂, N₂O), and energy use. Treating manure in biogas systems can reduce these total emissions by up to 30%, making it one of the most effective climate actions available on farms.

Biogas systems offer a practical climate solution: they reduce methane emissions from manure storage and replace fossil fuels with renewable biomethane. This enables dairy and beef farms to significantly reduce their environmental footprint and at the same time make manure a profitable raw material. This process is known as upcycling.
Arciplug® offers a scalable, practical solution that turns agricultural emissions into clean, local energy.

Project execution

Arciplug® supported the project with technical design, licensing, and project management. The plant was contracted in April 2021, construction began in spring 2022, and commissioning was completed in March 2023. EverBright served as the EPC contractor, ensuring successful delivery of a high-performance biogas facility.

PLUG FLOW Technology & Key Figures

Arciplug®’s scope of design and delivery for the Liaoning project includes the following areas: