What are Biogas Generator Sets for Farms?

Biogas generator sets for farms are integrated energy systems that utilize agricultural waste, such as livestock manure, crop straw, and food waste, as feedstock. Through anaerobic digestion, this waste is converted into biogas, which then drives a generator set to achieve combined heat and power (CHP) production.

By employing high-efficiency internal combustion engines, waste heat recovery, and automated controls, these systems maximize energy output. They create value through multiple revenue streams, including electricity sales, fuel substitution, value-added organic fertilizer production, and carbon credit trading.

How Biogas Generator Sets for Farms Work

⏺ Feedstock Reception and Pre-treatment

Waste materials like manure, straw, and food waste are transported to a reception pit for temporary storage before entering the pre-treatment system. Here, processes such as heating via heat exchangers and degradation in hydrolysis tanks homogenize and partially break down the material. This enhances its biodegradability, creating optimal conditions for efficient biogas production in subsequent stages.

⏺ Anaerobic Digestion and Biogas Production

The pre-treated feedstock is pumped into anaerobic digesters. Under the action of specific, highly efficient microbial consortia, it undergoes mesophilic or thermophilic fermentation. Organic matter is broken down in this oxygen-free environment, primarily producing biogas (mainly methane and carbon dioxide) and digestate (a liquid-solid slurry). This stage is the core of the biogas generation process.

⏺ Biogas Purification

The raw biogas first passes through a biological desulfurization unit to remove corrosive hydrogen sulfide. It then enters a biogas upgrading system to further remove impurities like carbon dioxide, thereby increasing the methane concentration. This purification ensures the gas meets the fuel quality standards required for power generation or compressed natural gas (CNG) production.

⏺ Biogas Power Generation and Energy Utilization

The purified biogas is fed into the biogas gensets for farms, driving an internal combustion engine or gas turbine that powers a generator to produce electricity. The generated electricity can be fed into the public grid or used directly to power the farm and surrounding facilities, enabling energy self-sufficiency and surplus power export.

⏺ Digestate Resource Recovery

The post-digestion digestate is separated into solid and liquid fractions via a dewatering system:

Solid Digestate: Can be further processed into organic fertilizer for soil amendment in farmlands.

Liquid Digestate: After undergoing hygienization treatment, it can be applied to fields as liquid organic fertilizer, closing the nutrient cycle.

⚫ Safety and Emergency Measures

The system is equipped with a biogas flare. This safely combusts and disposes of biogas during generator maintenance, system faults, or periods of biogas surplus, ensuring safe and stable operation.

Biogas Generator Sets for Farms: Design Considerations

Feedstock Type for Farm-based Biogas Plants

The selection and blending ratio of feedstock is the most critical design factor, directly influencing the technological pathway, pre-treatment requirements, and project economics.

corn	wheat	barley	rye
beet pulp	sugar beet residue	palm kernel shells	forage
corn straw	crop straw	fruit tree pruning waste	garden waste
cow dung	poultry manure	Food processing waste	sewage sludge

1. Livestock Manure

Dairy/Beef Cattle Manure: High volume, high moisture content, balanced carbon-to-nitrogen (C/N) ratio. Serves as an excellent base feedstock, providing essential microorganisms and nutrients for the digestion system.

Pig Manure: Higher organic content and biogas potential than cattle manure, but may require control of ammonia nitrogen concentrations.

Poultry Manure: High nitrogen content, low C/N ratio. Typically requires blending with high-carbon materials (e.g., straw) to avoid system inhibition.

2. Energy Crops

Specially cultivated corn, rye, barley, forage grasses: High biogas yield per ton, high energy density. Involves cultivation costs and potential land-use controversies (energy vs. food).

3. Agricultural Residues

Corn stover, wheat straw, barley straw, grain straw: Rich in cellulose, high biogas potential. Requires pre-treatment (e.g., shredding, ensiling) to improve degradation rate. Collection and transportation costs must be considered.

4. Agricultural Processing By-products

Beet pulp, sugar beet pulp: High sugar content, easily degradable, fast biogas production rate. Acts as an efficient co-substrate.

5. Food and Organic Waste

Food processing waste, food waste, municipal organic waste: High organic content, significant biogas potential. Often comes with tipping fees. Requires strict sorting and pre-treatment (e.g., removal of plastics, metals).

6. Landscape and Wood Waste

Yard waste, grass clippings, bark, wood: High lignin content, slow degradation. Often requires pre-treatment (e.g., chipping, composting) or mixing with more easily degradable feedstocks.

7. Other Organic Waste

Sewage Sludge: Stable supply source, but relatively low biogas yield. Commonly used in co-digestion.

Palm Kernel Shells: High hardness, requires crushing. Provides sustained biogas production, suitable for thermophilic or extended digestion processes.

Scale and Capacity

If you want to know the detailed parameters of biogas gensets for farms, please click here.

Advantages of Biogas Generator Sets for Farms

✔️Efficient and Complete Resource Conversion

The system fully converts waste like manure and straw into biogas and organic fertilizer, achieving comprehensive resource utilization and enhancing feedstock value.

✔️Highly Automated Operation

Integrated control panels, CAN bus, and HMI interfaces enable intelligent monitoring and adjustment of the entire process, spanning from gas mixing and pressurization to power generation and grid connection, thereby ensuring stable system performance.

✔️Flexible and Diverse Energy Output

The generated electricity can be used on-site or sold to the grid. Waste heat recovered during power generation can be used for digester heating or other thermal applications, boosting overall energy efficiency.

✔️Significant By-product Value

The digested slurry, after solid-liquid separation, yields solid organic fertilizer for soil improvement. The treated liquid fraction serves as liquid fertilizer, creating a closed-loop "waste-to-energy-to-fertilizer" value chain.

✔️Strong Feedstock Adaptability

Capable of co-processing various organic wastes (manure, straw, food waste, etc.). Supports flexible feedstock blending based on local supply, reducing collection and pre-treatment complexity.

✔️Flexible and Adjustable Configuration

Offers multiple power models from 400kW to 2000kW. System capacity can be matched to the farm's feedstock volume and energy demand, supporting phased construction and expansion for more rational investment.

✔️Environmental Compliance and Carbon Revenue

Achieves waste harmless treatment and greenhouse gas reduction. Generates stable income from electricity sales and extra revenue from commercial organic fertilizer. Additionally, the generated carbon emission reductions can be traded in carbon markets, directly translating environmental benefits into economic returns.

✔️Safe and Reliable System

Equipped with a biogas flare, gas purification units, and multi-stage control valves (e.g., gas control valves, exhaust bypass valves) to ensure safe gas disposal during maintenance or surplus conditions, guaranteeing long-term, stable operation.

Applications

Agriculture and animal husbandry are among the most widespread and mature fields for biogas power generation technology. By using anaerobic digestion to process organic waste like manure and crop residues, farms not only achieve resource recovery and effective control of odors and pollutants but also generate significant economic benefits through power generation for grid sale or self-consumption.

Many farms also introduce external organic waste streams like food waste or food processing residues for co-digestion to enhance biogas yield and project stability.

Example: PepsiCo Songjiang Factory Waste Resource Utilization Project (2023)

Location: Songjiang District, Shanghai, China

Treatment Capacity: Sludge 8500 t/year, Potato Peels 1500 t/year, Waste Potatoes 6005 t/year, Food Waste 55 t/year

Biogas Production: Average 4000 m³/day (Jan-May), Average 8000 m³/day (Jun-Dec)

Choosing the Right Biogas Technology Provider

⏺ Proven Experience

Request case studies and conduct site visits to reference projects with similar feedstock characteristics.

⏺ Technical Compatibility

Does the supplier specialize in wet/dry, mesophilic/thermophilic process systems suitable for your specific waste stream?

⏺ Compliance & Certification

Ensure their systems comply with all local regulations (e.g., PAS 110 standard, ABPR - Animal By-Products Regulations).

⏺ Long-term Support

Can they provide maintenance contracts, spare parts supply, and technical support services?

⏺ Financial Stability

The supplier should be a reliable and stable partner throughout the project's lifecycle.

⏺ Comprehensive Service Capability

Can they assist with planning, financing, and operational training?