Biogas from industrial wastewater: Technologies and yields by sector

La energy recovery from industrial liquid waste It has become one of the main strategies for moving towards more sustainable and efficient production models. 

In this sense, biogas from industrial wastewater represents a real opportunity to reduce energy costs, minimize waste and decrease the carbon footprint of multiple productive activities.

Sectors such as food, dairy or agro-industrial generate effluents with a high organic load that can be transformed into renewable energy through anaerobic biological processes. 

This capacity for utilization has driven the development of increasingly efficient technologies for the biogas generation from industrial effluentsespecially in sectors with intensive water and energy consumption.

In recent years, the industry has also begun to integrate water management and bioenergy within the same framework. circular economy strategy. 

Specialized companies such as ZITHER We develop solutions that allow the transformation of waste and liquid streams into energy resources, simultaneously reducing the environmental impact of industrial processes.

How is biogas produced from industrial wastewater?

Biogas production from industrial wastewater is primarily based on anaerobic digestion, a biological process in which different microorganisms degrade organic matter in the absence of oxygen.

During this process a gaseous mixture is generated composed primarily of methane (CH4) and carbon dioxide (CO2)Known as biogasThis gas can be used to produce electricity, heat, or even to become biomethane for injection into the grid or use as a renewable fuel.

If you want to know more about this topic, we invite you to read this article → What is an anaerobic reactor, what is it used for, and in which industries is it useful?.

Industrial wastewater with a high organic matter content is particularly suitable for this type of treatment:

• Effluents from the food industry.
• Dairy liquid waste.
• Vinasse and distillery streams.
• Brewery effluents.
• Agro-industrial by-products.

The great appeal of this model is that it allows converting a cost associated with waste treatment into arenewable energy source and operational savings.

Anaerobic technologies used in biogas generation

Biogas production from industrial wastewater is primarily based on anaerobic technology capable of transforming organic matter into renewable energy. 

This technology allows the valorization of organic matter present in wastewater through specific biological reactors capable of generating biogas with a high methane content.

UASB reactors

The UASB reactors (Upflow Anaerobic Sludge Blanket) They are one of the most widely implemented technologies in the anaerobic treatment of industrial wastewater.

Its operation is based on a upward flow of wastewater through a layer of anaerobic sludge composed of granular biomass. During this process, microorganisms break down the organic matter and generate biogas.

UASB reactors allow the treatment of up to 15 kg COD (Chemical Oxygen Demand)/m³/day and stand out for:

• • Significantly reduce energy consumption.

• Reduce sludge production.
• Promote the generation of biogas.
• To offer a stable and efficient operation.

This technology is commonly used in biogas production in the food industry due to the high biodegradability of its effluents.

EGSB Reactors

The EGSB reactors (Expanded Granular Sludge Bed) They are an evolution of UASB systems and are designed to work with higher hydraulic speeds y higher organic loads.

Its main difference is the external recirculation and the greater upward flow, which improves the contact between the wastewater and the anaerobic biomass and allows for increased efficiency in the removal of organic matter and improved biogas performance by industrial sector.

EGSB reactors can achieve loads of up to 25 kg COD/m³/day and require less installation area than UASBs.

IC reactors 

IC reactors (Internal Circulation) They represent one of the most advanced anaerobic technologies for the treatment of biogas from industrial effluents with high organic concentrations.

these systems They incorporate an internal recirculation mechanism powered by the gas generated during the process, which improves biomass retention and increases treatment efficiency.

This technology It can work with loads of up to 35 kg COD/m³/day and offers significant advantages in facilities with space limitations.

Biogas yield by industrial sector

Biogas yield by sector depends mainly on the composition of the wastewater, the concentration of organic matter, and the degree of biodegradability of the effluents.

Food & beverage industry

In general terms, the agri-food industries present one of the greatest potentials for the production of biogas from industrial wastewater, since they generate streams with high concentrations of sugars, starches, fats and biodegradable organic matter, which favors high levels of energy production.

Dairy sector

The dairy sector stands out for generating effluents with a high concentration of fats, proteins and lactose, highly biodegradable compounds that favor a high production of methane.

Dairy industries are considered particularly suitable for the implementation of anaerobic systems due to the stability and biodegradability of their waste streams. 

In addition to energy efficiency, this type of solution allows for...reduce purification costs and minimize the generation of sludge associated with conventional treatment.

Brewing and beverage industries

During the processes of making beer, soft drinks or fermented beverages, effluents with a high organic load and a high capacity for anaerobic biodegradation are produced.

In many cases, the biogas generated from industrial effluents is used directly in cogeneration systems to produce electricity and heat within the factory itself, reducing the consumption of fossil fuels and improving the energy sustainability of the facility.

Read this article about our role as a strategic partner in promoting biogas in Spain → SITRA becomes the strategic player in boosting the biogas industry in Spain.

Factors that influence biogas performance

Biogas yield by sector does not depend solely on the type of industry. There are multiple operational variables that influence the final energy production:

• Organic load: The higher the concentration of biodegradable organic matter, the greater the potential generation of methane.
• Operating temperature: Anaerobic digestion requires stable conditions to maximize microbiological activity.
• Presence of inhibitors: Certain chemical compounds, fats, or sudden pH changes can negatively affect the biological process.

• Technological design: The correct selection of the reactor and control systems is key to optimizing the biogas potential in industrial sectors.

SITRA's solutions for industrial biogas production

Biogas production from industrial wastewater requires a integral approach that combines engineering, water treatment, energy recovery and specialized operation. 

In this ambit, ZITHER It develops solutions aimed at transforming liquid waste and industrial by-products into renewable energy resources.

• Design and implementation of anaerobic reactors.
• Feasibility studies.
• Engineering and construction of biogas and biomethane plants.
• Upgrading services for the transformation of biogas into biomethane
• Crop protectors operation and maintenance of facilities.
• Management and valorization of by-products.

➡️ Contact with SITRA to develop biogas production solutions from industrial wastewater tailored to the needs of your sector.