Biogas model

Program v. 1

Name and address

Country
Street
City
ZIP-code
Company name
VAT no.
Contact person
Mail address
Phone no.


Welcome to the calculation model in the ALFA project.

The model calculations can be used to provide an estimate of what biogas production can be expected based on the entered data. The calculations are based on general assumptions and average considerations. The calculations cannot be used for the design and dimensioning of a specific biogas plant, they can be used to estimate the expected biogas production based on the available biomass.

Disclaimer:

Please note that any information entered by the user into this tool is not stored or retained by the system. All data is processed temporarily and is automatically deleted upon exiting the program. Users are responsible for saving by printing their results, as no data will be preserved beyond the active session. If desired, results may be printed during use; however, it is the user's responsibility to securely store any printed or exported materials.

Farm description

Number of farms for the holding Number
Distance between farms km
The total area of the farms Hectares
Type and number of animals
Animaltype
Number of animals
Area for spreading the digestate Hectares
Water consumption m3/year
Volume of facilities to store manure m3
Electrical power consumption on farm kWh/year
Heat consumption on farm kWh/year
Distance to existing biogasplant km
Distance to gas network km


In this section, we would like to have basic information about your farm.

A holding can consist of several farms. If the holding consists of more than one farm, we would like to know how big these are and how far apart they are.

Under "Type and number of animals", several different ones can be selected.

Information about the area, water consumption, electricity and heat consumption is only for informational purposes for ALFA hubs if they are to provide a service to the user.

If there are existing biogas plants nearby or the possibility of connecting to another outlet for the biogas, this is important to know.

Biomass

Method 1:
Animaltype
Number of animals
Method 2:
Biomass category
Biomass type
TS (%)
VS/TS (%):
Sp. meth. pot. (Nm3/kgVS):
Amount (ton/year)


In this section, it is specified which biomasses are available for biogas production.

It is important to choose these biomasses, as it is these choices which are the calculation basis for the biogas production. It is possible to choose between four different categories of biomass. When you have chosen the categori, options appear in the box with biomass types.

When you have chosen a biomass type, some default values for the dry matter content and for the organic part of the dry matter appear in the boxes below. If you have more precise information for the biomass in question, you can enter these instead of the default values.

You have to select all the biomasses that are available and add them one at a time.

The program adds all the biomasses together and calculates the expected biogas production based on these.

Results

Biomass treated total tons
Methane production Nm3/year
Methane content in gas %
Biogas production Nm3/year
Biogasprod. pr. ton biomass Nm3/tons
Plant size power kW
Plant size heat kW
Investment (1000)
Total cost pr. year
Total income pr. year


Under results, you can see a tally of the mass of the entered biomasses, the expected biogas production and the methane content in the gas.

Recommendations

Under recommendations, an initial recommendation is given which depends on calculations of the expected biogas production based on the biomasses entered.

Please note that any information entered by the user into this tool is not stored or retained by the system. All data is processed temporarily and is automatically deleted upon exiting the program. Users are responsible for saving by printing their results, as no data will be preserved beyond the active session. If desired, results may be printed during use; however, it is the user's responsibility to securely store any printed or exported materials.

Environment

The production of biogas is a good idea for society in general, but also for the individual farmer, because:

  • It produces renewable energy
  • The farmer gets a better fertilizer from livestock manure
  • Odor nuisances are limited
  • The environment is saved from emissions of greenhouse gases
  • The environment is saved from discharges of nutrients
  • Organic waste is utilized and contributes to recycling

The physical and chemical change that occurs with the slurry in the biogas reactor gives a changed fertilizer effect in the field. The most significant change is the increase in the content of plant-available ammonium nitrogen. This is an advantage, as it is primarily the ammonium nitrogen that the plants can utilize. By using the degassed biomass as fertilizer, there is therefore the possibility of a higher harvest yield and a saving on the purchase of nitrogen in commercial fertilizer.

The thin and easy-flowing degassed slurry penetrates the soil relatively quickly. It helps to reduce the risk of ammonia evaporation.

When slurry is degassed, a number of substances which are always in the slurry are broken down. When using degassed slurry, the odor nuisance that may be associated with the application is reduced.

The risk of infection is reduced by processing the livestock manure in a biogas plant. The relatively long residence time at high heat reduces any infectious germs in the biogas reactor. If necessary, sanitization can be established at the biogas plant.

Society

In connection with the establishment of biogas plants, increased employment is typically created in an area. Especially in the establishment phase, local craftsmen can benefit. After establishment, an effort must be made in connection with operation and maintenance of the facility.

The local community can be proud of contributing to the solution of society-created climate and environmental problems and at the same time contributing to the production of local renewable energy.

In biogas plants, significant volumes of residues from agriculture, households and industry are digested, ensuring the recycling and reuse of the content of nutrients as fertilizer. With an intelligent use of biogas, these can be used to ensure the recirculation of phosphorus, which is a limited resource.

Biogas production has the potential to make a substantial contribution towards EU climate target for 2030.

The net climate impact of biogas exceeds the CO2savings from substituting fossil fuels.

Not only does biogas substitute fossil fuels, but it also reduces the carbon footprint from methane emissions during agricultural manure storage. However, biogas production also has a climate impact in the form of methane loss, energy consumption, and transportation of biomass and manure.

Proper management of the stables, combined with biogas, can significantly reduce the climate impact of livestock manure.


General Recommendations for the Mitigation of Environmental Impacts

Biogas production from manure and agricultural residues is widely recognized as a sustainable practice. The produced biogas can be used to generate both heat and electricity through combined heat and power (CHP) systems, or upgraded to biomethane for direct use as a renewable substitute to natural gas. However, despite the potential of these biofuels as green solutions, their overall production chain contains critical environmental hotspots that should be thoroughly examined.

To better understand the environmental outcomes of biomethane production, it is important to evaluate its environmental performance throughout its entire life cycle. By applying the Life Cycle Assessment (LCA) methodology, all environmental impacts linked to biomethane production are quantified and grouped into various representative categories. Thus, aggregated environmental factors such as Global Warming Potential (GWP), Terrestrial Acidification Potential (AP) and Freshwater Eutrophication Potential (EP) offer valuable insights into all impacts associated with climate change, soil integrity, and aquatic ecosystems, respectively.

Global Warming Potential (GWP)

The GWP impact category evaluates the potential contribution of a product or process to climate change, by quantifying all produced greenhouse gas (GHGs) emissions such as carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O). These gases are converted based on their heat trapping ability compared to CO₂, leading to the utilized metric unit of kg CO₂eq. The most common GHG emission sources in a biomethane production plant, alongside some reflective mitigation strategies are presented in the following table.

GWP Source Impact Mitigation Strategy
Transportation of biomass to the biomethane production plant (fuel consumption) Optimization of transportation logistics, reducing fossil fuel consumption and subsequent GHG emissions.
Operation of the upgrading unit (high electricity demands) Installation of renewable energy sources to meet the plant’s electricity and thermal demands.
Operation of the Anaerobic Digestion unit (natural gas boilers)
Operation of the upgrading unit (CO₂ emissions during purification) Capture and valorization of CO₂ as material for chemical compounds and building materials.
Upgrading & Anaerobic Digestion units (biogas/methane slips) Frequent equipment maintenance to ensure gas-tight operating conditions.
Storage of digestate (methane emissions) Implementation of closed storage conditions.
Spreading of digestate (methane emissions) Further digestate processing for ammonium sulfate ((NH₄)₂SO₄) production as soil fertilizer.

Terrestrial Acidification Potential (AP)

The AP impact category measures the capacity of acidifying substances, such as sulfur dioxide (SO₂), nitrogen oxides (NOₓ) and ammonia (NH₃) to affect the pH of soil, significantly reducing its quality. All the aforementioned compounds are converted based on their acidifying potential compared to SO₂, leading to the utilized metric unit of kg SO₂eq. Emission sources linked to AP in a biomethane plant and mitigation strategies are shown below.

AP Source Impact Mitigation Strategy
Storage of manure/digestate (NH₃ emissions) Implementation of closed storage conditions.
Spreading of digestate (NH₃ volatilization) Low-emission application techniques (e.g., trailing hose spreaders, injections).
Anaerobic Digestion unit (SO₂, NOₓ from boilers) Installation of renewable energy sources for heat and electricity.
Spreading of digestate (soil acidification) Regular soil testing to optimize digestate application rates.

Freshwater Eutrophication Potential (EP)

The EP impact category evaluates the potential of unregulated nutrient discharge, like phosphates (PO₄³–) and nitrates (NO₃–), into water bodies. This nutrient release causes excessive algal blooms that deplete oxygen levels and harm aquatic life. The following table lists key nutrient discharge sources and mitigation strategies.

EP Source Impact Mitigation Strategy
Storage of digestate (PO₄³– & NO₃– leaching) Closed storage and maintenance to ensure leak-proof conditions.
Spreading of digestate (nutrient leaching) Controlled spreading based on soil nutrient needs.
Spreading of digestate (excessive nutrients) Further processing (separation, extraction, evaporation) to produce commercial fertilizer substitutes.
Upgrading unit (nutrient-rich wastewater) Wastewater treatment using appropriate filtration systems before discharge.

The biogas plant tool

The purpose of this model is to provide users with information about the possibility of giving value to manure and agricultural by-products through the production of biogas.

Biogas plants are complex systems, and a complete evaluation of their feasibility would therefore require the analysis of a large number of parameters and cannot be done without the inspection of a specialized technician. In the same way, a complete and reliable economic evaluation would require very detailed information on the organization responsible for the plant realization (for example a farm). The information obtained summarize the results of an automatic calculation tool and cannot be considered a feasibility study nor a commercial offer.

If the user considers positive this results and wants to deepen the results can contact the technical staff of ALFA-project. The version currently available can be used freely. Entered data and the calculations performed are not saved. It is therefore necessary for users to print and save a copy of the material themselves.

The authors of the tool accept the responsibility for the contents of this tool to the extent indicated above. The authors cannot be held responsible for improper use of the results contained by the tool, which are purely indicative and are subject to change subordinated to modifications and corrections of the tool.

The European Commission is not responsible for the use that may be made of the results obtained by using the tool.