Biogenic CO2 refers to carbon dioxide (CO2) that is produced by living organisms, such as plants and animals. Carbon dioxide (CO2) is present within the ‘raw’ biogas. But because of its inert nature, it is not combustible and therefore not required in the biomethane and Bio LNG fuels that are produced from the methane in the biogas. We give CO2 a second life in a number of industries.
What is biogenic CO2?
When living things breathe, eat, and grow, they release CO2 as a byproduct of their metabolic processes. This CO2 is considered biogenic because it is derived from biological sources. In contrast, fossil fuel combustion, which is a major source of CO2 emissions, produces CO2 that is considered non-biogenic because it comes from the decomposition of ancient plants and animals that were buried and subjected to heat and pressure over millions of years. Biogenic CO2 is not typically considered to be a significant contributor to climate change because it is part of the natural carbon cycle and is typically offset by the uptake of CO2 by plants through photosynthesis.
Our green solutions
Green Create produces biogas that we upgrade into many useful energy forms, such as Bio-Methane, Bio LNG and renewable energy. During the process of making biogas, we convert the surplus into byproducts such as organic fertilisers.
The CO2 in biogas is first separated from the methane using a membrane separation technology (similar to that of a reverse osmosis water treatment system) in a Biogas Upgrading Plant. The separated CO2 is then purified and liquified in a CO2 liquefaction plant after which it is stored on-site in pressurised storage tanks.
We transport the liquified Biogenic CO2 from the Green Create AD Plant using road tankers. Many industries including food and beverage, water treatment, electronics manufacturing, and in controlling chemical reactions use it.
Organic fertiliser, a byproduct of biomethane
Organic fertiliser is a by-product of biomethane. In the process of making the biogas, we’re left with a digestate which we use to make valuable organic fertiliser that is rich in Nitrogen, Phosphorus and Potassium (NPK).
What is organic fertiliser?
Organic fertilisers are plant or animal-based substances that are used to provide essential nutrients to soil and plants. Unlike synthetic fertilisers, which are made from chemicals and minerals, organic fertilisers are derived from natural materials and are considered to be more environmentally friendly. These can include compost, manure, bone meal, and other materials that are high in nitrogen, phosphorus, and potassium, which are essential for healthy plant growth. These fertilisers help to improve soil structure, increase the availability of nutrients to plants, and enhance the overall health and productivity of the soil.
At the Wijster facility in The Netherlands we are producing a 100% manure based granular fertiliser, with a dry matter content of 90% or more. The end product is recognized as export quality according the specifications of European norm: Regulation (EC) No 1069/2009 https://eur-lex.europa.eu/eli/reg/2009/1069/oj.
Our green solutions
Green Create produces biogas that we upgrade into many useful energy forms, such as Bio-Methane, Bio LNG and renewable energy. During the process of making biogas, we convert the surplus into byproducts such as organic fertilisers.
We make biogas in anaerobic digester tanks (reactors). After the process, we’re left with biogas and a digestate. This material from the reactors is separated into a solid and liquid fraction through a decanter centrifuge.
The solid fraction from this separation process is referred to as ‘dried digestate’ and is a valuable organic fertiliser rich in NPK. The solid digestate from the decanter centrifuge has a moisture content of approximately 72 per cent, so it’s still considerably wet.
To make the fertiliser easier to transport, we dry it further. A fertiliser with a moisture content of approximately 20 per cent remains. We can put it in a bag so it’s more accessible to a wider range of customers who may not have the necessary farm equipment to handle the bulk solids.
How do you use organic fertilisers?
The solid fertiliser of 72 per cent moisture can be used in its bulk form and spread on cropland as a fertiliser. The 20 per cent fertiliser can be processed into pellets, providing a more gradual release of nutrients into the soil. In addition, it’s less likely to be blown away by the wind.
Ammonium sulphate is a byproduct of biomethane
Ammonium sulphate is a byproduct of the production of biomethane. It is used as a fertiliser in the agricultural industry. And has a lower carbon footprint than artificial fertiliser, making it environmentally friendly.
What is ammonium sulphate?
Ammonium sulfate is a chemical compound with the formula (NH4)2SO4. It is a white crystalline solid that is highly soluble in water. It is commonly used as a fertiliser to provide plants with nitrogen and sulfur. Ammonium sulfate is produced by the reaction of sulfuric acid and ammonia and is typically sold as a granulated powder. Ammonium sulfate is also used in the production of dyes and other chemicals.
Our green solutions
Green Create produces biogas that we upgrade into many useful energy forms, such as Bio-Methane, Bio LNG and renewable energy. During the process of making biogas, we convert the surplus into byproducts such as organic fertilisers.
The materials used to make biogas are organic waste streams, such as poultry manure. This material is being ‘fed’ to the anaerobic digester tanks (reactors) and is typically diluted with water (or with recycled liquids). This is necessary so that it can be pumped to and from the reactors.
Some of the liquids for diluting the feed material are obtained by separating the digestate into solids and liquid fractions by means of a decanter centrifuge. The liquid fraction from the digestate is then used for diluting the feed material again. This continual recycling of liquids within the anaerobic digestion plant (AD) can lead to a build-up of ammonia within the reactors, inhibiting the anaerobic bacteria’s activity and reducing biogas production.
How do we make ammonium sulphate?
To reduce the ammonia levels within the reactors, the recycled liquids are first processed in an Ammonia Removal system called an ‘ammonia stripper’. In this process, the liquid digestate is heated, and the ammonia gas is removed from the liquids by spraying the digestate over a stream of air that carries away the volatile ammonia gas that is released from the heated liquids.
The ammonia-rich air is then ‘washed’ in a separate stage with an acidic solution of sulphuric acid and water. This ‘scrubs’ the ammonia gas from the air and transfers it again into a liquid form that is called ‘ammonium sulphate’.
The two types of ammonium sulphate
There are two types of ammonium sulphate: ammonium sulphate liquid and ammonium sulphate crystal. The liquid sulphate is stored in large storage tanks and can be removed by road tankers to be used in other locations. The sulphate can be further processed in a crystallisation plant that evaporates the moisture to create an ammonium sulphate crystal. This crystal can be used as a dry fertiliser that is more concentrated. Therefore it is more efficient to transport than the ammonium sulphate solution.
Renewable energy from Combined Heat and Power plants
The biogas we produce can also be used as fuel for biogas engines, in so-called Combined Heat and Power (CHP) plants. The biogas engines are similar to traditional diesel-fuelled generators that produce electricity. But in addition to electricity, the CHP plants can also generate renewable energy and heat.
What is renewable energy?
Renewable energy refers to energy sources that are naturally replenished and can be used indefinitely, such as wind and solar power. Unlike fossil fuels, which are finite and will eventually run out, renewable energy sources are abundant and can be sustainably produced. Renewable energy sources are also typically cleaner and more environmentally friendly than fossil fuels, having little or no greenhouse gas emissions. Examples of renewable energy sources include solar, wind, hydro, geothermal, and biomass. These energy sources can be used to generate electricity, power vehicles, and heat and cool buildings. Renewable energy is an essential part of a sustainable and low-carbon future.
Our green solutions
Green Create produces biogas that we upgrade into many useful energy forms, such as Bio-Methane, Bio LNG and renewable energy. During the process of making biogas, we convert the surplus into byproducts such as organic fertilisers.
Before the biogas can be used as a fuel it undergoes a few pre-treatment steps to reduce the moisture content of the saturated biogas and to reduce the levels of hydrogen sulfide (H2S). You’ll find the steps below: Step 1: the moisture content is reduced by lowering the temperature of the biogas. Step 2: the lower temperatures cause the excess moisture to condensate and drain away from the biogas. Step 3: the next step is to reheat the gas. Step 4: after which the H2S is removed by passing the biogas through Activated Carbon Filters which adsorb H2S from the biogas.
The approximate composition of biogas for use in a CHP is listed in the table below:
Property
Concentration
Methane (CH4)
60%
Carbon Dioxide (CO2)
40%
Hydrogen Sulphide (H2S)
50 ppm
Moisture content
50% relative humidity
Temperature
38 °C
Pressure
30 mbar (i.e. 0.03 bar)
Table 1: Typical properties of biogas for use in a CHP
What happens to the electricity of the CHP plant?
The electrical energy that is produced from the CHP plant can be used to directly provide the AD plant itself with power. This power can be used to run equipment such as pumps, conveyors and the control system. The Green Create AD Plants generate more energy through the production of biogas than the electrical power that is required to operate the plants.
Excess electrical energy can be introduced into the local electrical grid to be used by others, or the excess biogas can be upgraded to biomethane and/or Bio-LNG.
What happens to the heat from the CHP plant?
The heat energy produced from the CHP plants can be used within the AD Plant in one of the few processes that require heat, such as the heating of the reactors. The temperature of these reactors needs to be maintained at 38°C. So it can also be used within the ammonia removal system where the digestate from the reactors needs to be heated to 70°C. This helps remove ammonia from the digestate.
Bio LNG is liquified biomethane
Bio LNG (Liquified Natural Gas) is liquified biomethane and has a far lower impact on the environment than fossil fuels. This liquified biomethane is entirely made from organic waste streams, such as poultry manure. It is used for transport instead of diesel and is a sustainable transport fuel to help reach the goal of a carbon-free society.
What is Bio LNG?
Bio LNG is a liquid fuel and a product of biomethane, an environmentally friendly alternative to fossil fuels. At Green Create, we take biomethane a step further to create liquified natural gas. This upgraded biogas can be used as a replacement for diesel, making it a sustainable option. The approximate composition of Bio LNG is listed in the table below:
Parameter
Concentration
Methane (CH4)
99%
Carbon Dioxide (CO2)
50 ppm
Hydrogen Sulphide (H2S)
1 ppm
Moisture content
0.1 ppm
Temperature
-155°C
Pressure
2 bar
Table 1: Typical properties of Bio LNG
Our green solutions
Green Create produces biogas that we upgrade into many useful energy forms, such as Bio-Methane, Bio LNG and renewable energy. During the process of making biogas, we convert the surplus into byproducts such as organic fertilisers.
Bio LNG can be used by products that currently use LNG and other liquid fossil fuels, such as trucks and ships. Engines that use Bio LNG as a fuel are modified versions of those that use traditional liquid fossil fuels. Bio LNG produced at the Green Create AD Plants can be collected and transported by road tankers to be used offsite at offsite facilities and fuelling stations.
How is Bio LNG made?
The biomethane we make as a replacement for natural (fossil) gas can be upgraded to Bio LNG. This is done by removing any remaining CO2 and other contaminants from the biomethane. After that, we liquefy the biomethane to create Bio LNG. Different technologies are available for the polishing and liquefaction of biomethane, depending on the size of the liquefaction plant:
We remove the CO2 and other contaminants with a membrane system or with an amine scrubber.
The liquefaction of the methane is performed in a cryogenic process that lowers the temperature to -155°C, while the pressure is maintained at 1-4 bar(g). This makes the energy density of Bio LNG 600 times greather than that of the biomethane gas.
Biomethane has been produced through the process of anaerobic digestion
Biofuel biomethane is a unique renewable alternative to natural gas. To create this biofuel, we use mainly manure and other organic waste streams. The produced biomethane can be introduced into the natural gas grid to help reduce the usage of fossil fuels. Also: it has a negative carbon footprint and is thereby an environmentally friendly alternative to fossil fuels.
What is biomethane?
Biomethane is biogas produced through the process of anaerobic digestion of organic matter, such as poultry manure. This digestion process is performed on a large scale within a controlled environment, referred to as an ‘Anaerobic Digestion (AD) Plant’. In which microorganisms break down organic matter to produce biogas. The biogas is then processed to remove impurities, resulting in biomethane. It can be used as a transportation fuel, to generate electricity, or as a heating fuel.
Our green solutions
Green Create produces biogas that we upgrade into many useful energy forms, such as biomethane, Bio LNG and renewable energy. During the process of making biogas, we convert the surplus into byproducts such as organic fertilisers.
The feed material for the AD Plant is often provided through waste materials from other industries that are high in readily digestible organic matter. For example food waste, poultry manure or wastewater that contains blood, sugars and other digestible matter. These feed materials are sometimes pre-treated through screening and blending processes before being fed into the anaerobic digester tanks (reactors).
Within the reactors are microbial communities and bacteria that break down the organic matter in the absence of oxygen to form biogas. After the digestion process, the biogas and digestate remain. Digestate exists in two mixtures; a liquid and a solid one. The approximate composition of biogas is listed in the table below.
Property
Concentration
Methane (CH4)
60%
Carbon Dioxide (CO2)
40%
Hydrogen Sulphide (H2S)
2000 ppm
Moisture content
Saturated (i.e. 100% relative humidity)
Temperature
38 °C
Pressure
30 mbar (i.e. 0.03 bar)
Table 1: Typical properties of ‘raw’ Biogas
Property
Concentration
Methane (CH4)
95%
Carbon Dioxide (CO2)
5%
Hydrogen Sulphide (H2S)
1 ppm
Moisture content
< 110mg/Nm3
Temperature
15 °C
Pressure
12 bar
Table 2: Typical properties of Biomethane
From biogas to biomethane
The methane fraction within the biogas is valuable in that it can be combusted and therefore used as a fuel source in various industrial (and household) applications. To make the composition of biogas more similar to that of natural gas, we upgrade the biogas in a Biogas Upgrading Plant. Here we remove a significant portion of the CO2 and other contaminants. Resulting in a higher concentration of methane, hence biomethane. This biomethane can be used in many of the same applications as fossil fuels.
In some countries, there is a ‘natural gas grid’. A network of buried pipes carrying natural (fossil) gas to many different consumers around the country. The biomethane produced from the AD Plant can be introduced into the natural gas grid to help reduce the usage of fossil fuels. Different countries have different quality requirements for the biomethane that is injected into the gas grid. The quality parameters for each country are monitored very closely.
