WASTE TO ENERGY BIOGAZ™ SUSTAINABLE SOLUTION
NanoWater and Biotech Technologies have combined the efforts to create BioGaz™ System which is the combination of Wastewater Anaerobic System and a gas purification system.
Anaerobic treatment is a proven and energy efficient method for treating industrial wastewater. It uses anaerobic bacteria (Biomass) to convert organic pollutants or COD (Chemical Oxygen Demands) into biogas in an oxygen free environment. Anaerobic micro-organisms (specific to oxygen -free conditions) are selected for either ability to degrade organic matter present in industrial effluents, converting organic pollutants into biogas (methane + carbon dioxide) and a small amount of biosolids. The energy -rich biogas can then be used for boiler feed and /or combined Heat AND Power (CHP ) to produce green electricity and heat .
Biotech and NanoWater offers a sustainable solution of Biogas by implementing the waste to energy technology such as the production of biogas which has been considered as one of the best means to achieve sustainable energy development goals in many developing countries. Biogas is produced by the activities of bacteria that breaks down the biodegradable components in the absence of oxygen in an airtight chamber, the process is called anaerobic digestion.
What is BioGaz?
Biogas is a by-product of the anaerobic (without oxygen) breakdown of organic matter. The organic matter could be any of a number of materials, but on the farm, it most often comprises animal manure or other agricultural waste. The most important component in biogas is methane, a flammable gas that can be used in furnaces, for cooking, or even as an engine fuel.
Biogas contains carbon dioxide and small amounts of hydrogen, hydrogen sulfide, nitrogen.
When the biogas is filtered to remove the hydrogen sulphide, the resulting mixture can be burned as an energy source for cooking, lighting, or heating water or space.
When compressed it can be used as fuel for vehicles. On a commercial biogas can be used to generate electricity or even refined and fed into the gas grid.
What is Biogas Used for?
The primary use of the biogas produced by anaerobic digestion is in CHP (combined heat and power), also called cogeneration. This is a highly efficient way of generating heat and electricity. It can be used in the place of a conventional power station and boiler, cutting carbon emissions by up to 30%. Biogas can also be used as a fuel for motors Vehicle .
The gas mixture produced in the biodigester is called biogas and can be used as fuel. Biogas contains 55 to 65-% methane, 30 to 35-% carbon dioxide and other gases.Energy content of biogas is about 60% (depending on the methane content) compared to natural gas.
There are four stages of anaerobic digestion ,.
●Hydrolysis
In the initial phase, long-chain polymers are broken down into smaller parts (monomers), such as amino acids, fatty acids and sugars.
●Acidogenesis
Next, acidogenic bacteria cause these smaller components to ferment and break down further, creating volatile fatty acids, carbon dioxide, ammonia, hydrogen sulfide and other byproducts.
●Acetogenesis
Acetogens then further digest the molecules that have been created, producing acetic acid, more carbon dioxide, and hydrogen.
●Methanogenesis
this final part of the process is when the biogas used for energy, methane, is produced. Methanogens create methane, carbon dioxide and water using the products left over from the previous stages. The methane gas is then extracted to be used for energy, while the leftover digestate material shipped off to be used as fertilizer
BIOGAZ™ CONCEPT PLANT
Biogas purification methods
Biotech offers many different ways to maximize both the efficiency of biogas plants, and the usefulness and effectiveness of digestate. With the right advice and by choosing the correct technology, it is possible to make sound investment decisions which will not only increase plant efficient, but also improve the overall environmental profile of Anaerobic Digestion and maximize its benefits in terms of mitigating climate change.
Biogas is a gaseous fuel containing large amounts of methane (biomethane), which is produced by the anaerobic digestion of biological material under anaerobic conditions.
Anaerobic digestion (or AD) produces
- Biogas
- Co-product called digestate which can be a solid, liquid or combination of the two
International Purification Standards for Biogas
Gas utilities and public regulators have different specifications when it comes to the purity of the biogas they allow into their pipelines, for example, the heating value of the pipeline biogas should fall within a range between 960 and 1,100 BTUs per cubic foot. CO2 content should never go above two mole percent; oxygen, 0.4 mole percent; siloxanes, one part per million; and hydrogen sulfide, no more than .25 grams per 100 cubic feet. The ABC (American Biogas Council) has issued guidelines for biogas in vehicles. If and until quality measurements are standardized, biogas treatment system operators should be aware of the criteria set by the purchaser.
BIOTECH PURIFICTION PROCESS FOR THE BIOGAS
Biogas purification can take several forms. Here are a few of the most common:
BIOTILITY™ : FROM BIOGAS TO BIOMETHANE
The two main components of Biogas are Methane and Carbon Dioxide, but it also contains sulfuric acid and water. Biotility™ technology converts biogas to biomethane, a renewable natural gas (RNG), all the above components must be removed and separated. With Biotech technologies, upgrading system are able to convert small- and large-scale capacities of raw biogas into several usable products: RNG, CO₂ and Sulfuric-acid. For example, CO₂ can be captured and used in the agricultural industry.
APPLICATIONS
Biogas is a renewable fuel that can be used in a number of ways. Biogas can be used in boilers to provide heat only, in combined heat and power plants (CHP) to generate both electricity and heat, or upgraded to biomethane and then injected into the gas network or used as a vehicle fuel. Biotech has extensive experience in advising clients on all these methods. We also advise on the development of gas networks for biomethane.
FROM BIOGAS TO GRID INJECTION GAS
Biogas is made up of methane, carbon dioxide, hydrogen sulphide, water vapor and other minor constituents and particulates. The methane, and therefore the energy, content of the biogas can increase by removing the other constituents – the methane content can be increased to 98% or more. In this form, biomethane is suitable for injection into the gas network or used as a vehicle fuel. There are a number of technologies available for the removal of CO2, which are continually being improved and developed upon. It is important to choose the most appropriate technology for the task, based on plant-specific parameters.
In order to comply with the global climate commitment, all gas supply must by renewable and decarbonised by 2050. Therefore, Biotech is delivering a high-quality system which can provide a biomethane purity up to 99.5%. Moreover, we can clean the biogas which makes it possible to inject it into the gas grid.
To be able to inject into the gas grid the biogas needs to be dried, cleaned of impurities and upgraded to a higher methane content (> 96,5%) and has to meet the national quality standards of natural gas. The exact gas composition, the energy density and the Wobbe Index are measured and if required, the biomethane is enriched with propane to meet pipeline specifications. Furthermore, an odorant is added as biomethane (just like untreated natural gas) is odorless. This entire process, generally referred to as ‘upgrading’, is the core area of expertise of Biotech Technologies.
SAFTEY CONSIDERATION
Methane is extremely explosive when mixed with air at the proportions of 6-15 percent methane. Digester gas is heavier than air and settles to the ground, displacing oxygen. If hydrogen sulfide is present, the digester gas can be a deadly poison.Always vent the open side of manometers (static pressure gauges) and pressure relief valves to the outside, and provide plenty of ventilation if the digester is located indoors. Be careful when compressing and storing digester gas. Special equipment and special tanks must be used if the gas is stored at high pressures.