What is Biogas?
Biogas is produced from a micro biological fermentation process of organic matter under exclusion of oxygen(Anaerobic digestion). The main components of biogas are Methane and Carbon dioxide. Biogas can be used for producing thermal energy or can be utilized for cogeneration of electricity and heat. The energy density of biogas is depending on its methane content. Typically, one cubic meter [m3] of methane provides the energy content of approximately ten Kilowatt hours (9.97 kWh). Considering the biogas has a methane content of approximately 60%, one cubic meter of biogas provides approximately 6 Kilowatt hours of energy.
What is Anaerobic Digestion?
Anaerobic digestion (AD) is the process of micro-organisms breaking down organic materials in the absence of oxygen in an enclosed vessel. Anaerobic digestion produces biogas (consisting primarily of methane and carbon dioxide). AD systems are also often referred to as “biogas systems”. Depending on the system design, biogas can be combusted to run a generator producing electricity and heat (called a co-generation system), burned as a fuel in a boiler or furnace, or cleaned and used as a natural gas replacement. The AD process also produces an effluent (called digestate) that contains all the water, all the minerals and approximately half of the carbon from the incoming materials. Many manure based and energy crops based AD systems are located on farms. Farm-based AD systems work well with liquid manure. AD systems provide a valuable manure treatment option, since most other economically effective manure treatment systems (such as composting) require solid materials with dry matter greater than 30 per cent.
What are the Environmental Benefits of Anaerobic Digestion Systems?
Livestock confinement facilities generate large amounts of animal waste that can create serious environmental concerns. The concentrated waste product from decomposing livestock manure can be environmentally detrimental if it enters rivers, streams, or groundwater supplies. Decomposing manure also causes air quality concerns associated with odor, ammonia emissions, and the contribution of methane emissions to global climate change. Anaerobic digestion offers a number of air and water quality benefits, including:
- Odor control. The effluent odor from anaerobic digesters is significantly less than odors from conventional manure management systems. Odor reduction using anaerobic digestion can be very cost-effective when compared to other alternatives such as aeration. 6 Managing Manure with Biogas Recovery Systems Complete mix digester. Plug flow digester.
- Greenhouse gas reduction. Conventional liquid and slurry manure management practices emit large amounts of methane, a greenhouse gas that contributes to global warming. Biogas recovery systems capture and combust methane, thus reducing greenhouse gas emissions. In addition, by off-setting energy that would otherwise be derived from fossil fuels, biogas recovery and use can help reduce overall quantities of carbon dioxide, another critical greenhouse gas.
- Ammonia control. Ammonia emissions from livestock manures— especially emissions from anaerobic lagoons used in the treatment and storage of these manures—are a growing environmental concern. To control ammonia emissions, producers can cover manure storage tanks. Because gas handling is not required, the storage structures of anaerobic digester systems, which separate treatment and storage, are smaller and easier to cover than the larger structures of traditional systems.
- Water quality protection. Anaerobic digestion provides several water quality benefits. When an anaerobic digester system, especially a covered lagoon, is properly managed, phosphorous and metals, such as copper and zinc, will settle out in the process cells, thus reducing phosphorous and metals loadings to surface waters when manure is land-applied. Digester systems, especially heated digesters, isolate and destroy disease causing organisms that might otherwise enter surface waters and pose a risk to human and animal health. Anaerobic digestion also helps protect ground water. Synthetic liners provide a high level of groundwater protection for manure management systems. These protective liners are a more affordable option with anaerobic digester systems than with conventional lagoons, because the processed manure coming out of digester has much lower dry matter content. This avoids filling of the lagoon with dry matter. The concrete tanks used in complete mix digesters also effectively prevent untreated manure from reaching ground water.
Market Situation Biogas
Globally the production of biogas has increased significantly over the past decade, and is now considered a key source of energy production in Europe, exceeding 62 TWh in 2006.
The main contributor for this growth is the association of biogas plants with agricultural operations. By end of 2007, in Germany alone, there were more than 3,700 farming based biogas plants, with a total capacity of 1,270 megawatts of electricity being produced.
This trend is not only an important contributor for increased utilization of renewable energy, but more importantly a second source of sustainable income and profit for the farming operations in addition to the traditional agricultural and livestock commodities products.
Also, the development, operation and maintenance of the biogas operations accounts for additional sustainable jobs.
Federal and state regulations mandate that energy utilities have annual energy quotas, and to fulfill the required quotas the utilities must include (or produce) the required capacity of renewable energy in their portfolio.
Despite a lower purchase price for KWh in electricity, biogas operation is viable in US market due to other financial incentives by government funding.
Long-term contracts combined with government funding and tax incentives lower the risks for biogas operators and suppliers.
In Europe, Germany in particular, the Energy Regulation (EEG) has created optimum conditions for the continued growth and development of the biogas industry. Due to German energy regulations, the business model for biogas is extremely attractive to investors and operators, because it establishes energy contracts with guaranteed prices for at least 20 years.
In the United States, California has introduced specific regulations for biogas production that are similar to European models known as “Feed-In Tariff.”
Biogas as a key contributor for renewable energy:
Utilizing the energy created by turning biomass into biogas has been on the rise for the last decade. It is now considered one of the most viable sources of renewable and sustainable energy production in Europe.
Many different materials can be used for biogas production. Organic waste from landfills, municipal waste water, as well as other industrial organic waste products, and waste products from agricultural and farming operations can be used to create biogas.
The energy production from biogas is an essential part of the renewable energy portfolio in Europe. In 2007 in Germany alone, biogas contributed 22.4 Billion kWh, 49% of that was from landfills and municipal waste water. The remaining 51% was generated by utilizing organic waste from industrial and farming operations.
Biogas production technology and utilized organic materials:
Biogas is produced through fermentation, or the digestion of organic materials under exclusion of air and oxygen. The success of the digestion process depends on specific combinations of anaerobic bacteria, and other ambient conditions (temperature, ambient pH-value etc.)
Biogas production on farming operations utilizes animal manure. For increased biogas results the manure is combined with other renewable agricultural products such as, corn, sunflowers, switch-grass, and sorghum.
The main source of energy produced by this fermentation process is Methane gas. Additionally, other gases such as Carbon Dioxide, small amounts of Hydrogen Sulfide, Ammonia and Hydrogen are released into the atmosphere.
In addition to biogas, water and non digestible organic materials, which have similar properties to organic compost, can also be used to create extremely valuable organic fertilizer.
A high efficiency co-generation unit is used to convert biogas into electricity. The unit can also recover thermal energy for additional electrical production, or use that thermal energy to heat buildings and water for buildings. Additionally, if there is no electrical grid available for transporting the electricity, the high quality biogas can be used in place of natural gas.
The successful development of a biogas operation relies on strong support for the planning, financing, development, and service of each project. Balance 4 Earth, LLC. offers professional support for the entire biogas operation, coupled with excellent project management to assure successful results in all phases of every project.