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Anaerobic Digestion Nutrient Transformations
Anaerobic digestion (AD) is the process in which organic compounds are broken down by naturally occurring bacteria, including methanogenic microorganisms under oxygen free conditions, transforming organic matter into biogas (methane (CH4), carbon dioxide (CO2), water vapor, ammonia, and hydrogen sulfide) (Dugba and Zhang, 1999; AgSTAR, 2010b). The end products of this process include biogas, a renewable …
Anaerobic digestion is a manure treatment system that produces biogas. There are many benefits of digestion such as reductions in: odor, pathogens, and greenhouse gases (climate change). Producing biogas from manure yields useful by-products. The economics of digestion are dependent on state energy policies and co-digestion of off-farm wastes to generate revenue.
Cayuga County Regional Digester (New York)
This virtual tour highlights the Cayuga County Soil & Water Conservation District regional digester. This facility receives …
When manure is anaerobically digested, the biogas produced is primarily composed of methane and carbon dioxide, with lesser amounts of hydrogen sulfide, ammonia, and other gases. Each of these gases has safety issues. Overall, biogas risks include explosion, asphyxiation, disease, and hydrogen sulfide poisoning.
Extreme caution is necessary when working with biogas. Adequate ventilation, appropriate precautions, good work practices, engineering controls, and adequate personal protective equipment will minimize the dangers associated with biogas. Wherever possible, …
All anaerobic digesters perform the same basic function. They hold manure in the absence of oxygen and maintain the proper conditions for methane forming microorganisms to grow. There is a wide variety of anaerobic digesters, each performing this basic function in a subtly different way. Seven of the most common digesters are described in this article. Construction and material handling techniques can vary greatly within …
This page lists questions and answers from the C-Change GrassToGas project’s PA Extension newsletter. To be added to the newsletter mailing list, contact GrassToGas@psu.edu.
1. Question: Is switchgrass a good feedstock for biogas digesters?
Answer: Not usually. Anaerobic digestion involves microscopic organisms that eat energy-rich components such as sugars. Lignocellulosic biomass, such as switchgrass, contains sugars, but is structured in a way that specifically prevents easy access to its energy-rich components. Because of the limited accessibility to the energy-rich …
What is it?
The Grass-to-gas project is a 5-year, USDA-funded project that carries out research, extension, and education programs aimed at developing new approaches to Anaerobic Digestion that are economically beneficial to farmers and ecologically beneficial to farms.
The project is led by Iowa State University and Penn State University, with a team of partner farmers and companies all working together to grow this opportunity.
Demonstration Farms, where perennial grass production, cover crops, and their use in biogas …
From feedstock to fuel. Photos: D.Ciolkosz, M.Szala, Biodiesel Ed at U Idah
. CC license
Biomass is transformed into solid & liquid fuels, gas, electricity and heat using a variety of processing methods and equipment.
One of the main barriers to a successful biomass energy industry is the simple fact that most raw biomass is not immediately useful as an …
Learn about sustainability indicators used to gauge and evaluate a farm’s progress toward energy sustainability.
Solar installation at Harlow Farm, Westminster, VT. Photo: Susan Harlow
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What Is a Sustainability Indicator?
Sustainability indicators are measurable or observable features that can be used to test principles and criteria of sustainability. Sustainability indicators could include quantifiable measures of resource use efficiency, energy, food security, land use impacts…
This Biogas module provides reasonable expectations for investing in on-farm bio-digesters to convert animal waste to process heat and/or electricity. Learn how to calculate the number of animals needed to build a cost effective system.
Link to all of the Northeast Farm Energy IQ Curriculum, developed by Extension specialists from Penn State, Rutgers and University of Vermont.
This is part of the On Farm Energy Production Curriculum Series:
Bioenergy Feedstock Production | Biodiesel and SVO | Biogas | Wood …