Bioenergy is renewable energy generated when organic material (also called biomass) is converted into a fuel for heating, electricity and transportation applications. Sources of biomass feedstock include agricultural and forest residues, energy crops, algae, the organic portion of municipal solid waste and wastewater. Since New Jersey is a densely populated state, there is not much land available for growing bioenergy crops. However, due to the dense population, large quantities of organic wastes generated in the state can be converted into liquid or gaseous biofuels. Electricity generated by fuels from these feedstocks could qualify for either Class I or Class II Renewable Energy Certificates.
Currently, the Climate Change, Clean Energy & Sustainability Element is leading a collaborative effort with DEP regulatory programs, the New Jersey Board of Public Utilities, and academic institutions in the state to assess the feasibility and cost effectiveness of converting organic waste streams such as wastewater, food waste and municipal solid waste at landfills into high quality useable fuels for power generation. Utilizing these waste streams will allow facilities to reduce operating costs by using electricity generated onsite, thus reducing the electricity use from the PJM grid. Also, such applications will prevent the release of methane and other pollutants into the atmosphere, which will reduce regional greenhouse-gas and criteria pollutants emissions.
Wastewater treatment facilities in New Jersey are realizing the benefits of using anaerobic digestion to produce digester gas for onsite generation of electricity. This also reduces the volume of sludge requiring disposal at landfills and satisfying water quality standards. Furthermore, if treated properly, sludge can be converted into a beneficial reuse product (such as compost), creating another revenue stream for the wastewater treatment facilities. The Bureau of Climate Change and Clean Energy is conducting the applications research and working with stakeholders to provide insight on:
optimizing the anaerobic digestion process (operating characteristics of digesters and acceptable feedstock co-digestate),
digester gas cleanup and
more efficient and cleaner generators.
The main objective of this research is to provide technical and regulatory guidelines to wastewater treatment facilities in New Jersey for reducing their carbon footprint, maximizing the incentives from New Jersey Board of Public Utilities provided as Class I renewable energy certificates and reducing other waste streams that would negatively impact the environment and human health of New Jersey.
Food Waste to Energy
Pipeline Quality Biogas
Fertilizer/Compost for Agriculture and Landscaping
Co-Digestate in Wastewater Treatment
Class I Renewable Energy Certificates
As the United States Environmental Protection Agency and New Jersey focus upon the overall reduction of food waste, DEP is supporting activities associated with diverting organic wastes from landfills. One of the solutions is to encourage recycling activities to convert food waste into fertilizer/compost for agricultural and landscaping applications.
Another solution is the conversion of food waste through anaerobic digestion to produce biogas, which can be used to generate heat and electricity, or can be injected into the natural gas pipeline. Electricity produced from the combustion of biogas from food waste qualifies for Class I Renewable Energy Certificates from New Board of Public Utilities. Similar to the wastewater to energy initiative described above, the Bureau of Energy and Sustainability is conducting applications research and working with stakeholders to provide insight on:
optimizing the anaerobic digestion process (operating characteristics of digesters and acceptable feedstock co-digestate),
biogas cleanup and
more efficient and cleaner generators.
The Bureau of Energy and Sustainability is assessing various processes for producing biogas from food waste as well as exploring the use of specific types of food waste as co-digestate with wastewater to yield digester gas with higher energy densities.
Landfill Gas to Energy
Reduce Flaring of Methane
Reduce Operating Cost
Class I Renewable Energy Certificates
Landfill gas is a natural byproduct of the decomposition of organic material in a landfill and is made up of approximately 50-60% methane and 30-40% carbon dioxide. Municipal solid waste landfills are the third largest human-generated source of methane in the United States, with approximately 18 percent of total methane emissions in 2014. The landfill gas captured from these landfills can be used:
To generate electricity
As Direct use fuel for heating or cooling
As High energy density pipeline quality gas or vehicle fuel if converted into equivalent of natural gas, compress natural gas or liquefied natural gas.
The United States Environmental Protection Agency mandates the reduction of methane emissions from landfills, which prompts flaring of the methane gas or recovery and use for power generation. The New Jersey Board of Public Utilities categorizes electricity generated from the combustion of landfill gas as renewable energy, which automatically qualifies it for Class I Renewable Energy Certificates in New Jersey. However, due to the impurities in landfill gas, combustion of the fuel results in increased maintenance of the power generation systems and air pollution emissions that can exceed regulatory standards. Therefore, the Bureau of Energy and Sustainability is focusing on applications research to identify cleanup technologies that remove by-products from landfill gas to result in cleaner combustion, and reduced maintenance frequency and costs to the power generation systems. Also, for landfills that do not produce the required quantity and quality of liquefied natural gas for power generation, the Bureau of Energy and Sustainability continues to research the appropriate low oxides of nitrogen (NOX) and ultra-low NOX flares that can destroy methane while satisfying DEP’s regulatory air quality standards.
A Typical Landfill to Energy Project
Source: Advanced Disposal Services Inc.
Non-recycled Municipal Solid Waste to Energy
Direct Combustion or Conversion to Syngas
Reduce Need for Landfilling
Class II Renewable Energy Certificates
The portion of the municipal solid waste that is not recycled or reused comprises of some paper, plastics, food waste and yard trimmings that is either landfilled or combusted for energy recovery. The DEP’s Bureau of Energy and Sustainability is involved in the verification of projects that convert non-recycled municipal solid waste into energy and meet New Jersey’s clean air and solid waste standards.
