Report from Energy Vision and CALSTART highlights the environmental benefits of using gas produced from organic waste.
A newly released publication, Renewable Natural Gas (RNG): The Solution to a Major Transportation Challenge, reports that the use of renewable natural gas as a vehicle fuel is a technologically viable alternative to relying exclusively on petroleum-based fuels for transportation.
The publication was prepared by Energy Vision, a New York-based energy research organization, and CALSTART, a California-based clean transportation technology organization.
“Today we can turn this country’s expensive organic waste burden into a clean vehicle fuel solution,” says Energy Vision President Joanna Underwood. “Waste biogases can also be used to generate power and heat homes; but other renewable energy sources can meet those needs. Fossil-based and renewable natural gas used as vehicle fuels are the only options for displacing significant amounts of oil. By aggressively embracing this strategy as part of an overall energy plan, the new Obama Administration and the 113th Congress can achieve measurable progress in moving toward this country’s key clean air, climate change, energy, national security, economic and job creation goals. For many reasons, RNG is just what the doctor ordered.”
RNG is made from organic waste discarded by homes, industries and agricultural operations. Deposited in oxygen-free environments, including landfills or anaerobic digesters, the organics decompose and emit biogases that can be collected and refined into a fuel similar to fossil natural gas, says the report. RNG can either be blended with fossil natural gas or replace it. The report includes profiles of eight RNG projects that show what can be done with the use of RNG.
Three examples include:
- At the Fair Oaks Dairy in Indiana, biogases from liquid manure are harnessed into RNG fuel equal to 1.5 million diesel gallons a year, which is used to power 42 tanker trucks hauling milk to Michigan, Kentucky and Tennessee. Estimated fuel cost savings from the fuel switch totals more than $2.5 million a year.
- At a Waste Management landfill in California, biogases from decomposing wastes are refined by Linde N.A. into a clean fuel equal to 13,500 diesel gallons a day, which is trucked to refueling stations where it powers almost 400 refuse trucks.
- In St. Landry Parish, La., the community, in partnership with BioCNG-Cornerstone Environmental Group, opened a fueling station to supply 15 municipal vehicles with clean landfill-derived RNG fuel. The waste from 40,000 households is estimated to be able to power up to 50 vehicles, and the costs of the system will be fully recouped in four to five years.
Underwood says, “Communities of 40,000 or more may generate enough organics to produce fuel for their bus and truck fleets and more. But smaller communities, which have neighboring towns and nearby dairies, hotels, food processing plants or other organic waste sources, should begin to join together and explore pooling their wastes and investing in production of the fuel.”
The Energy Vision/CALSTART report summarizes nine obstacles to communities and companies that want to produce RNG for vehicle fuel. These challenges range from the up-front costs of constructing anaerobic digesters in which the biogases from wastes form, installing the technology needed to refine the biogases, existing standards that make it difficult to transport RNG through natural gas pipelines and provisions in the U.S. Tax Code that reward production of biogas for power generation but not for vehicle fuel.
The report does cite the following reasons for using RNG:
- Producing RNG fuel requires no drilling and avoids the environmental impacts of other fuel choices. Communities and companies need fuel for bus and truck fleets, and the diesel fuel used is now problematic. It is largely made from imported oil, it has volatile price swings and diesel emissions have recently been labeled a “known carcinogen” by the World Health Organization.
- Meanwhile, fossil natural gas is a domestic resource, is 80 percent cleaner than diesel and is 20-25 percent lower in greenhouse gases. While there is debate over the environmental and health impacts of obtaining the gas using the drilling technique known as horizontal hydraulic fracturing (“fracking”), RNG, produced from waste, has no environmental downside.
- Increased use of RNG can reduce the dependence on foreign oil. At the present time, 10 million diesel-powered buses and trucks for which natural gas engines are a fully commercial option should be a priority target for RNG use. While they make up just 4 percent of all vehicles, they consume 23 percent of all vehicle fuel – 38 billion gallons a year.
- The recently released national Future Transportation Fuels Study, commissioned by the Secretary of Energy, estimated that with today’s technologies RNG could displace 16 percent of diesel vehicle fuel used annually; when “thermal gasification” technologies for processing tough woody materials become commercially viable, production of RNG could displace 45 percent of U.S. diesel consumption, around 17.9 billion gallons a year. State and federal incentives could accelerate the shift.
- Using RNG as a vehicle fuel can strengthen the U.S. economy. The report estimates that using domestically produced RNG can eliminate the need to send almost $18 million abroad daily ($6.4 billion a year) for diesel oil. In addition, according to a 2011 American Gas Foundation study, the scaling up of RNG production in the United States has the potential to create at least 250,000 sustainable energy jobs.
- RNG can help meet U.S. climate change goals: As measured on a life cycle basis, from production and transport to use of this fuel, RNG’s carbon footprint is reduced by 88 percent or more, as compared to pre-2009 gasoline and diesel vehicles, according to the California Air Resources Board.
- RNG addresses the U.S.’s solid waste disposal challenge. The cost to collect and dispose of the food waste and yard trimmings (estimated to make up 28 percent of the country’s municipal waste stream), drains municipal budgets. However, it can be shipped less expensively to a site where it will be used as a feedstock for fuel production. In addition, the biosolids left after the gas is extracted from wastes processed in anaerobic digesters can be recycled into fertilizers and soil amendments.
The full report is available at http://energy-vision.org/wordpress/wp-content/uploads/2012/05/EV-RNG-Facts-and-Case-Studies.pdf