Closing the Loop: Fueling Trucks with the Organic Waste They Pick Up

When you placed your food waste at the curb last time, did you consider the journey it’s about to take? You could find it coming back down your street the next month as the fuel in the truck that picks up that week’s organic waste. That’s closer to Doc’s “flux capacitor” from the 1985 movie Back to the Future than most people ever imagined – and the fuel is powering trucks on American roads and around the world right now.

Biogas, or natural gas from organic sources, has been used for decades and was recognized as a renewable source for electricity. In the intervening years, natural gas fuel stations and the natural gas vehicle base has expanded, opening up the market for renewable natural gas (RNG) use in transportation.

Refuse operations across North America are embracing the opportunity to fuel trucks with the very waste they pick up. The RNG created with processed organic matter such as food scraps (or in other cases landfill gas) can power trucks equipped with a natural gas engine such as Cummins Westport ISX 12G or ISL G engines.

In North America, fleets and energy partnerships from Georgia to Quebec to California are embracing the concept, saving waste and money in the process. The vehicles operating on RNG from organic sources include refuse or sanitation trucks, pickup trucks, utility vehicles, and tractors.

The Columbus, Ohio quasar biodigestion facility

The New Face of Fueling: Renewable Natural Gas

This is the fourth installment in our guest blog series: A Wider Lens.

This series features first-hand accounts from people driving natural gas vehicles, industry leaders and decision-makers in the natural gas transportation industry.

By Guest Contributor, Harrison Clay, President of Clean Energy Fuels Corp. 

Subsidiary of Clean Energy Renewable Fuels. 

We all know what separates natural gas from the other “traditional” fuels—it's cleaner, cheaper and domestic—but in an era of innovation, I think too many folks are quick to dismiss natural gas as traditional.

Not anymore. Now we can produce pipeline quality natural gas from biogas and biomass feedstock sources, and it’s interchangeable with fossil natural gas. It’s called renewable natural gas and it’s not just semi-renewable—it’s 100 per cent renewable. It’s good for our businesses and our communities. And there's nothing “traditional” about it.

In October, Clean Energy launched the first commercially available renewable natural gas, called Redeem and it is currently available at stations in California.

Here’s how it’s made:

Renewable Natural Gas Fuel – Available at a Gas Station Near You (in California)

Clean Energy will offer Redeem, renewable natural gas fuel at 35 public stations in California.

A new type of natural gas fuel entered the commercial market last week: Clean Energy Fuels announced it will be selling ‘Redeem’ at 35 public stations throughout California. Redeem is a renewable natural gas fuel made from waste streams such as landfills, large dairies and sewage plants.

Renewable natural gas is produced from biogas and biomass feedstock sources and can be upgraded to pipeline quality gas (also known as biomethane) that is interchangeable with fossil natural gas. It can be used as a 100 per cent substitute for, or blended with conventional gas sources for use in vehicle engines.
It’s the first time a company will be offering this type of fuel for sale to the public. But it’s not the first time fleets have used the fuel. Waste Management, has been using biomethane from its landfill to fuel many of its more than 2,000 garbage trucks, the majority of which are equipped with engines supplied by Cummins Westport (CWI).

“When a company can produce its own fuel from its own landfill operations to power its own fleet, it really doesn’t get any better than that,” said Charlie Ker, refuse segment director for CWI. “And we’re seeing more and more examples of this happening in fleets across North America.”

Since 2008, Cummins Westport has sold about 8,000 natural gas engines in the waste recovery and recycling industry.

A New York Times article published on October 2 states that Clean Energy’s announcement came as a surprise to many in the transportation industry; widespread, publicly available renewable natural gas was not anticipated this year. The article’s author, journalist Diane Cardwell states that California’s state-level incentives are encouraging the adoption of cleaner fuels, as the state aims to reach 1990-level carbon emissions targets by 2020.

Clean Energy’s announcement states that Redeem is being produced at facilities in Dallas, Texas; Canton, Michigan and is constructing a third facility in Millington, Tennessee; it’s also being sourced from third parties.

Thousands of cars, taxis, shuttles and industrial fleets in California are now using Clean Energy’s Redeem fuel, including around 600 vehicles at the San Francisco International Airport, which announced on October 4 that it would be using Redeem fuel at the airport’s two CNG stations.

Related Reading:
Redeem Fuel: www.redeembycleanenergy.com.
Waste Management and Cummins Westport: http://rpn.baumpub.com/news/3664/on-the-road-to-natural-gas-in-the-waste-and-recycling-industry
Renewable Natural Gas: http://www.westport.com/is/natural-gas/biomethane

Renewable Natural Gas: From Biogas to Gas Tank

By Jonathan Morissette and Karen Graham 

Sustainable Energy Futures at Westport Innovations

This is the second in a series of blog posts that will highlight the market and environmental potential of renewable natural gas (RNG). Check back over the next six weeks as we explore the issues and opportunities for RNG in the transportation sector.

Our previous renewable natural gas (RNG) post was on the technologies currently used to transform organic waste into renewable vehicle fuel. This time, we’re exploring the steps needed to ensure the safe and efficient use of this fuel in natural gas engines.

Upgrading biogas into RNG suitable for engines is a lot like the upgrading processes for natural gas extracted from fossil sources, or even to traditional liquid fuels like gasoline or diesel. No energy source for transportation can be taken in its raw state and put right into an engine. Transport fuels must have impurities removed and their energy content raised to a set level, and RNG is no different.

In the case of RNG, this process involves three key steps: cleaning, compression, and distribution. While none of these steps are unique to RNG, the scale and location of RNG production introduces distinct considerations for producers and operators. The method for upgrading biogas into higher-grade fuel depends on the nature and size of the production facility, be it landfill gas, municipal waste streams or energy crops. Surveys of successful RNG projects in North America and Europe show that no single upgrading technology is preferred, so each site will choose the best technology for its needs.[i]

Regardless of the upgrading methods used, the aim is the same: to remove unwanted gases and moisture. The basic steps include removing water vapor, hydrogen sulfide and carbon dioxide, as well as removing residual contaminants such as siloxanes and trace gases. This can be accomplished by membrane separation, water scrubbing, chemical absorption, physical adsorption, bio-filtration, or cryogenic separation.

The degree of biogas refinement depends on the end-use, and transportation needs a relatively high degree of purity. Fuel standards for RNG can be established by regional governments or by engine manufacturers themselves. For example, the European Union is currently establishing an EU-wide standard for RNG, and in Austria a trade name called “methaPUR” has been established to market vehicle-quality RNG. [ii] [iii] Cummins Westport offers an online Fuel Quality Calculator that allows customers and fuel providers to be sure that natural gas from any source that meets specifications can safely be used in its engines.

The final stages – compression and distribution – undergo similar processes to conventional natural gas production. The key difference is the variety of scale and location of RNG production sites. Conventional natural gas typically delivers large volumes to large markets, but RNG production facilities can range from the micro- to the medium, to the very large[iv], and their customers can be private truck fleets, public access vehicle fueling stations, or grid-injection for delivery to a wide array of end customers. Some markets for RNG are “closed loop,” where the biogas from a privately-operated landfill powers part of the refuse vehicle fleet owned by the company, while others are much more open. In Sweden, nearly all RNG produced to vehicle engine standards is supplied into the pipeline network.

Whether produced in a closed loop or for public refuelling stations, a distinct advantage of RNG for transportation is that once the biogas has been cleaned and upgraded, it’s interchangeable with conventional natural gas for transportation, giving fuel providers and drivers a flexible range of options.

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[i] Petersson, Anneli, and Wellinger, Arthur (2009). Biogas Upgrading Technologies – Developments and Innovations. IEA Bioenergy, Task 37: Energy from Biogas and Landfill Gas.

[ii] http://www.greengasgrids.eu/sites/default/files/files/Biomethane%20standards%20-%20Jacques%20Dubost.pdf

[iii] http://www.methapur.com/

[iv] Waste Management describes its Altamont, California landfill gas site as the largest biofuel supplier in the world, capable of producing 13,000 gallons of liquid natural gas per day.

Renewable Natural Gas: Fueling Sustainable Transportation

Part 1: What is Renewable Natural Gas?

By Jonathan Morissette and Karen Graham 

Sustainable Energy Futures at Westport Innovations

This is the first in a series of blog posts that will highlight the market and environmental potential of renewable natural gas (RNG). Check back over the next six weeks as we explore the issues and opportunities for RNG in the transportation sector.

What is Renewable Natural Gas?

Renewable natural gas (RNG) is pipeline quality gas that can be used like fossil natural gas but is produced from what are called biogas and biomass feedstock sources, the technical term for any renewable, biological material such as plant matter or animal wastes. It can be a substitute for, or be blended with conventional natural gas for use in vehicle engines.

RNG is produced from a variety of sources, including:

• Landfill gas 
• Solid waste 
• Municipal waste water 
• Agricultural manure 
• Forestry waste 
• Energy crops 

RNG is produced in two ways: anaerobic digestion and thermal gasification.

Anaerobic digestion is the most commonly used and well-developed method. It requires only a low-oxygen environment for the organic matter to breakdown naturally by bacteria, and the equipment and process is commercially available.[i] This technique is best suited to using landfill and agricultural waste. The first biogas digester was built over 150 years ago, and the technology’s simplicity makes it appealing for a range of end uses who want alternative fuels, including transportation use. It’s in commercial use for transportation in parts of Europe, led by Sweden and Germany, and in the U.S., mainly California.

Thermal gasification is a mature and well-established industrial process developed to convert coal or organic matter into gaseous products by the application of high temperatures in oxygen controlled environments. Thermal gasification will help use promising second generation energy crops like poplar or willow trees and switchgrass. While thermal gasification of coal is a mature technology, thermal gasification of biomass into RNG is still pre-commercial with successful demonstration plants in Europe, and commercial scale implementation expected by 2020.[ii] 

The end product of organic matter breakdown is biogas, which is naturally discharged into the atmosphere where it contributes to smog and climate change (methane, carbon dioxide and nitrous oxide). Landfill sites are ideal for capturing and using biogas generated from decomposing waste. Many cities and smaller communities have developed projects to capture, clean and upgrade the biogas from their landfill sites. They use the RNG in their own applications (such as garbage pickup vehicles) or supply it to the pipeline grid. A benefit of RNG for transportation is that it turns waste (such as manure and food scraps) into usable vehicle fuel. By capturing these natural emissions before they enter the atmosphere, the air quality around the collection site is immediately improved and greenhouse gases (GHG) are reduced. Using RNG for transportation helps to reduce GHG emissions as the naturally-produced methane is converted to carbon dioxide, a less potent greenhouse gas.[iii]

Once produced and refined to pipeline quality RNG, this resource can serve any of the end-use applications that fossil natural gas does today. It can be compressed and dispensed as vehicle fuel, injected into pipeline networks, used to manufacture plastics or fertilizer, or liquefied for long-distance and heavy-duty transportation. Because RNG is interchangeable with fossil natural gas, the two fuels can be blended together in a range of proportions at either the pipeline or the pump. As long as RNG is pipeline (and vehicle engine) quality, it can be used wherever the market or regulatory environment supports it for transportation. In Sweden in 2011, 43.9 percent of all produced biogas was used as transport fuel, and in Germany some fueling stations offer 100 percent RNG for natural gas vehicles.[iv],[v]

Current estimates of RNG’s potential show the significant contribution it can make to fuel security and sustainability even in the near term. In the U.S. this renewable resource has been estimated at 4.8 trillion cubic feet, around 20 percent of total current U.S. natural gas consumption.[vi] Within the European Union, production is expected to reach 48bcm by 2020 with the potential for 200 bcm.[vii] 

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[i] Brad Rutledge, “California Biogas Industry Assessment: White Paper,” WestStart-Calstart (April 2005):
http://www.calstart.org/Libraries/Publications/California_Biogas_Industry_Assessment_White_Paper.sflb.ashx 
[ii] Salim Abboud et al.,“Potential Production of Methane from Canadian Wastes,” Canadian Gas Association (October 2010):
http://www.cga.ca/publications/documents/PotentialProductionofMethanefromCanadianWastes- ARCFINALReport-Oct72010.pdf. 

[iii] United States Environmental Protection Agency, “Landfill Methane Outreach Program—Benefits of Landfill Gas Energy,” last updated September 2012, accessed March 2013: http://www.epa.gov/lmop/basic-info/index.html#a04
[iv] Gabriela Vanciu and Nina Miresashvili, “Biogas cars in Sweden: An emerging market,” Jönköping University (May 2012).
[v] NGV Journal, “Germany: 18 additional CNG filling stations now provide 100% biomethane,” last updated December 18, 2012, last accessed March 22, 2013.
[vi] National Petroleum Council, “Renewable Natural Gas for Transportation: An Overview of the Feedstock Capacity, Economics, and GHG Emission Reduction Benefits of RNG as a Low-Carbon Fuel,” (March 2012).
[vii] Floris van Foreest, “Perspectives for Biogas in Europe,” Oxford Institute for Energy Studies Working Paper series (December 2012).