What If We Included Biogas In Waste-to-Energy Investments?

By Patrick Serfass | August 20, 2013

Early July, the U.S. DOE Bioenergy Technologies Office issued a request for information regarding waste-to-energy (WTE) technologies. The American Biogas Council was pleasantly surprised that questions included biogas, and had lots to say in response. In this month’s column I’ll share just the main points.

In the biogas industry’s eyes, we are a WTE industry. Biogas systems take valuable resources considered by most to be waste, and use a natural, biological process to turn it into energy and other valuable coproducts. To most people, however, WTE only relates to combustion, incineration or gasification of waste to create heat (for steam to make electricity) or synthesis gases. The DOE has taken a similar narrow view on other terms; their biomass program has famously only focused on liquid, direct substitutes (drop-in) for gasoline or diesel, leaving out multitudes of other biomass industry needs. As a result, taking an appropriately inclusive view of WTE was both surprising and welcome.

Biogas systems, turning waste into energy using anaerobic digestion (AD), is proven with thousands of commercial installations around the world, predominantly outside the U.S. Even with that maturity, research and development (R&D) is still needed to evolve in our rapidly changing energy world.
Today, the segment of the biogas industry focused using food waste, industrial organics and municipal solid waste to feed biogas systems is just starting to grow, while the established segments, mostly farms and wastewater facilities, expand. There’s great opportunity because there’s a lot of waste, but globally, the WTE industry tends to mature most rapidly in markets where waste disposal and energy costs are high. In the U.S., however, the low costs of waste disposal and energy generation have stunted efforts. As an industry, we have to get more creative in the way we develop biogas systems that are competitive in this environment.

Communities and states striving to reach landfill diversion targets of 75 percent, and in some cases zero waste, will find it impossible to do so without diverting the organic fraction of waste (often 25 percent or more) to organics recycling facilities like biogas systems. Therefore, it makes sense for government entities to invest in infrastructure and permitting improvements for biogas development as an essential public service for generating renewable energy, reducing disposal and reaching greenhouse gas and low-carbon fuel goals.

Over many years, federal policy has failed to recognize the many benefits of biogas systems—emissions reduction, waste reduction, odor reduction, renewable energy generation, soil amendment production, nutrient separation and dozens of related economic and social benefits—which has put the U.S. in last place when it comes to biogas R&D. Federal policy has focused on systems with fewer benefits overall, putting the U.S. far behind in the R&D and implementation of biogas systems, a key WTE technology. In the meantime, countries including Germany, Netherlands, the U.K. and India have advanced the technology and the biogas industry with more than 20,000 installations. Here’s where the biogas industry wants some R&D:

• Biogas upgrading to biomethane and compressed vehicle fuels.

• Higher efficiency, lower-cost biogas to electricity conversion equipment.

• Enhanced pretreatment systems for unique or contaminated waste streams before they enter the digester.

• Greater container mixing effectiveness and net energy efficiency.

• Coproduct/digestate processing for nutrient sequestration and separation.

• Higher-efficiency heat exchangers and waste heat utilization.

In the U.S., where the term “biofuel” usually connotes only liquid fuels, lack of R&D funding puts biogas in a disadvantaged position. This has limited the number of public and private researchers with expertise in the field, and without a steady stream of technology advancements, industry growth and investment is slowed. Increased R&D could lead to larger, private investments and industry growth.

While AD biogas for transportation fuel is given credit under the EPA’s renewable fuel standard, there are no federal policies or subsidies to encourage the use of biogas for thermal energy production, whether as a medium-Btu fuel via a dedicated pipeline or as a high-Btu fuel injected into the interstate pipeline network. This is in stark contrast to the massive support provided to geothermal and solar thermal technology.

A steady investment over the next 10 years would build the U.S. capacity for renewable energy generation, create new products to support American agriculture, move communities and states towards zero waste, regain U.S. R&D leadership and create a multitude of economic and social benefits that we can all use.

Author: Patrick Serfass
Executive Director, American Biogas Council