Speaking at the Pacific Institute for Climate Solutions Biofuel Forum, four distinguished experts in the field of renewable natural gas (RNG), Jennifer Davison, Alex Boston, Chris Bush, and  Brent Sauder say that the future of this “greener fuel” is already flowing through municipal pipe lines. Unlike conventional biofuels that rely heavily on the cultivation of food crops for fuel, RNG is produced with municipal “”feedstocks”, such as sewage, agricultural byproducts, and landfill volatiles.   Such feedstocks are ordinarily regarded as waste products and are expensive to dispose of, posing environmental harm. When processed into RNG, wastes are converted to methane by anaerobic respiration in digester tanks. Diversion of waste materials brings multiple environmental benefits including a reduction in municipal and agricultural sewage entering watersheds, production of nitrogen and phosphorus rich fertilizer, and offsetting non-renewable fossil fuel emissions.  

At the tail end of stoves pipes, furnaces, and RNG powered trucks however, the actual burning of RNG is no cleaner than conventional natural gas.  Combustion is combustion and RNG produces the same amount of particulates and carbon emissions as it’s fossil fuel equivalent. RNG does have the potential to reduce total greenhouse gas emissions however in that the diversion of landfill gas, sewage and agricultural wastes prevents methane emissions from the decomposition of wastes that are subjected to open decomposition in the environment.

Each of the  four speakers extolled the virtues of RNG and each has played a significant role in bringing the fuel to consumers.  It was clear that in dedicating themselves to promoting the benefits of RNG, each risked falling into the trap of perpetuating our reliance on a carbon emitting combustion-based fuel.  As a member of the audience it was interesting to watch this paradox unfold as RNG was presented as almost a carbon-free alternative to natural gas.

Jennifer Davinson, with the BC ministry of Energy, Mines and Petroleum Resources spoke about her work to provide the infrastructure necessary to pump RNG into municipal supplies.  She serves as the liaison between the provincial government and local producers. Her work is vital for securing a government mandate for BC RNG products entering the market. Unfortunately some of the data that she presented was alarmingly flawed and at one point she said that BC’s use of RNG was the GHG savings equivalent of taking 500,000 off of the road.  Careful questioning by the audience seeking clarification revealed that GHG emissions from RNG would be nearly the same however they would not be coming from a fossil fuel source.

Brent Saunder the executive chair of the BC Bioenergy Network supported similarly controversial sentiments when advocating for the use of residual wastes from industrial forest management.   He indicated that BC could be a world leader the use of forest fuels for biogas and a major exporter of pellet fuels to Europe. One of the major problems with using forest wastes is that they must be transported long distances for processing which requires fossil fuels.  Even if waste products could be harvested in a manner that does not undermine forest nutrient cycling, transportation still provides a significant hurdle to the use of forest wastes as green fuel.

Chris Bush and Alex Boston offered a more measured, pragmatic take on RNG production suggesting that it can be used a bridge to non-combustible fuels, while stressing the use of agricultural, sewage, and landfill gas as feedstocks.  Their concept was simple, yet innovative, deriving value from waste while eliminating waste. A promising idea and hopefully the start of a revolution.