Paths To Decarbonization On The Waterways

It’s been barely six months since Vanderbilt University released its study entitled “Decarbonization of the Inland Waterways Sector in the United States – Pathways and Challenges to A Zero-Carbon Future.” The study was prepared for ABS. One of its principal authors is Craig Philip, Ph.D., former CEO of Ingram Barge Company and now research professor of Civil and Environmental Engineering and director of the Vanderbilt Center for Transportation and Operational Resiliency. David Sehrt, former chief engineering officer at Ingram, co-authored, along with two Vanderbilt professors, Leah Dundon and Madeleine Allen.

The study looked at many different measures of emissions in the inland waterway mode compared to other modes. It confirms that the inland waterways move far more ton-miles of cargo per gallon of fuel than other modes and is the least “carbon intensive.” That is, it emits by far the lowest amount of carbon per ton-mile—about 50 metric tons per million ton-miles, vs. 650 metric tons for trucks.
It examines a number of technologies being explored or developed to reduce carbon emissions on the rivers.

It looks at battery technologies, hydrogen, liquefied natural gas and other means that have been explored to lower waterways emissions. It also looks frankly at challenges specific to the waterways, such as channel depths that limit how big towboats can get to accommodate heavier new technology, whether large batteries, LNG tanks, methanol tanks or hydrogen converters. While it doesn’t discount any possible solution, it admits that some are not economically feasible without substantial federal help.

The inland marine sector is not subject to the timetables and goals of the International Maritime Organization, and the report admits, “There are no current market or regulatory incentives likely to drive a near-term (next 5-10 years) transition to zero-carbon propulsion technologies.”

But that doesn’t mean internal pressure isn’t there. Both public and private decarbonization initiatives take many forms, such as companies adopting supply-chain emissions reporting systems relied on by customers. 

The study concludes, “Methanol and biofuels present the most realistic near-term approaches to alternative fuels” on the inland waterways. That’s especially true of so-called renewable diesel, which is made from plants and differs from earlier biofuels formulations that hit blendwall limits. There are currently seven approved chemical and technological pathways by which vegetable oils can be turned into renewable diesel, resulting in slightly different formulas. Since they can be used in existing diesel engines and have nearly the same energy density, they have attracted great interest. Energy companies are investing billions of dollars in new plants to crush soybeans and refine them into fuel.  While some renewable bio-diesels have higher NoX emissions, as the Vanderbilt study points out, they offer the quickest immediate applicability. 

During last week’s meeting of the Inland Waterways Users board, Matt Woodruff said, “As our nation’s emphasis on different parts of the transportation puzzle changes, and we’re talking about decarbonization, the inland waterways have a good story to tell. Right now, we’re the lowest carbon mode of transportation, but we have the potential—and for many around this table, their companies are looking at ways—to reduce that even further, to be cleaner and greener, and [to ask] how we can continue to step up and raise the bar in terms of efficiency and low carbon solutions to moving cargo.”

The inland marine transportation industry has a proven record of taking it upon itself to maintain its advantages.  Examples include voluntarily increasing contributions to the Inland Waterways Trust Fund via a higher diesel fuel tax and self-imposing its own safety and environmental compliance efforts by groups such as AWO.  There is no question that help will be needed to make decarbonization economically feasible, but it is inspiring to see an industry that is already the clear choice for reducing environmental impact gear up to innovate and constantly improve.  Efforts already underway and options being explored will be the center of two education panels at this year’s Inland Marine Expo on May 24, including “Maintaining the Environmental Advantage: Alternative Fuels” and “Electric and Hybrid Technology & Applications.”

There is a lot to consider, and we encourage you to join the conversation.