Fueling the Hydrogen Revolution with RNG

Stewart Stewart of BayoTech discusses the U.S. hydrogen industry, its potential to utilize RNG, and the company’s rollout of regional hubs.
By Anna Simet | April 14, 2022

The hydrogen economy is here and now. The rapidly growing opportunity is significant, and the RNG industry has a key role to play, according to BayoTech Chief Commercial Officer Stewart Stewart, who briefed the RNG industry on opportunities in hydrogen production from RNG, its advantages and what the sector currently looks like during a March webinar sponsored by the Coalition for Renewable Natural Gas.

The hydrogen industry has traditionally served three very large, centralized industries, which Stewart categorizes as oil and gas refineries, methanol production and fertilizer production from ammonia. “In those value chains, hydrogen is traditionally produced in very large plants and shipped over long distances to their users,” he says. “The growth opportunity we’re focused on is in emerging applications—that’s where the growth will really come from over the next two decades.”

 Stewart says current hydrogen markets are approaching about $220 billion, and that’s projected to increase by 50% and then double over the next 10 to 15 years. So, where is that growth coming from and why? Some examples of emerging applications include fuel cell mobility, hydrogen blending such as gas grid injections for natural gas, industrial end use applications such as chemical plants or glass production, as well as primary or backup power for data centers and smaller, off-grid or temporary power installations, according to Stewart.  “Hydrogen is certainly a hot topic in area of energy transition and decarbonization, and it’s important to understand why hydrogen has benefits in the energy industry.”

Stewart provides a comparison of hydrogen and natural gas, diesel and gasoline, highlighting its greater efficiency. “Hydrogen has the same amount of energy per kilogram as one gallon of gasoline or diesel, typically,” he says. “But by leveraging a fuel cell combined with an electric motor drivetrain, the efficiency is about two to three times greater than it would be in an internal combustion engine on compress natural gas, diesel or gasoline.”

As for emissions, hydrogen has zero—but why not simply use low-emission technologies already widely available today like compressed natural gas (CNG), rather than fuel cells and hydrogen production? Stewart says its important to understand the true advantages from the emissions standpoint.

How Far Can a Car Go on 1 Million Btu?
A traditional gasoline vehicle filled with 1 million British thermal units (Btu) of gasoline can drive about 200 miles, according to research done by the U.S. DOE, NREL and EERE. “If you look at the total CO2 emissions on a well-to-wheel basis, it produces about 430 grams of CO2 equivalent per mile,” Stewart says.

The same amount of energy put into a CNG vehicle doesn’t go as far and is not as efficient, though there are some carbon benefits. “It can only reach about 175 miles per million Btu, but the value chain is more carbon efficient—you have about a 10% savings in total CO2 well-to-wheel emissions, at 390 grams of CO2 equivalent per mile. Now, if you took that million Btu of fuel as natural gas, converted it into hydrogen and used it in a fuel cell vehicle with its electric drivetrain, you would now go 255 miles—46% further than a CNG vehicle and 28% further than a gasoline vehicle.” And, because of the advantage of lower well-to-wheel emissions, Stewart adds, there is a dramatic drop of emissions from a carbon intensity standpoint, by about 35 to 40% in just 255 grams of CO2 equivalent per mile. “That’s just using pipeline natural gas and converting it into hydrogen,” he says.

The bigger opportunity within the value chain is the replacement of the methane source with RNG. “Now, not only do you get the additional mileage of 46% further, but you also get zero emissions in both production and use, by using RNG. Or you could even go carbon negative.”

As for the common pathway of biomethane and RNG to hydrogen, it involves steam methane reforming (SMR)—the most common production method in the U.S.—during which methane reacts with steam to produce a hydrogen-rich syngas and ultimately, carbon negative hydrogen. Beginning with anaerobic digestion, the raw biogas requires cleaning/upgrading, with the separation of CO2, sulfur and any other impurities like siloxanes to get closer to pipeline quality natural gas. “The next step looks similar to the infrastructure of upgrading to RNG, but goes a step further by adding on-site hydrogen production,” Stewart says. “There is another step you can add to the process, which is carbon capture and storage, and this can be applied in one or two places, or both,” Stewart says. “The CO2 can be captured off the biomethane upgrading process when it is being separated, or as part as the SMR on-site hydrogen production process—both are CO2-rich sources.”  While BayoTech doesn’t do CCS systems, Stewart says, they have some partnerships with companies to put in CCS systems.

Potential and Buildout
As for real potential in the U.S., the total of potential of hydrogen from biogas is estimated to be greater than 4.2 million metric tons per year, from a variety of sources, including landfill gas (2.8 million metric tons (MT)year), wastewater (600,000 MT/year), animal waste (500,000 MT/year), and industrial and commercial projects (300,000 MT/year), according to Stewart. “If you take all of those in sum, that give sustainable, readily available biogas potential as supporting as many as 11 million fuel cell vehicles on a daily basis.” There are currently around 200 active or developing RNG projects across the U.S. Stewart adds, but the potential is closer to around 43,000, per data from the RNG Coalition.

BayoTech currently operates an on-site hydrogen generator at its headquarters in Albuquerque, New Mexico. Commercial units have a footprint of about 50 feet long by 25 feet wide and produce about 1 ton of hydrogen per day, being fed with less than 200 MMBtu of RNG per day. “We plan to develop larger plants that have a 5- or 10-ton scale, going forward,” Stewart says. The modular, compact design of the systems allows for them to be built quickly and use a lot less energy than traditional hydrogen production methods, he says, by leveraging a bayonet-style design reactor. “It uses the internal heat of the reaction to heat up the incoming RNG, so that it reaches about 500 or 600 degrees Celsius before it even gets to the furnace,” he explains. “That high efficiency allows us to match what would happen at an industrial plant, but doing so on a local basis. High energy efficiency and the avoided liquefaction and long-haul transportation result in lower carbon emissions than legacy technologies.”

Bayotech’s solutions to move and distribute hydrogen include high-pressure storage, transport and dispensing product lines that support local hydrogen distribution. The company is in the process of rolling out a nationwide network of hydrogen hubs—filling stations similar to gas stations, Stewart says, with three expected to come online in the fourth quarter of this year. The first will be in Albuquerque, New Mexico, in partnership with New Mexico Gas Company. Hydrogen produced at the hub will be used by New Mexico Gas in a pilot project to demonstrate the safe and effective blending of hydrogen into the company’s natural gas distribution system. It will produce 1,000 kilograms per day of hydrogen for transportation and industrial use. Additional projects are planned for California, Oklahoma and Missouri, as well as other locations in the U.S. and U.K.

The design of regional hydrogen hubs will be focused on producing low carbon, local hydrogen supply for end users within a 200-mile radius.

Stewart closed with discussing the U.S. DOE’s recent announcement of a $9.5 billion investment in the development clean hydrogen hubs, for which the department currently seeking regional applications. “It will be a 50/50 grant match program with private investment, designed to bring hundreds of tons of clean hydrogen into production over the next few years, and is current structured toward at least four regional hubs,” he says, adding that BayoTech is interested in partnering to seek funding. According to U.S. DOE data, the U.S. currently producers about 10 million metric tons of hydrogen annually.

 “RNG has a key role to play in the hydrogen economy,” Stewart adds. “It’s not strictly an electrolysis game. RNG is the only way to create carbon negative hydrogen, and is the only carbon negative transportation fuel solution out there.”

Author: Anna Simet
Editor, Biomass Magazine