As the world moves towards a low-carbon energy future, fossil-fuel-rich Alaska is trying to get on the green train.
A joint project underway by the University of Alaska Fairbanks and the US Department of Energy’s Pacific Northwest National Laboratory is examining whether ammonia could be made from vast proven reserves of natural gas on the North Slope with the hydrogen contained in ammonia used as a carbonless fuel. .
The research is supported by the Advanced Manufacturing Office of the US Department of Energy.
“It’s an interesting concept,” said Corri Feige, Alaska Natural Resources Commissioner. But Feige noted that there could be technical issues with liquid ammonia because it is “very corrosive to steel,” and the introduction into the Trans-Alaska pipeline system, or TAPS, for shipment. “could have adverse effects”.
However, others are interested in Alaska’s ammonia-hydrogen connection. Tim Fitzpatrick, spokesperson for Project Alaska LNG, promoter of an 800-mile pipeline from the North Slope, said the ammonia could be made in an existing ammonia plant, albeit on the back burner, in Nikiski. near the terminus in southern Alaska.
“We think ammonia could add a lot of value to our project,” which would also ship LNG, said Fitzpatrick. Agrium Corp. is studying a restart of the plant but is blocked by an insufficient supply of natural gas.
There is a big advantage if the issues can be resolved. Hydrogen is increasingly seen as the fuel of the future because its emissions are essentially water, and industries and businesses around the world are studying how to use it.
“There is huge interest in hydrogen today, and a lot of money is pouring into research into how it can be used,” said Nathan Prisco, the DOE / university project principal investigator.
Daimler-Benz recently announced plans to incorporate hydrogen fuel cells into heavy-duty trucks, reducing dependence on diesel.
The downside of hydrogen is that it can be expensive to produce, transport and store. The process of making green hydrogen, essentially separating water molecules with renewable energy, is not cheap, and making it from natural gas, called blue or sometimes gray hydrogen, n does not have the same environmental benefits.
Prisco said that using ammonia as an intermediate “carrier” for hydrogen solves some of the problems. Making liquid ammonia from natural gas is a conventional process, and liquid ammonia can be shipped like propane through pipelines, he said.
Growing interest in ammonia-hydrogen
Interest in the ammonia-hydrogen connection is increasing. Mitsubishi recently made a deal to buy ammonia from Saudi Arabia for use as a carbon-free fuel in power plants, the only pollutant being nitrous oxide, which power plants are equipped to handle.
“Japan’s largest electric utility, JERA, plans to burn ammonia as a clean fuel in its coal-fired power plants,” Prisco said. “It’s just for a rapid energy transition. In the future, Japan plans to use ammonia turbines or high efficiency fuel cells.
The ammonia would also be shipped to new hydrogen refueling stations under construction in the European Union which are equipped to “crack” the hydrogen from the ammonia on site.
Brian Murphy, senior hydrogen analyst at S&P Global Platts Analytics, said there is a lot of interest in using ammonia as a fuel in shipping.
“Shipping is a major source of carbon emissions, accounting for around 2% of global emissions,” he said. Japanese companies are also at the forefront of demonstrating ammonia-fueled maritime vessels.
The idea for Alaska is for the ammonia to be made from some of the 8 billion cubic feet of gas now produced on the slope but mostly re-injected underground, and at a high cost.
The gas is produced with approximately 280,000 bpd of crude oil in the Prudhoe Bay field. The crude is sent to the market via the TAPS, but the gas is reinjected because there is no gas pipeline yet from the producers on the north slope.
So far, research indicates that an optimal project for the North Slope could involve 120,000 b / d of liquid ammonia produced from 330 million cf / day of gas from a set of three gas plants. ‘10,000 t / day ammonia, said Prisco. TAPS now transports less than 500,000 b / d of crude oil and has a large spare capacity (the pipeline once moved 2 million b / d).
However, there can be technical issues in mixing ammonia with crude oil in TAPS, and this is the focus of current research, Prisco said. It must also be demonstrated that ammonia can be economically separated from the flow of mixed liquids at Valdez, the southern terminus of TAPS.
“Most of the ammonia can be recovered in bulk, but the excess ammonia will likely end up in the Valdez vapor recovery system, where it needs to be processed,” said Prisco.
There could be effects of ammonia on the chemistry and sales quality of crude shipped in TAPS, which will need to be compensated for in the quality bank mechanism that TAPS shippers use to adjust for differences in the quality of different crudes produced. on the northern slope.
There is also the issue of what to do with the carbon left on the North Slope when ammonia is made from methane. Typically, “for every metric ton of ammonia produced, there are 2 metric tons of carbon dioxide emitted,” Prisco said.
“However, capturing carbon dioxide from an ammonia plant is less expensive than capturing it from the flue gases of a power plant,” and costs can range between $ 40 and $ 60 / mt, a he declared. The overall cost of producing ammonia with the extracted carbon dioxide could be $ 200 to $ 240 / mt, compared to $ 120 / mt without carbon capture, Prisco said.
However, new federal carbon capture tax credits could help. If the carbon dioxide is used in enhanced oil recovery on the North Slope, which producers believe is possible, a tax credit of $ 35 / mt could apply. U.S. carbon capture credits are phased in and will be fully in place in 2026.
If geological sequestration can be accomplished, CO2 could be injected into depleted oil reservoirs. This is now done with the hazardous waste on the slope.
Murphy, at Platts Analytics, sees potential hurdles in the cost of TAPS installations and adaptations, as well as mixing ammonia with crude oil, but is puzzled by the possibility that the depleted oil reservoirs on the slope. north can be used for carbon storage and the infrastructure is now in place on the slope for injection.
Prisco said Alaska’s cold climate is another plus. Some carbon capture technologies work best in cold weather, just as large oil processing plants on the slope become more efficient in winter, Prisco said.
There is also a geographic advantage. Valdez is also closer or as close to Japan than other sources of ammonia, Prisco said. Shipping costs for liquid ammonia from the Persian Gulf are estimated at $ 40 / mt and $ 80 / mt from the US Gulf Coast; while Valdez’s cost is likely to be closer to $ 40 / mt or less, Prisco said.
However, a competitor in the market, Murphy said, will be the major projects planned in Australia to produce green hydrogen, with water supplied by renewable solar and wind facilities.
But he agreed that Alaska could be competitive in the market if the issues could be resolved. Prisco believes that large volumes of ammonia could be shipped to customers in Asia as a low-carbon fuel for power generation and ultimately as a source of pure hydrogen for use. in vehicles and other applications.
“Compared to other projects around the world, Alaska has a strong hand to play in the transition ahead,” said Prisco.
Feige agrees: “Alaska has a vast array of natural resources that could be utilized as new technologies are developed that utilize raw materials found here and benefit from environmental conditions such as cold temperatures for more efficiency. “
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