Aqua Ammonia Not Always A Good Choice For Power.

08 May 2023

• A non viable study.
• Only Anhydrous Ammonia should be considered in the study due to safety, transportability and better fuel choices for storage. A better choice at a Fuel Stop is Anhydrous Ammonia at 160 Kilos H2 per ton.
• We have known for years that Anhydrous Ammonia reduces exhaust temperature….much like propane at a blend of about 20% to 30% without engine damage.
• Aqua Ammonia, Ammonium Hydroxide as various blends should never be considered viable for a diesel engine dual fuel as it is much more dangerous than Anhydrous Ammonia as proven in agriculture.
• Aqua Ammonia is an exercise in hauling water…at 7.5 to 8 pounds per gallon. Ammonia is known to be 5.14 lbs. per gallon at 60 degrees F and stored to keep well.
• Aqua Ammonia is not a fuel choice due to concentration variations in storage of 15% to 22%. It can be useful in Power Plants.
• Non Viable Research.

Comments from Guy J Swanson.

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Study on effects of ammonia-diesel blends in CI engines

17 April 2023

An international team from the Middle East has investigated the characteristics of diesel engines powered by petroleum diesel fuel blended with different volumetric percentages of aqueous ammonia. A paper on their findings—including useful literature background on combustion of diesel/gasoline and ammonia—is published in the journal Fuel.

The researchers used Diesel-RK modeling and simulation software—developed at Bauman Moscow State Technical University—in their analysis of three volumetric blends of ammonia along with diesel: 40% NH₄OH + 60% Diesel; 50% NH₄OH + 50% diesel; and 60% NH₄OH + 40% diesel. The numerical analysis is based on a multizone combustion model. In the zone-based approach, the governing equations for each zone are solved as open systems.

In the simulations, the team used a constant engine speed of 1500 RPM, an injection pressure of 160 bar, and 20° BTDC injection timing. The compression ratio was kept constant at 15.5.

The results show that adding ammonia solutions decreases combustion pressure and heat release and increases Sauter mean diameter (a representation of the mean diameter of a collection of particles) and ignition delay.

The researchers found that generally the use of aqueous ammonia drops engine performance regardless of the percentage of NH₄OH used. Since 40%, 50%, and 60% of NH₄OH have lower heating values than diesel, BSFC is reduced by 7.15, 10.4%, and 15.38%, respectively.

Because the addition of ammonia reduces combustion temperature significantly, a noticeable reduction in NO_x emissions was achieved, reaching up to 61.75% in the case of 60% NH₄OH. The results highlighted a reduction in soot emissions (43.4% for 40% NH₄OH, 51.04% for 50% NH₄OH, and 49% for 60% NH₄OH) because the diesel was replaced with a no-carbon fuel, hence the engine produced less smoke compared to with the baseline case (pure diesel).

Resources

·         Mohamed F. Al-Dawody, Wisam Al-Obaidi, Emad D. Aboud, Mohammed A. Abdulwahid, Khaled Al-Farhany, Wasim Jamshed, Mohamed R. Eid, Zehba Raizah, Amjad Iqbal (2023) “Mechanical engineering advantages of a dual fuel diesel engine powered by diesel and aqueous ammonia blends,” Fuel, Volume 346, doi: 10.1016/j.fuel.2023.128398