Browsing by Subject "Ammonia"

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    AN ANALYSIS OF GREEN HYDROGEN TO AMMONIA MARKET OPPORTUNITIES
    (2022-04-22) Gulati, Akash
    Building off a previous internship with a large renewable energy company, this Masters Project analyzes the additional cost for conversion, transportation, and cracking of hydrogen to ammonia. Previous work for the client analyzed three additional hydrogen conversion and transportation pathways. All four pathways are summarized below. • Hydrogen compression, gaseous trucking, onsite gaseous storage • Hydrogen compression, pipeline transportation, onsite gaseous storage • Hydrogen liquefaction, liquid trucking, onsite liquid storage, vaporization • Hydrogen storage, ammonia generation, liquid ammonia trucking, onsite liquid ammonia storage, ammonia cracking back to hydrogen (analyzed here) This masters project found that the conversion of hydrogen to ammonia as a transportation pathway is never the cheapest option on a dollar per kilogram H2-mile basis. This is because the pathway requires many chemical and thermodynamic conversions, each with their own efficiency losses: generation of renewable electricity, electrolysis to generate hydrogen, the Haber-Bosch process to produce ammonia, ammonia storage, ammonia transportation, and subsequent cracking of ammonia back to hydrogen. In total the pathway analyzed in this MP has a 24% cycle efficiency. In addition to analyzing the ammonia conversion pathway, the client requested an analysis of the existing hydrogen and ammonia markets. Much of this Masters Project is devoted to developing a thorough understand of the many use cases, generation technologies, and transportation pathways for these two crucial molecules. Additionally, the client requested an analysis of the major players in the ammonia-based fertilizer market as a basis for a market entry strategy into this space. Research found that hydrogen can be made from renewable electricity, steam, coal, or almost any other energy source, each with its own level of associated carbon emissions. Hydrogen is used primarily for oil and gas refining, ammonia production, methanol production, steelmaking, transportation, and many other applications. Once made, hydrogen can be transported as a compressed gas in trucks or pipelines, as a liquid in trucks, or converted to ammonia for transportation. Ammonia is made by combining hydrogen with nitrogen using the Haber-Bosch process. The color (grey, green, blue, etc.) of hydrogen that is used is a large determinant of the carbon intensity of the ammonia produced. Ammonia is used primarily for fertilizer production, and to a lesser extent in the refining of oil and gas and the production of specialty chemicals. Once made, ammonia can be transported in gaseous pipelines, or liquefied and transported on trucks, barges, or ships. Most major ammonia producers have committed to decarbonizing their operations. This will require the use of green hydrogen to produce green ammonia as a feedstock. It is estimated that 15% of the global ammonia market will be served by green hydrogen by 2030. This represents a large opportunity for renewable energy companies such as my client. Ammonia manufacturing is also a highly concentrated market, with seven US manufacturers representing 70% of the total production capacity. Strategic analysis of the existing markets found that the two key market advantages for renewable energy companies are location and market growth. Renewable electricity is cheap in the areas where ammonia is currently made. This removes conversion and transportation costs from the Levelized Cost of Hydrogen calculation and allows green hydrogen to be more competitive, although still not at parity with grey hydrogen. Additionally, although currently nascent, the market for green ammonia is expected to reach $500 million by 2025 and $1.5 billion by 2050. As the market grows, renewable energy companies will have ample opportunities to sell electricity to ammonia producers. The two main market entry challenges identified in this analysis are competition from industrial gases manufacturers and the lack of national regulatory support in the form of carbon pricing. Industrial gases manufacturers currently own the customer relationships with ammonia producers and are expected to be very protective and cost competitive. Most the industrial gases companies have short term decarbonization plans that involve the implementation of blue hydrogen, and longer-term plans involving green hydrogen. Additionally, none of the states with high volumes of ammonia production currently have a carbon tax. This results in green hydrogen and ammonia being more expensive than the currently used grey hydrogen and ammonia. The client should begin their ammonia entry by developing small scale hydrogen off-taker agreements with large ammonia manufactures who are interested in green hydrogen. By bringing hydrogen production expertise in-house the client for this MP will be able to reduce the price gap between green and grey hydrogen and become a market leader in this emerging and quickly grown space.
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    Estimation of in-canopy ammonia sources and sinks in a fertilized Zea mays field.
    (Environ Sci Technol, 2010-03-01) Bash, JO; Walker, JT; Katul, GG; Jones, MR; Nemitz, E; Robarg, WP
    An analytical model was developed to describe in-canopy vertical distribution of ammonia (NH(3)) sources and sinks and vertical fluxes in a fertilized agricultural setting using measured in-canopy mean NH(3) concentration and wind speed profiles. This model was applied to quantify in-canopy air-surface exchange rates and above-canopy NH(3) fluxes in a fertilized corn (Zea mays) field. Modeled air-canopy NH(3) fluxes agreed well with independent above-canopy flux estimates. Based on the model results, the urea fertilized soil surface was a consistent source of NH(3) one month following the fertilizer application, whereas the vegetation canopy was typically a net NH(3) sink with the lower portion of the canopy being a constant sink. The model results suggested that the canopy was a sink for some 70% of the estimated soil NH(3) emissions. A logical conclusion is that parametrization of within-canopy processes in air quality models are necessary to explore the impact of agricultural field level management practices on regional air quality. Moreover, there are agronomic and environmental benefits to timing liquid fertilizer applications as close to canopy closure as possible. Finally, given the large within-canopy mean NH(3) concentration gradients in such agricultural settings, a discussion about the suitability of the proposed model is also presented.
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    Experimental evaluation of evolution and coevolution as agents of ecosystem change in Trinidadian streams.
    (Philos Trans R Soc Lond B Biol Sci, 2009-06-12) Palkovacs, EP; Marshall, MC; Lamphere, BA; Lynch, BR; Weese, DJ; Fraser, DF; Reznick, DN; Pringle, CM; Kinnison, MT
    Evolution has been shown to be a critical determinant of ecological processes in some systems, but its importance relative to traditional ecological effects is not well known. In addition, almost nothing is known about the role of coevolution in shaping ecosystem function. Here, we experimentally evaluated the relative effects of species invasion (a traditional ecological effect), evolution and coevolution on ecosystem processes in Trinidadian streams. We manipulated the presence and population-of-origin of two common fish species, the guppy (Poecilia reticulata) and the killifish (Rivulus hartii). We measured epilithic algal biomass and accrual, aquatic invertebrate biomass, and detrital decomposition. Our results show that, for some ecosystem responses, the effects of evolution and coevolution were larger than the effects of species invasion. Guppy evolution in response to alternative predation regimes significantly influenced algal biomass and accrual rates. Guppies from a high-predation site caused an increase in algae relative to guppies from a low-predation site; algae effects were probably shaped by observed divergence in rates of nutrient excretion and algae consumption. Rivulus-guppy coevolution significantly influenced the biomass of aquatic invertebrates. Locally coevolved populations reduced invertebrate biomass relative to non-coevolved populations. These results challenge the general assumption that intraspecific diversity is a less critical determinant of ecosystem function than is interspecific diversity. Given existing evidence for contemporary evolution in these fish species, our findings suggest considerable potential for eco-evolutionary feedbacks to operate as populations adapt to natural or anthropogenic perturbations.
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    Unprecedented loss of ammonia assimilation capability in a urease-encoding bacterial mutualist.
    (BMC Genomics, 2010-12-02) Williams, Laura E; Wernegreen, Jennifer J
    BACKGROUND: Blochmannia are obligately intracellular bacterial mutualists of ants of the tribe Camponotini. Blochmannia perform key nutritional functions for the host, including synthesis of several essential amino acids. We used Illumina technology to sequence the genome of Blochmannia associated with Camponotus vafer. RESULTS: Although Blochmannia vafer retains many nutritional functions, it is missing glutamine synthetase (glnA), a component of the nitrogen recycling pathway encoded by the previously sequenced B. floridanus and B. pennsylvanicus. With the exception of Ureaplasma, B. vafer is the only sequenced bacterium to date that encodes urease but lacks the ability to assimilate ammonia into glutamine or glutamate. Loss of glnA occurred in a deletion hotspot near the putative replication origin. Overall, compared to the likely gene set of their common ancestor, 31 genes are missing or eroded in B. vafer, compared to 28 in B. floridanus and four in B. pennsylvanicus. Three genes (queA, visC and yggS) show convergent loss or erosion, suggesting relaxed selection for their functions. Eight B. vafer genes contain frameshifts in homopolymeric tracts that may be corrected by transcriptional slippage. Two of these encode DNA replication proteins: dnaX, which we infer is also frameshifted in B. floridanus, and dnaG. CONCLUSIONS: Comparing the B. vafer genome with B. pennsylvanicus and B. floridanus refines the core genes shared within the mutualist group, thereby clarifying functions required across ant host species. This third genome also allows us to track gene loss and erosion in a phylogenetic context to more fully understand processes of genome reduction.