Name: ammonia synthesis at low pressure
Uploaded: 2017-08-23T13:00:00
Description: Watch this Scientific Journal Video about Ammonia Synthesis at Low Pressure at JoVE.com

This work was primarily supported by ARPA-E, a part of the US Department of Energy, by the Minnesota Environment and Natural Resources Trust Fund, as recommended the Legislative-Citizen Commission on Minnesota Resources, and by MNDRIVE, an initiative of the University of Minnesota. Additional support came from the Dreyfus Foundation.

1. Pilot Plant Start-up
<ol>
	<li>Nitrogen production system
	<ol>
		<li>Turn on the air dryer, the air compressor, and the nitrogen generator. Verify that there is at least 800 kPa of air in the air compressor tank. This keeps sending nitrogen to the buffer tank until there is no more than 0.004% (40 ppm) oxygen in the nitrogen.</li>
		<li>Turn on the nitrogen gas booster. The gas booster starts to fill the nitrogen supply tanks, at pressures as high as 17 MPa.</li>
	</ol>
	</li>
	<li>Hydrogen...

<ol>
	<li>Erisman, J. W., Sutton, M. A., Galloway, J., Klimont, Z., Winiwarter, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+a+century+of+ammonia+synthesis+changed+the+world.">How a century of ammonia synthesis changed the world.</a> Nat Geosci. 1 (10), 636-639 (2008).</li><li>Vojvodic, A., Medford, A. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exploring+the+limits:+A+low-pressure,+low-temperature+Haber-Bosch+process.">Exploring the limits: A low-pressure, low-temperature Haber-Bosch process.</a> Chem Phys Lett. 598, 108-112 (2014).</li><li>Jennings, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Catalytic Ammonia Synthesis. , (1991).</li><li>. Nitrogen (Fixed) - Ammonia Available from: <a target="_blank" href="https://minerals.usgs.gov/minerals/pubs/commodity/nitrogen/mcs-2016-nitro.pdf">https://minerals.usgs.gov/minerals/pubs/commodity/nitrogen/mcs-2016-nitro.pdf</a> (2016)</li><li>Wojcik, A., Middleton, H., Damopoulos, I., Van herle, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ammonia+as+a+fuel+in+solid+oxide+fuel+cells.">Ammonia as a fuel in solid oxide fuel cells.</a> J Power Sources. 118 (1-2), 342-348 (2003).</li><li>Zamfirescu, C., Dincer, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+ammonia+as+a+sustainable+fuel.">Using ammonia as a sustainable fuel.</a> J Power Sources. 185 (1), 459-465 (2008).</li><li>Christensen, C. H., Johannessen, T., S&#248;rensen, R. Z., N&#248;rskov, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Towards+an+ammonia-mediated+hydrogen+economy?.">Towards an ammonia-mediated hydrogen economy?.</a> Catalysis Today. 111 (1-2), 140-144 (2006).</li><li>Hummelsh&#248;j, J. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=reversible+high-density+hydrogen+storage+in+compact+metal+ammine+salts.">reversible high-density hydrogen storage in compact metal ammine salts.</a> J Am Chem Soc. 130 (27), 8660-8668 (2008).</li><li>Ni, M., Leung, M. K. H., Leung, D. Y. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ammonia-fed+solid+oxide+fuel+cells+for+power+generation-A+review.">Ammonia-fed solid oxide fuel cells for power generation-A review.</a> Int J Energy Res. 33 (11), 943-959 (2009).</li><li>Zamfirescu, C., Dincer, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ammonia+as+a+green+fuel+and+hydrogen+source+for+vehicular+applications.">Ammonia as a green fuel and hydrogen source for vehicular applications.</a> Fuel Process Technol. 90 (5), 729-737 (2009).</li><li>Ertl, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+Science+and+Catalysis-Studies+on+the+Mechanism+of+Ammonia+Synthesis:+The+P.+H.+Emmett+Award+Address.">Surface Science and Catalysis-Studies on the Mechanism of Ammonia Synthesis: The P. H. Emmett Award Address.</a> Catal Rev. 21 (2), 201-223 (2006).</li><li>Nielsen, A., Kjaer, J., Bennie, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rate+equation+and+mechanism+of+ammonia+synthesis+at+industrial+conditions.">Rate equation and mechanism of ammonia synthesis at industrial conditions.</a> J Catal. 3 (1), 68-79 (1964).</li><li>. DE-FOA-0001569 Sustainable Ammonia Synthesis Available from: <a target="_blank" href="https://science.energy.gov/~/media/grants/pdf/foas/2016/SC_FOA_0001569.pdf">https://science.energy.gov/~/media/grants/pdf/foas/2016/SC_FOA_0001569.pdf</a> (2016)</li><li>Sustainable Ammonia Synthesis - Exploring the scientific challenges associated with discovering alternative, sustainable processes for ammonia production. DOE Roundtable Report Available from: <a target="_blank" href="https://science.energy.gov/~/media/bes/pdf/reports/2016/SustainableAmmoniaReport.pdf">https://science.energy.gov/~/media/bes/pdf/reports/2016/SustainableAmmoniaReport.pdf</a> (2016)</li><li>Reese, M., Marquart, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Performance+of+a+Small-Scale+Haber+Process.">Performance of a Small-Scale Haber Process.</a> Ind Eng Chem Res. 55 (13), 3742-3750 (2016).</li><li>Schl&#246;gl, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Catalytic+Synthesis+of+Ammonia-A+"Never-Ending+Story".">Catalytic Synthesis of Ammonia-A "Never-Ending Story".</a> Ange Chemie Int Ed. 42 (18), 2004-2008 (2003).</li><li>Dyson, D. C., Simon, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetic+Expression+with+Diffusion+Correction+for+Ammonia+Synthesis+on+Industrial+Catalyst.">Kinetic Expression with Diffusion Correction for Ammonia Synthesis on Industrial Catalyst.</a> Ind Eng Chem Fund. 7 (4), 605-610 (1968).</li><li>Temkin, M., Pyzhev, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetics+of+ammonia+synthesis+on+promoted+catalysts.">Kinetics of ammonia synthesis on promoted catalysts.</a> Acta Physiochim USSR. 12, 327-356 (1940).</li><li>Annable, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+the+Temkin+kinetic+equation+to+ammonia+synthesis+in+large-scale+reactors.">Application of the Temkin kinetic equation to ammonia synthesis in large-scale reactors.</a> Chem Eng Sci. 1 (4), 145-154 (1952).</li><li>Guacci, U., Traina, F., Ferraris, G. B., Barisone, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+Application+of+the+Temkin+Equation+in+the+Evaluation+of+Catalysts+for+the+Ammonia+Synthesis.">On the Application of the Temkin Equation in the Evaluation of Catalysts for the Ammonia Synthesis.</a> Ind Eng Chem Prod DD. 16 (2), 166-176 (1977).</li><li>Hummelsh&#248;j, J. S., S&#248;rensen, R. Z., Kustova, M. Y., Johannessen, T., N&#248;rskov, J. K., Christensen, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+nanopores+during+desorption+of+NH3+from+Mg(NH3)6Cl2.">Generation of nanopores during desorption of NH3 from Mg(NH3)6Cl2.</a> J Am Chem Soc. 128 (1), 16-17 (2006).</li><li>Huberty, M. S., Wagner, A. L., McCormick, A., Cussler, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ammonia+absorption+at+haber+process+conditions.">Ammonia absorption at haber process conditions.</a> AIChE Journal. 58 (11), 3526-3532 (2012).</li><li>Himstedt, H. H., Huberty, M. S., McCormick, A. V., Schmidt, L. D., Cussler, E. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ammonia+synthesis+enhanced+by+magnesium+chloride+absorption.">Ammonia synthesis enhanced by magnesium chloride absorption.</a> AIChE Journal. 61 (4), 1364-1371 (2015).</li><li>Malmali, M., Wei, Y., McCormick, A., Cussler, E. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ammonia+Synthesis+at+Reduced+Pressure+via+Reactive+Separation.">Ammonia Synthesis at Reduced Pressure via Reactive Separation.</a> Ind Eng Chem Res. 55 (33), 8922-8932 (2016).</li><li>Wagner, K., Malmali, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Column+absorption+for+reproducible+cyclic+separation+in+small+scale+ammonia+synthesis.">Column absorption for reproducible cyclic separation in small scale ammonia synthesis.</a> AIChE Journal. , (2017).</li></ol>

Critical Steps of the Reaction-absorption Experimental Apparatus:
Make sure that there is no impurity in the nitrogen and hydrogen system. The absorbent materials will change after each cycle. In most cases, at high temperature and in the presence of ammonia, the absorbent materials fuse and form a large solid concrete. According to the thermodynamic properties of each metal halide and ammine complex, the appropriate temperatures for absorption and desorption should be employed. Before each test,...

Ammonia is a key industrial chemical. It is produced through the Haber-Bosch process, which is known as one of the most important innovations of the 20th century1,2. Ammonia synthesis is carried out in the presence of a heterogeneous catalyst at elevated temperatures (&#62; 375 &#176;C) and pressures (&#62;100 bar)3. Such high temperature and pressure requirements make ammonia synthesis very energy- and capital-intensive. Approximately, 150 million tons of ammonia are produced each year4, which accounts for 1-3% of the world&#39;s energy consumption, 5% of the natural gas consumption, and up to 3% of the climate-changing gas emissions5,6,7.
Ammonia has two major potential uses. First, ammonia is a synthetic nitrogen fertilizer1. Without this fertilizer, half of the current population would not have access to sufficient food. Second, ammonia can serve as an energy vector, either as a carbon-neutral liquid fuel or as an indirect hydrogen carrier8,9,10,11. Typically, renewable resources (e.g. wind) are available in underpopulated rural areas, where it can be captured; this type of isolated wind and solar energy is called &#34;stranded&#34;. In this scenario, the electrical and thermal energies from the renewable energy source are converted to energy-dense carbon-neutral liquid ammonia. The liquid ammonia produced can then be shipped to urban centers, where it can be directly used in ammonia-based fuel cells12 and internal combustion engines13, or it can be decomposed into hydrogen and then be used in hydrogen fuel cells or hydrogen stations. As a result, we can move the wind of the U.S. prairies to the crowded urban areas of the U.S.
Mostly because of the fertilizer use, ammonia manufacture is a major industry. At room temperature, the ammonia synthesis reaction is exothermic and hence&#8212;at least, in principle&#8212;spontaneous14, however, achieving the reaction under ambient conditions is extremely difficult because of the strong nitrogen-nitrogen bond15. To overcome this, Fritz Haber famously used high temperatures to achieve fast kinetics, but these high temperatures meant that the reverse reaction inhibited the production. To reduce the inhibitions of this reverse reaction, Haber used high pressure to improve conversion. He carried out the large-scale reaction in a gun barrel, which still decorates the BASF plant in Ludwigshafen.
The necessity to use both high temperature and pressure when the reaction could potentially run under much more modest conditions has frustrated chemists for over a century2. Even after the process was commercialized, Karl Bosch and a huge cohort at BASF churned through the entire periodic table looking for better catalysts. While Bosch had little success, the search still continues. Even last year, a new research program aimed at seeking a new catalyst was initiated16,17. The detailed chemistry of ammonia synthesis is now well understood14, and if the search for the new catalyst is successful, it would certainly be worth the effort. However, in our view, the past failures reduce the chance of future success.
In the following text, small-scale ammonia synthesis process is described, and the motivation to investigate an alternative process is explained.
The Small-Scale Process:
Wind-Generated Ammonia 
We are improving the Haber-Bosch process for synthesizing ammonia, seeking a much smaller, simpler process which can be operated locally but produces negligible amounts of carbon dioxide. The feasibility of local ammonia manufacture from wind has already been demonstrated in a pilot plant located in Morris, MN, and shown in Figure 118. Morris sits on the Buffalo Ridge, a formation of sixty miles of rolling hills in the southwest corner of Minnesota. The ridge has unusually steady, strong wind, rolling across the prairie. As a result, it is a mecca for wind-generated electricity.
With this electricity, we already manufacture ammonia from wind, using this plant which is forty thousand times smaller than the existing commercial operations for fossil fuels. Some wind-generated electricity is used to make nitrogen from air by pressure swing adsorption, an established method for air separation used, for example, for patients with emphysema who need oxygen-enriched air. However, more of the electricity is used to make hydrogen by electrolysis of water. These gases are combined over a conventional catalyst in the process shown schematically in Figure 2. After the reaction, the gases are separated by chilling to condense the liquid ammonia. The unreacted gases, as well as the uncondensed ammonia, are recycled.
Details of the Pilot Plant 
In our pilot plant, the University of Minnesota Renewable Hydrogen and Ammonia Pilot Plant, the electric power is provided from a co-located 1.65 MW wind turbine. The pilot plant uses approximately 10% of the power generated, with the remaining power used at the University of Minnesota, Morris campus.
The hydrogen production system uses an electrolyzer, a booster compressor, and a thermal chiller. This system produces 0.54 kg of hydrogen gas per hour, which is stored at 2,400 psi using 24 kWh of electricity. Water from an on-site well is purified using a reverse osmosis and deionization system. The water is then supplied to the electrolyzer at a rate of up to 15 L/h. Nitrogen is generated using a nitrogen generator, a pre-air compressor, an air dryer, and a booster compressor. The nitrogen gas is stored at 2,400 psi using approximately 6 kWh of electricity.
The synthesis of ammonia uses a custom skid. It includes a compressor, a reactor, a refrigeration cooling loop, and a 20 kW electric heater. The skid uses approximately 28 kWh of electricity to produce 2.7 kg of ammonia per hour which is then stored at 150 psi. The ammonia production process is controlled with integrated PLC and HMI systems. The produced hydrogen and nitrogen are stored on site in 18 nitrogen storage tanks and 54 hydrogen storage tanks. The ammonia is also stored onsite within a 3,100-gallon vessel.
Wind Generation is Expensive 
The electricity for this process is made from wind, and so the fuel for making ammonia is free, without using any fossil fuel. However, the capital costs for this pilot plant are dominated by the investments for hydrogen production and for ammonia synthesis. The operations to date suggest that the cost of making small-scale ammonia are about twice that of conventional ammonia based on fossil fuels. While we continue to optimize our process, we believe that small-scale wind generated ammonia will not be competitive at the current natural gas prices. The capital costs per mass ammonia made could be reduced by a larger conventional process, or by an alternative process like that described next in this paper.
The Absorption Process:
Absorption Enhances Production 
The catalyst used for ammonia synthesis has remained almost unchanged during the last century19. As a result, we have carried out a different approach in this research. We apply the current catalyst and operating temperature, but absorb ammonia at modest pressures as soon as it is formed. We recycle any unreacted hydrogen and nitrogen. The process is schematically like that in Figure 3, similar to the conventional process, but with a packed bed absorber replacing the condenser.
Initial Reaction Kinetics Do Not Change 
Experiments with this system at low conversion show an initial reaction rate that is consistent with many of the earlier studies on this system3,14,15,20,21,22,23, as shown in Figure 4. The left panel shows the initial rates, which vary strongly with temperature. While these rates also vary with pressure, the variations are smaller, as shown in the right panel. In our new process, we use the same catalyst and similar operating conditions, but seek ways to improve ammonia production by using absorption at a lower pressure. We thus hope to reduce the capital costs for ammonia synthesis.
Absorption Enhances Conversion 
In our work, we replaced the condenser in the small process with a packed bed, which is a cylindrical vessel filled with small particles of the absorbent. We have emphasized absorbents made primarily of magnesium chloride and calcium chloride11,24. Such ammine absorbents have two effects. First, they reduce the ammonia concentration present in the recycled gases to near zero. Second, they effectively reduce the time for separation to near zero. This strategy is productive25,26,27. For example, in Figure 5, we show that the rate of making ammonia, which is proportional to the drop in the total pressure in the system, is much greater with absorption than without. In particular, the reaction at 90 bar, shown by the red circles, is less complete than the reaction with the absorbent, shown by the blue triangles27. This is true even though the reaction without absorbent takes place at a pressure almost twice that of the reaction with absorption. In earlier experiments (not shown here), we also showed that the eventual conversion of the process is about 20% without absorbent but over 95% with absorbent.
The rate of reaction varies much less with temperature with absorption than without. This is shown in Figure 6, which again reports ammonia synthesis as total pressure versus time27. Changing the reaction temperature by 60 &#176;C has little effect on the reaction rate. This contrasts with the initial rates in Figure 4, which shows a change of reaction rate of almost an order of magnitude. The results in Figure 4 and Figure 6 are different because the effect of the reverse reaction has been reduced, so the chemical kinetics are no longer the only step responsible for the overall rate.

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	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Experimental Apparatus</td>
			<td style="width:131px;"></td>
			<td style="width:119px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Magnesium Chloride</td>
			<td style="width:131px;">Sigma Aldrich</td>
			<td style="width:119px;">7786-30-3</td>
			<td>St. Louis, MO</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Calcium Chloride</td>
			<td style="width:131px;">Sigma Aldrich</td>
			<td style="width:119px;">10043-52-4</td>
			<td>St. Louis, MO</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Ultra Pure Hydrogen</td>
			<td style="width:131px;">Matheson</td>
			<td>SG PHYF30050</td>
			<td>New Brighton, MN</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Ultra Pure Nitrogen</td>
			<td style="width:131px;">Matheson</td>
			<td>SG G1881112</td>
			<td>New Brighton, MN</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Iron Based Catalyst</td>
			<td style="width:131px;">Clariant/Sud Chemie</td>
			<td style="width:119px;">-</td>
			<td>Charlotte, NC</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Variable Piston Pump</td>
			<td style="width:131px;">PumpWorks Inc.</td>
			<td style="width:119px;">PW2070N</td>
			<td>Minneapolis, MN</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Omega Ceramic Heater</td>
			<td style="width:131px;">Omega</td>
			<td style="width:119px;">CRFC-36/115-A</td>
			<td>Stamford, CT</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PID Controller</td>
			<td style="width:131px;">Omega</td>
			<td style="width:119px;">CN96211TR</td>
			<td>Stamford, CT</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Signal Conditioner</td>
			<td style="width:131px;">Omega</td>
			<td style="width:119px;">DRG-SC-TC</td>
			<td>Stamford, CT</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Pressure Transducer</td>
			<td style="width:131px;">WIKA</td>
			<td style="width:119px;">50426877</td>
			<td>Lawrenceville, Georgia</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Mass Flow Controller</td>
			<td style="width:131px;">Brooks Instruments</td>
			<td style="width:119px;">SLA5850</td>
			<td>Hatefield, PA</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Name</td>
			<td style="width:131px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td>Comments</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Pilot Plant</td>
			<td style="width:131px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Electrolyzer</td>
			<td style="width:131px;">Proton OnSite</td>
			<td style="width:119px;">H6 Series</td>
			<td>Wallingford, CT</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Gas Booster</td>
			<td style="width:131px;">PDC Machine</td>
			<td style="width:119px;">3 2500&#160;</td>
			<td>Warminster, PA</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Wind Turbine</td>
			<td style="width:131px;">Vestas</td>
			<td style="width:119px;">V82</td>
			<td>Portland, OR</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Chiller</td>
			<td style="width:131px;">Thermal Care</td>
			<td style="width:119px;">SQ Series</td>
			<td>Niles, IL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Water Purifier</td>
			<td style="width:131px;">Elga Pure Lab</td>
			<td style="width:119px;">S-15</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Nitrogen Generator</td>
			<td style="width:131px;">Innovative Gas System</td>
			<td style="width:119px;">NS-10</td>
			<td>Huoston, TX</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Air Compressor</td>
			<td style="width:131px;">Hydrovane</td>
			<td style="width:119px;">HV05</td>
			<td></td>
		</tr>
	</tbody>
</table>

ammonia synthesis at low pressure

Ammonia can be synthesized at low pressure by the use of an ammonia selective absorbent. The process can be driven with wind energy, available locally in areas requiring ammonia for synthetic fertilizer. Such wind energy is often called &#34;stranded,&#34; because it is only available far from population centers where it can be directly used.
In the proposed low pressure process, nitrogen is made from air using pressure swing absorption, and hydrogen is produced by electrolysis of water. While these gases can react at approximately 400 &#176;C in the presence of a promoted conventional catalyst, the conversion is often limited by the reverse reaction, which makes this reaction only feasible at high pressures. This limitation can be removed by absorption on an ammine-like calcium or magnesium chloride. Such alkaline metal halides can effectively remove ammonia, thus suppressing the equilibrium constraints of the reaction. In the proposed absorption-enhanced ammonia synthesis process, the rate of reaction may then be controlled not by the chemical kinetics nor the absorption rates, but by the rate of the recycle of unreacted gases. The results compare favorably with ammonia made from a conventional small scale Haber-Bosch process.

A pilot plant in Morris, MN has demonstrated the feasibility of using wind for local ammonia manufacture18, as shown in Figure 1. The wind generates electricity, which is used to make nitrogen and hydrogen through the pressure swing absorption of air and through the electrolysis of water, respectively. A reactor uses a conventional catalyst to combine the nitrogen and hydrogen gases, making ammonia. The ammonia is then separated using ...

Watch this Scientific Journal Video about Ammonia Synthesis at Low Pressure at JoVE.com

Ammonia Synthesis at Low Pressure

Ammonia can be synthesized at low pressure by using a conventional catalyst and an ammonia selective absorbent.

Ammonia can be synthesized at low pressure by the use of an ammonia selective absorbent. The process can be driven with wind energy, available locally in ...

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Gold Nanostar Synthesis with a Silver Seed Mediated Growth Method

The physical, chemical and optical properties of nano-scale colloids depend on their material composition, size and shape 1-5. There is a great interest ...

Low Molecular Weight Protein Enrichment on Mesoporous Silica Thin Films for Biomarker Discovery

The identification of circulating biomarkers holds great potential for non invasive approaches in early diagnosis and prognosis, as well as for the ...

Induction of Adhesion-dependent Signals Using Low-intensity Ultrasound

In multicellular organisms, cell behavior is dictated by interactions with the extracellular matrix. Consequences of matrix-engagement range from ...

High Throughput Microfluidic Rapid and Low Cost Prototyping Packaging Methods

In this work, 3 different packaging and assembly techniques are presented. They can be classified into two categories: one-time use and reusable packaging ...

Design and Construction of Artificial Extracellular Matrix (aECM) Proteins from Escherichia coli for Skin Tissue Engineering

Design and Construction of Artificial Extracellular Matrix aECM Proteins from Escherichia coli for Skin Tissue Engineering

Recombinant technology is a versatile platform to create novel artificial proteins with tunable properties. For the last decade, many artificial proteins ...

Rod-based Fabrication of Customizable Soft Robotic Pneumatic Gripper Devices for Delicate Tissue Manipulation

Soft compliant gripping is essential in delicate surgical manipulation for minimizing the risk of tissue grip damage caused by high stress concentrations ...

Synthesis of Hydrogels with Antifouling Properties As Membranes for Water Purification

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and ...

Power Input Measurements in Stirred Bioreactors at Laboratory Scale

The power input in stirred bioreactors is an important scaling-up parameter and can be measured through the torque that acts on the impeller shaft during ...

Quantifying Microorganisms at Low Concentrations Using Digital Holographic Microscopy (DHM)

Quantifying Microorganisms at Low Concentrations Using Digital Holographic Microscopy DHM

Accurately detecting and counting sparse bacterial samples has many applications in the food, beverage, and pharmaceutical processing industries, in ...

Making Conjugation-induced Fluorescent PEGylated Virus-like Particles by Dibromomaleimide-disulfide Chemistry

The recent rise in virus-like particles (VLPs) in biomedical and materials research can be attributed to their ease of biosynthesis, discrete size, ...