Author Archives: NH3 Fuel Association

Advances in Making High Purity Nitrogen for Small Scale Ammonia Generation

David Toyne*, Solutions for Automation, USA; Jay Schmuecker, Pinehurst Farm, USA

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

The presentation will address recent developments in the Solar Hydrogen Demonstration Project in which hydrogen, nitrogen and ammonia are made from solar power, water, and air; and used to fuel a modified John Deere farm tractor.

In industrial applications very pure nitrogen is made by cryogenic distillation of air. Using Pressure Swing Absorption systems alone it is extremely difficult to achieve the required purity. An improved method was developed for making high purity nitrogen, for smaller systems.
Will discuss how, when Oxygen contaminates the reactor catalyst, Hydrogen is used to purge the catalyst, and subsequently used as fuel. Continue reading

Scale up and Scale Down Issues of Renewable Ammonia Plants: Towards Modular Design

Antonio Sánchez, Mariano Martin*, University of Salamanca, Spain

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

Renewable sources of energy such as biomass, solar, wind or geothermal just to mention some of the most widely extended are characterized by a highly distributed production across regions (EPA, 2017). Total renewable energy available is more than enough to provide for society needs, but the traditional production paradigm is changing. Economies of scale have featured current industry and its infrastructures based on large production complexes (i.e Dow, Exxonmobil or BASF hubs). The well-known six tenths rule has extensively been used in the chemical industry to scale up or down the cost of technologies. This rule is suitable for large chemical complexes, where economies of scale are a critical point. However, distributed production completely changes this paradigm. Distributed production corresponds to the production at small scales (Pepermans et al., 2005). This new production scheme results in the use of a number of individual units so that the cost is no longer a continuous function. The step forward is modularization of chemical plants. The plants will be built in the form of modulus that are easily assembled at any place to make the most of distributed resources (Baldea, 2017). The advantages of these plants are straightforward, easy and quick deployment and low investment risk to exploit resources even in remote places. However, the disadvantages must be also considered including the environmental impact of the transportation of the plants and of the products (EPA, 2017). Continue reading

Ammonia Absorption and Desorption in Ammines

Collin Smith, Mahdi Malmali, Chen-Yu Liu, Alon McCormick, E L Cussler*, University of Minnesota, USA

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

While adsorption onto solids is a common separation process, absorption into solids is much less often used. The reason is that absorption is usually assumed ineffective because it includes very slow solute diffusion into the solid. An exception may be the separation of ammonia from nitrogen and hydrogen using ammines, especially at temperatures close to those used in ammonia synthesis. There, ammonia can be selectively absorbed by calcium chloride; nitrogen and hydrogen are not absorbed. The kinetics of ammonia release seem to be diffusion controlled. The kinetics of absorption are consistent with a first order reaction and diffusion in series, so the rate controlling step changes with the amount of absorption. The potential of this separation in the distributed production of ammonia is discussed both as a source of fertilizer and as a means of wind energy storage.

Read the abstract at the AIChE website.

DOWNLOAD

Download this presentation [PDF].

RELATED NH3 FUEL CONFERENCE PAPERS

2018: Design Optimization of an Ammonia-Based Distributed Sustainable Agricultural Energy System
2017: Design Optimization of a Distributed Ammonia Generation System
2017: Lower Pressure Ammonia Synthesis
2016: Small Scale Low-Pressure Ammonia Synthesis
2015: Potential Strategies for Distributed, Small-Scale Sustainable Ammonia Production [PDF]
2014: Life-cycle greenhouse gas and energy balance of community-scale wind powered ammonia production
2013: Ammonia Production Using Wind Energy
2012: Lessons Learned in Developing a Wind-to-Ammonia Pilot Plant [PDF]
2011: Production of Anhydrous Ammonia from Wind Energy — Anatomy of a Pilot Plant, The Sequel [PDF]
2010: Production of Anhydrous Ammonia from Wind Energy — Anatomy of a Pilot Plant [PDF]
2009: Ammonia from Wind, Progress Update [PDF]
2008: Ammonia from Wind, an Update [PDF]
2007: Ammonia from Wind, an Update [PDF]
2006: Wind to Ammonia [PDF]

LINKS

Department of Chemical Engineering and Materials Science, University of Minnesota
West Central Research & Outreach Center, University of Minnesota
Learn more about the 2018 NH3 Fuel Conference

Importance of Reaction Mechanism Involved in Design of the Catalyst and the Reactor for Future Ammonia Synthesis

Ken-ichi Aika, Tokyo Institute of Technology, Japan

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

The ammonia synthesis reaction is considered to involve several elementary steps [1]:

N2 + 2* → 2N(a) (1)
H2 + 2* → 2H(a) (2)
N(a) + H(a) → NH(a) + * (3)
NH(a) + H(a) → NH2 (a) + * (4)
NH2 (a) + H(a) → NH3(a) + * (5)
NH3(a) → NH3 + * (6)

Here, the symbol * indicates empty sites. For most metal catalysts, the dissociative adsorption of dinitrogen (step 1) is the rate-determining step, and all the other steps and its reverse step (from 2 to 6) are fast enough to be almost in equilibrium for each reaction step. The synthesis rate is considered to be the same as the rate for step (1), and is proportional to the dinitrogen pressure and square of the empty site concentration. Continue reading

Development of Catalytic Reactors and Solid Oxide Fuel Cells Systems for Utilization of Ammonia

Koichi Eguchi*, Kyoto University, Japan, Yosuke Takahashi, Noritake Co., Japan, Takahiro Matsuo, IHI Corporation, Japan, Hayahide Yamasaki, Nippon Shokubai Co., Japan, Hidehito Kubo, Toyota Industries, Japan, Akihiro Okabe, Mitsui Chemicals, Japan, Takenori Isomura, Tokuyama Corp., Japan

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

Hydrogen is the primary fuel source for fuel cells. However, the low volume density and difficulty in storage and transportation are major obstacles for the practical utilization. Among various hydrogen carriers, ammonia is one of the promising candidates because of its high hydrogen density and boiling point and ease in liquefaction and transportation. The reaction temperature of ammonia cracking to nitrogen and hydrogen, being about 600°C or higher, is close to the operating temperature of solid oxide fuel cells (SOFCs). The integration of these two devices is beneficial in terms of heat and energy managements and will lead to the development of simplified power generation systems.

Several catalyst materials, i.e., cracking, autothermal cracking, and combustion of ammonia have been investigated and used for the SOFC systems. A demonstration of the stack-level ammonia-fueled SOFC systems is an important step for the actual utilization of ammonia-fueled SOFCs. In this study, 200 W class and 1 kW class SOFC stacks were applied for ammonia fueled generation systems. Continue reading

Functionalized Ordered Mesoporous Silica Composites As Potential Ammonia Storage Materials

Zhu Ming*, Pan Xingxiang, Mei Hua, NJtech, Nanjing, China

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

Ammonia may provide an alternative energy supplier for its strong capability as hydrogen carrier. However, it is a problem that how to storage this kind of chemical at relatively high temperature, for example 300°C in fuel cell. In this work, a composite material based on metal halides and ordered mesoporous silica framework is developed and used to target ammonia at relatively high temperature. The silica framework is fabricated via evaporation induced self-assembly method and has tunable mesoporous structure with addition of hexadecyl trimethyl ammonium bromide (CTAB). Several metal salts at various concentrations are added to the mesoporous framework via wetness impregnation method. It is reported that ammonia storage capability is further enhanced by functionalization with relative metal sites. Along with capacity measurements, the incorporation of metal salts on mesoporous silica is studied using microscopy, X-ray diffraction and porosity characterization techniques. Results show that well-dispersed metal crystal trapped in submicron-sized porous structure can improve diffusion rate and increase pore accessibility while maintaining structural integrity at relatively high temperature. Capacity measurements show that functionalized metal/silica composite can work as potential materials for ammonia storage. It is also a thermal stable material for only 3% weight loss over 300°C. Continue reading

Material Discovery and High Throughput Exploration of Ru Based Catalysts for Low Temperature Ammonia Decomposition

Katie McCullough*, Travis Williams, Benjamin Ruiz, Jochen Lauterbach, University of South Carolina, USA

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

High throughput experimentation gives us the unique ability to generate massive, multidimensional datasets that are not typical for heterogeneous catalysis studies. Here, we show the synthesis and catalytic screening of over 100 different Ru based bimetallic catalyst combinations using 33 different metals that were synthesized via incipient wetness impregnation. The catalysts were analyzed using Wide Angle X-ray Scattering (WAXS) for phase identification. Catalysts were screened for ammonia decomposition activity using a 16-channel parallel plug flow reactor. Fourier transform infrared (FT-IR) imaging was used to analyze all 16 effluent streams in parallel in under one minute.

All results obtained from WAXS characterization and catalyst screening were fed into a machine learning algorithm to extract the activity descriptors and elemental characteristics that are responsible for ammonia decomposition activity at different operating temperatures. The knowledge extracted from this materials agnostic machine learning algorithm was used to design a second iteration of catalysts, where features that contributed to the greatest change in activity were accentuated. Continue reading

Development of a Highly Efficient COx-Free Ammonia Dehydrogenation System for Fuel Cell Applications

Young Suk Jo1*, Junyoung Cha1,2, Hyuntae Sohn1, Suk Woo Nam1,2 and Chang Won Yoon1,3; [1] Fuel Cell Research Center, Korea Institute of Science and Technology (KIST), South Korea, [2] Green School, Korea University, South Korea, [3] Kyunghee University, South Korea

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

The shortage of fossil fuels and emission of carbon dioxide to the environment have attracted an interest in discovering renewable energy as the next generation energy source. Owing to its intermittent and unpredictable nature, however, excess renewable energy needs to be stored and reused on demand. In the regard, hydrogen, which possesses a high gravimetric energy density and carbon free combustion process, has been extensively researched as a promising renewable energy carrier. However, the distribution and storage of hydrogen still raise important challenges due to the low volumetric energy density of hydrogen for its wide utilization. Currently, gaseous hydrogen transportation by pipeline and batch transportation using liquefied/compressed hydrogen have been implemented, but are either not economically viable, particularly for long distance transport, or significantly energy-intensive. Therefore, a lot of attention recently has been paid to the liquid chemical hydrogen storage materials such as liquid ammonia, cycloalkanes and heterocycles, formic acid, and so forth.

Among the candidates, liquid ammonia is an excellent hydrogen carrier owing to its high gravimetric and volumetric hydrogen storage capacities and moderate condensation conditions compared to other chemical hydrogen storage materials. Furthermore, the production and distribution activities of ammonia are already well-established processes internationally. The liquid ammonia can be dehydrogenated at the temperatures of ≤ 550 °C leading to hydrogen and nitrogen as major products with no carbon release to the environment. All these properties make liquid ammonia highly intriguing as a hydrogen carrier for power generation in conjunction with fuel cells.

The present study demonstrates a > 1kW-class COx-free power generation system including an ammonia feed, a dehydrogenation reactor, a i-butane burner, a heat exchanger, a hydrogen purification unit and a PEMFC. Continue reading

Catalytic Membrane Reactors for Efficient Delivery of High Purity Hydrogen from Ammonia Decomposition

Zhenyu Zhang*, Simona Liguori, J. Douglas Way, Colin A. Wolden, Colorado School of Mines, USA

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

The deployment of fuel cell electric vehicles is constrained by the paucity of hydrogen fueling stations and price, which is dominated by the costs of hydrogen storage and transportation. With more hydrogen per volume than liquid H2 and an extensive distribution infrastructure in place, ammonia is a promising vector for efficient hydrogen distribution. In this talk we describe the development of innovative catalytic membrane reactor (CMR) technology for the delivery of high purity H2 from ammonia cracking. Continue reading

Ammonia As a Hydrogen Carrier for PEM Fuel Cells

Yoshitsugu Kojima, Hiroshima University, Japan

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

Ammonia (NH3) is easily liquefied by compression at 1 MPa and 25°C, and has highest volumetric hydrogen density of 10.7 kg H2 /100L. It has high gravimetric hydrogen density of 17.8 wt%. The heat of formation of NH3 is about 1/10 of combustion heat of hydrogen. NH3 has advantages as a hydrogen carrier for fuel cell vehicles (FCVs).

ISO 14687-2:2012 specifies the quality characteristics of hydrogen fuel. The maximum concentration of NH3 and N2 for the FCVs is 0.1ppm and 100 ppm, respectively. The minimum H2 purity is 99.97%. We need component technologies to produce high-purity hydrogen from ammonia, together with those to improve hydrogen energy efficiency. Continue reading