Production Of Synthetic Ammonia Research Articles

Megawatts to methane – a deep drop in emissions reduction transition for existing regional gas-based ammonia plants

Synthetic ammonia production sustains food production for more than half of the world’s population. Many regional ammonia plants convert all ammonia to ammonium nitrate fertiliser. With these, all carbon in the feed ends up as carbon dioxide (CO2), with around 2 tonnes of CO2 released per tonne of ammonia produced using natural gas. Conveniently, ammonia plants produce a substantial pre-concentrated CO2 stream. Ammonia plants are high-capex, long-life assets that operate for 40+ years. With the energy transition, replacing such assets is very high cost and will dramatically impact the cost of food production. Further, green energy is highly variable, leading to the need for additional supply side assets to stabilise energy supply. This paper outlines a transition approach for a 30% CO2 reduction (also a 43% case) to extend the useful life of these assets while re-using much of the plant, with the ability to turn on/off the green energy with minimal disruption for stable operation. The example plant is based on a typical 750 tpd ammonia gas Steam Methane Reforming (SMR) plant. The approach considers adding and integrating green power and biogas into this plant to reduce net reportable CO2 emissions. Methanation of CO2 has been demonstrated in several projects and is considered key in developing a transition pathway for an existing gas-based plant, extending its operational life and flexibility to operate with varying degrees of variable green energy supply. Further, whilst Synthetic Natural Gas (SNG) is used in this case, the approach can be beneficially applied with methanol and other Power-to-X opportunities.

Life Cycle Environmental Impact Assessment of Sulfur-Based Compound Fertilizers: A Case Study in China

The reduced atmospheric sulfur input has led to sulfur deficiency in plants. Sulfur-based compound fertilizers have been widely used in order to provide necessary sulfate. However, their environmental impacts have been less studied. A life cycle assessment approach is applied to evaluate the environmental impact of sulfur-based compound fertilizers from “cradle to grave”, with a typical fertilizer produced in China as a case study and 1 ton fertilizer as a functional unit. The results show the environmental impacts mainly related to human carcinogenic toxicity, fossil resource scarcity, freshwater eutrophication, freshwater ecotoxicity, terrestrial acidification, and marine ecotoxicity. Synthetic ammonia production, conversion, and fertilizer use processes are the key processes, which contribute 26.6, 18.7, and 23.9%, respectively. Electricity, potassium chloride, hard coal, rock phosphate, and emission pollutants from fertilizer use are key factors, contributing 17.6, 16.0, 14.2, 10.0, and 17.1%, respectively. Sensitivity analysis shows that electricity and potassium chloride are the important factors to be optimized in the overall system. These results can be used to optimize the fertilizer industry and frame policies in order to mitigate the overall environmental impacts of sulfur-based compound fertilizer products under a life cycle framework.

Using Atomically Dispersed Bimetallic Active Sites to Probe the Nitrate Reduction Mechanism to Ammonia

The production of synthetic ammonia via nitrogen reduction is a critical step toward producing fertilizers, central the supporting global food security. To date, the energy-intensive and greenhouse gas-emitting Haber-Bosch process remains the only way to produce ammonia on industrial scale. Recently, significant research efforts have focused on identifying carbon- neutral and distributed pathways to synthesize ammonia, mainly via the electrochemical reduction of dinitrogen (N2).1 This approach, however, is limited by the low N2 solubility, competing hydrogen evolution reactions, and the stability of the N≡N triple bond. A promising alternative pathway to ammonia production is through the reduction of nitrate (NO3 -), a more kinetically and thermodynamically favorable nitrogen precursor. The reduction of nitrate to ammonia provides dual benefits as both a carbon-neutral pathway to ammonia and as a way of denitrification to remove all-too-prevalent and environmentally harmful nitrate contamination, while creating a useful product.2 Although there exists in the literature several works using metal catalysts for the nitrate reduction reaction (NTRR) to ammonia, only very recently have single atom catalysts (SAC) been applied to nitrate reduction.3 , 4 The NTRR is an 8e- transfer reaction, in which the exact electron transfer pathways, either a direct 8e- transfer or by 2 + 6e- pathway, in which a nitrite (NO2 -) intermediate is desorbed and reabsorbed. These processes are not well-studied on SACs. In this talk, we will present a series of atomically dispersed iron and molybdenum, mono and bi-metallic nitrogen doped carbon (M-N-C, M = Fe, Mo, FeMo) electrocatalysts for the NTRR. Our catalysts show potential for faradic efficiencies over 90%, while exhibiting outstanding stability over 48 hours of operation. Furthermore, our results suggest distinct NTRR mechanisms over Fe and Mo active sites, revealing new insights into preferred NTRR pathways over varying single atom sites. Such a detailed understanding of the NTRR electron transfer pathway will not only advance development of high performance, selective SACs, but stands to provide a new route to environmentally responsible ammonia synthesis. References (1) Choi, J.; Suryanto, B. H. R.; Wang, D.; Du, H. L.; Hodgetts, R. Y.; Ferrero Vallana, F. M.; MacFarlane, D. R.; Simonov, A. N. Identification and Elimination of False Positives in Electrochemical Nitrogen Reduction Studies. Nat. Commun. 2020, 11 (1).(2) van Langevelde, P. H.; Katsounaros, I.; Koper, M. T. M. Electrocatalytic Nitrate Reduction for Sustainable Ammonia Production. Joule 2021, 5 (2),(3) Zhu, T.; Chen, Q.; Liao, P.; Duan, W.; Liang, S.; Yan, Z.; Feng, C. Single-Atom Cu Catalysts for Enhanced Electrocatalytic Nitrate Reduction with Significant Alleviation of Nitrite Production. Small 2020, 16 (49).(4) Niu, H.; Zhang, Z.; Wang, X.; Wan, X.; Shao, C.; Guo, Y. Theoretical Insights into the Mechanism of Selective Nitrate-to-Ammonia Electroreduction on Single-Atom Catalysts. Adv. Funct. Mater. 2020, 2008533 (3), 1–8.. Figure 1

Catalysts for nitrogen reduction to ammonia

The production of synthetic ammonia remains dependent on the energy- and capital-intensive Haber–Bosch process. Extensive research in molecular catalysis has demonstrated ammonia production from dinitrogen, albeit at low production rates. Mechanistic understanding of dinitrogen reduction to ammonia continues to be delineated through study of molecular catalyst structure, as well as through understanding the naturally occurring nitrogenase enzyme. The transition to Haber–Bosch alternatives through robust, heterogeneous catalyst surfaces remains an unsolved research challenge. Catalysts for electrochemical reduction of dinitrogen to ammonia are a specific focus of research, due to the potential to compete with the Haber–Bosch process and reduce associated carbon dioxide emissions. However, limited progress has been made to date, as most electrocatalyst surfaces lack specificity towards nitrogen fixation. In this Review, we discuss the progress of the field in developing a mechanistic understanding of nitrogenase-promoted and molecular catalyst-promoted ammonia synthesis and provide a review of the state of the art and scientific needs for heterogeneous electrocatalysts. The artificial synthesis of ammonia remains one of the most important catalytic processes worldwide, over 100 years after its development. In this Review, recent developments in enzymatic, homogeneous and heterogeneous catalysis towards the conversion of nitrogen to ammonia are discussed, with a particular focus on how mechanistic understanding informs catalyst design.

Carbon dioxide capture characteristics from flue gas using aqueous 2-amino-2-methyl-1-propanol (AMP) and monoethanolamine (MEA) solutions in packed bed absorption and regeneration columns

Increasing concentration of CO2 in the atmosphere contributing potential negative impact to the environment has been the subject of worldwide attention over the past few decades. CO2, one of the main greenhouse gases (GHG) is getting emitted to the environment from different industries such as fossil fuelled power plants, cement industry, refinery and synthetic ammonia production units etc. Gas scrubbing using aqueous alkanolamine solutions is the most promising retrofit option for post combustion carbon dioxide capture in recent days. The present study investigates an effective means of eliminating CO2 from flue gas using two primary amines, namely conventional monoethanolamine (MEA) and a sterically hindered amine, 2-amino-2-methyl-1-propanol (AMP). The CO2 absorption characteristics were experimentally examined in a packed column under various process conditions viz. CO2 partial pressure, gas and liquid flow rates, solvent concentrations and operating temperature and pressure. While the regeneration of solvent was studied at the temperature range from 368 to 382K. The present work reports mainly a comparative study of absorption and regeneration behaviour of the two alkanolamines which necessarily include the specific rate of absorption, percentage of CO2 absorbed, CO2 loading during absorption and residual CO2 after solvent regeneration and regeneration efficiency. The specific rate of absorption of AMP and MEA are observed to be (2.11–4.03)×10−5kmol/m2s and (5.36–9.55)×10−5kmol/m2s, respectively. The maximum percentage of CO2 absorbed using MEA is 99.13% and AMP is 98.88%. In case of solvent loading capacity (moles of CO2 per mole of amine) AMP is much better than MEA; the value is 0.777 moles for AMP as compared to MEA value 0.478 moles. The regeneration efficiency of AMP ranging from 96.39 to 97.26% is superior over MEA which is in the range of (79.91–81.55) %. The entire experimental absorption rate data are plotted with the response surface methodology (RSM) fitted data which shows a good agreement with the experimental value for both the amine solvents.

Study of general trends of modern development of ammonia production

The evolution stages of synthetic ammonia production were considered in the paper. In the context of these stages, according to the results of analytical studies, general development trends of ammonia production in the present conditions, in particular for Ukraine, which cover both problems and individual tasks, required for overcoming and solving them were analyzed and determined. It was shown that the need to solve food program is associated with the trend of ever-increasing nitrogen fertilizers production volume, both in the world and in Ukraine, which is accompanied by a corresponding increase in the ammonia production volume. It was proved that, in the coming decades, the natural gas will continue to be the main raw material in the ammonia production technology. Herewith, a tendency to increase their energy efficiency by upgrading instrumental-technological design of the most energy intensive stages, in particular ammonia condensation, in order to reduce electricity and natural gas consumption rates, which can be achieved by utilizing low-grade heat of flows with the temperature less than 100° C is especially relevant for domestic units. The latter can be achieved by using steam-ejector refrigeration systems.

Preventing the formation of scaling in the water cycle

The problems of scaling in the cooling equipment of synthetic ammonia production. Theoretical and experimental study on the choice of a method of preventing the formation of scale (scale formation). Shows a diagram of connections with anti-scale methods of thermal resistance, given the physico-chemical phenomena at the ground level of functioning of chemical engineering systems and properties of water-technological system (PTS). Selected reagent method using complexing to control scaling in heat exchange equipment at low degrees of supersaturation crystallizing systems. The boundaries and applicability of formal statistical models in the description of the Cree-crystallization of sparingly soluble salts from solutions through the formation of the nuclear complex. On the basis of theoretical and experimental studies determined the dose and conditions of entry-hydroxyethyl reagent denfosfonovoy acid (HEDP) and its zinc complex Zn-HEDP in vodoobo-cycle company commander in the production of synthetic ammonia (branch "Nitrogen" of "UCC" URALCHEM"). Presents chemical compositions of sediments and the results of processing the back of the cooling water solutions HEDP, which increased performance capacitor turbocharger syngas to normative values.

Assessment of policy alternatives and key technologies for energy conservation and water pollution reduction in China’s synthetic ammonia industry

Synthetic ammonia production is an energy intensive industry in China that creates considerable water pollution. The complex structure of the sector and its dynamic development make effective environmental policy for the synthetic ammonia industry a challenge. In this paper, we established a bottom-up technology model for China’s synthetic ammonia industry. Production of synthetic ammonia was divided into 12 combinations according to different feedstock types, production processes and plant sizes. 9 key energy conservation technologies and 8 key pollution prevention technologies were incorporated into the model. 4 policy scenarios were designed to project future water pollution emission and energy consumption trends: (1) production capacity replacement, (2) promoting cleaner technologies, (3) upgrading end-of-pipe treatment and (4) a combination of the above three measures. Furthermore, a Monte Carlo stochastic simulation method was introduced to explore the correlations between environmental performances and different structural factors and technologies. Plant size was found to be the most relevant factor for reducing water pollution. However, raw material types and corresponding production processes are more relevant for energy conservation. Finally, the relative importance of all pollution prevention and energy conservation technologies was also assessed through stochastic simulations.

98/03538 Application of peat soil coal briquet to the production of synthetic ammonia. I

98/03538 Application of peat soil coal briquet to the production of synthetic ammonia. I

An investigation of the removal of hydrogen from gas mixtures using misch-metal-based hydrogen storage metals

In order to recover helium from the purge gas of synthetic ammonia production unit using Sichuan natural gas as the raw material, the present authors developed several multicomponent misch-metal hydrogen storage alloys with widely different plateau pressures. Experiments were carried out on the removal of hydrogen from simulated gas mixtures composed of H 2-Ar in different proportions. The effect of the change in various technological parameters, involving pressure, temperature and the rate of flow, and the effect of various combinations of alloys with different plateau pressures was investigated. The results showed that, with favourable technological parameters, the concentration of remnant hydrogen could be reduced to less than 0.2%.

Ammonium bicarbonate used as a nitrogen fertilizer in China

This article reports a modified process for the production of synthetic ammonia, in which CO2 in the converted water gas is removed by the synthesized ammonia itself, and the precipitated NH4HCO3 serves as the final product of the factory. NH4HCO3 pills weighing about 1 g are used to overcome the poor physical properties of the NH4HCO3 powder. Extensive field experiments laid down on various soil areas in China showed good crop responses when NH4HCO3 pills were deep dressed. A laboratory process for the preparation of coated NH4HCO3 pills as a slow-release fertilizer is described. The crop response to slow-release NH4HCO3 pills is discussed.

Reliability of high-pressure gas compressors in synthetic ammonia production

Reliability of high-pressure gas compressors in synthetic ammonia production

The Development of the Modern Ammonia Oxidation Process

By the end of the first world war the manufacture of nitric acid by ammonia oxidation over a platinum catalyst was a technically established process. The rapid increase in production of synthetic ammonia enabled this method to become the principal source of industrial nitric acid, and further development of the process in terms both of technical progress and in the size of unit plant has been determined by economic factors.

Recent Developments in By-Products From Bituminous Coal

Abstract After pointing out that the by-product oven has displaced the beehive oven as a producer of metallurgical coke, the author discusses the increasing value of by-products as compared to that of the coke itself. He then takes up successively the subjects of competitive sources of gas for industrial and domestic use; utilization of the hydrogen in coke-oven gas for the production of synthetic ammonia; competition between synthetic and by-product ammonia; utilization of sulphur in coke-oven gas in the production of ammonium sulphate; processes for the recovery of sulphur in connection with gas purification; recovery of phenols from ammonia still wastes; benzol and light oils; production of resins from coal by-products; tar and tar products; and the hydrogenation of coal tar.

Obituaries

AN account of the life and work of Dr. Luigi Casale, written by Dr. J. F. Crowley, who has been closely associated with the Italian chemist, appears in the issue of Chemistry and Industry for Mar. 11. Casale was born in 1882 at Langosco and was educated at Turin. He became head of the organic chemistry laboratory in the institute of general chemistry in the University of Turin in 1913. In 1915 he became head of the pharmaceutical chemistry laboratory of the University of Naples, where he carried out important investigations for the Italian War Office. Dr. Casale became interested in nitrogen fixation in 1917, and shortly after 1920 commercial plants for the production of synthetic ammonia by his process were in operation. The Casale process has been adopted in many parts of the world: the total capacity of the plants completed or in course of construction using this process amounts to 250,000 tons of ammonia per annum. The total world output of synthetic ammonia in 1925 was 350,000 tons. Dr. Crowley refers to the great personal charm of Dr. Casale, his high qualities as an investigator, and the loss which applied science has sustained by his early death.

The Production of Synthetic Ammonia

The Production of Synthetic Ammonia

The Production of Synthetic Ammonia.

The Production of Synthetic Ammonia.