Byproduct Ammonium Research Articles

Potential application of the by-product ammonium nitrate from uranium purification facility as a nutrient enriched fertiliser

Potential application of the by-product ammonium nitrate from uranium purification facility as a nutrient enriched fertiliser

Silica Gel Supported Chlorosulfonic Acid Catalyzed Beckmann Rearrangement of Cyclohexanone Oxime in Liquid Phase

The Beckmann rearrangement of cyclohexanone oxime in the liquid phase using fuming sulfuric acid as a catalyst is a traditional method, which brings many problems, such as environmental pollution, corrosion of equipment, and difficulty in treating the by-product ammonium sulfate. This paper designs and prepares a silica gel-supported chlorosulfonic acid solid acid catalyst for the liquid-phase Beckmann rearrangement of cyclohexanone oxime to caprolactam. The factors affecting the preparation of the catalyst and the optimal reaction conditions for Beckmann rearrangement were investigated. It was found that the best catalyst preparation conditions were as follows: mass ratio of silica gel: chlorosulfonic acid of 1:0.2, room temperature, stirring time of 3 hours, solvent dichloromethane, and silica gel mesh size of 100-200 mesh, and best Beckmann rearrangement conditions were as follows: mass ratio of cyclohexanone oxime: catalyst of 1:1, temperature of 140°C, solvent benzonitrile volume of 40 mL/g cyclohexanone oxime, reaction time of 5 hours. Under the above conditions, the conversion of cyclohexanone oxime is 74%, and the selectivity of caprolactam is 40%.

Potential application of the by-product Ammonium Nitrate from Uranium Purification Facility as a Nutrient Enriched Fertilizer

Potential application of the by-product Ammonium Nitrate from Uranium Purification Facility as a Nutrient Enriched Fertilizer

Central Carbon Metabolism, Sodium-Motive Electron Transfer, and Ammonium Formation by the Vaginal Pathogen Prevotella bivia.

Replacement of the Lactobacillus dominated vaginal microbiome by a mixed bacterial population including Prevotella bivia is associated with bacterial vaginosis (BV). To understand the impact of P. bivia on this microbiome, its growth requirements and mode of energy production were studied. Anoxic growth with glucose depended on CO2 and resulted in succinate formation, indicating phosphoenolpyruvate carboxylation and fumarate reduction as critical steps. The reductive branch of fermentation relied on two highly active, membrane-bound enzymes, namely the quinol:fumarate reductase (QFR) and Na+-translocating NADH:quinone oxidoreductase (NQR). Both enzymes were characterized by activity measurements, in-gel fluorography, and VIS difference spectroscopy, and the Na+-dependent build-up of a transmembrane voltage was demonstrated. NQR is a potential drug target for BV treatment since it is neither found in humans nor in Lactobacillus. In P. bivia, the highly active enzymes L-asparaginase and aspartate ammonia lyase catalyze the conversion of asparagine to the electron acceptor fumarate. However, the by-product ammonium is highly toxic. It has been proposed that P. bivia depends on ammonium-utilizing Gardnerella vaginalis, another typical pathogen associated with BV, and provides key nutrients to it. The product pattern of P. bivia growing on glucose in the presence of mixed amino acids substantiates this notion.

Production of Potash and N‐Mg Compound Fertilizer via Mineral Shoenite from Kunteyi Salt Lake: Phase Diagrams of Quaternary System (NH4)2SO4‐MgSO4‐K2SO4‐H2O in the Isothermal Evaporation and Crystallization Process

AbstractBased on the requirement of the new technology for producing potassium sulfate and N‐Mg compound fertilizer, boussingaultite, by the reaction of the mineral shoenite from Kunteyi Salt Lake, Qinghai province, and the industrial byproduct ammonium sulfate, the solubilities of the quaternary system (NH4)2SO4‐MgSO4‐K2SO4‐H2O at 25.0°C in the isothermal evaporation and crystallization process were measured using the isothermal evaporation method, and the corresponding phase diagrams were plotted. According to the diagram, this system contains six saturation points and six solid phase fields of crystallization, which correspond to (K1‐m,(NH4)m)2SO4, (NH4)2SO4·MgSO4·6H2O, K2SO4·MgSO4·6H2O, MgSO4·6H2O, (K1‐n,(NH4)n)2SO4·MgSO4·6H2O and MgSO4·7H2O, respectively. By analyzing and calculating the isothermal evaporation and dissolution phase diagram of this quaternary system at 25.0°C, K2SO4 and (NH4) 2SO4·MgSO4·6H2O can be separated via K2SO4·MgSO4·6H2O and (NH4)2SO4 as raw materials. Theoretical calculations about the proposed process were carried out and verified by experiment, which indicated that the yield of potassium sulfate was improved and the magnesium resources were fully utilized.

Graphitic Carbon Nitride Supported Ultrafine Pd and Pd-Cu Catalysts: Enhanced Reactivity, Selectivity, and Longevity for Nitrite and Nitrate Hydrogenation.

Novel Pd-based catalysts (i.e., Pd and Pd-Cu) supported on graphitic carbon nitride (g-C3N4) were prepared for nitrite and nitrate hydrogenation. The catalysts prepared by ethylene glycol reduction exhibited ultrafine Pd and Pd-Cu nanoparticles (∼2 nm), and they showed high reactivity, high selectivity toward nitrogen gas over byproduct ammonium, and excellent stability over multiple reaction cycles. The unique nitrogen-abundant surface, porous structure, and hydrophilic nature of g-C3N4 facilitates metal nanoparticle dispersion, mass transfer of reactants, and nitrogen coupling for nitrogen gas production to improve catalytic performance.

Biomimetic Hydrogel Composites for Soil Stabilization and Contaminant Mitigation.

We have developed a novel method to synthesize a hyper-branched biomimetic hydrogel network across a soil matrix to improve the mechanical strength of the loose soil and simultaneously mitigate potential contamination due to excessive ammonium. This method successfully yielded a hierarchical structure that possesses the water retention, ion absorption, and soil aggregation capabilities of plant root systems in a chemically controllable manner. Inspired by the robust organic-inorganic composites found in many living organisms, we have combined this hydrogel network with a calcite biomineralization process to stabilize soil. Our experiments demonstrate that poly(acrylic acid) (PAA) can work synergistically with enzyme-induced carbonate precipitation (EICP) to render a versatile, high-performance soil stabilization method. PAA-enhanced EICP provides multiple benefits including lengthening of water supply time, localization of cementation reactions, reduction of harmful byproduct ammonium, and achievement of ultrahigh soil strength. Soil crusts we have obtained can sustain up to 4.8 × 103 kPa pressure, a level comparable to cementitious materials. An ammonium removal rate of 96% has also been achieved. These results demonstrate the potential for hydrogel-assisted EICP to provide effective soil improvement and ammonium mitigation for wind erosion control and other applications.

Corrosion Characteristics of Downstream Metal Material of Boiler System in Solution of By-product Ammonium Bisulfate from SCR Denitrification

Corrosion Characteristics of Downstream Metal Material of Boiler System in Solution of By-product Ammonium Bisulfate from SCR Denitrification

End of the line for caprolactam plant

Fibrant, a producer of the nylon feedstock caprolactam, plans to shut down its Augusta, Ga., plant over the next 16 months, eliminating about 600 jobs. The firm attributes the decision to a protracted global oversupply of—and scant profits for—the commodity chemical. Formed in late 2015 out of DSM’s caprolactam operations, Fibrant is owned 65% by the private equity firm CVC Capital Partners and 35% by DSM. The price of caprolactam “has dropped substantially below the product cost, and prospects for recovery are poor,” says Pol De Turck, Fibrant’s CEO. The decision to close down “was the only viable course of action,” he says. The firm also produces by-product ammonium sulfate, which is sold as a fertilizer. Shutting down the Augusta operation, which dates back to 1966, will eliminate about 230,000 metric tons of annual caprolactam production capacity. DSM and others use the monomer to make nylon 6 engineering resins, fibers,

Kinetic and equilibrium study of the chromatographic separation of glycine and ammonium

Abstract Background Glycine is extensively applied in the field of food, medicine, agrochemistry, etc. It is usually commercially produced by the chemosynthesis method, which generates large amounts of by-product ammonium chloride. Methods In this paper, the separation of glycine and ammonium chloride was performed with chromatographic column, and deionized water as eluent. The adsorption equilibrium constant K of glycine and ammonium chloride was evaluated by frontal analysis. Based on the equilibrium-dispersive model and a linear driving force of chromatography, the overall mass transfer coefficient k m , axial dispersion coefficient D L , and bed voidage ε t of the column were obtained by moment analysis. Results At 50°C, the equilibrium constants measured were found to be 0.72 and 0.19 for glycine and ammonium chloride, respectively. At 60°C, the equilibrium constants increased to 0.80 and 0.21 for glycine and ammonium chloride, respectively. The value of axial dispersion coefficient D L of glycine had the same order of magnitude with ammonium chloride and was about two times larger than that of ammonium chloride. Their k m at 50°C and 60°C were 1.30 and 0.77 and 2.41 and 0.84 min−1 for glycine and ammonium chloride, respectively. Conclusions The obtained parameters used to simulate the elution curve and the simulation and experimental results matched well, which showed that the parameters obtained were effective. The results make foundation for further study on large-scale separation of glycine from ammonium chloride by SMB chromatography.

Reducing ammonia emissions and losses with coke-oven gas in absorbers

A new patented atomizer operates effectively in absorbers for the removal of ammonia from cokeoven gas. Its introduction reduces the ammonia losses with coke-oven gas from 0.05 to 0.025 g/m3 (the standard is 0.03 g/m3) and increases the yield of the corresponding byproduct—ammonium sulfate. The corrosive action of coke-oven gas in the plant’s gas channels is also reduced; the concentration of volatile ammonia in wastewater from the biochemical treatment system is reduced; and atmospheric emissions of ammonia are reduced to 78 t/yr. The inclination of the new centrifugal-jet atomizers and their relative geometric dimensions may be selected; the flame length and width may be adjusted to the required values, along with the intensity and dispersity of spraying. In our view, the new centrifugal-jet atomizers are also expedient for other systems.

Technology for Processing Ammonium Rhodanide of Coking Plants into High-Purity Ammonium Thiocyanate and Thiourea

The regularities of the reversible reaction of isomerization of ammonium thiocyanate (NH4NCS) into thiourea (NH2)2CS), and the reverse reaction, were analyzed. An ecologically clean and highly efficient method for the extraction, purification, separation, and production of isomers from the coal byproduct ammonium thiocyanate was developed based on the measured volatilities of NH4NCS and (NH2)2CS.

Aluminium borates: synthesis via a precipitation process and study of their formation by DSC analysis

Aluminium borates have been synthesized via a precipitation process. Their formation has been studied by DSC analysis and X-ray diffraction. Aqueous solutions of aluminium nitrate and boric acid in various proportions were precipitated into solutions of ammonium carbonate, acting as a base like ammonia. The resulting mixtures were evaporated to dryness in order to recover the soluble boron species (ammonium borate). The by-product ammonium nitrate was decomposed at 300 °C. The DSC analysis, at 5 K min −1, showed the crystallization temperature of aluminium borates to decrease regularly with the increase of the boron content in the sample, from 900 °C for the A 9B 2 compound (abbreviation of 9Al 2O 3⋅2B 2O 3) to 670 °C for a composition “AB 2”. A 9B 2 was stable, at least up to 1200 °C. For boron-richer compositions, like “A 6B 2”, a boron-excess A 9B 2 solid solution was crystallized at the detriment of A 4B 2. This metastable solid solution decomposed at 1000 °C into A 9B 2 and boron oxide. Even for the composition “A 4B 2”, A 9B 2 crystallized along with A 4B 2. The latter compound was found to be stable up to 1000 °C, and to decompose into A 9B 2 and boron oxide at higher temperature, without any sign of melting. This decomposition was confirmed by thermogravimetric analysis. The problem of volatilization of boric acid or boric oxide, often encountered in the synthesis of borates, is avoided.

Formation of uniform size anatase nanocrystals from bis(ammonium lactato)titanium dihydroxide by thermohydrolysis

Bis(ammonium lactato)titanium dihydroxide decomposes in neutral aqueous solution at temperatures above 100 °C to produce anatase nanocrystals of preferentially oblate habitus, and with a very narrow size distribution. There is almost no dependence of size on precursor concentration, and a time dependence is observed only in the very beginning of crystal growth. The crystal size is mainly determined by the reaction temperature, increasing from ca. 2 nm at 120 °C to about 20 nm at 300 °C. We assume the temperature dependent formation of a layer of byproduct ammonium lactate at the crystallite surface where it interferes with growth reactions. After removal of this layer, continued heating yields larger crystallites in typical anatase shapes, indicating that Ostwald ripening has now become effective.

Economical nitrogen?sulfur fluids

The National Fertilizer & Environmental Research Center (NFERC) has developed and begun introduction of a new family of nitrogen—sulfur (NS) suspensions with several advantages. The new NS suspensions have a substantial economic advantage over ammonium thiosulfate-based solutions and they are considerably higher in grade and more versatile than ammonium sulfate-based solutions currently on the market. In some areas, the NS suspensions are less expensive sources of nitrogen alone than UAN solutions, urea, or ammonium nitrate. High-quality, long-storing NS suspensions can be produced from the lowest quality, wet by-product ammonium sulfate (AS) fines. These new products provide an excellent means for long-term storage, handling, and application of by-product AS fines, which are inexpensive but do not store, handle, or apply well as a solid. In August of 1989, NFERC produced 500 tons of 25-0-0-10S N-S suspension, stored the material through winter, and introduced the product during the spring 1990 season through several dealers in the Southeast.

Update on ammonia scrubbing. A state‐of‐the‐art review, highlighting, recent successes and pointing to problem areas with recommended solutions

A review is presented of the history and development of the ammonia scrubbing process leading to the design of the 1970's, with an analysis of the successes and problems to update the state of the art for use in the 1980's. The analysis is highlighted by the many successes, including SO/sub 2/ emission control, reliability, controllabiling, energy efficiency, and low capital cost. Problem areas include corrosion of booster blowers and mist eliminators that are easily solved by proper material choice or alternate blower location. Numerous alternates for by-product ammonium sulfate handling are reviewed, providing alternate means of processing.

Direct acid pressure leaching of chalcocite concentrate

A hydrometallurgical process for the recovery of pure copper from an intimate mixture of chalcocite and pyrite is discussed. The dissolution of the copper can be accomplished by pressure leaching in an ammoniacal ammonium sulfate solution which results in the production of byproduct ammonium sulfate. In some locations this byproduct is undesirable, and an alternative process has been developed in which the chalcocite concentrate is leached directly in dilute sulfuric acid under an overpressure of air. This procedure converts the sulfide sulfur in the chalcocite to elemental sulfur and gives copper extractions of up to 98%. Any pyrite in the chalcocite concentrate is only slightly attacked during the leach and can thus be conveniently separated from the copper bearing solution together with the elemental sulfur. Sulfuric acid and ferric sulfate which are produced by the oxidation of a small portion of the pyrite, are removed from the leach solution by the addition of limestone. The copper is then recovered from the neutralized solution either by electrolysis or by reduction with hydrogen under pressure. The sulfuric acid which is regenerated in the copper winning operation is recirculated to the leaching step.

News and Views

IT was announced last week that Lord Bledisloe is resigning his post as Parliamentary Secretary to the Ministry of Agriculture to take up the appointment of chairman of the Imperial Grassland Association, which is being formed under the auspices of Imperial Chemical Industries, Ltd., with the object of improving the pasture land of Great Britain and of the Overseas Empire. Lord Bledisloe has rightly earned a great reputation as one who has taken the keenest interest in all phases of agriculture and has devoted so much of his energies to the furtherance of its well-being. Whilst his loss to the Government will be keenly felt, his new position will offer plenty of scope for his great enthusiasm and his wide experience of agricultural matters. The formation of the Imperial Grassland Association, further details of which will be awaited with great interest, is a further step in the developments which have been fostered in recent years by Imperial Chemical Industries, Ltd., through their associated companies, Synthetic. Ammonia and Nitrates, Ltd., and Nitram, Ltd. The former company, at its great works at Billingham-on-Tees, now possesses plant with a total output capacity of fixed nitrogen equivalent to about 1000 tons of ammonium sulphate per day, and further big extensions are planned involving the production of a wide range of fertilisers. Nitram, Ltd., besides being responsible for the sale of the ammonium sulphate and other fertilisers produced at Billingham, as well as for most of the by-product ammonium sulphate produced in Great Britain, has recently established an agricultural research and advisory department, under the directorship of Sir Frederick Keeble, and with a strong scientific staff and well-equipped laboratories and experimental farm.