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Mass and Energy Balances
Published in Martyn S. Ray, Martin G. Sneesby, Chemical Engineering Design Project, 2020
Martyn S. Ray, Martin G. Sneesby
Heat flows within the process are highest around the reactor where high temperatures and high flow rates coincide. The heat of reaction liberates 20.93 MW of heat which is mostly transferred directly to the high temperature coolant (a eutectic mixture of sodium nitrate and potassium nitrite, commonly called foundry salt). Heat not transferred to the cooling salt, about 2.61 MW, remains with the process and causes a temperature rise of approximately 155°C. Heat is recovered from the cooling salt in high pressure process boilers, creating approximately 24 T/hr of superheated HP steam which can be exported and/or used to produce electricity. Control of the reactor temperatures is important to maintain an overall high energy efficiency and to maximise steam production. The temperature rise across the reactor should be minimised without sacrificing conversion or selectivity. The characteristic mass flows, temperatures and energy flows (i.e. the process energy balance) are summarised in Table 7.2.
Fractional Factorial Designs
Published in John Lawson, Design and Analysis of Experiments with R, 2014
The authors of the article felt that the experiment had given them evidence that factor A (the inhibitor) had little effect, and they confirmed this by citing other published reports. They also felt the experiment showed main effects D (magnesium sulfate) and F (potassium nitrite) were insignificant. However, due to the confounding of two-factor interactions with the second largest effect (in absolute value) and the fact that nothing clearly stuck out on the half-normal plot of effects, no definite conclusions could be drawn. They decided to run another resolution V 25−1 follow-up experiment using factors B, C, E, G, and H with defining relation I = BCEGH and factors A, D, and F held constant at the mid-point of the levels used in the first experiment. This was a 16-run design, but if it could be safely assumed that main effects A, D, and F were negligible in the first set of sixteen experiments, then eight of the sixteen runs for the proposed follow-up design were already completed.
Components of Energetic Compositions
Published in John A. Conkling, Christopher J. Mocella, Chemistry of Pyrotechnics, 2019
John A. Conkling, Christopher J. Mocella
Notably, this is a strongly endothermic reaction—the reaction takes in heat instead of releases it—with a heat of decomposition value of +75.5 kcal/mol of KNO3; consequently, high-energy output fuels must be used with saltpeter to achieve rapid-burning rates. When mixed with a simple organic fuel such as lactose, potassium nitrate may burn with some difficulty and stop at the potassium nitrite (KNO2) stage in its decomposition (Shimizu, Fireworks—The Art, Science and Technique 1981).
POM-based compounds as capacitor materials and their photoelectric-sensing properties toward inorganic ions
Published in Journal of Coordination Chemistry, 2021
Chen Wang, Jun Ying, Xinyue Zhang, Baoyue Zhang, Aixiang Tian, Yanping Zhang
There have been many studies on electrocatalysis of potassium nitrite. In 1994, Lapkowski et al. reported a new sensitive layer for the amperometric detection of nitrite ions [13]. In 2006, Bond et al. reported mechanistic analysis of the electrocatalytic properties toward nitrite in aqueous media [14]. Currently POM-based compounds as photoelectric sensors in different fields have attracted more attention. In 2019, Han et al. synthesized three hour glass-type phosphomolybdate based crystalline materials, which have lower detection limit and higher sensitivity for sensing Cr(VI) through electrochemical methods [15]. In 2020, Wang’s group reported a pH-stable Ag(I) multifunctional luminescent sensor, which can detect different organic solvents and heavy metal ions [16]. In our previous work, we obtained a Keggin-type compound for detecting Hg2+ with the quenching efficiency of 81.8% [17]. Cr(VI) ions are the most harmful pollutant to human health which exist in polluted water sources. The application of POM-based compounds in detecting polluted water containing Cr(VI) is a meaningful and promising research area.
Synthesis of multiple single crystal diamonds by DC-GD-CVD
Published in Surface Engineering, 2019
Ji-lei Lyu, Shao-long Wang, Bo Wang, Kazhihito Nishimura, Nan Jiang
The experiments were performed using a commercial of 30 kW DC-GD-CVD system. Commercially available (100) type Ib HPHT SCD seeds (number: 24; dimensions: 4 mm × 4 mm × 1 mm; Huajing Co., Ltd., China) were used as substrates. First, all the seeds were cleaned in a boiling mixture of sulphuric acid and potassium nitrite (the volume ratio of nitric acid/sulphuric acid = 1:1, t = 373 K) for 2 h to remove the organic, metallic and graphitic contaminants, then cleaned ultrasonically with deionised water and acetone in Pyrex beaker for 15 minutes, and finally blew by nitrogen for 5 min to remove the residual deionised water and acetone. After the above treatment, these seeds were placed on a molybdenum (Mo) holder and the distance between each seed was set as 2 mm (as shown in Figure 1(a)).
2,4-D mediated moderation of aluminum tolerance in Salvinia molesta D. Mitch. with regards to bioexclusion and related physiological and metabolic changes
Published in International Journal of Phytoremediation, 2023
Debabrata Dolui, Mirza Hasanuzzaman, Masayuki Fujita, Malay Kumar Adak
Reactive oxygen species, like hydrogen peroxide (H2O2) was determined spectrophotometrically by using potassium iodide and potassium phosphate buffer (pH 7.0) and reading the absorbance at 390 nm (Guo et al.2019). For superoxide (O2●−) determination, NBT reduction was done in phosphate buffer saline (pH 7.8) with hydroxyl ammonium chloride following incubation in NBT solution. The absorbance was read at 540 nm to determine O2●− and potassium nitrite (KNO2−) was used as standard (Li et al.2019).