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Explosives and Propellants: Power to Breach Mountains, Wage war and Visit the Moon
Published in Richard J. Sundberg, The Chemical Century, 2017
Hydrazine derivatives are also used as fuels in rockets and missiles. The oxidants used are nitric acid or N2O4. These materials ignite on contact and are called hypergolic fuels. The Space Shuttles used NH2NH2/N2O4 for the thrusters. In 1964, Shell introduced an iridium catalyst that permitted use of NH2NH2 without an oxidant. Derivatives of hydrazine, in particular CH3NNH2 and (CH3)2NNH2 can be used in place of NH2NH2. The main engines of the Russian Proton Rockets use unsym-dimethylhydrazine and N2O4. The Titan-II rocket used a 50:50 mixture of H2NNH2 and (CH3)2NNH2. The hydrazine fuel mixtures are corrosive and very toxic.
Chemicals from Non-hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Hydrazine is mainly used as a foaming agent in the preparation of polymer foams and other significant uses also include use as a precursor to polymerization catalysts, pharmaceuticals, and agricultural chemicals. Additionally, hydrazine is used as a rocket fuel because its combustion is highly exothermic: H2NNH2+O2→N2+2H2O
Water Treatment
Published in Carl Bozzuto, Boiler Operator's Handbook, 2021
Some plants cannot tolerate the additional dissolved solids that result from sulfite addition. These are primarily nuclear plants, heat recovery steam generators (HRSGs), and super critical (or once-through) boilers. These plants will use all volatile treatment (AVT). This treatment uses hydrazine as the oxygen scavenger. The hydrazine reacts with oxygen to form water and nitrogen gas. The water is desirable. The nitrogen must be removed first in the condenser and then in the deaerator. Hydrazine is hazardous and must be handled with care. Wear that protective clothing.
Sodium carboxymethyl cellulose hydrogels containing reduced graphene oxide (rGO) as a functional antibiofilm wound dressing
Published in Journal of Biomaterials Science, Polymer Edition, 2019
Nor Hazwan Ali, Mohd Cairul Iqbal Mohd Amin, Shiow-Fern Ng
The synthesis process of rGO may determine the graphene cytotoxicity. For the purposes of wound treatment, the use of toxic materials in the synthetic process should be avoided. The most widely used method to reduce GO is the utilization of hydrazine hydrate, because it has the capability to produce stable rGO and remove most of the oxygenated functional groups [40]. However, residual traces of hydrazine could be highly toxic and extremely hazardous in the case of skin contact [41]. In this study, sodium hydroxide was used in the synthesis of rGO as a less toxic option, and it is widely used in multiple industries. Therefore, the risk of rGO hydrogel in causing cytotoxicity to the HDF cells was mitigated.
Synthesis of morphology controllable aluminum nitride by direct nitridation of γ-AlOOH in the presence of N2H4 and their sintering behavior
Published in Journal of Asian Ceramic Societies, 2018
Angga Hermawan, HyoungWon Son, Yusuke Asakura, Takao Mori, Shu Yin
Finally, the present method emphasized the possibility of the AlN powder synthesis with various unique morphologies at relatively low temperature by using morphology controllable γ-AlOOH as a precursor and hydrazine as a nitriding agent. Though experimentally promising, the hydrazine utilization may become a practical challenge, as it is toxic and flammable material. Thus, to increase the safety, the hydrazine solution can be supplied at a low concentration below the explosion limit.
Evaluation of octadecylamine for the corrosion inhibition of Incoloy 800
Published in Corrosion Engineering, Science and Technology, 2021
Subrata Kuilya, Veena Subramanian, S. Bera, S. Rangarajan
In Indian pressurised heavy water reactors (PHWRs), Incoloy 800 is being used as the structural material for steam generators. The corrosion of structural materials in secondary water circuit is controlled by maintaining the pH in the range of 8.5–9.2, by the addition of a very low concentration of all volatile amines such as ethanolamine (ETA) which is known as the all volatile treatment (AVT) [1]. In recent years, addition of film forming amines (FFAs) along with the pH controlling amine is gaining popularity [2–4]. The FFAs are known to further reduce the corrosion of materials to extremely low values and hence, they can be utilised in wet lay-up procedure, wherein a particular component of the plant will not be in use for a long time [5,6]. Most of the operating reactors worldwide are ≥25 years old [6,7]. Any refurbishments of major components, such as steam generators or coolant channels etc., would lead to long-term shut down of the reactor. Under these conditions, the components need to be preserved by using ‘lay-up’ process till the reactor starts up. Normally during shut down periods, systems and components are drained and opened to atmosphere and hence, wet surfaces and moisture condensation can result in uniform corrosion of carbon steel and for other materials, localised corrosion is possible in the presence of impurities. For such systems two types of lay-up processes, such as wet and dry lay-up, are followed. In dry lay-up, the entire water is drained and the humidity also will be removed continuously by blowing dry hot air into the component to be preserved [7,8]. A dewpoint of <10°C or <50% relative humidity has to be achieved. Maintaining O2 free atmosphere by N2 also is adopted. The drawback of this technique is that it requires high manpower and hardware efforts to maintain less humid and oxygen-free atmosphere for long durations. On the other hand, in wet lay-up process, the entire system to be preserved will be filled with demineralised water free of O2. This is achieved by using chemicals like Hydrazine. There is always a need to avoid using hydrazine as it is toxic and carcinogenic.