Safety of the monopropellant's production at the purification stage

2018 ◽  
Vol 150 ◽  
pp. 172-176 ◽  
Author(s):  
S.V. Efremov ◽  
O.V. Romantsova ◽  
V.B. Ulybin
Keyword(s):  
Purification Stage

scholarly journals Triethanolamine as an efficient cosolvent for biodiesel production by CaO-catalyzed sunflower oil ethanolysis: An optimization study

2019 ◽  
Vol 73 (6) ◽  
pp. 351-362 ◽  
Author(s):  
Dusica Djokic-Stojanovic ◽  
Zoran Todorovic ◽  
Dragan Troter ◽  
Olivera Stamenkovic ◽  
Ljiljana Veselinovic ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
Sunflower Oil ◽  
Acid Ethyl Ester ◽  
Fatty Acid Ethyl Ester ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Calcium Leaching ◽  
Stirred Reactor ◽  
Optimization Study ◽  
Purification Stage

Triethanolamine was applied as an efficient ?green? cosolvent for biodiesel production by CaO-catalyzed ethanolysis of sunflower oil. The reaction was conducted in a batch stirred reactor and optimized with respect to the reaction temperature (61.6-78.4?C), the ethanol-to-oil molar ratio (7:1-17:1) and the cosolvent loading (3-36 % of the oil weight) by using a rotatable central composite design (RCCD) combined with the response surface methodology (RSM). The optimal reaction conditions were found to be: the ethanol-to-oil molar ratio of 9:1, the reaction temperature of 75?C and the cosolvent loading of 30 % to oil weight, which resulted in the predicted and actual fatty acid ethyl ester (FAEE) contents of 98.8 % and 97.9?1.3 %, respectively, achieved within only 20 min of the reaction. Also, high FAEE contents were obtained with expired sunflower oil, hempseed oil and waste lard. X-ray diffraction analysis (XRD) was used to understand the changes in the CaO phase. The CaO catalyst can be used without any treatment in two consecutive cycles. Due to the calcium leaching into the product, an additional purification stage must be included in the overall process.

Investigation of flocculant influence on the kinetic parameters of copper recovery in aqueous solution with metal zinc

2019 ◽  
pp. 4-11
Author(s):  
A. V. Kolesnikov ◽  
I. V. Tsyganova
Keyword(s):  
Zinc Powder ◽  
Spectrophotometric Analysis ◽  
Copper Recovery ◽  
Relative Molecular Mass ◽  
Velocity Change ◽  
High Speeds ◽  
Ammonia Complex ◽  
Mixing Rates ◽  
Purification Stage ◽  
Molecular Substances

We studied a number of models for the description of copper reduction by fine zinc powder in aqueous solutions. The experimentswere carried out in devices with a magnetic stirrer at mixing speeds of 40–150 rpm and temperatures of 15–50 °C. We investigated the influence exerted on the process by macromolecular flocculants such as non-ionic magnafloc 333, cationic besflok 6645 and anionic besfloc 4034. Under industrial conditions, these flocculants are used at the hydrolytic solution purification stage and then they are fed to cementing purification together with the clarified solution. Aqueous flocculant solutions of 2,5 g/l containing 2–4 g/l of zinc dust and 50–200 mg/l of flocculant were used in the experiments. Copper content in the initial and final solutions was quantitatively determined by spectrophotometric analysis with the preliminary copper transfer to the ammonia complex. Experiment duration varied from 1 to 8 min. The degree of copper reduction from solutions was 10–90 %. It was found that at low mixing rates the process kinetics can be described by the kinetic equation of the first order. At high speeds, the kinetics of the studied heterogeneous reactionwith added flocculants is more adequately described by the velocity change equation as a square root of the process duration. It wasshown that the highest constant of cementation rate is observed in experiments without the addition of surfactants. Anionic flocculant slows down the cementation process to a lesser extent than cationic one, which is consistent with the theory of electrochemical processes and shows that the discharge of copper cations under these conditions limits the cementation process. Regularities revealed in the studied process remain as temperature increases. It was noted that the addition of high-molecular substances with a relative molecular mass of 20 million in an amount of 50–200 mg/l inhibit the cementation process. This fact must be taken into account in industrial conditions where cementing purification from copper and other impurities is carried out from flocculant-containing solutions.

scholarly journals Artemisia annua Growing Wild in Romania—A Metabolite Profile Approach to Target a Drug Delivery System Based on Magnetite Nanoparticles

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2245
Author(s):  
Adina-Elena Segneanu ◽  
Catalin Nicolae Marin ◽  
Ioan Ovidiu-Florin Ghirlea ◽  
Catalin Vladut Ionut Feier ◽  
Cornelia Muntean ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Artemisia Annua ◽  
Metabolite Profile ◽  
Ecological Environment ◽  
Carrier System ◽  
Isolation And Purification ◽  
Positive Mode ◽  
Purification Stage ◽  
Profile Approach ◽  
Carrier Systems

The metabolites profile of a plant is greatly influenced by geographical factors and the ecological environment. Various studies focused on artemisinin and its derivates for their antiparasitic and antitumoral effects. However, after the isolation and purification stage, their pharmaceutical potential is limited due to their low bioavailability, permeability and lifetime. The antibacterial activity of essential oils has been another topic of interest for many studies on this plant. Nevertheless, only a few studies investigate other metabolites in Artemisia annua. Considering that secondary metabolites act synergistically in a plant, the existence of other metabolites with antitumor and high immunomodulating activity is even more important. Novel nano-carrier systems obtained by loading herbs into magnetic nanoparticles ensures the increase in the antitumor effect, but also, overcoming the barriers related to permeability, localization. This study reported the first complete metabolic profile from wild grown Romanian Artemisia annua. A total of 103 metabolites were identified under mass spectra (MS) positive mode from 13 secondary metabolite categories: amino acids, terpenoids, steroids, coumarins, flavonoids, organic acids, fatty acids, phenolic acids, carbohydrates, glycosides, aldehydes, hydrocarbons, etc. In addition, the biological activity of each class of metabolites was discussed. We further developed a simple and inexpensive nano-carrier system with the intention to capitalize on the beneficial properties of both components. Evaluation of the nano-carrier system’s morpho-structural and magnetic properties was performed.

Environmental assessment of a biorefinery: case study of a purification stage in biomass gasification

2018 ◽  
Vol 11 (3) ◽  
pp. 113-120 ◽  
Author(s):  
Samir Meramo-Hurtado ◽  
Karina Ojeda-Delgado ◽  
Eduardo Sanchez-Tuiran
Keyword(s):  
Environmental Assessment ◽  
Biomass Gasification ◽  
Purification Stage

Capacity of small wastewater treatment plants and their effects on the groundwater

2000 ◽  
Vol 41 (1) ◽  
pp. 85-88 ◽  
Author(s):  
S. Kunst ◽  
K. Kayser ◽  
H.-M. Lenz
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Simulation Program ◽  
Lower Saxony ◽  
Biological Purification ◽  
Purification Stage ◽  
Pre Treatment

In order to gain an updated evaluation of the purification capacity of small wastewater treatment plants (SWTPs), several districts in Lower Saxony were questioned on this matter. The incoming results were then compared to and completed by existing results published in reference literature. A simulation program was run to estimate the COD loads which leach out into the groundwater at the effluents of SWTPs. The results gained from the questionnaire and the literature are indicating that vertical filters, wastewater lagoons and rotating biological discs are especially suitable types of SWTPs. The results of the simulation show that a percolation of the effluent of efficient plants can be regarded as harmless given a percolating distance of 60 or better yet 120 cm. This is different with the subsoil irrigation where the passage through the soil is virtually the biological purification stage. Then, even after having passed through the soil for 250 cm, considerably high COD loads are still emitted into the groundwater. As this kind of SWTP is very frequently used in Lower Saxony, it would be worthwhile to increase the efficiency of the pre-treatment of wastewater before the percolation by adding simple aggregates to the plants. This should be examined in future analyses.

scholarly journals Analisis Pembuatan Asam Lemak Hidroksamat Dari Minyak Kelapa Melalui Metode Enzimatis

2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Muhsinun Muhsinun
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Hydroxamic Acid ◽  
Coconut Oil ◽  
Hydroxamic Acids ◽  
Raw Material ◽  
Enzymatic Method ◽  
Purification Stage ◽  
Acid Sample ◽  
Synthesis Stage

Generally, fatty hydroxamic acids (FHA) are synthesized from basic ingredients containing fatty acids.Fatty acids can be obtained from coconut oil among several other sources. Coconut oil contains fatty acids with medium and long chains so it has enormous potential as a raw material for the synthesis of hydroxamic fatty acids. The purpose of this research is to synthesize FHA from coconut oil enzymatically and determine the amount of FHA products produced. The method used is the enzymatic method which includes several stages of work, namely the synthesis stage, the multiplication stage, and the purification stage. From the research results, the percentage obtained from the synthesis was around 48.58% of hydroxamic fatty acids from coconut oil after propagation using the synthesis conditions.The number of hydroxamic acid groups in 1 gram of dry hydroxamic fatty acid sample was 2.97 mmol. Thus, from the two results mentioned above, it was concluded that hydroxamic fatty acids can be synthesized from coconut oil

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