Effect of Cement Raw Material and Oxygen Concentration on SNCR Reaction

2018 ◽  
Vol 913 ◽  
pp. 969-975
Author(s):  
Ya Li Wang ◽  
Li Nan ◽  
Si Yu Peng ◽  
Yun Ning Zhang ◽  
Mei Na Chen ◽  
...  

As the selective non-catalytic reduction denitration(SNCR denitration) was used in cement decomposition furnaces under the high concentration cement raw materials and complex flue gas composition , the denitration efficiency is poor and the reducing agent is largely consumed.In order to meet the more stricter requirements of environmental protection, there is an urgent need to improve the denitration efficiency of SNCR and reduce the escape of reducing agentsin order to prevent the unnecessary waste caused by excessive use of reducing agents and secondary atmospheric pollution.Therefore, studying the effect of cement raw materials and O2 concentration on SNCR process is very important. In this paper, the initial concentration of NO and the ammonium to nitrogen ration (CNH3/CNO) was 800ppm and 1.5, respectively. The effects of cement raw material and oxygen concentration on the reaction process of NH3+NO+O2 in the temperature range of 750°C -1100°C were investigated by means of denitration rate, in Situ DRIFTS analysis.The results demonstrate when O2 concentration was 5% and denitration temperature was 950°C, the deNOx rate reached a maximum of 89.64%, which due to O2 promoted NH3 and NO to react with O2 to produce N2 and H2O. However,under the effect of cement raw material, O2 can promote NH3 which was adsorbed on the surface of cement raw material to react with O2 and produce NO and H2O, and the reaction of oxidation of NH3 is dominant, therefore, the denitration reaction is inhibited. .When O2 concentration was 5% and temperature was 850°C, the deNOx rate reached a minimum value of -109.09%. the high concentration cement raw material and flue gas composition reduce the denitration efficiency of cement kiln.

2017 ◽  
Vol 6 (2) ◽  
pp. 327-330 ◽  
Author(s):  
Olga Driesner ◽  
Fred Gumprecht ◽  
Ulrich Guth

Abstract. The simultaneous in situ measurement of O2 and CO eq.  in cement kilns is a great challenge due to the high process temperatures and high dust load. The standard method for measurement for flue gas in cement kilns is extractive. Extractive measurements have a higher response time due to the flue gas conditioning including the length of heated extraction lines for electrochemical or optical analysis. This delayed response is not optimal for fast process control.A probe was developed for this purpose in which the in situ solid electrolyte oxygen sensor and an in situ CO eq.  mixed potential sensor are implemented. Due to the high temperatures, the probe is cooled by a water–coolant mixture. In order to prevent deposits of raw material forming and sintering on the probe, it rotates 90° in programmable intervals. In addition, an automated probe plunger pneumatically removes plugging at the probe flue gas entrance, also in programmable intervals. These self-cleaning functions allow the probe to continually stay in the process for combustion optimisation (low excess O2 and CO) and enable the plant operator to measure additional process-related gas components (NO, SO2, HCl etc.) and optimise the SNCR (selective non-catalytic reduction) for NOx reduction. Combustion air supply can be adapted very quickly due to the in situ sensors, which has been demonstrated by a CEMTEC® probe over years (Märker Cement Harburg, 2017).


Author(s):  
O. A. Kyslychenko ◽  
V. V. Protska ◽  
I. O. Zhuravel

Introduction. Parmelia perlata is a widespread lichen that belongs to the Parmeliaceae family. In Ayurvedic medicine thalli of Parmelia perlata are used for the treatment of a series of diseases of different genesis. Literature data contain information that the representatives of Parmeliaceae family show a wide spectrum of biological activity, in particular, possess anti-bacterial, cardiotonic, spasmolytic, antioxidant and other types of activity.The aim of the study – to learn the mineral composition of parmelia perlata thalli of Kazakh and Russian production.Materials and Methods. For the study of the composition of micro- and macroelements by the atomic-absorption spectroscopy method Parmelia perlata thalli of Kazakh and Russian production were used.Results and Discussion. As a result of the study the content of 19 mineral elements in Parmelia perlata thalli of Kazakh and Russian production was determined. The dominating elements in both studied objects were calcium and silicon. The content of calcium in the raw material of Kazakh production comprised 2270.00 μg/100 g, and in the raw material of Russian production – 1938.00 μg/100 g. The content of silicon in the raw materials studied comprised 1815.00 μg/100 g and 1619.00 μg/100 g respectively. The content of iron and magnesium in both samples was almost identical, while the content of sodium and potassium in the raw material of Russian production was 1.5 times higher than in the raw material of Kazakh production. Both samples were found to accumulate magnesium and zinc in quite high concentration. The content of heavy metals in both raw material samples was within the limit of maximum permissible concentration for medicinal plant material and food products according to the requirements of the current legislation.Conclusions. The obtained results can be used at working out medicines on the basis of Parmelia perlata thalli and the quality control methods for the raw material.


2004 ◽  
Vol 58 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Dejan Skala ◽  
Sandra Glisic

Biodiesel is defined as a fuel which may be used as pure biofuel or at high concentration in mineral oil derivatives, in accordance with specific quality standards for transport applications. The main raw material used for biodiesel production is rapeseed, which contains mono-unsaturated acids (about 60%) and also poly-unsaturated fatty acids (C 18:1 and C 18:3) in a lower quantity, as well as some undesired saturated fatty acids (palmitic and stearic acids). Other raw materials have also been used in research and the industrial production of biodiesel (palm oil, sunflower oil, soybean oil, waste plant oil, animal fats, etc). The historical background of biodiesel production, installed industrial capacities, as well as the Directive of the European Parliament and of the Council (May 2003) regarding the promotion of the use of biofuels or other renewable fuels for transport are discussed in the first part of this article. The second part focuses on some new concepts for the future development of technology for biodiesel production, based on the application of non-catalytic transesterification under supercritical conditions or the use of lipases as an alternative catalyst for this reaction.


2021 ◽  
Vol 13 (23) ◽  
pp. 13483
Author(s):  
Michele Borroni ◽  
Carlo Massimo Pozzi ◽  
Sara Daniotti ◽  
Fabiana Gatto ◽  
Ilaria Re

Nutraceuticals are an ever-expanding market worldwide, facing the unstoppable transition towards a green economy. Developing economically feasible and sustainable alternatives to current raw materials for the extraction of nutraceuticals is, therefore, essential to reach these goals and, at the same time, achieve social and economic competitiveness. This paper intends to propose an economical and environmentally sustainable feedstock for chlorogenic acid (CGA) and inulin, whose current extraction from green coffee and chicory, respectively, is unsustainable. Our approach is based on the multi-criteria decision-making approach (MCDA), supported by the analytical hierarchy process (AHP), ranking the performance of competitor biomasses according to economic, social, and technological criteria. The results of this study highlight cardoon (Cynara cardunculus) as a promising raw material for the extraction of CGA and inulin in virtue of the high concentration, low-input growth regime, and the possibility of being grown on marginal lands. Nevertheless, cardoon biomass availability is currently scarce, extraction methods are underdeveloped, and consequently, the obtained product’s price is higher than the benchmark competitors. Policies and investments favoring sustainable cultivations could stimulate cardoon employment, linking economic advantages and land requalification while limiting phenomena such as desertification and food competition in the Mediterranean basin.


2019 ◽  
Vol 118 ◽  
pp. 01036
Author(s):  
Xiuru Liu ◽  
Yiqing Sun ◽  
Fangming Xue ◽  
Jingcheng Su ◽  
jiangjiang Qu ◽  
...  

SO3 is one of pollutants in flue gas of coal power plants. It mainly derived from coal combustion in boiler and selective catalytic reduction denitrification system. The content of SO3 in flue gas were influenced by the combustion mode, sulfur content in fuel, composition of denitrification catalyst and fly ash. SO3 and water vapour generated H2SO4 droplets. Sulfate secondary particles in atmosphere could cause haze, acid rain and other disastrous weather. High concentration of SO3 could cause blockage and corrosion and affect the safe operation of the units. The generation mechanism of SO3 was discussed. The latest research progress on control and removal technology of SO3 was summarized. The study in this paper provides a reference for pollutant treatment in coal-fired power plants.


2013 ◽  
Vol 838-841 ◽  
pp. 2338-2341
Author(s):  
Marcela Fridrichová ◽  
Karel Dvořák ◽  
Iveta Hájková

The insufficient occurrence of raw material resources on our territory was one of the historical reasons for marginal production of sulphated binders from secondary raw-material resources. Also the unprofitability of material production based on calcium sulphate was related to this fact. This was changed in the end of the last century when formation of waste raw materials increased with industrial development. Secondary gypsums became basic raw material for production of plaster boards, plaster mixtures and anhydrite self-levelling mixtures. Wet flue gas cleaning desulphation process during which the energogypsum is formed is nowadays realised in major part of our power stations. Annual production of the energogypsum produced in this way in particular power stations is about 250 kt. The energogypsum is generally stored in stock piles as a so called stabilisate and partially is delivered to cement works as a solidification regulator. Chemogypsum is produced in chemical works where waste waters with content of SO42- occur, which must be desulphated with lime in water ambient. Further it is formed in citric acid productions where also sulphated waters occur. Last but no least it is also produced in industrial production of phosphates. Production of titanium dioxide is another example of the industry where the possibility of gypsum formation exists.


2018 ◽  
Vol 913 ◽  
pp. 893-899
Author(s):  
Dong Zhu Ma ◽  
Jian Li ◽  
Ling Zhang ◽  
Peng Guo ◽  
Zi Qiang Wen ◽  
...  

Mg-Mo-V-Ti catalysts of low temperature denitrification were prepared by dipping method. In order to study the activity of selective catalytic reduction, the catalyst was placed in a fixed bed reactor. Industrial flue gas was simulated with cylinder gas. Results indicate that the 0.1wt% content of MgO catalyst has good performance on denitration activity and sulfur resistance. The effects of oxygen content, space velocity and reaction temperature on the activity of the 0.1MgO-6MoO3-3V2O5-TiO2 wt% catalyst were investigated. With the increase of oxygen concentration, the denitrification efficiency increases when the oxygen concentration is less than 8%. When the oxygen content is greater than 8%, the denitrification efficiency is almost the same. The denitrification efficiency decreases with the increase of space velocity. The removal efficiency of NO 0.1MgO-6MoO3-3V2O5-TiO2 wt% catalyst over increases first and then becomes stable with the increase of temperature, and the conversion efficiency of SO2 is less than or equal to 2.2% at 120~240 °C.


2021 ◽  
pp. 382-387
Author(s):  
Е.А. Миронова ◽  
Е.С. Романенко ◽  
Н.А. Есаулко ◽  
М.В. Селиванова ◽  
Т.С. Айсанов ◽  
...  

Производство напитков функционального назначения в настоящее время имеет актуальное значение, при этом наиболее перспективными являются напитки, приготовленные на основе натуральных соков с добавлением ингредиентов, выделенных из растительного сырья, в том числе из плодово-ягодного. Помимо органических кислот, аминокислот, витаминов, пектиновых веществ, полифенолов и природных углеводов, эти напитки насыщены также дефицитными микронутриентами, оказывающими позитивное действие на состояние человеческого организма. В статье представлены результаты исследований по разработке рецептур и технологии производства высококачественных функциональных напитков на основе виноградного сока прямого отжима, обладающих улучшенными потребительскими свойствами за счет включения в их состав экстрактов плодово-ягодного сырья - фейхоа, ежевики и черной смородины. Приведена оценка показателей качества и безопасности разработанных напитков и процессуально-технологическая схема их производства. Работа выполнена на базе учебно-научной лаборатории технологии виноделия и продуктов питания из растительного сырья Ставропольского ГАУ. Для определения физико-химических показателей и пищевой ценности сырья, полупродуктов и приготовленных функциональных напитков применяли современные общепринятые методы исследований согласно действующих ГОСТ. Разработка технологии производства напитков на основе виноградного сока с применением плодово-ягодных экстрактов является особенно важной и актуальной задачей в связи с наличием разнообразной и доступной сырьевой базы на Юге России, а также высокой концентрацией в данном регионе плодоперерабатывающих производств, оснащенных современным высокопроизводительным оборудованием. Полученные нами результаты могут способствовать целенаправленному применению разработанных напитков в санаторно-курортном лечении населения для решения проблемы оптимизации питания и повышения пищевого статуса населения России. The production of functional beverages is currently of urgent importance, while the most promising are drinks prepared on the basis of natural juices with the addition of ingredients extracted from vegetable raw materials, including fruit and berry. In addition to organic acids, amino acids, vitamins, pectin substances, polyphenols and natural carbohydrates, these drinks are also saturated with scarce micronutrients that have a positive effect on the state of the human body. The article presents the results of research on the development of recipes and technology for the production of high-quality functional beverages based on direct-pressed grape juice, which have improved consumer properties due to the inclusion of extracts of fruit and berry raw materials - feijoa, blackberry and black currant in their composition. The evaluation of quality and safety indicators of the developed beverages and procedural and technological scheme of their production is given. The work was carried out on the basis of the educational and scientific laboratory of winemaking technology and food products from vegetable raw materials of the Stavropol State Agrarian University. To determine physicochemical parameters and nutritional value of raw materials, intermediates and prepared functional beverages, modern generally accepted research methods were used in accordance with the current GOST. The development of technology for the production of beverages based on grape juice using fruit and berry extracts is a particularly important and urgent task due to the presence of a diverse and affordable raw material base in the South of Russia, as well as a high concentration of fruit processing plants accomplished by modern high-performance equipment in this region. The results obtained by us can contribute to the purposeful use of the developed beverages in sanatorium treatment of the population to solve the problem of optimizing the nutrition and improving the nutritional status of the population of Russia.


2015 ◽  
Vol 1102 ◽  
pp. 27-32
Author(s):  
Yu Yen Cheng ◽  
Mei Fang Lu ◽  
Jim Jui Min Lin

While conducting research for dioxin emission factor for stationary source emission, it is found that some factors come from overestimation. The cause of discrepancy for estimating process comes often from lacking understanding of the process. The result of this study for secondary aluminum refining emission factors indicates that if raw materials are scraps, the factors averaged at 541 ng I-TEQ/Ton-raw materials. If waste aluminum is used as the raw material, factors averaged at 1338 ng I-TEQ/Ton-raw material. The factors based on site sampling for coal-fired power generation process is 24.84-549.62 ng I-TEQ/Ton-fuel. It varies according to coal sources. Emission factor for cement producing process is 95.4-102.66 ng I-TEQ/Ton-raw material. Due to fewer differences in operating traits, raw materials and fuel application for cement producing process, emission factors have smaller differences. The reliability for emission variables is relatively higher.


Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2416 ◽  
Author(s):  
Monika Sachadyn-Król ◽  
Sofia Agriopoulou

In this review, the primary objective was to systematize knowledge about the possibility of improving the health-promoting properties of raw plant products, defined as an increase in the content of bioactive compounds, by using ozone. The greatest attention has been paid to the postharvest treatment of plant raw materials with ozone because of its widespread use. The effect of this treatment on the health-promoting properties depends on the following different factors: type and variety of the fruit or vegetable, form and method of ozone treatment, and dosage of ozone. It seems that ozone applied in the form of ozonated water works more gently than in gaseous form. Relatively high concentration and long contact time used simultaneously might result in increased oxidative stress which leads to the degradation of quality. The majority of the literature demonstrates the degradation of vitamin C and deterioration of color after treatment with ozone. Unfortunately, it is not clear if ozone can be used as an elicitor to improve the quality of the raw material. Most sources prove that the best results in increasing the content of bioactive components can be obtained by applying ozone at a relatively low concentration for a short time immediately after harvest.


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