Papers by cemil koyunoğlu
IOP conference series, Dec 1, 2017
The hydrogenation of coal by molecular hydrogen has not been appreciable unless a catalyst has be... more The hydrogenation of coal by molecular hydrogen has not been appreciable unless a catalyst has been used, especially at temperatures below 500 °C. Conversion under these conditions is essentially the result of the pyrolysis of coal, although hydrogen increases the yield of conversion due to the stabilization of radicals and other reactive species. Curtis and his co-workers has shown that highly effective and accessible catalyst are required to achieve high levels of oil production from the coprocessing of coal and heavy residua. In their work, powdered hydrotreating catalyst at high loadings an oil-soluble metal salts of organic acids as catalyst precursors achieved the highest levels of activity for coal conversion and oil production. Red mud which is iron-based catalysed has been used in several co-processing studies. It was used as an inexpensive sulphur sink for the H 2 S evolved to convert Fe into pyrrohotite during coal liquefaction. In this study, Elbistan Lignite (EL) processed with manure using red mud as a catalyst with the range of concentration from 3% to 12%. The main point of using red mud catalyst is to enhance oil products yield of coal liquefaction, which deals with its catalytic activity. On the other hand, red mud acts on EL liquefaction with manure as a catalyst and represents an environmental option to produce lower sulphur content oil products as well.
IOP conference series, Dec 1, 2017
The hydrogenation of coal by molecular hydrogen has not been appreciable unless a catalyst has be... more The hydrogenation of coal by molecular hydrogen has not been appreciable unless a catalyst has been used, especially at temperatures below 500 °C. Conversion under these conditions is essentially the result of the pyrolysis of coal, although hydrogen increases the yield of conversion due to the stabilization of radicals and other reactive species. Curtis and his co-workers has shown that highly effective and accessible catalyst are required to achieve high levels of oil production from the coprocessing of coal and heavy residua. In their work, powdered hydrotreating catalyst at high loadings an oil-soluble metal salts of organic acids as catalyst precursors achieved the highest levels of activity for coal conversion and oil production. Red mud which is iron-based catalysed has been used in several co-processing studies. It was used as an inexpensive sulphur sink for the H 2 S evolved to convert Fe into pyrrohotite during coal liquefaction. In this study, Elbistan Lignite (EL) processed with manure using red mud as a catalyst with the range of concentration from 3% to 12%. The main point of using red mud catalyst is to enhance oil products yield of coal liquefaction, which deals with its catalytic activity. On the other hand, red mud acts on EL liquefaction with manure as a catalyst and represents an environmental option to produce lower sulphur content oil products as well.
Cleaner chemical engineering, Sep 1, 2022
In this study, the ignition delay measurement was determined numerically by using some practical ... more In this study, the ignition delay measurement was determined numerically by using some practical equations. Outboard ignition engines take the fuel-air mixture into the cylinder and compress it. High compression ratio is an important parameter that increases engine efficiency. The compression ratio is kept away from the knock limit, which is also defined by self-ignition of the mixture. The ignition system should be able to initiate combustion without igniting the mixture at the appropriate moment and causing undesired mechanical and thermal stresses. The temperature at the tip of the spark plug at the time of ignition is proportional to the blur of the gauge voltage and usually ranges from 500-800 o C. A well-working flue gas should have a porcelain temperature of less than 500 o C and no more than 850 o C. The temperature at the end of the isolator is crucial for the development of ignition and combustion. Higher tip temperatures, premature ignition, and low temperatures cause spark plug contamination and kicking. Accumulation of unburned or slightly burnt hydrocarbons in the interior of the buoy is indicated as the responsibility of the contamination and therefore the singlet. Hydrocarbon deposits reduce electrical insulation too much over time, preventing the syringe from forming between spark plug nails. In our work, evaluations were made on hydrocarbon deposits in terms of insulator temperature and system self-cleaning temperature and so on.
European journal of technique, Jul 4, 2022
IOP Conference Series: Earth and Environmental Science, 2017
Given the high cost of the tetraline solvent commonly used in liquefaction, the use of manure wit... more Given the high cost of the tetraline solvent commonly used in liquefaction, the use of manure with EL is an important factor when considering the high cost of using tetraline as a hydrogen transfer source. In addition, due to the another cost factor which is the catalyst prices, red mud (commonly used, produced as a byproduct in the production of aluminium) is reduced cost in the work of liquefaction of coal, biomass, even coal combined biomass, corresponding that making the EL liquefaction an agenda for our country is another important factor. Conditions for liquefaction experiments conducted for hydrogen transfer from manure to coal; Catalyst concentration of 9%, liquid/solid ratio of 3/1, reaction time of 60 min, fertilizer/lignite ratio of 1/3, and the reaction temperature of 400 °C, the stirred speed of 400 rpm and the initial nitrogen pressure of 20 bar was fixed. In order to demonstrate the hydrogen, transfer from manure to coal, coal is used solely, by using tetraline (also known as a hydrogen carrier) and distilled water which is not hydrogen donor as a solvent in the co-liquefaction of experiments, and also the liquefaction conditions are carried out under an inert (N2) gas atmosphere. According to the results of the obtained liquefaction test; using tetraline solvent the total liquid product conversion percentage of the oil + gas conversion was 38.3 %, however, the results of oil+gas conversion obtained using distilled water and EL combined with manure the total liquid product conversion percentage was 7.4 %. According to the results of calorific value and elemental analysis, only the ratio of (H/C) atomic of coal obtained by using tetraline increased with the liquefaction of manure and distilled water. The reason of the increase in the amount of hydrogen due to hydrogen transfer from the manure on the solid surface of the coal, and also on the surface of the inner pore of the coal during the liquefaction, brings about the evaluation of the coal as a structure involved in the recycling through the liquefaction plant if it is being installed. As a result of this study, results obtained from oil + gas data shows that when distilled water is used instead of tetraline during liquefaction of EL combined with manure, abundant crude hydrogen transfer takes place not because of using distilled water as a solvent but only with manure considered as a hydrogen sources. Furthermore, while adding manure into coal of liquefaction is also an alternative for current oil production.
Energy, Sep 1, 2019
In this work, the liquefaction of coal and biomass with direct liquefaction strategy was explored... more In this work, the liquefaction of coal and biomass with direct liquefaction strategy was explored. The point of liquefaction is both to utilize a greater amount of the current coal and biomass assets all the more productively and to create an alternative liquid fuel to oil. Along these lines, the procedure parameters must be resolved to expand the liquefaction efficiency. In addition, it is proposed to do the liquefaction efficiency, particularly in the reactant conditions, to expand the measure of oil. Process parameters were controlled by utilizing Factorial Experimental Design technique in the liquefaction procedures. The solid/liquid ratio was changed as 1/2-1/4, the catalyst concentration was 2-6%, the temperature was 375-400 o C and the duration was 30-90 min. Starting nitrogen pressure was set at 30 bar, stirring speed was 400 rpm, coal/biomass proportion was settled at 1/1. Tetralin as a solvent and MoO 3 as catalyst were utilized. Toward the finish of the liquefaction procedure, the total conversions were computed in view of the acquired non-reactive solid (char). As indicated by the outcomes obtained, the most total conversion (81.9%) was acquired at a solid/liquid proportion of 1/2, a catalyst concentration of 2%, a reaction time of 90 min and a reaction temperature of 400°C. In light of total conversions and elective liquid fuel (oil) in the given conditions, the solid/liquid ratio should be taken as 1/2, the catalyst concentration is 2%, the reaction time is 30-90 min and the reaction temperature is 400 °C. The lowest reaction time found, in this study, is the innovative solution for reducing co-liquefaction cost preferred.
DergiPark (Istanbul University), Jan 10, 2022
Genetic studies of the Rhinolophus affinis shown as the source of COVID-19 point to a species fou... more Genetic studies of the Rhinolophus affinis shown as the source of COVID-19 point to a species found primarily in China. It is essential to protect the population of this species in the World in order to prevent the decrease in the population of this species of bats, which plays an essential role in the pollination of plant foods that make up the human food sources because they are used in soup making. The most significant food sources of bats are; insects belonging to Chrysopidae and Hemerobiidae family, Cockroach insects, Dictyopterous and Dipterous insects and mosquitoes creates. For example; The giant brown bat alone can eat between 3000 and 7000 mosquitoes overnight. Bats combat their large populations annually by consuming more than millions of forest and agricultural pests and provide a unique benefit to ecology. Meanwhile, wet areas are also crucial for the continuation of ecological balance and the continuity of insects and bats. Because these areas regularly provide water and insect support, thus having a significant impact on the bat population. Bats are also vital for rainforests. Bats ensure that about 95 percent of the trees in this region reproduce by carrying pollen and seeds.
Journal of Biochemistry and Analytical studies, 2020
Volume 4-Issue 2 clear in logic development, (2) completely transparent in operation, (3) easily ... more Volume 4-Issue 2 clear in logic development, (2) completely transparent in operation, (3) easily to repeat the reported results by other investigators, (4) with high potential in stimulating other sequence-analyzing methods, and (5) very convenientto be used by the majority of experimental scientists (3). " Using graphic approaches to study biological and medical systems can provide an intuitive vision and useful insights for helping analyze complicated relations there in as shown by the eight master pieces of pioneering papers from the then Chairman of Nobel Prize Committee Sture Forsen (see, e.g., [3,4], and many follow-up papers (see, e.g., [5] and a long list paper cited in a comprehensive review [6]) Study Results In Detail The study indicates that hydroxychloroquine and chloroquine are effective in SARS-CoV-2 experimentally. It has also been effective in COVID 19 patients in China. The study was evaluated according to the hydroxychloroquine effect of viral loads of the virus on the respiratory tract. In the study, viral loadings of nasopharyngeals wabs were determined by using 600mg hydroxychloroquine daily between 1-16 March in COVID 19 patients living in France. Azithromycin addition was made depending on their clinical appearance. Patients who
Insights in Biomedicine, 2019
"Earth Overshoot Day" means that we will begin to manage with the foods that are produced in 1 ye... more "Earth Overshoot Day" means that we will begin to manage with the foods that are produced in 1 year in our world on 4 August, which we passed, and only the foods that are stocked in the markets. Albert Einstein tried to draw attention to the use of energy stored in the form of carbohydrates as nutrients in addition to the fertility-enhancing features of the bees, with a question mark from many years ago with the interpretation of "all bees have vanished and humanity has 4 years left." The depletion of the agricultural resources declared on August 4 has turned out to be a threat to humanity.
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2017
ABSTRACT In this study, Elbistan lignite (EL) and manure were liquefied under catalytic condition... more ABSTRACT In this study, Elbistan lignite (EL) and manure were liquefied under catalytic conditions in an inert atmosphere. Red mud, tetralin, and distilled water were used as a catalyst and solvent, respectively. The liquefaction studies were carried out under catalytic conditions in the catalyst concentration of 9%, solvent/solid ratio of 3/1, reaction time of 60 min, waste/lignite ratio of 1/3, and at temperature of 400°C. Stirring speed and initial nitrogen pressure were kept constant at 400 rpm and 20 bar, respectively. At the end of liquefaction process, the soluble liquefaction products were separated by successive solvent extraction to preasphaltene, asphaltene, and oils. Oil products characterized by H-NMR to be able to differ hydrogen transfer from manure to EL surface. To obtain the hydrogen transfer way, liquefaction experiments conducted under inert atmosphere which does not related to hydrogen reaction, other above experimental conditions were kept same but only solvent type changed. The reason of using distilled water instead of tetraline is tetraline known as hydrogen donor but not water. Because water behaves supercritical conditions during the liquefaction stage. EL liquefied alone while using tetraline however EL liquefied with manure with using distilled water as a solvent. The obtained oil products form both experiments characterized by H-NMR. The radical groups diffraction and range values are not changed significantly shows that manure behaved as an hydrogen donor. So, EL with manure is the one great option to reduce cost of hydrogen source for direct coal liquefaction plant.
Interdisciplinary Applications of the Life Cycle Assessment Tool, 2021
Algal Biotechnology for Fuel Applications
It is well known that the use of algae-based fuels is not widespread as theydo not meet the neces... more It is well known that the use of algae-based fuels is not widespread as theydo not meet the necessary fuel standards. The amount of oil products obtained fromtraditional biomass sources exceeds that obtained from algae. However, ecology canprovide more assistance in increasing the current efficiency of oil production fromalgae. Depending on the species, effective results can be obtained through theproduction of fatty acids and biofuels. The amount of fuel produced by a single speciesshould be weighted against the amount of oil produced by a combination of species.The presence of genetic diversity, particularly in two types of algae mixtures, isunavoidable in order to improve the quality of fuel produced. The lipid obtained undergenetically diverse population is highlighted in this study.
Algal Biotechnology for Fuel Applications
This chapter provides basic economic information that readers will needduring the operation phase... more This chapter provides basic economic information that readers will needduring the operation phase before establishing any algae business. The subject has beenreinforced with simple examples.
Algal Biotechnology for Fuel Applications
Large amounts of residues are obtained after lipid extraction whenproducing biodiesel from microa... more Large amounts of residues are obtained after lipid extraction whenproducing biodiesel from microalgae. From these residues, animal feed or bioethanolproduction may be obtained. Another alternative biofuel that can be obtained frommicroalgae biomass residues is bio-oil from pyrolysis or hydrothermal processes. Outof these, microalgae for biofuel production stand out due to the high thermal value ofAlgal biomass of around 24 MJ / kg. The organic components of the biological masscan be thermally decomposed in the production of fuel by thermochemicalapplications, such as direct combustion, gasification, pyrolysis, and liquefaction. Withthe hydrothermal liquefaction process, microalgae are converted into liquid crude oilwith or without a catalyst. The reaction takes place at 280-370 °C and 10-25 MPapressure on wet biomass in water. Biological oil production by hydrothermalliquefaction method from microalgae has gained considerable attention in recent years.Compared to the biodiesel obtai...
Algal Biotechnology for Fuel Applications
Algae have been produced or evaluated as a nutritional supplement inanimal husbandry, rather than... more Algae have been produced or evaluated as a nutritional supplement inanimal husbandry, rather than as an alternative energy source for many years. As aresult of biomass energy research, which has accelerated in recent years with theimpact of rising oil prices, algae have started to be seen as a promising energy source.Despite being successful in laboratory research, pilot, and small-scale experiments, alsocalled third-generation biofuel technologies and aiming to use many algae species innature as an energy source, the desired yield cannot be obtained if ideal processescannot be created in large-scale local productions. In general, algae may contain about15-77% fat although the volume varies by species. Compared to other oil plants, theirhigh oil content and growth efficiency make algae attractive for biodiesel and biogasproduction. The production of these fuels from algae has the potential to respond to theincreasing global energy need and, in part, to contribute to the prevention o...
Algal Biotechnology for Fuel Applications
In order to better evaluate the water potential of our world, we will now takea look at the vario... more In order to better evaluate the water potential of our world, we will now takea look at the various aquatic products that have had a significant impact on the biotechindustry, from research materials to nutritional additives.
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Papers by cemil koyunoğlu