scholarly journals Comparison of Flotation and Screening as Separation Method in Coal Recovery From Tailings by Agglomeration

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Özüm YAŞAR ◽  
Tuncay USLU

Dependency of Turkey on foreign energy adversely affects the economy of the country and may cause energy shortage in the near future. As a primary domestic energy source, coal is used for energy production in addition to imported oil and gas. However, significantamount of fine coal is lost together with tailings in coal washeries. Recovering of fine coals from these tailings will make an economiccontribution to country. In the present study, fine coals were recovered from tailings of a coal washery in Turkey by using oil agglomeration method. Flotation was used in agglomerate separation stage of oil agglomeration. Results were compared with that of previousstudy in which agglomerates were recovered by screening. The performance of the process increased sharply when flotation was usedinstead of screening in agglomerate separation stage. A clean coal with 28% ash was recovered from the washery tailings containing55% ash by 85% combustible recovery.

2018 ◽  
Vol 327 ◽  
pp. 29-42 ◽  
Author(s):  
Özüm Yaşar ◽  
Tuncay Uslu ◽  
Ercan Şahinoğlu

2019 ◽  
Author(s):  
Anders Andreasen

In this article the optimization of a realistic oil and gas separation plant has been studied. Two different fluids are investigated and compared in terms of the optimization potential. Using Design of Computer Experiment (DACE) via Latin Hypercube Sampling (LHS) and rigorous process simulations, surrogate models using Kriging have been established for selected model responses. The surrogate models are used in combination with a variety of different evolutionary algorithms for optimizing the operating profit, mainly by maximizing the recoverable oil production. A total of 10 variables representing pressure and temperature various key places in the separation plant are optimized to maximize the operational profit. The optimization is bounded in the variables and a constraint function is included to ensure that the optimal solution allows export of oil with an RVP < 12 psia. The main finding is that, while a high pressure is preferred in the first separation stage, apparently a single optimal setting for the pressure in downstream separators does not appear to exist. In the second stage separator apparently two different, yet equally optimal, settings are revealed. In the third and final separation stage a correlation between the separator pressure and the applied inlet temperature exists, where different combinations of pressure and temperature yields equally optimal results.<br>


Author(s):  
Kau-Fui Vincent Wong ◽  
Guillermo Amador

As society continues advancing into the future, more energy is required to supply the increasing population and energy demands. Unfortunately, traditional forms of energy production through the burning of carbon-based fuels are dumping harmful pollutants into the environment, resulting in detrimental, and possibly irreversible, effects on our planet. The burning of coal and fossil fuels provides energy at the least monetary cost for countries like the US, but the price being paid through their negative impact of our atmosphere is difficult to quantify. A rapid shift to clean, alternative energy sources is critical in order to reduce the amount of greenhouse gas emissions. For alternative energy sources to replace traditional energy sources that produce greenhouse gases, they must be capable of providing energy at equal or greater rates and efficiencies, while still functioning at competitive prices. The main factors hindering the pursuit of alternative sources are their high initial costs and, for some, intermittency. The creation of electrical energy from natural sources like wind, water, and solar is very desirable since it produces no greenhouse gases and makes use of renewable sources—unlike fossil fuels. However, the planning and technology required to tap into these sources and transfer energy at the rate and consistency needed to supply our society comes at a higher price than traditional methods. These high costs are a result of the large-scale implementation of the state-of-the-art technologies behind the devices required for energy cultivation and delivery from these unorthodox sources. On the other hand, as fossil fuel sources become scarcer, the rising fuel costs drive overall costs up and make traditional methods less cost effective. The growing scarcity of fossil fuels and resulting pollutants stimulate the necessity to transition away from traditional energy production methods. Currently, the most common alternative energy technologies are solar photovoltaics (PVs), concentrated solar power (CSP), wind, hydroelectric, geothermal, tidal, wave, and nuclear. Because of government intervention in countries like the US and the absence of the need to restructure the electricity transmission system (due to the similarity in geographical requirements and consistency in power outputs for nuclear and traditional plants), nuclear energy is the most cost competitive energy technology that does not produce greenhouse gases. Through the proper use of nuclear fission electricity at high efficiencies could be produced without polluting our atmosphere. However, the initial capital required to erect nuclear plants dictates a higher cost over traditional methods. Therefore, the government is providing help with the high initial costs through loan guarantees, in order to stimulate the growth of low-emission energy production. This paper analyzes the proposal for the use of nuclear power as an intermediate step before an eventual transition to greater dependence on energy from wind, water, and solar (WWS) sources. Complete dependence on WWS cannot be achieved in the near future, within 20 years, because of the unavoidable variability of these sources and the required overhaul of the electricity transmission system. Therefore, we look to nuclear power in the time being to help provide predictable power as a means to reduce carbon emissions, while the other technologies are refined and gradually implemented in order to meet energy demand on a consistent basis.


2012 ◽  
Vol 41 ◽  
pp. 80-85 ◽  
Author(s):  
Xianbiao Bu ◽  
Weibin Ma ◽  
Huashan Li

1991 ◽  
Vol 28 (01) ◽  
pp. 39-45
Author(s):  
Edward E. Horton

As oil exploration and production moves farther offshore, innovative technology is required to exploit energy resources in ever deeper waters. This paper covers two areas of deepwater production: offshore Brazil and the Gulf of Mexico. The types of wells and their capacity are described as well as the alternative platform designs, both fixed and semisubmersible, being used to recover both oil and gas from depths greater than 1500 ft. The paper outlines why these deepwater regions are of interest now and describes developments that are expected in the near future.


2016 ◽  
Vol 8 (10) ◽  
pp. 165 ◽  
Author(s):  
John Vourdoubas ◽  
Vasiliki K. Skoulou

<p>The landfill gas (LFG) produced from the existing landfill site in Heraklion city, Crete island, Greece, is not currently exploited to its full potential. It could however be exploited for power generation and/or combined heat and power (CHP) production in near future by fully unlocking its energy production potential of the gas generated from the landfill site. This gas (LFG) could feed a 1.6 MW<sub>el</sub> power plant corresponding to the 0.42% of the annually consumed electricity in Crete. The LFG utilization for power generation and CHP production has been studied, and the economics of three energy production scenarios have been calculated. An initial capital investment of 2.4 to 3.2 M €, with payback times (PBT) of approximately 3.5 to 6 years and Net Present Values (NPV) ranging between 2 to 6 M € have been calculated. These values prove the profitability of the attempt of bioenergy production from the biogas produced from the existing landfill site in Heraklion city, Crete. Based on the current economic situation of the country, any similar initiative could positively contribute to strengthening the economy of local community and as a result the country, offering several other socioeconomic benefits like e.g. waste minimization, creation of new job positions etc. by increasing, at the same time, the Renewable Energy Sources (RES) share in energy production sector etc. Apart from the favorable economics of the proposed waste to energy production scheme, all the additional environmental and social benefits make the attempt of a near future exploitation of the landfill gas produced in Heraklion, an attractive short term alternative for waste to bio-energy production.</p>


2020 ◽  
Vol 4 (1) ◽  
pp. 11
Author(s):  
Anders Andreasen

In this article, the optimization of a realistic oil and gas separation plant has been studied. Using Latin Hypercube Sampling (LHS) and rigorous process simulations, surrogate models using Kriging have been established for selected model responses. The surrogate models are used in combination with an evolutionary algorithm for optimizing the operating profit, mainly by maximizing the recoverable oil production. A total of 10 variables representing pressure and temperature at various key places in the separation plant are optimized to maximize the operational profit. The optimization is bounded in the variables and a constraint function is included to ensure that the optimal solution allows export of oil with a Reid Vapor Pressure (RVP) < 12 psia. The main finding is that, while a high pressure is preferred in the first separation stage, apparently a unique optimal setting for the pressure in downstream separators does not appear to exist. In the second stage separator, apparently different, yet more or less equally optimal, settings are revealed. In the third and final separation stage a correlation between the separator pressure and the applied inlet temperature exists, where different combinations of pressure and temperature yields equally optimal results.


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