scholarly journals Research on Optimization of Coal Slime Fluidized Bed Boiler Desulfurization Cooperative Operation

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 75
Author(s):  
Yangjian Xiao ◽  
Yudong Xia ◽  
Aipeng Jiang ◽  
Xiaofang Lv ◽  
Yamei Lin ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Sulfur Content ◽  
Flue Gas ◽  
Thermal Efficiency ◽  
Low Cost ◽  
Optimization Strategy ◽  
Two Stage ◽  
Emission Standard ◽  
Desulfurization Process ◽  
Coal Slime

The semi-dry desulfurization of slime fluidized bed boilers (FBB) has been widely used due to its advantages of low cost and high desulfurization efficiency. In this paper, the cooperative optimization of a two-stage desulfurization processes in the slime fluidized bed boiler was studied, and a model-based optimization strategy was proposed to minimize the operational cost of the desulfurization system. Firstly, a mathematical model for the FBB with a two-stage desulfurization process was established. The influences of coal slime elements on combustion flue gas and the factors that may affect the thermal efficiency of the boiler were then analyzed. Then, on the basis of the developed model, a number of parameters affecting the SO2 concentration at the outlet of the slime fluidized bed boiler were simulated and deeply analyzed. In addition, the effects of the sulfur content of coal slime, excess air coefficient, and calcium to sulfur ratio were also discussed. Finally, according to the current SO2 emission standard, the optimization operation problems under different sulfur contents were studied with the goal of minimizing the total desulfurization cost. The results showed that under the same sulfur content, the optimized operation was able to significantly reduce the total desulfurization cost by 9%, consequently improving the thermal efficiency of the boiler, ensuring the stable and up-to-standard emission of flue gas SO2, and thus achieving sustainable development.

scholarly journals Modified Combined Cycle With Pressure Fluidized Bed Combustion Boiler

1992 ◽  
Author(s):  
Jacek Dzierzgowski ◽  
Stanislaw Sobkowski
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Thermal Efficiency ◽  
Combined Cycle ◽  
The Other ◽  
Fluidized Bed Combustion ◽  
Air Stream ◽  
Gas Turbine Compressor

The article describes conversion of conventional steam cycle with 200 MW turbine into combined steam-gas cycle with pressure fluidized bed combustion boiler. In order to raise cycle thermal efficiency an additional combustion chamber before a gas turbine was introduced. Two modifications of the combined cycle were considered. In one of them natural gas in the additional combustion chamber is burnt with the boiler flue gas only. In the other gas is burnt with additional air stream taken from behind the gas turbine compressor. Optimizing calculations of the cycle thermal efficiency in function of some cycle’s main parameters were carried out.

Emission Characteristicsof of PCBs of Combustion of Sludge-Coal Water Slurry in Fluidized Bed

2013 ◽  
Vol 340 ◽  
pp. 382-387 ◽  
Author(s):  
Xiao Li Zhao ◽  
Wei Zhu
Keyword(s):  
Fly Ash ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Circulating Fluidized Bed ◽  
Bottom Ash ◽  
Emission Characteristics ◽  
Emission Standard ◽  
Water Slurry ◽  
Sludge Incineration ◽  
Coal Water Slurry

Sludge-coal water slurry (SCWS) can be produced by mixing coal water slurry (CWS) with sewage sludge according to differenct ratio. This paper focuses on the combustive feasibility of SCWS in a commercial circulating fluidized bed, and on the emission characteristics of polychlorinated biphenyls (PCBs) in flue gas fly ash and bottom ash during combustion of SCWS. The results indicated that incineration can do very well with the temperature 1000 degree, sludge coal water slurry (SCWS) can be effective in improving sludge incineration rate, if the proportion of sludge is 20%~30%,amounts of PCBs is relatively small in flue gas fly ash and bottom ash. So the best burning rate is 20%-30%. Although incineration flue gas fly ash and bottom ash emission standard don't have PCBs regulations, but since PCBs are toxic organic pollutants, it should be strictly regulated.

Application of Disk Aerators to Recarbonation of Alkaline Wastewater from Wet Gasification of Carbide

1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Flue Gas ◽  
Carbonic Acid ◽  
Low Cost ◽  
Flue Gases ◽  
Carbon Dioxide Content ◽  
Patent Claim ◽  
Phase Dispersion

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.

scholarly journals Investigation of the emission control of sulfur trioxide aerosols based on heterogeneous condensation and the deflectors tray of the desulfurization tower

RSC Advances ◽  
2020 ◽  
Vol 10 (63) ◽  
pp. 38515-38523
Author(s):  
Rui Zhang ◽  
Xiaodong Si ◽  
Lingling Zhao ◽  
Linjun Yang ◽  
Hao Wu
Keyword(s):  
Flue Gas ◽  
Sulfur Trioxide ◽  
Emission Control ◽  
Flue Gas Desulfurization ◽  
Heterogeneous Condensation ◽  
Desulfurization Process

In this paper, control over the emission of sulfur trioxide aerosols was investigated based on heterogeneous condensation in the wet flue gas desulfurization process.

scholarly journals Low-Cost Organic Adsorbents for Elemental Mercury Removal from Lignite Flue Gas

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2174
Author(s):  
Marta Marczak-Grzesik ◽  
Stanisław Budzyń ◽  
Barbara Tora ◽  
Szymon Szufa ◽  
Krzysztof Kogut ◽  
...  
Keyword(s):  
Flue Gas ◽  
Low Cost ◽  
Elemental Mercury ◽  
Mercury Content ◽  
Flue Gases ◽  
Mercury Removal ◽  
Gas Purification ◽  
Gas Temperature ◽  
Corn Straw ◽  
Flue Gas Purification

The research presented by the authors in this paper focused on understanding the behavior of mercury during coal combustion and flue gas purification operations. The goal was to determine the flue gas temperature on the mercury emissions limits for the combustion of lignites in the energy sector. The authors examined the process of sorption of mercury from flue gases using fine-grained organic materials. The main objectives of this study were to recommend a low-cost organic adsorbent such as coke dust (CD), corn straw char (CS-400), brominated corn straw char (CS-400-Br), rubber char (RC-600) or granulated rubber char (GRC-600) to efficiently substitute expensive dust-sized activated carbon. The study covered combustion of lignite from a Polish field. The experiment was conducted at temperatures reflecting conditions inside a flue gas purification installation. One of the tested sorbents—tire-derived rubber char that was obtained by pyrolysis—exhibited good potential for Hg0 into Hg2+ oxidation, resulting in enhanced mercury removal from the flue. The char characterization increased elevated bromine content (mercury oxidizing agent) in comparison to the other selected adsorbents. This paper presents the results of laboratory tests of mercury sorption from the flue gases at temperatures of 95, 125, 155 and 185 °C. The average mercury content in Polish lignite was 465 μg·kg−1. The concentration of mercury in flue gases emitted into the atmosphere was 17.8 µg·m−3. The study analyzed five low-cost sorbents with the average achieved efficiency of mercury removal from 18.3% to 96.1% for lignite combustion depending on the flue gas temperature.

scholarly journals Two-stage multi-tasking transform framework for large-scale many-objective optimization problems

2021 ◽  
Author(s):  
Lu Chen ◽  
Handing Wang ◽  
Wenping Ma
Keyword(s):  
Large Scale ◽  
Original Problem ◽  
Optimization Problems ◽  
Reference Points ◽  
Optimization Strategy ◽  
Two Stage ◽  
Decision Space ◽  
Second Stage ◽  
Decision Variables ◽  
Objective Space

AbstractReal-world optimization applications in complex systems always contain multiple factors to be optimized, which can be formulated as multi-objective optimization problems. These problems have been solved by many evolutionary algorithms like MOEA/D, NSGA-III, and KnEA. However, when the numbers of decision variables and objectives increase, the computation costs of those mentioned algorithms will be unaffordable. To reduce such high computation cost on large-scale many-objective optimization problems, we proposed a two-stage framework. The first stage of the proposed algorithm combines with a multi-tasking optimization strategy and a bi-directional search strategy, where the original problem is reformulated as a multi-tasking optimization problem in the decision space to enhance the convergence. To improve the diversity, in the second stage, the proposed algorithm applies multi-tasking optimization to a number of sub-problems based on reference points in the objective space. In this paper, to show the effectiveness of the proposed algorithm, we test the algorithm on the DTLZ and LSMOP problems and compare it with existing algorithms, and it outperforms other compared algorithms in most cases and shows disadvantage on both convergence and diversity.

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