Delayed Coking. Figure 6.6 shows a flow scheme in a delayed coking progress and a photograph of a delayed coking unit. The s above the drums that contain the drill stems are used to drill out the coke from the coke drums at the end of the coking cycle. ... while coke is removed intermittently in a semi-continuous process scheme ...
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Radical release and evolution during the coking process were studied to improve the understanding of chemical and carbon structural transformation during the coking process. The ESR technique was used to detect unpaired electrons on stable radicals to investigate the structural transformation from the plastic layer to semi-coke during pyrolysis.
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The removal effects of main toxic organic pollutants in semi-coking wastewater by combined treatment process were investigated, while the genotoxicity relevance of wastewater from different treatment units were monitored by using Vicia faba bioassays. Results showed that 37 kinds of toxic organic po …
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Five benzenes, 11 phenols, and five polycyclic aromatic hydrocarbons (PAHs) were investigated as the dominant contaminants in semi-coking wastewater. Because of residual extractant, the phenols extraction process increased acute toxicity to V. fischeri and immobilization and lethal toxicity to D. magna.
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discharge of semi-coking wastewater, and solve its dif-cult degradation and dicult treatment. 2 Experimental Process 2.1 Water Sample Collection The semi-coking wastewater in this paper was col-lected from a semi-coke plant with an annual output of 1 million tons in Shaanxi Province, China. The waste-
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Delayed coking process variables include process operating variables, feedstock properties and engineering variables. ... Typically, coke can be divided into spherical shot coke (isotropic, amorphous, with almost no pores), sponge coke (semi-isotropic), and needle coke (anisotropic, regular crystalline structure, containing numerous fine pores ...
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Materials. The carbon source was semi-coking wastewater acquired from Yulin, Shaanxi, China. The content of phenols in semi-coking wastewater was determined by (National Standard, 2014), and the content was about 3,000 mg L −1 (Wang et al., 2020).The chemicals, including, formaldehyde, ethanol, acetone, potassium hydroxide, and hydrochloric acid, were purchased …
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MODERN DELAYED COKING PROCESS The delayed coker is the only main process in a modern petroleum refinery that is a batch-continuous process. The flow through the tube furnace is continuous. The feed stream is switched between two drums. One drum is on-line filling with coke while the other drum is being steam-stripped, cooled, decoked, pressure
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3.1 The Heating Rate of Coal in Coking Chamber Temperature conditions in a coal charge during coking depend on the location towards heating walls of a coke oven. In general, temperature distribution in a coal charge during coking process is mainly connected with the location towards heating walls and with the time of coking. Three zones have
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As illustrated in Fig. S1, the designed semi-coking wastewater treatment processes of a coking enterprise in Yulin, Shanxi Province, China, consisted of pretreatment, biological treatment and advanced oxidation process with a capacity of ∼3000 m 3 /d. The pretreatment units included an oil-water separator, two ammonia-stripping towers, and a ...
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The removal effects of main toxic organic pollutants in semi-coking wastewater by combined treatment process were investigated, while the genotoxicity relevance of wastewater from different treatment units were monitored by using Vicia faba bioassays. Results showed that 37 kinds of toxic organic pollutants were detected in the crude sewage, most of them were …
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This review examines the technological bottlenecks, potential solutions, and future development directions in the treatment and resource utilization of semi-coking wastewater (SCOW) in China.
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In this paper, five coking coals with different degrees of metamorphism were selected for coking experiments. XPS and HRTEM techniques were used to study the evolution of the carbon structure of the coking coal during the coking process, which provided theoretical support and a practical basis for a more reasonable, efficient, and environmentally friendly use …
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Due to the late emergence of the semi-coke industry, there was no mature treatment process for semi-coke wastewater at home and abroad, and the existing treatment methods were mostly based on coking wastewater with similar water quality [8].At present, semi-coke wastewater treatment usually includes a two-stage process.
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The detailed information about the molecular structure transformation in the thermoplastic stage has not been acquired. Therefore, the insight into and the establishment of the 3D carbon structures of the semi-coke during the coking process is crucial for achieving a comprehensive understanding of the carbon structure evolution.
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Delayed coking is a semi-continuous process in which the heated charge is transferred to large soaking (or coking) drums, which provide the long residence time needed to allow the cracking …
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The degassed coal is semi-coke, it is broken into 3-4mm particle size, and briquetted with binder, then oxidized at 200-300 degrees Celsius to obtain hardened briquette. Finally, the briquette is coked at a temperature higher …
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As seen in Supplementary Figures S1,S2 and Supplementary Table S1, N and S elements in semi-coking wastewater were detected by XRD and GC-MC analysis.Moreover, elemental analysis was employed to investigate the element species and content of the intermediate product NSPR. Supplementary Table S2 illustrates the results, which confirm that …
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In order to address the low thermal efficiency of low-rank coal combustion and the accompanying serious environmental issues, formed coke was prepared using a carbonization consolidation method with low-rank coal …
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Once the temperature of the coal charge exceeds the thermoplastic range, condensation, cross-linking, and repolymerization reactions take place. This results in the …
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All reagents were analytically pure and can be used directly without purification. The wastewater sample was BPSCW collected from a coal chemical plant in Hebei Province. The plant used a "semi-coke wastewater pretreatment + A/O" (Text S1) process to treat semi-coking wastewater. The characteristics of BPSCW were shown in Table S1.
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Semi coke is the solid products, obtained from low-rank bituminous coal, lignite, or peat by carbonization at low temperature (500–750 °C) in a retort furnace. In general, semi coke is also a by-product or intermediate product of the conversion of coal into liquid and gaseous …
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This study employs a combined phenolic condensation-persulfate advanced oxidation technology to treat high-concentration semi-coking wastewater, focusing on …
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Semi-coke is made by charging coal into hot ovens, usually in the temperature range 350-500°C. Layers of plastic coal are formed parallel to the heated oven surfaces and these move …
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This paper provides a review of the state-of-the-art research in the open literature on the carbon structure evolution in the semi-coke region following the last stage of the plastic layer transformation. Coking coals exhibit thermoplastic fluid-like behavior due to the change of chemical structures in plastic layers when heated in the coke ovens. Once the temperature of …
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Light oil (coal), semi-coking process chemical information summary.
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THE METHOD OF MANAGING THE PROCESS OF SEMI-COXING SLASS1A IN A GAS-GENERATOR by adjusting the magnitude of the vacuum by changing the flow rate of the return gas, the temperature in the gas discharge by changing the flow rate of air, the ratio of the flow rate of the return gas and air by changing the flow rate of air, which is different in that, in order to …
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Semantic Scholar extracted view of "Treatment effects and genotoxicity relevance of the toxic organic pollutants in semi-coking wastewater by combined treatment process." ... GC/MS was used to investigate the organic pollutants removal in the activated sludge process for treating coking plant wastewater. A new C 18 mini column was applied for ...
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coking wastewater, but the COD concentration of semi-coking wastewater is approximately 10 times higher, and the concentrations of ammonia nitrogen and phenols are also significantly higher than coking wastewater (Bokun et al., 2020). Semi-coking wastewater is the most harmful type of wastewater due to its high COD and high toxicity (Ma et al.,
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Figure 1 shows the process of treating semi-coking wastewater. The pilot scale process was designed to handle 5–10 t/d of raw semi-coking wastewater. Methyl isobutyl ketone was used as the extractant, whereas the extractant to wastewater volume ratio was 1 to 8, respectively. In addition, the extraction time was 15 min.
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As can be seen from Table 1, with the increase of pyrolysis final temperature, the percentage content of volatile matter, moisture, H, O, and S elements in semi-coking dust gradually decreases.This is because with the increase of temperature, water in lignite evaporates, and lignite structure contains a large number of oxygen-containing functional group structures, …
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carbon structures of the plastic layer change and become solid to form semi-coke [11–13]. ... changes of chemical structures and micro-composition during the coking process. 2. Materials and Methods
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The microbial community consisting of Pseudomonas stutzeri N2 and Rhodococcus qingshengii FF could effectively and simultaneously remove phenols and petroleum hydrocarbons, and these two strains possess great potential of being applied in aerobic biological treatment process of large-scale semi-coking wastewater.
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In this study, the distribution profiles, emission characteristics, and health risks associated with 43 volatile and semi-volatile organic compounds, including 15 phenols, 18 polycyclic aromatic hydrocarbons (PAHs), 6 BTEX, and 4 other compounds, were determined in the wastewater treatment plant (WWTP) of a coking factory (plant C) and the succeeding final …
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Semi-coking wastewater contains a rich source of toxic and refractory compounds. Three-dimensional electro-Fenton (3D/EF) process used CuFe 2 O 4 as heterocatalyst and activated carbon (AC) as particle electrode was constructed for degrading semi-coking wastewater greenly and efficiently. CuFe 2 O 4 nanoparticles were prepared by coprecipitation method and …
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The emergent semi-coking wastewater had the characteristics such as large amounts of discharge, high toxicity, high concentration ammonia nitrogen and chemical oxygen demand (COD), which make it more difficult to treat by biological method (Ailijiang et al., 2021).Phenols and petroleum hydrocarbons with higher concentration were concurrently …
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The variation of biotoxicity in the semi-coking wastewater treatment processes implies that the coagulation and adsorption processes resulted in more efficient biotoxicity …
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The process optimization experiment was carried out by adjusting the dilution multiples of semi-coking wastewater to 20, 50, 100, 200, 500 and 1000, respectively. It can be seen from Fig. 4 b that the removal rates of COD, NH 3 -N and VP continued to increase when diluted 20–200 times, and the removal rate decreased when diluted 200 ∼1000 ...
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