Investigation of factors affecting coke strength after reaction (CSR) and developing a statistical model for CSR prediction

Download
2018
Ünsal, Barış
This study was aimed at investigating the coke strength after reaction (CSR) prediction before coke production by regression modelling. Initially, quality parameters of studied coals, namely Australian, American and Canadian coals, were categorized to understand fluctuation in the parameters. Parameters studied consist of proximate analysis, physical properties, rheological properties, ash chemistry, petrographical analysis and coke quality parameters of the coals. After understanding remarkable difference in coal quality parameters relative to origin, regression analysis was performed for the coals under study. Highly correlated parameters were detected by correlation analysis, performed via Excel and Minitab, considering both Pearson Correlation Coefficient and p - values. Devore states that two variables show strong relationship when correlation coefficient of them is above 0.8. Absolute values of correlation coefficients above 0.8 evaluated as highly correlated. Absolute values of correlation coefficients between 0.6 and 0.8 and p – values below 0.05 also evaluated as highly correlated. Then, best subset analysis was carried out by Minitab to indicate best alternative regression model. Decision of which parameters are included into model was given by evaluating R – square, R – square (adj) and R – square (pred) of best subset analysis model alternatives. For studied Australian, American and Canadian coals, CSR prediction models were developed individually. Categorization and origin base CSR prediction model development studies created the base of CSR prediction model for coal blends. Precision of the models controlled by mean hypothesis and whether residues of model are equal to zero or not was checked. 1 – sample t test, 2 – sample t test and one-way ANOVA test were used for mean hypothesis. In addition, Origin base CSR prediction models were comprised with formulas retrieved from literature. At the end of study, CSR prediction models were developed with 96.5 %, 93.41 %, 86.21 % and 80.99 % R – square for Australian, American, Canadian coals and coal blends respectively.

Suggestions

Characterization and reactivity studies for chemical loop gasification of high sulfur lignites
Kanca, Arzu; Üner, Deniz; Department of Chemical Engineering (2013)
The objective of this study was to characterize and to determine the gasification reactivity of Tuncbilek lignites. The ultimate analysis of Tuncbilek lignite revealed that the elemental composition is 37.7% C, 3.6% H, 1.6% N, and 5.4% S, while the proximate analysis indicated 4.7 ± 0.9% moisture 27.9 ± 0.1% volatiles and 37.9 ± 0.2% ash. In this context, four different reactions during gasification namely, pyrolysis, oxidation, hydrogenation, and wet air oxidation were investigated separately. Carbon resid...
Investigation into Ex-Situ and In-Situ Iodine Doped Plasma Polymerized Fluorene-type Thin Films
Mansuroglu, Dogan; Uzun Kaymak, İlker Ümit (2019-01-01)
Effect of doping is investigated by applying iodine dopant to plasma polymerized fluorene (C13H10)-type thin films utilizing two separate techniques: ex-situ and in-situ doping. In this study, the thin films are produced using a mixture of biphenyl and methane in a capacitively coupled glow plasma system. Produced thin films are characterized using a fourier transform infrared spectrometer, an ultraviolet-visible spectrometer, a scanning electron microscope, and a two-point probe technique of the current - ...
Determination of susceptibility to intergranular corrosion and electrochemical reactivation behaviour of AISI 316L type stainless steel
Aydogdu, G. H.; Aydınol, Mehmet Kadri (2006-11-01)
In this study, double loop electrochemical potentiokinetic reactivation (DLEPR) test was applied to determine the degree of sensitization in 316L type stainless steel, where obtained results were correlated with revealed microstructures after oxalic acid test and weight loss measurements of Streicher and Huey acid tests. Best agreement was provided with test parameters which are 1 M H2SO4 and 0.005 M KSCN at 0.833 mV/s scan rate at 30 degrees C. Specimens were classified structurally as absence of chromium ...
Assessment of Aleatory and Epistemic Uncertainty for Ground-Motion Intensity Measure Prediction in Turkey
Ertuğrul, Zehra (2019-02-01)
In this study, we quantify the reduction in total sigma (sigma(total)) of the Turkish ground-motion predictive models by partially removing the ergodic assumption. By partitioning residuals into four components: repeatable source-specific and site-specific deviations from the population mean as well as site-corrected within-event and source-corrected between-event parts, event-corrected single-station standard deviation (phi(ss)) and source-corrected between-event standard deviation (tau(ss)) models were de...
Performance evaluation of soft copy display systems according to AAPM TG18 protocol
OLĞAR, TURAN; Kamberli, E. (Springer Science and Business Media LLC, 2013-06-01)
The purpose of this study was to evaluate the display performance of the liquid crystal display monitors according to the American association of physicists in medicine task group 18 (AAPM TG18) protocol at prior and after new calibration. We measured minimum and maximum luminance, luminance ratio, luminance and contrast response, luminance angular and spatial dependency, resolution, veiling glare and chromaticity quantitatively for 33 medical displays. Display noise was evaluated only visually. The mean ma...
Citation Formats
B. Ünsal, “Investigation of factors affecting coke strength after reaction (CSR) and developing a statistical model for CSR prediction,” M.S. - Master of Science, Middle East Technical University, 2018.