Petroleum Coke FBC Ash: A Detailed Look at Calcium in the Ash

2003 ◽  
Author(s):  
E. J. Anthony ◽  
L. Jia ◽  
S. M. Burwell
Keyword(s):  
Chemical Analysis ◽  
Sulfur Content ◽  
Petroleum Coke ◽  
Elemental Analysis ◽  
Current Work ◽  
Free Lime ◽  
Lime Content ◽  
Coke Combustion ◽  
Bed Material ◽  
Calcium Compounds

Petroleum coke combustion is different from coal and its behaviour in an FBC environment clearly illustrates this. Analysis of bed ash from the CFBC boilers owned and operated by the Nelson Industrial Steam Company Ltd. (NISCO) was examined in detail to determine the fate of calcium in the ash using a range of techniques. These analyses have shown a free lime content, which is significantly lower than expected based on the elemental analysis of the bed material. Using different methods of analyses than have been typically used for FBC ashes (coal in particular) it would appear that between 6 to 7% of the total CaO in the samples is combined in the form of acid soluble and insoluble other calcium compounds (OCC). This translates to about 30% less free lime (depending on the ash sulfur content) in the sample than would be calculated based on a standard chemical analysis of the bed ash. This current work has identified about 1% of the missing CaO in the form of acid insoluble Ca and Mg vanadates with perhaps as much as 2% of the remaining missing CaO present as soluble OCC.

Understanding the Behavior of Calcium Compounds in Petroleum Coke Fluidized Bed Combustion (FBC) Ash

2006 ◽  
Vol 128 (4) ◽  
pp. 290-299 ◽  
Author(s):  
E. J. Anthony ◽  
L. Jia ◽  
S. M. Burwell ◽  
J. Najman ◽  
E. M. Bulewicz
Keyword(s):  
Particle Size ◽  
Fluidized Bed ◽  
Petroleum Coke ◽  
Bound Water ◽  
Mineral Matter ◽  
Fluidized Bed Combustion ◽  
Free Lime ◽  
Size Fractions ◽  
Lime Content ◽  
Calcium Compounds

With growing understanding of the differences between solid residues from the fluidized bed combustion of petroleum coke and of coal, the significance of fuel-derived and sorbent-derived components of the ash has become clearer. It is well documented that hydration of the ashes is necessary prior to disposal or utilization or as a reactivation method. Initially, hydration of the lime was thought to involve water reacting only with CaO to form Ca(OH)2 but when the free lime content of the ashes is looked at before and after hydration, it is apparent that the process is more complex. Detailed analyses have shown that the free lime can decrease and vary within the same ash in different particle size ranges. The complexity of the reactions is reflected in problems with the assessment of the free lime content of the materials and the effect of hydration on different particle size fractions of the ash. The free lime content of the ash is significantly lower than expected based on the elemental analysis. Bed ash from the circulating fluidized bed combustion boilers owned and operated by the Nelson Industrial Steam Company Ltd. (NISCO) was examined in detail to elucidate the fate of calcium in the ash during hydration, using a range of techniques. The objective of the study is to determine the amount of CaO available for hydration/reactivation and to better understand interactions of Ca and other mineral components of the ash. Analysis results indicate that in NISCO ashes up to about 6% of the analytical CaO may be combined as acid soluble and insoluble OCCs (other calcium compounds). This implies up to about 10% less free lime than would be inferred from standard chemical analyses. About 1% of the missing CaO can be present as acid insoluble Ca and Mg vanadates, with up to 2% bound in soluble OCCs. The remaining 3-4% is still not accounted for. It is clear that even very minor quantities of mineral matter, other than CaO or CaSO4, associated mainly with the coarser size fractions, are important. The amount of bound water in the hydrated ash, other than that combined in portlandite or brucite, can be as large as 3-5%. This cannot be ignored when sample mass change on hydration or heating is used as a measure of the extent of CaO to Ca(OH)2 conversion.

Agglomeration and Fouling in Petroleum Coke-Fired FBC Boilers

1998 ◽  
Vol 120 (4) ◽  
pp. 285-292 ◽  
Author(s):  
E. J. Anthony ◽  
F. Preto ◽  
L. Jia ◽  
J. V. Iribarne
Keyword(s):  
Petroleum Coke ◽  
Alkali Metals ◽  
Size Range ◽  
Current Work ◽  
Industrial Scale ◽  
Specific Level ◽  
Virtual Absence

Experiments have been done subjecting ashes from industrial-scale FBC boilers to sulphating conditions in an oven for up to 105 days. These show that sulphation by itself causes agglomeration in the virtual absence of V, K, and Na, the elements normally associated with ash softening and classical fouling. In addition, it has been demonstrated that sulphation goes to completion over long periods of time and, at a specific level which differs from one ash to another, results in agglomeration. These experiments have also shown that there is a size range (75–300 μm) in which the agglomeration is worst, and particles that are smaller or larger either do not agglomerate or agglomerate more weakly. Added “inert” coal-derived ash decreases or prevents the agglomeration. However, this ash does not appear to chemically combine with the sulphate, but acts by mechanically separating the sulphating particles. Finally, if alkali metals are present they can cause agglomeration at levels lower than those at which either the alkalis or sulphation separately cause agglomeration, i.e., they operate synergistically to cause fouling. Current work is being directed at examining these phenomena at higher temperatures (900°C and above).

scholarly journals Preparation of β-belite using liquid alkali silicates

2017 ◽  
Vol 67 (328) ◽  
pp. 140 ◽  
Author(s):  
P. Koutník
Keyword(s):  
Silica Fume ◽  
Raw Materials ◽  
Mineralogical Composition ◽  
Potassium Silicate ◽  
X Ray Diffraction ◽  
Free Lime ◽  
Burning Temperature ◽  
Lime Content ◽  
Powdered Limestone ◽  
Alkali Silicates

The aim of this study is the preparation of β-belite by a solid-state reaction using powdered limestone, amorphous silica and liquid alkali silicates. The raw materials were blended, the mixtures were agglomerated and then burnt. The resulting samples were characterized by X-ray diffraction analysis and scanning electron microscopy. Free lime content in the β-belite samples was also determined. The effects of CaO/SiO2 ratio (1.6–2.1), burning temperature (800–1400 °C), utilization of different raw materials (silica fume, synthetic silica, potassium silicate, sodium silicate, potassium hydroxide) and burning time (0.5–16 h) on free lime content and mineralogical composition were investigated. The purest ?-belite samples were prepared from a mixture of powdered limestone, silica fume and liquid potassium silicate with a ratio CaO/SiO2 = 2 by burning at temperatures between 1100 and 1300 °C for more than 2 h. Decreasing of the CaO/SiO2 ratio led to rankinite formation and lower a burning temperature led to the formation of wollastonite.

scholarly journals Suggestion Petroleum Coke from Iraq Oil Mix. (T-21A+T-5) & PF2 as Alternative Fuel for Cement and Metallurgy

2021 ◽  
pp. 35-47
Author(s):  
Sherwan Mohammad Simo ◽  
Salah Aldin Naman ◽  
Kanaan Ramadan Ahmed ◽  
Akhmetov Arslan Faritovich ◽  
Lapshin Igor Gennadievich
Keyword(s):  
Sulfur Content ◽  
Petroleum Coke ◽  
Alternative Fuel ◽  
Petroleum Products ◽  
Fuel Oil ◽  
Crude Oils ◽  
Volatile Substances ◽  
High Sulfur Content ◽  
Higher Temperature ◽  
Lower Temperature

The feasibility of utilizing petroleum coke as an alternative fuel for cement kilns and other industries was suggesting. The feedstock using in this study are mixture (T-21A+T-5) Tawke and Shekhan PF2 AT residues were obtained from two Iraqi-Kurdistan crude oils by removing distillates boiling point up to 350°C  using the atmospheric distillation unit. The coking processing of AT residues at high temperatures to produce gas, coking distillates and petroleum coke. Coking of AT residues were carried out at temperature 450-460°C and atmospheric pressure, at this temperature, the duration of heat treatment of the feed was 2h. 45 min for Tawke and 2h. 15 min for Shekhan. The choice of temperature and time of the experiments was made on the basis that a lower temperature increases the duration of the process, and at a higher temperature a significant reduction in the duration of the process according to GOST methods, it becomes difficult to obtain the target product with the required content of volatile substances. An increase in the duration of the coking process about 3 hours and more in all cases leads to a decrease in the content of volatile substances. The study was suggested petroleum coke can be using instead of fuel oil on industry effectiveness in cost reduction when switched over from fuel oil to petroleum coke. in the last of this work, after all the measurements and characteristic obtained, two types of treatment scheme were proposed for how to refine these types of crude oils, which give petroleum products with a high sulfur content. The research proposed the technological, ecological and economic aspects of petroleum coke as fuel, including high sulfur content, use as energy in the electrical field (electro energy), and as an alternative fuel for cement production and metallurgical manufacture.

Fuel Flexibility and Petroleum Coke Combustion at Provence 250 MW CFB

2003 ◽  
Author(s):  
Thierry Le Guevel ◽  
Philippe Thomas
Keyword(s):  
Sulfur Content ◽  
Petroleum Coke ◽  
Heat Exchangers ◽  
Critical Role ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Cfb Boiler ◽  
Fluid Bed ◽  
Low Sulfur Content

The Provence 250 MWe CFB boiler was originally designed in 1992 for a local coal (Provence lignite) with a high sulfur and high ash content. This large CFB, features a pant leg bottom furnace, 4 cyclones and 4 fluid bed heat exchangers to provide the active temperature control of the furnace and reheated steam final temperature. After start up in 1995 with this local coal, several other fuel types were burnt. Mainly 3 fuels were tested over the last 5 years, on a long term basis, with various degrees of combination with the Gardanne coal up to full firing alone: • a lean coal (Gard, France), low volatile bituminous type, not far from semi anthracite type coals, • an imported coal, representative of low ash low sulfur content imported coal, • a petroleum coke, with a high sulfur content. This last test demonstrates the widest flexibility with regards to fuel reactivity range of a CFB plant with this architecture. The fuel, limestone and ash handling/injection systems were able to cope with this fuel diversity without equipment modifications. Since these tests were conclusive both on the pollutant emissions and on the operating concern, a permit to burn petroleum coke in commercial operation in a 250 MWe CFB boiler has been obtained in December 2001. This paper presents the main features and the results of the petroleum coke tests performed and compare them with the feedback on operating conditions of the boiler and emissions performances for Provence lignite and imported coal. These positive results demonstrate the wide fuel capability of large CFB boilers with this boiler architecture. First, they emphasize the critical role of advanced cyclones to accept fuels with very different reactivities and minimize limestone consumption. Second, these results show the role of the Fluid Bed Heat Exchangers system to control actively the furnace temperature, while controlling the reheated steam temperature without using spray.

Utilization of High-Sulfur Petroleum Coke and Sulfur Transfer Behavior

2011 ◽  
Vol 347-353 ◽  
pp. 1637-1641
Author(s):  
Xiao Rui Wang ◽  
Ming Lin Jin ◽  
Hui Cun Qian ◽  
Nan Gao ◽  
Xiao Ming Hou ◽  
...  
Keyword(s):  
High Temperature ◽  
Sulfur Content ◽  
Petroleum Coke ◽  
Boiler Fuel ◽  
Xps Spectra ◽  
Sulfur Transfer ◽  
Recovery System ◽  
Coal Blending ◽  
Transfer Behavior ◽  
Gaseous Sulfur

The presence forms of sulfur in High-sulfur petroleum coke and high temperature transfer was studied in this paper. It was found that a part of sulfur escape in the form of gaseous compounds through heating coke without air. The present structure of sulfide is inferred to be thiophene according to XPS spectra. The scientific calculation for amount of high sulfur petroleum coke can be continued according to the sulfur content of petroleum coke, sulfur transfer agent and permissible content of sulfur in the coke. The gaseous sulfur caused by the high sulfur petroleum coke which is directly used as boiler fuel and coal blending can be recycled through the original sulfur purification recovery system, meanwhile, the purification load rises.

A novel support vector machine ensemble model for estimation of free lime content in cement clinkers

2020 ◽  
Vol 99 ◽  
pp. 479-487 ◽  
Author(s):  
Xiaoyan Liu ◽  
Jiao Jin ◽  
Weining Wu ◽  
Fabian Herz
Keyword(s):  
Support Vector Machine ◽  
Support Vector ◽  
Ensemble Model ◽  
Free Lime ◽  
Lime Content ◽  
Cement Clinkers

Synchrotron-based X-ray absorption spectroscopy study of vanadium redox speciation during petroleum coke combustion and gasification

Fuel ◽  
2018 ◽  
Vol 227 ◽  
pp. 279-288 ◽  
Author(s):  
Marc A. Duchesne ◽  
Jinichiro Nakano ◽  
Yongfeng Hu ◽  
Aimee MacLennan ◽  
James Bennett ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Petroleum Coke ◽  
Spectroscopy Study ◽  
X Ray ◽  
Coke Combustion ◽  
X Ray Absorption ◽  
Vanadium Redox ◽  
Redox Speciation
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