scholarly journals Study on the Predicting Technique of Ash Deposition Tendency in the Entrained-Flow Coal Gasifier. 1st Report. Relationship between Ash Melting Characteristics and Deposition Characteristics.

2001 ◽  
Vol 67 (663) ◽  
pp. 2776-2782 ◽  
Author(s):  
Kazuyoshi ICHIKAWA ◽  
Yuso OKI ◽  
Jun INUMARU ◽  
Masami ASHIZAWA
Keyword(s):  
Ash Deposition ◽  
Entrained Flow ◽  
Coal Gasifier ◽  
Melting Characteristics ◽  
Ash Melting ◽  
Deposition Tendency

Investigation of chemical composition and morphology of ash deposition in syngas cooler of an industrialized two-stage entrained-flow coal gasifier

Energy ◽  
2020 ◽  
Vol 194 ◽  
pp. 116901 ◽  
Author(s):  
Guangyu Li ◽  
Shisen Xu ◽  
Xuebin Zhao ◽  
Ruijin Sun ◽  
Chang’an Wang ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Ash Deposition ◽  
Two Stage ◽  
Entrained Flow ◽  
Coal Gasifier

scholarly journals Effects of temperature and additives on ash transformation and melting of high-alkali-chlorine coal

2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3501-3510
Author(s):  
Jingbin Zi ◽  
Daoyang Ma ◽  
Zia Rahman ◽  
Xuebin Wang ◽  
Hao Li ◽  
...  
Keyword(s):  
Coal Ash ◽  
Ash Deposition ◽  
High Sodium ◽  
Melting Characteristics ◽  
Ash Melting ◽  
Calcium Magnesium ◽  
Effects Of Temperature ◽  
High Alkali ◽  
Main Component ◽  
High Aluminum

The high contents of sodium and chlorine in Shaerhu coal aggravate severe slag-ging ash deposition and corrosion in boilers. Adding proper additives is an effec-tive way to reduce slagging ash deposition and corrosion. Based on the experi-mental study, this paper investigated the effect of combustion temperature, types of additives, and its amount on the ash transformation and melting of high sodium chloride Shaerhu coal. The ash melting characteristics, elemental compositions and mineral compositions of the ash produced under different conditions were characterized. Results showed that the contents of calcium, magnesium, and sul-phur in the coal ash varied slightly with the temperature increasing. Chlorine and sodium released rapidly from coal at 550-815?C and 550-700?C, respectively. At 1050?C, calcium silicate was observed as the main component of the ash. The addition of different additives had no significant effect on chlorine and sodium capture. The addition of silicon species lowered the ash fusion temperatures, while the aluminum had an opposite effect. To prevent the furnace from slagging, a high aluminum additive is proposed to be adopted.

Numerical Simulation of Coal Ash Particle Behavior in Entrained Flow Coal Gasifier

2003 ◽  
Author(s):  
Hiroaki Watanabe ◽  
Kazuyoshi Ichikawa ◽  
Maromu Otaka ◽  
Jun Inumaru
Keyword(s):  
Numerical Simulation ◽  
Gas Phase ◽  
Coal Gasification ◽  
Current Model ◽  
Electric Power Industry ◽  
Central Research ◽  
Ash Deposition ◽  
Entrained Flow ◽  
Coal Gasifier ◽  
Coal Particles

The objective of this study is to develop an evaluation tool for a design and performance of a coal gasifier by a numerical simulation technique. In the present paper, a gas-particle two phase reacting flow calculation is carried out for a prediction of phenomena in an entrained flow coal gasifier due to coal and ash particles behavior, such as ash deposition on the wall. A transportation of the coal particles is modeled via a Lagrangian manner. The ash particle adhesion on the wall of the gasifier is discriminated by an empirical ash adhesion model based on a liquid phase fraction concept in the ash particle. The gas phase properties are calculated by three dimensional time-mean Eulerian conservation equations. The turbulent flow field is determined by the k-ε two equations model. Radiative heat transfer is calculated by the discrete transfer radiation method. Coal gasification reaction model is composed of three chemical processes in the current model: a pyrolysis, a char gasification and gas phase reactions. 2 tons/day (t/d) air-blown pressurized entrained flow coal gasifier, which has been constructed and operated by Central Research Institute of Electric Power Industry (CRIEPI) was targetted. As a result, a relationship between an operating condition (air ratio) of the gasifier and the gasifier performance is presented. The trend of the ash deposition on the gasifier inner wall is also presented. Comparison between the computational and the experimental results shows that the most feature of the gasifier performance and the profile of the ash deposition have been captured by the present model. It was confirmed that the numerical simulation approach is very useful for the assessment of gasifier performance and operation support.

Evaluation of abnormal burner operation in an entrained flow coal gasifier using numerical modeling

2021 ◽  
pp. 116859
Author(s):  
Joonyeong Nam ◽  
Mukyeong Kim ◽  
Geun Sohn ◽  
Changkook Ryu ◽  
Bongkeun Kim ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Entrained Flow ◽  
Coal Gasifier ◽  
Burner Operation

scholarly journals Markov Chain Simulation of Coal Ash Melting Point and Stochastic Optimization of Operation Temperature for Entrained Flow Coal Gasification

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4245
Author(s):  
Zhang ◽  
Guan ◽  
Hou ◽  
Zhang ◽  
Li ◽  
...  
Keyword(s):  
Markov Chain ◽  
Melting Point ◽  
Stochastic Programming ◽  
Optimization Model ◽  
Coal Gasification ◽  
Coal Ash ◽  
Entrained Flow ◽  
Sample Data ◽  
Ash Melting ◽  
Mc Simulation

In the entrained flow coal gasification process, the gas production is critically affected by the operating temperature (OT) and coal ash melting point (AMP), and the AMP is one of key factors for the determinations of OT. Considering the fact that coal is a typical nonhomogeneous substance and the coal ash composition varies from batch to batch, this paper proposes the application of the Markov Chain (MC) method in simulation of the random AMP series and the stochastic optimization of OT based on MC simulation for entrained flow coal gasification. The purpose of this paper is to provide a more accurate optimal OT decision method for entrained flow coal gasification practice. In this paper, the AMP was regarded as a random variable, and the random process method, Markov Chain, was used to describe the random AMP series of feed coal. Firstly, the MC simulation model about AMP was founded according to an actual sample data, 200 sets of AMP data from an industrial gasification plant under three simulation schemes (the sample data were individually divided into 16, eight and four state groups,). The comparisons between the simulation results and the actual values show that the founded MC simulation model descries the AMP series very well. Then, a stochastic programming model based on MC simulation for OT optimization was developed. Finally, this stochastic programming optimization model was optimized by genetic algorithm (GA). Comparing with the conventional OT optimization method, the proposed stochastic OT optimization model integrated MC simulation can ascertain a more accurate OT for guiding the coal gasification practice.

scholarly journals Experimental Investigation of Ash Deposit Behavior during Co-Combustion of Bituminous Coal with Wood Pellets and Empty Fruit Bunches

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2087 ◽  
Author(s):  
Tae-Yong Jeong ◽  
Lkhagvadorj Sh ◽  
Jong-Ho Kim ◽  
Byoung-Hwa Lee ◽  
Chung-Hwan Jeon
Keyword(s):  
Melting Temperature ◽  
Power Plants ◽  
Bituminous Coal ◽  
Coal Ash ◽  
Milling Process ◽  
Drop Tube ◽  
Ash Deposition ◽  
Wood Pellets ◽  
Empty Fruit Bunches ◽  
Ash Melting

In Korea, oil-palm empty fruit bunches (EFBs), which are byproducts of the crude palm-oil milling process, are among the most promising potential energy sources for power plants. However, the slagging and fouling characteristics of EFBs during combustion have not yet been fully studied. Accordingly, in this study, we investigated the fundamental ash behavior of EFBs in comparison to that of wood pellets (WPs) using a thermomechanical analyzer (TMA) and a drop-tube furnace (DTF). Ash melting and the deposition of ash particles were investigated with traditional prediction indices at several biomass blending ratios. The results demonstrated that, as the ratio of WPs to EFBs increases, the melting temperature decreases and the slagging propensity increases because of the increased biomass alkali content. Moreover, the penetration derived using the TMA shows a higher melting peak at which rapid melting occurs, and the melting temperature distribution is decreased with increased biomass blending. Conversely, the DTF results show different phenomena for ash deposition under the same blending conditions. Blend ratios approaching 10% WP and 15% EFB result in gradual decreases in ash deposition tendencies because of the lower ash contents of the co-combusted mass compared to that of the single coal ash. Further biomass addition increases ash deposition, which is attributable to ash agglomeration from the biomass. Thus, this study demonstrates that blending ratios of 10% WP and 15% EFB provide optimal conditions for co-combustion with the selected bituminous coal. In addition, it is shown that the slagging propensity of EFB is higher than that of WP owing to its ash content and simultaneous agglomeration.

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