Chemical Equilibrium Prediction on Release of Na,K,Cl and S-Species during Gasification of Biomass, Soft and Hard Chinese Coal at Elevated Temperature and Pressure by Fact Sage

2013 ◽  
Vol 634-638 ◽  
pp. 723-730 ◽  
Author(s):  
Gul E Rana Jaffri ◽  
Ke Fa Cen ◽  
Zhi Hua Wang
Keyword(s):  
Elevated Temperature ◽  
Power Plants ◽  
Combustion Process ◽  
Severe Problem ◽  
Gas Cleaning ◽  
Saw Dust ◽  
Temperature And Pressure ◽  
Chinese Coal ◽  
Cleaning Technology ◽  
Hot Gas Cleaning

The release of alkali species can cause of severe problem of hot corrosion during gasification especially at high temperature and pressure. The direct use of coal may harmful for power plants. The aim of work to obtained comprehensive knowledge prior utilization of coal. Therefore, thermodynamic equilibrium calculations were performed by Fact Sage 5.2 and simulated the gasification environment at elevated temperature and pressure. Four hard and soft Chinese coal such as Yungui (Vad<6.6%), Xiao Tun(Vad<11.1), Datong (Vad <23.18), Ping Zhuan (Vad<31.84) ,and Saw dust (Vad<68.80) and Saw dust char (Vad<3.39) belongs to anthracite, Sub-bituminous, lignite, biomass and biomass char were selected and releasing order was calculated by plotting mole fraction of each species Vs temperature (1000 to 1400°C) at 1 bar and VS pressure (5 to 15bar ) at 1000°C. On the basis of predicted releasing order the H2S species can be predicted most stable species for gasification at elevated temperature and pressure. The high released amount of SO2, H2S, NaCl, KCl and HCl was obtained for YUN, DAT,SAD and SADChar at (1400°C-1000°C) temperature and (15-5bar) pressure. Comparing with high pressure the predicted release of KCl and HCl was observed higher but SO2, H2S, and NaCl release was found lower than elevated temperature during combustion process. The above available predicted information is valuable for development of hot gas cleaning technology.

New Energy Development and Energy Chemical Engineering (Topic Field) Released of Alkali Species under High Pressure Gasification of Pakistani Coal

2015 ◽  
Vol 1094 ◽  
pp. 141-145
Author(s):  
Gul E Rana Jaffri ◽  
Syed Ali Rehan Shah Jaffri
Keyword(s):  
High Pressure ◽  
Power Plants ◽  
Chemical Engineering ◽  
Elevated Pressure ◽  
Severe Problem ◽  
Gas Cleaning ◽  
Gasification Process ◽  
Inorganic Species ◽  
Cleaning Technology ◽  
Hot Gas Cleaning

Inorganic species are released during pressurized gasification, can cause severe problem of hot corrosion. The direct utilization of coal is harmful for power plants. The aim of work to obtained comprehensive knowledge of release alkali species Na-,K-,Cl and S-species prior to carry out experiment. Therefore thermodynamic equilibrium calculations were performed by Fact Sage 5.2 and simulated the gasification environment at elevated pressure.Three soft Pakistani coal such as Lakhra (Vad < 41.44%), Thar (Vad < 42.02%) and Sor-range ((Vad < 21.11%) belong to Lignite and sub-bituminous coal were selected and releasing order was calculated by plotting mole fraction of each species Vs pressure (5 to 15bar ) at 1000°C.On the basis of predicted releasing order the H2S can be predicted most stable species under gasification at elevated pressure. The high released amount of SO2, H2S, NaCl, KCl and HCl was predicted for LKH and SRC at 5 and 15 bar pressure and 1000°C temperature. Comparing with high pressure the predicted released of H2S was found higher than SO2, NaCl, KCl and HCl at 15 bar pressure while the released of SO2was observed lower than H2S, NaCl, KCl and HCl at 5 bar pressure during gasification process. The above available predicted information is valuable for hot gas cleaning technology.

Energy Chemical Engineering (Topic Field) Simulation for Influence of High Pressure on Release of Inorganic Species during Combustion of Pakistani Coal

2014 ◽  
Vol 1008-1009 ◽  
pp. 328-331 ◽  
Author(s):  
Gul E Rana Jaffri
Keyword(s):  
High Pressure ◽  
Chemical Engineering ◽  
Combustion Process ◽  
Elevated Pressure ◽  
Thermal Conversion ◽  
Gas Cleaning ◽  
Stable Species ◽  
Inorganic Species ◽  
Cleaning Technology ◽  
Hot Gas Cleaning

The inorganic species are highly volatile, released during thermal conversion process and especially at high pressure combustion leads to several problems of fouling, slagging and corrosion when they reach the colder part of plant. The comprehensive knowledge of release alkali species Na-,K-,Cl and S-species is required prior to carry out experiment. Therefore thermodynamic equilibrium calculations were performed by Fact Sage 5.2 and simulated the combustion environment at elevated pressure. Three soft Pakistani coal such as Lakhra (Vad < 41.44%), Thar (Vad < 42.02%) and Sor-range ((Vad < 21.11%) belong to Lignite and sub-bituminous coal were selected and releasing order was calculated by plotting mole fraction of each species VS pressure (5 to 15bar ) at 1000°C. On the basis of predicted releasing order the SO2 can be predicted most stable species under combustion at elevated pressure. The high released amount of SO2, H2S, NaCl, KCl and HCl was predicted for LKH, THC and SRC at 5 and 15 bar pressure and 1000°C temperature.Comparing with high pressure the predicted released of SO2 was found higher than H2S, NaCl, KCl and HCl at 5 bar pressure while the released of H2S was observed lower than SO2, NaCl, KCl and HCl at 15 bar pressure during combustion process. The above available predicted information is valuable for hot gas cleaning technology.

scholarly journals Quality assessment of gas produced from different types of biomass pellets in gasification process

2019 ◽  
Vol 38 (2) ◽  
pp. 406-416 ◽  
Author(s):  
Marcel Mikeska ◽  
Jan Najser ◽  
Václav Peer ◽  
Jaroslav Frantík ◽  
Jan Kielar
Keyword(s):  
Gas Turbines ◽  
Combustion Engine ◽  
Calorific Value ◽  
Internal Combustion ◽  
Combustion Gas ◽  
Gas Cleaning ◽  
Gasification Process ◽  
Different Types ◽  
Before And After ◽  
Cleaning Technology

Gas from the gasification of pellets made from renewable sources of energy or from lower-quality fuels often contains a number of pollutants. This may cause technical difficulties during the gas use in internal combustion gas engines used for energy and heat cogeneration. Therefore, an adequate system of gas cleaning must be selected. In line with such requirements, this paper focuses on the characterization and comparison of gases produced from different types of biomass during gasification. The biomass tested was wood, straw, and hay pellets. The paper gives a detailed description and evaluation of the measurements from a fix-bed gasifier for the properties of the produced gases, raw fuels, tar composition, and its particle content before and after the cleaning process. The results of elemental composition, net calorific value, moisture, and ash content show that the cleaned gases are suitable for internal combustion engine-based cogeneration systems, but unsuitable for gas turbines, where a different cleaning technology would be needed.

scholarly journals Characterization of Austenitic Stainless Steels with Regard to Environmentally Assisted Fatigue in Simulated Light Water Reactor Conditions

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 307
Author(s):  
Matthias Bruchhausen ◽  
Gintautas Dundulis ◽  
Alec McLennan ◽  
Sergio Arrieta ◽  
Tim Austin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Fatigue Life ◽  
Elevated Temperature ◽  
Strain Rate ◽  
Power Plants ◽  
Research Effort ◽  
Hold Time ◽  
Strain Range ◽  
Austenitic Steels ◽  
Mean Strain

A substantial amount of research effort has been applied to the field of environmentally assisted fatigue (EAF) due to the requirement to account for the EAF behaviour of metals for existing and new build nuclear power plants. We present the results of the European project INcreasing Safety in NPPs by Covering Gaps in Environmental Fatigue Assessment (INCEFA-PLUS), during which the sensitivities of strain range, environment, surface roughness, mean strain and hold times, as well as their interactions on the fatigue life of austenitic steels has been characterized. The project included a test campaign, during which more than 250 fatigue tests were performed. The tests did not reveal a significant effect of mean strain or hold time on fatigue life. An empirical model describing the fatigue life as a function of strain rate, environment and surface roughness is developed. There is evidence for statistically significant interaction effects between surface roughness and the environment, as well as between surface roughness and strain range. However, their impact on fatigue life is so small that they are not practically relevant and can in most cases be neglected. Reducing the environmental impact on fatigue life by modifying the temperature or strain rate leads to an increase of the fatigue life in agreement with predictions based on NUREG/CR-6909. A limited sub-programme on the sensitivity of hold times at elevated temperature at zero force conditions and at elevated temperature did not show the beneficial effect on fatigue life found in another study.

scholarly journals Co-Combustion Studies of Low-Rank Coal and Refuse-Derived Fuel: Performance and Reaction Kinetics

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3796
Author(s):  
Mudassar Azam ◽  
Asma Ashraf ◽  
Saman Setoodeh Setoodeh Jahromy ◽  
Sajjad Miran ◽  
Nadeem Raza ◽  
...  
Keyword(s):  
Activation Energy ◽  
Waste Management ◽  
Energy Demand ◽  
Power Plants ◽  
Combustion Process ◽  
Isoconversional Methods ◽  
Low Rank ◽  
Heating Rates ◽  
Average Activation Energy ◽  
Refuse Derived Fuel

In connection to present energy demand and waste management crisis in Pakistan, refuse-derived fuel (RDF) is gaining importance as a potential co-fuel for existing coal fired power plants. This research focuses on the co-combustion of low-quality local coal with RDF as a mean to reduce environmental issues in terms of waste management strategy. The combustion characteristics and kinetics of coal, RDF, and their blends were experimentally investigated in a micro-thermal gravimetric analyzer at four heating rates of 10, 20, 30, and 40 °C/min to ramp the temperature from 25 to 1000 °C. The mass percentages of RDF in the coal blends were 10%, 20%, 30%, and 40%, respectively. The results show that as the RDF in blends increases, the reactivity of the blends increases, resulting in lower ignition temperatures and a shift in peak and burnout temperatures to a lower temperature zone. This indicates that there was certain interaction during the combustion process of coal and RDF. The activation energies of the samples were calculated using kinetic analysis based on Kissinger–Akahira–Sunnose (KAS) and Flynn–Wall–Ozawa (FWO), isoconversional methods. Both of the methods have produced closer results with average activation energy between 95–121 kJ/mol. With a 30% refuse-derived fuel proportion, the average activation energy of blends hit a minimum value of 95 kJ/mol by KAS method and 103 kJ/mol by FWO method.

scholarly journals A large fixed bed reactor for MRI operando experiments at elevated temperature and pressure

2021 ◽  
Vol 92 (4) ◽  
pp. 043711
Author(s):  
Harm Ridder ◽  
Christoph Sinn ◽  
Georg R. Pesch ◽  
Jan Ilsemann ◽  
Wolfgang Dreher ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Temperature And Pressure

Corrosion Rate Measurement by Hydrogen Effusion In Dynamic Aqueous Systems At Elevated Temperature and Pressure

CORROSION ◽  
1959 ◽  
Vol 15 (4) ◽  
pp. 29-32
Author(s):  
M. KRULFELD ◽  
M. C. BLOOM ◽  
R. E. SEEBOLD
Keyword(s):  
Elevated Temperature ◽  
Corrosion Rate ◽  
Flow Velocity ◽  
High Flow ◽  
Low Flow ◽  
Aqueous Systems ◽  
Effusion Rates ◽  
Temperature And Pressure ◽  
Effusion Method ◽  
Hydrogen Effusion

Abstract A method of applying the hydrogen effusion method to the measurement of corrosion rates in dynamic aqueous systems at elevated temperature and pressure is described. Data obtained in low carbon steel systems are presented, including (1) reproducibility obtained in measured hydrogen effusion rates at a flow velocity of 1 foot per second at a temperature of 600 F and 2000 psi, and (2) a quantitative comparison between the hydrogen effusion rates in static and in low flow velocity dynamic systems at this temperature and pressure. Some observations are included on corrosion rate measurements in a high flow velocity (30 feet per second) loop by the hydrogen effusion method. Implications of these measurements with regard to the comparison between high flow velocity corrosion and low flow velocity corrosion are mentioned and some data indicating high local sensitivity of the hydrogen effusion method are noted. Some possible difficulties involved in the method are pointed out. 2.3.4

Evaluation of Si Coating on Ferritic Steels by CVD-FBR Technology in Steam Oxidation

2009 ◽  
Vol 289-292 ◽  
pp. 413-420 ◽  
Author(s):  
F.J. Bolívar ◽  
L. Sánchez ◽  
M.P. Hierro ◽  
F.J. Pérez
Keyword(s):  
Power Plants ◽  
Protective Coatings ◽  
Steam Oxidation ◽  
Steam Turbines ◽  
X Ray Diffraction ◽  
Steam Power ◽  
Factors Affecting ◽  
Steam Power Plants ◽  
Temperature And Pressure ◽  
Major Factors

The development of new power generation plants firing fossil fuel is aiming at achieving higher thermal efficiencies of the energy conversion process. The major factors affecting the efficiency of the conventional steam power plants are the temperature and, to a lesser extent, the pressure of the steam entering the turbine. The increased operating temperature and pressure require new materials that have major oxidation resistance. Due to this problem, in the last years numerous studies have been conducted in order to develop new coatings to enhance the resistance of steels with chromium contents between 9 and 12% wt against steam oxidation in order to allow operation of steam turbines at 650 0C. In this study, Si protective coatings were deposited by CVD-FBR on ferritic steel P-91. These type of coatings have shown to be protective at 650 0C under steam for at least 3000 hours of laboratory steam exposure under atmospheric pressure. Morphology and composition of coatings were characterized by different techniques, such as scanning electron microscopy (SEM), electron probe microanalysis, and X-ray diffraction (XRD). The results show a substantial increase of steam oxidation protection afforded by Si coating by CVD-FBR process.

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