The influence of sorbent properties and reaction temperature on sorbent attrition, sulfur uptake, and particle sulfation pattern during fluidized-bed desulfurization

2002 ◽  
Vol 174 (11-12) ◽  
pp. 151-169 ◽  
Author(s):  
Fabio Montagnaro ◽  
Piero Salatino ◽  
Fabrizio Scala
Keyword(s):  
Fluidized Bed ◽  
Reaction Temperature ◽  
Sulfation Pattern

Pilot-Scale Study on Improving SNCR Denitrification Efficiency by Using Gas Additives

2018 ◽  
Vol 17 (3) ◽  
Author(s):  
Zhou Weiqing ◽  
Liu Meng ◽  
Huang Baohua ◽  
Qiu Xiaozhi
Keyword(s):  
Low Temperature ◽  
Fluidized Bed ◽  
Reaction Temperature ◽  
Temperature Region ◽  
Circulating Fluidized Bed ◽  
Catalytic Reduction ◽  
Pilot Scale ◽  
Incomplete Oxidation ◽  
Optimal Value

Abstract The experiment of improving Selective Non-Catalytic Reduction (SNCR) denitrification efficiency with gas additives (CH4 and C3H8) was carried out in the 50 kW circulating fluidized bed (CFB) pilot-scale equipment. The results show that the denitrification efficiency can reach 20 % when the reaction temperature is 650 °C, and the optimum mole ratio of C3H8/NH3 is 0.5. The denitrification efficiency can exceed 50 % when the mole ratio of C3H8/NH3 is 0.4 and the reaction temperature is 720 °C. However, the CH4 additive does not promote denitrification at this temperature. When the reaction temperature is 760 °C, the optimum denitrification efficiency of CH4 is 60 %, and the required CH4/NH3 is 0.8. Once the amount of CH4 exceeds the optimal value, the denitrification efficiency is suppressed. In addition, the concentrations of N2O and CO in the gas increase significantly with an increase of gas additives. Due to the incomplete oxidation of C3H8, a large amount of C2H4 is produced in the low-temperature region (< 750 °C) of SNCR.

Catalytic Conversion of Octanoic Acid over HZSM-5 Catalyst

2014 ◽  
Vol 926-930 ◽  
pp. 60-63
Author(s):  
Yi Bin Liu ◽  
Yu Zhen Li ◽  
Xue Ding ◽  
Zhao Jun Chen
Keyword(s):  
Fluidized Bed ◽  
Reaction Temperature ◽  
Octanoic Acid ◽  
Catalytic Conversion ◽  
Fluidized Bed Reactor ◽  
Product Distribution ◽  
Reactor System

Catalytic conversion experiment of octanoic acid over HZSM-5 catalyst was carried out in a fixed fluidized bed reactor system. The effects of reaction temperature and catalyst to oil ratio on product distribution were investigated. The results showed that temperature influenced the LCO, gasoline and CO yields obviously. LCO yield decreased while CO yield increased with increasing reaction temperature. Gasoline yield reached maximum at 450 oC. CO is the major oxygenated product, and the yield increased linearly with increasing catalyst to oil ratio..

Steam Gasification Characteristics of a Pine-Nut Shell in a Thermobalance and a Fluidized Bed Reactor

2005 ◽  
Vol 277-279 ◽  
pp. 637-643 ◽  
Author(s):  
Seon Ah Roh ◽  
Sung Real Son ◽  
Sang Done Kim ◽  
Woon Jae Lee ◽  
Yong Kuk Lee
Keyword(s):  
Partial Pressure ◽  
Fluidized Bed ◽  
Reaction Temperature ◽  
Calorific Value ◽  
Fluidized Bed Reactor ◽  
Steam Gasification ◽  
Diffusion Control ◽  
Exponential Factor ◽  
Pine Nut ◽  
Cold Gas Efficiency

Pyrolysis kinetics of a pine nut shell in a thermo gravimetric analyzer (TGA) and the combustion and steam gasification kinetics of a pine nut shell’s chars in a thermobalance reactor were determined. Also, the steam gasification characteristics of the pine nut shell were determined in a fluidized bed reactor. The maximum pyrolysis reaction rate is obtained at 360oC from the TGA and DTG studies. The activation energy and the pre-exponential factor of the char were determined from the Arrhenius plot based on the shrinking core model. The effects of the reaction temperature (350oC - 950oC) and the O2 partial pressure on the combustion kinetics and that of the steam partial pressure (0.4 - 0.8atm) on the gasification kinetics were determined in a thermobalance reactor. In the combustion reaction, the activation energies and the pre-exponential factors are found to be 21.7 kcal mol-1 at 61.9 s-1atm-1 and 2.36 kcal/mol at 0.0029 s-1atm-1 in the reaction control and the pore-diffusion control regimes, respectively. The reaction order is found to be 1.0 with respect to the O2 partial pressure at 750oC. In the steam gasification reaction, the activation energy and the pre-exponential factor are found to be 16.9 kcal mol-1 at 0.0076s-1atm-1 and 2.67 kcal mol-1 at 0.00036s-1atm-1 in the reaction control and the pore-diffusion control regimes, respectively. The reaction order is found to be 0.77 with respect to the H2O partial pressure at 750oC. The effects of the gas velocity (2Umf - 4Umf), reaction temperature (700oC - 850oC), steam/carbon ratio (0.56 - 1.12) and O2/C ratio (0.16 - 0.32) on the gas composition, gas yield, cold gas efficiency and the calorific value of the product gas were determined in a fluidized bed reactor (10 cm-i.d. × 1.6m-high) with the feeding rate of the pine nut shell of 1 - 3 kg hr-1. The carbon conversion, calorific value, cold gas efficiency and the total product gas yield increased with an increasing temperature. The hydrogen concentration increases with an increasing reaction temperature and the gas velocity and steam/carbon ratio as well as the hydrogen concentration decreases with an increasing O2/C ratio in the fluidized bed reactor.

scholarly journals Catalytic Methanol to Hydrocarbons Transformation Particularities in Case of Micro Structured Flows Application

2022 ◽  
Vol 8 (1) ◽  
pp. 17-24
Author(s):  
R. Brovko ◽  
L. Mushinskii ◽  
V. Doluda
Keyword(s):  
Fluidized Bed ◽  
Reaction Temperature ◽  
Feed Rate ◽  
Average Diameter ◽  
Predominant Formation ◽  
Medium Size ◽  
Scale Production ◽  
Liquid Hydrocarbons ◽  
Monolithic Catalyst ◽  
Methanol Feed Rate

The methanol into hydrocarbons transformation is a complex catalytic reaction accompanied by the formation of a wide range of hydrocarbons and proceeding on the surface of acid sites of various zeolites. Zeolite H-ZSM-5 considered to be most often used catalyst for this process. H-ZSM-5 is a highly dispersed material with a crystal diameter of 1–20 microns, which complicates its direct use in reactors with a fixed catalyst bed due to the high hydraulic pressure drop of the catalytic bed. Traditionally in industry, this issue is solved by using complex reactor systems with a fluidized bed, which is justified for large-scale production. In small and medium-size plants, the use of fluidized bed systems is not economically feasible. One of the possible solutions to this problem is the use of a monolithic catalyst with a supported layer of H-ZSM-5 zeolite. This article presents a study of the catalytic activity of a zeolite-containing microstructured monolith in methanol into hydrocarbons transformation. The monolith was synthesized by pressing a zeolite-containing mass followed by drying, calcining, and secondary growth of the zeolite on the monolith surface. A sample of a monolith with an average channel diameter of 0.5, 1.0, 1.5, 2.0 mm were synthesized this way. Samples of the microstructured catalyst were tested at varying temperatures from 250 to 450 °C and at varying the specific methanol feed rate from 0.65 to 2.3 kg (MeOH)/(kg (Cat) h). For this purpose, the monolithic catalyst was placed in a reactor for testing microstructured catalysts, which consisted of a pump, a temperature controller, a catalytic reactor, a condenser, a separating funnel, and a chromatograph. Varying the conditions showed that for the preferential production of gaseous C1–C4 hydrocarbons, it is advisable to carry out the reaction under the following conditions: the average diameter of the catalyst channels is 2 mm, the reaction temperature is 350 °C, the methanol feed rate is 1.65 kg (MeOH)/(kg (Cat) h). For the predominant formation of liquid hydrocarbons of the C5–C8 fraction, it is advisable to carry out the transformation of methanol into hydrocarbons under the following conditions: the average diameter of the catalyst channels is 1 mm, the reaction temperature is 350 °C, the methanol feed rate is 0.65 kg (MeOH) / (kg (Cat) h). For the predominant formation of liquid hydrocarbons of the C9–C12 fraction, it is advisable to carry out the transformation of methanol into hydrocarbons under the following conditions: the average diameter of the catalyst channels is 0.5 mm, the reaction temperature is 350 °C, and the methanol feed rate is 0.65 kg (MeOH) / (kg (Cat) h).

Catalytic Cracking Law of Recycle Oil over Equilibrium Catalyst

2013 ◽  
Vol 781-784 ◽  
pp. 223-226
Author(s):  
Yi Bin Liu ◽  
Xue Ding ◽  
Wei Li
Keyword(s):  
Fluidized Bed ◽  
Reaction Temperature ◽  
Catalytic Cracking ◽  
Space Time ◽  
Reaction Conditions ◽  
Product Distributions ◽  
Cracking Performance ◽  
Equilibrium Catalyst

Catalytic cracking experiment of recycle oil was carried out in fixed fluidized bed apparatus. The effects of reaction temperature, catalyst to oil ratio and space time on product distributions were investigated. Low conversion of recycle oil was exhibited due to poor cracking performance, moreover, reaction conditions showed obvious influence on gasoline yield.

Thermodynamic Analysis of Hydrogen Production From Coal Char Gasification in Triple-Bed Circulating Fluidized Bed

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xianan Xiang ◽  
Guangcai Gong ◽  
Chenhua Wang ◽  
Ninghua Cai ◽  
Kun Tang ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Reaction Temperature ◽  
Circulating Fluidized Bed ◽  
Combustion Process ◽  
Pyrolysis Process ◽  
Pyrolysis Gas ◽  
Model Studies ◽  
Gasification Process ◽  
Gasification Efficiency ◽  
Gasification Reaction

Abstract The triple-bed circulating fluidized bed gasifier is a new type of the gasification process in which the combustion process, pyrolysis process, and gasification process of the fuel are carried out in different reactors. The inert heat carrier is used to transfer heat between the reactors. In this way, the gasification efficiency of char is improved since the tar and pyrolysis gas generated in the pyrolysis process will no longer hinder the gasification of the char. The thermodynamic equilibrium model is used to simulate the gasification process of the triple-bed circulating fluidized bed, and the sub-models are established to simulate combustion, pyrolysis, and gasification processes. The simulation results agree well with the experimental values. Besides, the model studies the effects of key parameters such as the gasification reaction temperature and the ratio of steam to C (S/C) on gasification performance. Results showed that higher gasification reaction temperature has a positive effect on gasification performance, S/C may not be too high, and excessive water vapor will directly affect the gasification reaction.

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