Methanol to olefins—prediction of the performance of a circulating fluidized-bed reactor on the basis of kinetic experiments in a fixed-bed reactor

1994 ◽  
Vol 49 (24) ◽  
pp. 5377-5390 ◽  
Author(s):  
Hendrik Schoenfelder ◽  
Juergen Hinderer ◽  
Joachim Werther ◽  
Frerich J. Keil
Fuel ◽  
2021 ◽  
Vol 288 ◽  
pp. 119575
Author(s):  
Nassim Bouchoul ◽  
Houcine Touati ◽  
Elodie Fourré ◽  
Jean-Marc Clacens ◽  
Catherine Batiot-Dupeyrat

Author(s):  
Wen-Zhi Lu ◽  
Li-Hua Teng ◽  
Wen-De Xiao

Dimethyl ether (DME) is regarded as an environmentally benign fuel for vehicles. Two kinds of reactor technologies for DME synthesis have been proposed by previous researchers: the fixed-bed and the slurry reactor. As the reactions are highly exothermic and the temperature window of the catalyst is very narrow, the fixed-bed reactor provides a limited heat removal capability and a low conversion of the syngas. The slurry reactor can provide an effective temperature control but a very high inter-phase mass transfer resistance is added by the liquid medium. The Fluidized bed reactor can be an ideal reactor for DME synthesis as it possesses both high heat and mass transfer efficiencies. In this paper, a two-phase model is used to theoretically analyze the DME synthesis in a fluidized bed reactor, with both phases assumed to be in plug flow and taking into account the changes in bubble diameter resulting from the reaction. Three reactions take place simultaneously when DME is manufactured from the syngas (H2 + CO): a) CO+2H2 = CH3OH; b) 2CH3OH = DME+H2O; and c) CO+H2O = CO2+H2. The simulation shows that, at the reactor outlet, the equilibrium approaches of the three reactions are 0.32, 0.1, and 0.61, respectively. When H2/CO=1.0, the CO conversion and DME selectivity in a fluidized bed reactor are 62% and 95%, while those in a fixed-bed reactor are 9% and 86%. In a slurry reactor, the CO conversion and DME selectivity are 17% and 70%, respectively. Therefore, the fluidized-bed is the most promising candidate reactor for conducting the DME synthesis from syngas. Effects of the operating conditions on the performance of DME synthesis in the fluidized-bed reactor are discussed in details. The optimal H2/CO ratio is between 1.0-1.5, and increasing the pressure is shown to improve the reactor performance.


1997 ◽  
Vol 91 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Youchu Li ◽  
Yongqi Lu ◽  
Fengming Wang ◽  
Kai Han ◽  
Wensheng Mi ◽  
...  

1970 ◽  
Vol 46 (3) ◽  
pp. 313-322 ◽  
Author(s):  
ATMK Hasan ◽  
M Mohiuddin ◽  
MB Ahmed ◽  
IJ Poly ◽  
M Asadullah ◽  
...  

The objective of the present work is to install a modified suitable and compatible reactor system for the efficient production of renewable liquid fuel (bio-oil) from agro-based bio-mass. This new type of reactor system contains a combustor connected with the upper end of the reactor chamber. The bottom end of the reactor is connected with the bottom part of the combustor by a stainless steel pipe through which hot sand is circulated by the force of air pump. Thus, effective heat transfer from the continuously circulated heated sand as well as efficient biomass conversion into the reactor can be obtained. In this work, jute stick and bagasse abundantly available in Bangladesh were pyrolyzed separately in a continuous feeding circulating fluidized bed reactor at around 500°C for bio-oil production. The total bio-oil yields from bagasse and jute stick were about 69.5 wt% and 68.2 wt% respectively, which are higher than the yields obtained from fixed bed pyrolysis reactor. The total yields of char contents were 19.4 wt% and 21.7wt% after complete pyrolysis of bagasse and jute stick respectively, which are less than that of char yields obtained from fixed bed pyrolysis reactor. Physical and chemical analyses of bio-oils were carried out by conventional methods. The density, viscosity, pH, acid value, water, lignin, solid and ash contents of bio-oils obtained from both jute stick and bagasse were found to be 1.1 g/cc, 3.1 cp, 4.1, 126.3 mgKOH/g, 14.0 wt%, 2.5wt%, 0.05wt%, 0.03wt%, and 1.12 g/cc, 3.2cp, 4.0, 127.1 mgKOH/g, 13.0 wt%, 2.5wt%, 0.015wt%, 0.025wt%, respectively. Key words: Renewable energy; Bio-mass; Bio-oil; Pyrolysis; Fluid bed circulating reactor DOI: http://dx.doi.org/10.3329/bjsir.v46i3.9036 BJSIR 2011; 46(3): 313-322


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