Occurrence of pyrophoric iron immune to chemical washing in vacuum distillation columns

2012 ◽  
Vol 25 (3) ◽  
pp. 604-608 ◽  
Author(s):  
Constantinos Plellis – Tsaltakis
1963 ◽  
Vol 13 (8) ◽  
pp. 329-334
Author(s):  
A. G. Ward ◽  
G. H. Broomfield
Keyword(s):  

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1152
Author(s):  
Le Cao Nhien ◽  
Nguyen Van Duc Long ◽  
Moonyong Lee

Furfural is only derived from lignocellulosic biomass and is an important chemical used in the plastics, agrochemical, and pharmaceutical industries. The existing industrial furfural production process, involving reaction and purification steps, suffers from a low yield and intensive energy use. Hence, major improvements are needed to sustainably upgrade the furfural production process. In this study, the conventional furfural process based on a continuous stirred tank reactor and distillation columns was designed and optimized from an actual aqueous xylose solution via a biomass pretreatment step. Subsequently, a reactive distillation (RD) and extraction/distillation (ED) configuration was proposed for the reaction and purification steps, respectively, to improve the process efficiency. RD can remove furfural instantly from the reactive liquid phase and can separate heavy components from the raw furfural stream, while the ED configuration with toluene and butyl chloride used as extracting solvents can effectively separate furfural from a dilute aqueous stream. The results showed that the hybrid RD-ED process using a butyl chloride solvent saves up to 51.8% and 57.4% of the total investment costs and total annual costs, respectively, compared to the conventional process. Furthermore, environmental impacts were evaluated and compared for all structural alternatives.


2019 ◽  
Vol 36 (1) ◽  
pp. 187-214
Author(s):  
Chao Yang ◽  
Guangsheng Luo ◽  
Xigang Yuan ◽  
Jie Chen ◽  
Yangcheng Lu ◽  
...  

Abstract This paper presents a comprehensive review of the remarkable achievements by Chinese scientists and engineers who have contributed to the multiscale process design, with emphasis on the transport mechanisms in stirred reactors, extractors, and rectification columns. After a brief review of the classical theory of transport phenomena, this paper summarizes the domestic developments regarding the relevant experiments and numerical techniques for the interphase mass transfer on the drop/bubble scale and the micromixing in the single-phase or multiphase stirred tanks in China. To improve the design and scale-up of liquid-liquid extraction columns, new measurement techniques with the combination of both particle image velocimetry and computational fluid dynamics have been developed and advanced modeling methods have been used to determine the axial mixing and mass transfer performance in extraction columns. Detailed investigations on the mass transfer process in distillation columns are also summarized. The numerical and experimental approaches modeling transport phenomena at the vicinity of the vapor-liquid interface, the point efficiency for trays/packings regarding the mixing behavior of fluids, and the computational mass transfer approach for the simulation of distillation columns are thoroughly analyzed. Recent industrial applications of mathematical models, numerical simulation, and experimental methods for the design and analysis of multiphase stirred reactors/crystallizers, extractors, and distillation columns are seen to garnish economic benefits. The current problems and future prospects are pinpointed at last.


2019 ◽  
Vol 19 (7) ◽  
pp. 3108-3122 ◽  
Author(s):  
Yu-Jen Shih ◽  
Syuan-Yao Syu ◽  
Chiu-Wen Chen ◽  
Chih-Feng Chen ◽  
Cheng-Di Dong

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