scholarly journals Factors Influencing Gas Generation Behaviours of Lump Coal Used in COREX Gasifier

2019 ◽  
Vol 38 (2019) ◽  
pp. 30-41
Author(s):  
Runsheng Xu ◽  
Jianliang Zhang ◽  
Wei Wang ◽  
Haibin Zuo ◽  
Zhengliang Xue

AbstractThe influences of coal rank, particle size, temperature and gasifier atmosphere on the gas generation of lump coals used in COREX gasifier were investigated. The results showed that an increase in gasifier temperature and a decrease in particle size hardly affected the final mass loss of lump coals but strongly enhanced the gas generation rate. When the temperature was greater than 1000 °C, a decrease in coal rank increased the gas yield but had little effect on the gas generation rate. Moreover, the promotion ability of the atmosphere for the gas generation rate of lump coal from low to high was as follows: N2, CO2, CO and H2. Considering energy conservation, to improve the gas generation rate of the gasifier, the coal rank and particle size should be decreased first, and afterwards, an increase in reduction potential of the atmosphere in gasifier is also encouraged.

2018 ◽  
Vol 9 ◽  
pp. 2432-2442 ◽  
Author(s):  
Malkeshkumar Patel ◽  
Joondong Kim

Co3O4 has been widely studied as a catalyst when coupled with a photoactive material during hydrogen production using water splitting. Here, we demonstrate a photoactive spinel Co3O4 electrode grown by the Kirkendall diffusion thermal oxidation of Co nanoparticles. The thickness-dependent structural, physical, optical, and electrical properties of Co3O4 samples are comprehensively studied. Our analysis shows that two bandgaps of 1.5 eV and 2.1 eV coexist with p-type conductivity in porous and semitransparent Co3O4 samples, which exhibit light-induced photocurrent in photoelectrochemical cells (PEC) containing the alkaline electrolyte. The thickness-dependent properties of Co3O4 related to its use as a working electrode in PEC cells are extensively studied and show potential for the application in water oxidation and reduction processes. To demonstrate the stability, an alkaline cell was composed for the water splitting system by using two Co3O4 photoelectrodes. The oxygen gas generation rate was obtained to be 7.17 mL·h−1 cm−1. Meanwhile, hydrogen gas generation rate was almost twice of 14.35 mL·h−1·cm−1 indicating the stoichiometric ratio of 1:2. We propose that a semitransparent Co3O4 photoactive electrode is a prospective candidate for use in PEC cells via heterojunctions for hydrogen generation.


Author(s):  
C. L. Hannon ◽  
J. Gerstmann ◽  
F. B. Mansfeld ◽  
Z. Sun

This paper describes the results of a research project to develop a non-toxic corrosion in hibitor for the protection of carbon steel surfaces of ammonia-water absorption heat pumps through the use of rare earth metal salt (REMS) compounds. Chromate compounds are currently used as corrosion inhibitors in these systems, but are toxic, environmentally harmful, and their use is being phased out. Corrosion concerns in ammonia-water absorption systems are primarily those of non-condensable (NC) gases generated by corrosion reactions impeding the heat and mass transfer processes in the system. The research focused on the development of a dual-protection REMS based strategy of applying a cerium-oxide/hydroxide coating to the metal surface in a process called cerating, in conjunction with a cerium-sulfate solution-based inhibitor. A laboratory test was conducted in test rigs designed to simulate the conditions of temperature and ammonia concentration found in the desorber component of advanced ammonia-water absorption systems. The test compared the NC gas generation rate in a rig with cerated steel surfaces to a rig using sodium chromate as a solution based inhibitor. The cerated test rig demonstrated an NC gas generation rate about 3 times lower than that of the chromate protected rig. Neither rig showed any indications of significant corrosion activity. This work has shown that cerating can provide superior suppression of NC gas generation in ammonia-water absorption systems compared to sodium chromate, in a process that is simple and readily applicable to the commercial manufacture of equipment.


2020 ◽  
Vol 14 (4) ◽  
pp. 444-452
Author(s):  
Ling Fang ◽  
Lin Liu ◽  
Siyi Luo ◽  
Junzhi Wang ◽  
Zongliang Zuo ◽  
...  

In this work, we studied the kinetics and behavior of wood panel wastes containing ureaformaldehyde resins. For this purpose, we used a TG-FTIR coupled system to analyze the gaseous products of the pyrolysis. With the results, we obtained the models that provide theoretical evidence and data support for the studied reactions. According to our findings, the pyrolysis of the ureaformaldehyde components displayed two stages, and the second stage presented a higher intensity. At a temperature of 900 °C, the gas generation rate for hard UF (UF1) was 32.6% higher than that for soft UF (UF2). When temperature increased from 600 °C to 900 °C, the increase of the gas generation rate was relatively small. In addition, the reaction order was obtained using the CoatsRedfern method, which provided a value for the reaction order of 1.4. The activation energy of UF1 was slightly higher than that of UF2. The FTIR analysis indicated that the main gaseous products of the pyrolysis of the urea-formaldehyde resin samples were CO2, H2O, and other compounds containing the C–H and the N–H bond as well as carbonyl groups. In addition, it was determined that Nitrogen was mainly present in the form of hydronitrogen compounds but not as nitrogen oxides. These last may represent a higher degree of pollution.


2010 ◽  
Vol 157 (2) ◽  
pp. B266 ◽  
Author(s):  
Shu-Yen Liu ◽  
J. K. Sheu ◽  
Chun-Kai Tseng ◽  
Jhao-Cheng Ye ◽  
K. H. Chang ◽  
...  

2011 ◽  
Author(s):  
Shu-Yen Liu ◽  
Jhao-Cheng Ye ◽  
Yu-Chuan Lin ◽  
Kuo-Hua Chang ◽  
Ming-Lun Lee ◽  
...  

2020 ◽  
Vol 26 (4) ◽  
pp. 520
Author(s):  
Najmeh Amirmahani ◽  
Shahram Sadeghi ◽  
Ghazal Yazdanpanah ◽  
Aida Tayebiyan ◽  
Alireza Nasiri ◽  
...  

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