Catalytic Gasification Activity of Na₂CO₃ and Comparison with K₂CO₃ for a High-Aluminum Coal Char

Abstract

The catalytic performance of Na2CO3 for high-aluminum coal gasification was specially investigated, and the effect of the ash constituents in Sunjiahao (SJH) high-aluminum coal char on the catalytic activity of Na2CO3 and a comparison with that of K2CO3 were also studied through steam gasification experiments of SJH char catalyzed by Na2CO3 or K2CO3 carried out using a thermogravimetric analyzer and a fixed-bed reactor at 800 °C, respectively. The results indicate that the steam gasification rates of SJH char and acid-treated SJH char catalyzed by Na2CO3 are higher than those by K2CO3 with equal masses of catalyst. Na2CO3 can be used as the catalyst for high-aluminum coal gasification at 800 °C. The effect of the ash components on the catalytic activity of Na2CO3 is larger than that of K2CO3 in the catalytic steam gasification of SJH high-aluminum coal char at 800 °C. The X-ray diffraction (XRD) patterns of the steam gasification ashes of SJH char impregnated with Na2CO3 or K2CO3 reveal that the main composition is aluminosilicate, which is proved to have no catalytic activity. For catalytic steam gasification of acid-treated SJH char, the catalytic action of Na2CO3 is better because of the superior mobility and poor volatility of Na2CO3.

Catalytic effect of alkali and alkaline earth metals in different occurrence modes in Zhundong coals

“…The carbon conversion ( X ) was calculated using the following equation: where m 0 represents the initial mass of the sample before gasification, m t indicates the instantaneous mass of the sample at time t , and m ∞ is the total mass of ash.…”

“…Ding et al confirmed that Na 2 CO 3 has excellent catalytic performance for coal pyrolysis and gasification by loading Na 2 CO 3 into coal. Wang and collaborators compared the catalytic activity for coal gasification of the two additives K 2 CO 3 and Na 2 CO 3 and found that the catalytic activity of Na 2 CO 3 is larger than that of K 2 CO 3 . And McKee et al pointed out that alkali metal carbonates are generally the most active catalysts for gasification of coal by CO 2 and H 2 O.…”

Formation, fates and roles of catalytic precursors generated from the K2CO3-carbon interactions in the K2CO3-catalyzed CO2 gasification of coal char

“…under high temperature condition. On the other hand, for the low graphitization degree of coal char, in which oxygen-containing functional groups were present, the interaction followed route (2). The presence of oxygen groups helped to stabilize potassium on the carbon surface [22,23].…”

“…However, high temperature and pressure are required in the traditional coal gasification process. These requirements increase the capital and the operating expenses of the process considerably [1,2]. Recently, catalytic gasification has been investigated intensively in view of its advantages of lower operating temperature, higher efficient throughput and better economical performance [3,4].…”

Study of pyrolysis product distribution characteristics of lignite in the context of electrochemical catalytic gasification

“…3 As a representative third-generation gasication technology, catalytic gasication has the potential to achieve efficient coal conversion at a low thermochemical reaction temperatures. [4][5][6] Catalytic gasication research has largely focused on catalyst development; single-component catalysts, composite catalysts, and disposable catalysts are most common. Single-component and composite catalysts have good catalytic effects.…”