Effect of bed materials on slagging and fouling during Zhundong coal gasification

Abstract

The suitable bed material is important to inhibit ash-related problems including agglomeration and slagging in furnace and fouling on tail heated surfaces during coal gasification in fluidized bed. For newfound high-alkali vast-reserve Zhundong coal in China, the selection of bed material in fluidized bed should be paid more attention because of its more serious ash-related issues. Five bed materials including quartz, kaolin, corundum, sludge ash, and phosphate rock were used to investigate their feasibility to solve the ash-related issues of two typical types of Zhundong coal including Tianchimulei coal and Shaerhu coal. All of five bed materials could effectively impact the release and transformation of alkali and alkaline earth metal species, especially Na species. The capture order of Na by five bed materials from high to low was sludge ash, quartz, kaolin, corundum, and phosphate rock for the two types of coal, and ash fusion temperatures of residual ash added different bed materials were in orders of phosphate rock > corundum > sludge ash > kaolin > quartz for Tianchimulei coal and corundum > phosphate rock > sludge ash > kaolin > quartz for Shaerhu coal. This influence of bed materials was mainly related to their chemical compositions, especially Al-, Si-, and P-based compounds. Due to the strong capture of alkali and alkaline earth metal-based compounds and high ash fusibility temperature, sludge ash was suggested as the appropriate selection of the bed material during Zhundong coal gasification in fluidized bed. Moreover, this suggestion would contribute to the sewage sludge treatment.

A review on converting plastic wastes into clean hydrogen via gasification for better sustainability

“…Maya et al 40 stated that gasification process reduces acidification of the air compared with incineration process. Furthermore, gasification, unlike landfills, has no gas leakage and reduces CO 2 emissions as compared with incineration 40‐42 . Less dioxin formation occurs since the gasification process is carried out with a smaller amount of oxygen compared with combustion.…”

“…While the dioxin formation occurring with the gasification process is 2 e‐11 g/m 3 , 1.8 e‐7 g/m 3 of dioxin is released into the atmosphere as a result of burning the biogas produced in the storage areas in torches 40,43 . Therefore, the use of plasma gasification in the disposal of plastic wastes has increasingly become common in recent years thanks to its advantages such as energy recovery, a significant reduction in the use of landfill sites, and low emission values compared with incineration 24‐45 . Especially, the ability to produce high energy content fuel by using the syngas from the gasification of plastic wastes makes this process promising for research and development today 36,46‐48 …”

“…Furthermore, gasification, unlike landfills, has no gas leakage and reduces CO 2 emissions as compared with incineration. [40][41][42] Less dioxin formation occurs since the gasification process is carried out with a smaller amount of oxygen compared with combustion. While the dioxin formation occurring with the gasification process is 2 e-11 g/m 3 , 1.8 e-7 g/m 3 of dioxin is released into the atmosphere as a result of burning the biogas produced in the storage areas in torches.…”

Coal char characteristics variation in the gasification process and its influencing factors

“…However, the traditional mining technology will discharge a large amount of coal gangue, mine water, and waste gas, and damage the ecological environment, a clean, safe, and efficient mining method need to be developed. Underground coal gasification provides powerful technique supports for clean coal mining (Proshunin and Poturilov, 2016; Qi et al., 2017).…”

Ash deposit characteristics of blended coal in coal combustion process

“…The successful operation of gasification depends on coal characteristics. The suitable of feedstock material is important to inhibit ash-related problems including, agglomeration and slagging in the furnace and fouling on the hot surfaces during coal gasification (Qi et al, 2017). Gasification is an incomplete combustion process, converting a variety of carbon-based feedstock into a clean synthetic gas (syngas), which is primarily a mixture of hydrogen (H 2 ) and carbon monoxide (CO) as fuels.…”