Preparing Coal Water Slurry from BDO Tar to Achieve Resource Utilization: Combustion Process of BDO Tar-Coal Water Slurry

Abstract

1,4-Butanediol (BDO) is an important organic and fine chemical raw material. BDO is widely used, but the waste liquid (BDO tar) discharged from the BDO production plant is complex in composition, contains salt, and is complicated to handle. The incineration treatment of BDO tar has a certain impact on the environment. In this study, BDO tar was treated by the method of waste-coal water slurry, and the combustion process of blending BDO tar was studied. The results showed that most of the organic components in BDO tar are lost in the early stage of combustion, which make the thermal weight loss of BDO tar-coal water slurry (BCWS), in the temperature range of 150−300 °C, more obvious. During the combustion of the sample, the thermogravimetry curves migrated to the low-temperature zone, indicating that the incorporation of BDO tar improves the combustion performance of the slurry. The presence of BDO tar causes BCWS to release more heat during intense combustion. Na + in BDO tar is the main reason for the catalysis of BCWS combustion. The main mechanism of this action is that the position containing the alkali metal Na becomes the active center in the combustion process, making it relatively easier for the sample to reach the ignition point. The alkali metal Na is uniformly dispersed on the surface and pores of the carbon particles, making the combustion process of BCWS more stable and sufficient. The incorporation of alkali metal Na causes the sample to be converted into a mixture of rod zeolite and calcium−aluminum−silicon eutectic during high temperature, which affects the combustion process and crystal conversion process.

Review and Perspectives of Anionic Dispersants for Coal–Water Slurry

“…Blending the waste with coal powder to prepare a waste–coal–water slurry (WCWS) has become an important way for resource utilization and waste disposal, reducing the use of fossil fuels and natural raw materials and alleviating the shortage of capacity for waste disposal . During the combustion and gasification of WCWS, the inorganic components in waste materials are deposited in fly ash and slag, and the organic fractions are turned into small molecule gases. ,− Due to the high calorific value of combustible waste that can decrease the ignition temperature, the technologies of low-temperature WCWS combustion make the concentrations of pollutant emissions reduced considerably. − …”

Effect of Pore Structures on 1,4-Butynediol Hydrogenation over Mesoporous Ni/Al2O3-SiO2 Catalysts

“…2−4 The common manufacture of BDO is based on the hydrogenation of 1,4-butynediol (BYD) via the Reppe process that involves the reaction of coal-based formaldehyde with acetylene. 5 Owing to the unsaturated property of CC bonds, hydrogenation of BYD to BDO is a two-step process with the initial hydrogenation of BYD to 1,4-butenediol (BED) and the subsequent hydrogenation of BED to BDO 6 (Scheme 1). However, the accompanying BED intermediate with an allyl alcohol structure is preferably converted to its highly unstable isomerization product γ-hydroxybutanal (γ-HALD), which results in the formation of aldol condensation byproduct 2hydroxytetrahydrofuran (HTHF), and in turn reduces the selectivity of the BDO product.…”

“…The common manufacture of BDO is based on the hydrogenation of 1,4-butynediol (BYD) via the Reppe process that involves the reaction of coal-based formaldehyde with acetylene . Owing to the unsaturated property of CC bonds, hydrogenation of BYD to BDO is a two-step process with the initial hydrogenation of BYD to 1,4-butenediol (BED) and the subsequent hydrogenation of BED to BDO (Scheme ).…”