Abstract

To get a high concentration of coal water slurry (CWS) for gasification application, semicokes were prepared by pyrolysis of Dongrong long flame coal (DRC) at medium–low temperature. The obtained semicokes were characterized by thermogravimetry, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope, and nitrogen adsorption-desorption methods. After preparation, the adsorption experiment of sodium lignin sulfonate (NaLS) on these semicokes was also carried out. It was found that medium–low temperature pyrolysis have changed the pore structure, surface properties, and molecular structure of DRC, which increased the saturated adsorption capacity of semicokes for NaLS dispersant. The enhanced adsorption capacity for dispersant can significantly reduce the apparent viscosity of CWS and increase its concentration. Under the optimized pyrolysis conditions, the maximum solid concentration of CWS prepared with as-prepared semicokes reached up to 68.09% when the dosage of NaLS disperdant was 1%, which met the gasification application of CWS. Such medium–low temperature pyrolysis method is an effective way to large-scale development and utilization of low rank coal through modifying their physicochemical properties.

摘要

为了获得用于气化应用的高浓度水煤浆（CWS），通过在中低温下热解东荣长焰煤（DRC）制备半焦。通过热重分析、傅里叶变换红外光谱、X射线光电子能谱、X射线衍射、扫描电子显微镜和氮吸附-脱附方法对所得半焦进行表征。制备后，还进行了木质素磺酸钠（NaLS）对这些半焦的吸附实验。结果表明，中低温热解改变了DRC的孔隙结构、表面性质和分子结构，提高了半焦对NaLS分散剂的饱和吸附能力。增强的分散剂吸附能力可以显着降低水煤浆的表观粘度并提高其浓度。在优化的热解条件下，当NaLS分散剂用量为1%时，半焦制备的水煤浆最大固含量可达68.09%，满足水煤浆气化应用。这种中低温热解法是通过改变低阶煤的理化性质，大规模开发利用低阶煤的有效途径。