ABSTRACT

The high-rank coal reserves are limited and getting depleted at an escalating rate to meet the demands of growing population. This concern has compelled the scientific community to use the young high ash coals. The coal water slurry fuel is one promising way to use low-quality coal as an economical liquid fuel. Due to poor physico-chemical and surface properties of such coals, these systems appear to be unsustainable. This research presents a sustainable solution to use the existing low-quality coals efficiently without any modification in the already installed systems. The Indian coal possessing high moisture and oxygen functional groups was successfully irradiated with microwaves, resulting in the improvement of morphological, physical, chemical and rheological characteristics. These changes are due to the elimination of the Hydroxyl (-OH⁻) and Carboxyl (-COOH⁻) groups, which are observed to contribute the most to the hydrophilicity of the coal particles. The morphological investigations reveal the breaking up of the bigger particles into fines upon microwave irradiation. The treated coals exhibit physico-chemical and surface properties similar to high-rank coals but still possess high ash that does not pose any issue with the normal operation of the system.

摘要

高阶煤炭储量有限，并且正以不断升级的速度枯竭，以满足不断增长的人口需求。这种担忧迫使科学界使用年轻的高灰分煤。水煤浆燃料是利用劣质煤作为经济液体燃料的一种很有前景的方法。由于这些煤的物理化学和表面性质较差，这些系统似乎是不可持续的。这项研究提出了一种可持续的解决方案，可以有效地使用现有的低质量煤炭，而无需对已安装的系统进行任何修改。印度煤具有高水分和氧官能团成功地用微波辐照，从而改善了形态、物理、化学和流变特性。这些变化是由于消除了羟基（-OH^- ) 和羧基 (-COOH ^- ) 基团，观察到它们对煤颗粒的亲水性贡献最大。形态学研究揭示了在微波照射下较大的颗粒分解成细粒。处理后的煤表现出与高级煤相似的物理化学和表面特性，但仍然具有高灰分，不会对系统的正常运行造成任何问题。