Investigation on gaseous pollutants emissions during co-combustion of coal and wheat straw in a fluidized bed combustor.
Investigation on gaseous pollutants emissions during co-combustion of coal and wheat straw in a fluidized bed combustor.
复制标题
DOI：
10.1016/j.chemosphere.2019.124853
复制
发表时间：
2020-02
期刊：
影响因子：
8.8
通讯作者：
Zeyu Xue;Z. Zhong;Xudong Lai
中科院分区：
文献类型：
--
作者：
Zeyu Xue;Z. Zhong;Xudong Lai
煤和麦秆（WS）的混合燃烧是在实验室规模的 BFB 燃烧室中进行的。研究了燃料成分（煤，70%煤+30%WS）、温度（750、800、850、900、950°C）、二次空气比例（0、10%、20%、30%）对气态污染物释放的影响。采用烟气分析仪在线测量烟气（FG）中CO、NOx和SO2浓度。通过 ICP-OES 收集、消解和分析飞灰 (FA)、底渣 (BS) 和床料 (BM)，以确定重金属（例如 Pb、Zn、Cr 和 Cd）的分布。结果表明，混燃可有效降低CO、NOx和SO2的排放量以及飞灰中的碳含量，从而改善煤的单独燃烧。混燃时增加二次风可分别通过增强扰动和促进硫酸盐化来减少CO排放和SO2排放，而NO排放量在20%时达到最低。与煤单独燃烧相比，混燃抑制了Zn、Cd和Pb的释放。在混燃中，高温增加了它们在烟气中的比例。对于Zn、Pb和Cd来说，其在底部固体中的含量增加，而Cr的比例减少。二次风显着降低了飞灰中Zn、Pb的含量并转移至烟气中，底部固体中Zn、Pb含量降低，Cd含量增加。
Co-combustion of coal and wheat straw (WS) was conducted in a lab-scale BFB combustor. Fuel composition (coal, 70%coal+30%WS), temperature (750, 800, 850, 900, 950 °C), secondary air ratio (0, 10%, 20%, 30%) were varied to on the release of gaseous pollutant was studied. CO, NOxand SO2concentration in flue gas (FG) were measured on-line by a flue gas analyzer. Fly ash (FA), bottom slag (BS) and bed material (BM) were collected, digested and analyzed by ICP-OES to determine the distribution of heavy metals (e.g. Pb, Zn, Cr and Cd). Results indicated that co-combustion could improve the combustion of coal alone by reducing CO, NOxand SO2emission and carbon content in fly ash effectively. In co-combustion the increasing secondary air could reduce CO emission and SO2by enhancing disturbance and promoting sulfation respectively while the minimum NO emission was reached at the ratio of 20%. Co-combustion restrained the release of Zn, Cd and Pb compared with coal combustion alone. In co-combustion, high temperature increased their portion in the flue gas. For Zn, Pb and Cd, their content in the bottom solids increased while the portion of Cr decreased. Secondary air decreased their content in fly ash and transferred into flue gas significantly and in bottom solids content of Zn and Pb decreased while Cd increased.