厨余垃圾与不同燃料物混烧排污及热值效应分析

Pollutants emission and calorific value effect during kitchen waste co-combustion with different combustible fuel

以原煤、焦炭、秸秆、橡胶和塑料作为厨余垃圾掺混原料,CO、NO_X、混烧热值、底灰比率作为分析对象,通过温度和掺混比梯度研究了其各自的焚烧效应及污染物排放量关系。试验结果显示:厨余垃圾掺混原煤和焦炭混烧样在600~800℃低温范围内CO产量最大,可达3.2~3.4mg,在1000℃左右达热解平衡,CO产量最小。随垃圾和原料样掺混比增加,原煤和焦炭CO产量逐渐降低,秸秆、橡胶和塑料样平缓升高。掺混原煤和焦炭虽对减少CO产量影响较小,而秸秆、橡胶和塑料样可抑制CO的不完全燃烧和热解产量;秸秆混烧样的NO_X在温度和掺混比梯度中都表现出最高的产出量。以污染物CO和NO_X为参考相,厨余垃圾掺混橡胶和塑料混烧最为理想,污染物产出量远小于其他原料,且温度在800~900℃、掺混比为5∶5范围内为最适宜燃烧条件。以热能和重金属回收为参考相,掺混焦炭样底灰比重最高,重金属富集度较为集中,内能发热量可满足再利用和回收要求。

T h e compound fuel was m a d e by mixing kitchen waste with coal , coke , straw , rubber and plastic respectively. T h e CO and NOx emission , and bottom ash ratio （ ash weight of the mixed fuel to that of the su m of the two separate fuels rfter they are burned） and calorific value of the mixed fu-els were measured under different burning temperatures and fuel percentages. T h ethat , kitchen waste with coal and coke produced C O up to 3.2 -3. 4 m g under low combustion tem-perature of 600 - 800℃; at about 1000℃ , the pyrolysis equilibrium was reached when the least CO was produced. With the increase of the ratio of kitchen waste in the mixed fuel （ kitchen waste - coal , kitchen waste - coke） , the production of CO decreased gradually , while the CO production was on the reverse as for that of straw , rubber and plastic. Blending of raw coal and coke had insignifi-cant effect on reducing CO production , while straw , rubber and plastic could inhibit thederived from incomplete combustion and pyrolysis. Under any temperature and blending ratio , themixed fuel of straw generated highest emission of N O x . With the pollutants C O and N O ence ,kitchen waste mixed with rubber and plastic was the most ideal fuel , generating least pollutant among other raw materials , and the temperature of 800 - 900℃ , mixing ratio of 5 ： 5 was found the most suitable combustion condition. Taking the heat and heavy metal as the reference, the bottom ashratio of the kitchen waste - coke was the highest, in such ash, ^ a v y metals were the heat of internal energy could meet the requirements of recycling and reuse.