Effect of Phosphorus Transformation on the Reduction of Particulate Matter Formation during Co-combustion of Coal and Sewage Sludge
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- 作者：Jiankun Zhuo ; Shuiqing Li ; Lei Duan ; Qiang Yao
- 刊名：Energy & Fuels
- 出版年：2012
- 出版时间：June 21, 2012
- 年：2012
- 卷：26
- 期：6
- 页码：3162-3166
- 全文大小：454K
- 年卷期：v.26,no.6(June 21, 2012)
- ISSN：1520-5029
文摘
Co-combustion of municipal sewage sludge with coal receives renewed attention, for its advantage of low pollutant emissions other than the high thermal efficiency and possibly optimal operation. In this paper, the effect of phosphorus on particulate matter (PM10) formation during co-combustion of coal and sewage sludge was intensively investigated in a 25 kW one-dimensional, down-fired pulverized coal combustor. PM10 was collected from the furnace centerline in the outlet of the flue gas cooler using a two-stage nitrogen-aspirated, water-cooling isokinetic sampling probe, followed by an electric low-pressure impactor (ELPI). The particle size distributions (PSDs) of the PM10 mass concentration during co-combustion exhibit a high sub-micrometer peak and a relatively low super-micrometer peak compared to those in pure coal combustion. Considering the high ash content of sewage sludge, at a 15% thermal blending ratio, the mass concentration of the total fly ash and PM10+ (dp > 10 渭m) increases from 1088 to 5059 mg N鈥? m鈥? and from 547 to 4403 mg N鈥? m鈥?, respectively, with respect to pure coal combustion. However, the mass concentrations of fine particulates, including PM1, PM2.5, and PM10, still maintain the similar emission level with coal combustion. The phosphonation of inorganic matters during the cooling of flue gas obviously reduces the mass concentration of fine particles. When the fraction of sewage sludge was 15% (on a thermal basis), the phosphate and P2O5 were appreciably rich in the ultrafine mode. The PSDs of phosphorus indicate the intermediate mode, knowing as a fact that the formed phosphates of inorganic metals cause finer particles to form larger agglomerates.