石化剩余污泥理化性能与热动力学特性研究

Study on Physicochemical and Thermodynamic Properties of Petrochemical Excess Sludge

针对石化废水生物处理产生的剩余污泥处置难题,考察利用其中所含油类及生物质热值的可行性,采用XRF,FT-IR,XRD,GC,TG-DSC等分析手段,表征其理化性质及热动力学特性。结果表明:干基石化剩余污泥晶体种类主要为α-石英相,CaO,Fe_(2)O_(3)两种助溶剂质量分数较高,分别为39.2%和18.6%,Cl和Cr_(2)O_(3)含量最低;污泥中包含N—H,—CO—NH—,—CO—X—,CO_(2)^(-3),SiO_(2)^(-4),SO_(4)^(2-)等;重金属含量相对较低,其中Zn含量为50.44 mg/kg、Cu含量为2.14 mg/kg、Ni含量为6.44 mg/kg;石油烃含量丰富,m(C10~C14)∶m(C16~C28)∶m(C30~C40)为5∶18∶2,油脂类C16~C28含量最高,达29.77 g/kg;200~500℃时石化剩余污泥失重速率达到最大,800℃以上污泥热失重趋于结束。综合燃烧特性分析表明,随着升温速率的增大,试样的着火温度介于252.17~256.49℃,燃尽温度、最大失重速率、平均失重速率和综合燃烧特性指数(S)随之呈现升高的趋势。在较高的升温速率下污泥S值越大,综合燃烧特性越好。本研究对石化剩余污泥热值焚烧利用及焚烧飞灰的处置有一定应用参考价值。

In order to solve the problem of sludge disposal from biological treatment of petrochemical wastewater,the feasibility of utilizing the calorific value of oil and biomass contained in it was investigated.The physicochemical properties and thermodynamic properties of sludge were characterized by XRD,FT-IR,XRD,gas chromatography and TG-DSC.The results show that,the crystal types of dry base petrochemical excess sludge are mainlyα-quartz phase.The mass fraction of Cao and Fe_(2)O_(3) is 39.2%and 18.6%respectively,and the content of Cl and Cr_(2)O_(3) is the lowest;the sludge contains N—H group,—CO—NH—group,—CO—X—group,CO_(2)^(-3) group,SiO_(4)^(2-) group,SO_(4)^(2-) group,etc;the content of heavy metals was relatively low,with Zn content of 50.44 mg/kg,Cu content of 2.14 mg/kg and Ni content of 6.44 mg/kg;the content of petroleum hydrocarbon is rich,m(C10—C14)∶m(C16—C28)∶m(C30—C40)is 5∶18∶2,and the content of oil C16—C28 is the highest,reaching 29.77 mg/kg.In the temperature range of 200—500℃,the weight loss rate of petrochemical excess sludge reaches the maximum,and the thermal weight loss of sludge tends to end when the temperature is above 800℃;The comprehensive analysis of combustion characteristics shows that,with the increase of heating rate,the ignition temperature of the sample is between 252.17—256.49℃.The burnout temperature,maximum weight loss rate,average weight loss rate and comprehensive burnout characteristic index S increase monotonously.The higher the S value of sludge,the better the comprehensive combustion characteristics.This study has a certain application reference value for the incineration utilization of petrochemical excess sludge and the disposal of incineration fly ash.