污泥微波热解制备生物气及其脱硫研究

发布时间：2018-03-30 05:32

本文选题：污泥　切入点：微波热解　出处：《哈尔滨工业大学》2015年硕士论文

【摘要】：污泥微波高温热解技术具有减量化程度高,能够有效的固定重金属,杀灭污泥中的致病微生物,实现无害化的优点,而且热解过程中能够产生富含H2和CO的生物气,能够作为燃料使用,具有很好的工程应用的前景。本研究利用自主设计搭建的微波实验平台,以连续的产生高品质生物气为目标。实验通过间歇运行,以气象色谱作为检测方法,探究热解终温、停留时间、升温速率及活性炭添加量对污泥热解产气的影响规律,得出污泥微波热解的最优化条件;以最优化条件作为微波连续热解的运行参数,进行连续热解,获取富含H2和CO的生物气。污泥热解过程中还会释放硫化氢,造成空气污染,实验通过XPS、GC-MS、气象色谱的检测方法,分别对污泥热解产生的固体残渣、生物油和生物气进行检测,探究含硫物质的转化规律和硫化氢的产生条件,通过生石灰与污泥混合共同热解的方法,实现对硫化氢的固定,并且利用化学吸收法对产生气体中的硫化氢进行去除,得到清洁的生物气。实验采用单因素分析法对污泥影响因素进行研究。(1)热解终温越高污泥的产气率越高,气体中的H2和CO组分也越高,热解终温的最佳值为900℃;(2)升温速率的升高对污泥的产气具有促进作用,污泥中H2和CO组分也有所增长;(3)在一定范围内适当的增加污泥热解的停留时间能够产生更多的生物气,并且气体中的H2和CO含量也更高,实验得出最佳的停留时间为50 min;(4)活性炭是污泥热解的吸波物质,增加活性炭能够增加热解的传热效率,增加产气量和H2和CO组分含量,实验得出的活性炭的最佳添加比例为30%。通过以上实验得出微波热解的最佳条件:热解终温900℃、微波功率1600 W、停留时间50 min、活性炭添加比30%。用以上得出的最佳条件进行微波连续高温热解,运行时间为6h,共计热解污泥28 kg,产生生物气16.13 kg,产气率为57.8%,其中H2和CO体积分数之和为67%,产生生物油为5.49 kg,剩余的固体残渣的质量为6.33 kg,减量达77.4%,实验结果达到预期。通过气相色谱仪对污泥连续热解产生的生物气进行检测,得到生物气中的硫化氢浓度进行检测,结果为0.375 mg/m3,远超过烟气排放标准的规定值。实验利用间歇实验法对污泥热解产生硫化氢的机理进行研究,对热解产生的三相产物进行分别测定,利用XPS对污泥的热解残渣进行分析,发现主要的含硫物质为硫醇,无机硫化物,噻吩,亚砜和砜和硫酸,随温度的升高脂肪族硫醇减少而无机硫化物和噻吩含量增加;通过GC-MS对污泥热解的液相组分进行检测,生物油主要组成为脂肪族-S化合物,芳香族-S化合物和噻吩-S的化合物。随着温度的升高,生物油中的脂肪族-S和芳香族-S含量减少,而噻吩-S的含量增加;通过气象色谱对生物气进行检测,硫化氢的浓度在100℃~500℃区间升高迅速,在500℃~800℃增长缓慢,800℃达到最大值,通过分析,无机硫化氢、脂肪族-S和芳香族-S在不同的阶段都会分解释放硫化氢。实验采用污泥中添加5%的Cao共同热解,探究Ca O脱除硫化氢的机理,即Cao与硫化氢形成Ca S,使含硫物质转换到固体残渣中,从而实现生物气中含硫物质的去除,在微波连续运行实验中进行污泥生石灰共同加热,生石灰添加量越高,则硫化氢的去除率越高,生石灰添加量为15%时测定硫化氢的浓度为0.091 mg/m3,去除率达到75.6%,具有显著的去除效果,并且对产生的生物气通过三种脱硫方法对残留的硫化氢进行进一步的去除,比较三种脱硫方法的效果,选择铜铁吸收法作为合适的脱硫方法硫化氢去除率达到94.8%以上,生物气可以进行直接利用。
[Abstract]:Sludge microwave pyrolysis technology has a high degree of reduction and fixation of heavy metals can effectively kill pathogenic microorganisms, sludge, harmless advantages, and the pyrolysis process can produce rich H2 and CO bio gas, can be used as fuel, has a good prospect of engineering application. This study uses the microwave experimental platform independent design and build, to continuously produce bio gas high quality as the goal. Through the experiment of intermittent operation, detection method in gas chromatography as research, pyrolysis temperature, residence time, heating rate and activated carbon addition on effect of sludge pyrolysis gas, the optimum conditions of microwave pyrolysis of sludge; with the optimum conditions as the operation parameters of continuous microwave pyrolysis, continuous pyrolysis, get rich in H2 and CO will release hydrogen sulfide gas. Biological sludge pyrolysis process, air pollution caused by experiment Through XPS, GC-MS, detection method of gas chromatography and solid residue were produced on sludge pyrolysis, bio oil and bio gas detection, condition inquiry and transformation of hydrogen sulfide sulfur containing substances, through the method of lime and sludge mixed co pyrolysis of hydrogen sulfide, fixed, and the use of chemical absorption method for removal the hydrogen sulfide gas, clean biogas. Analysis of influencing factors of single factor experiment using sludge pyrolysis temperature (1). The higher the sludge gas production rate is high, H2 and CO in the group of gas is higher, the optimum value of final pyrolysis temperature is 900 DEG C; (2) the increase of the heating rate of sludge gas promotes the sludge H2 and CO were also increased; (3) in a certain range appropriate to increase the residence time of sludge pyrolysis to produce more raw material gas, and the gas in H2 And the content of CO is higher, the optimum residence time of 50 min; (4) activated carbon absorbing material pyrolysis of sludge, adding activated carbon can increase the heat transfer efficiency of pyrolysis gas production increased, and H2 and CO content, the optimum conditions of activated carbon results that the best proportion is 30%. according to the above experiments: the microwave pyrolysis pyrolysis temperature of 900 DEG C, microwave power 1600 W, the residence time of 50 min, the optimum conditions of activated carbon added than 30%. the microwave continuous pyrolysis, operation time is 6h, a total of 28 kg biological sludge pyrolysis, gas 16.13 kg, gas production rate was 57.8%. The H2 and CO volume fraction is 67%, producing bio oil is 5.49 kg, the quality of the solid residue remaining for 6.33 kg, reduced by 77.4%, to achieve the desired experimental results. Detected by gas chromatograph to produce continuous pyrolysis of sludge bio gas, was born Detection of hydrogen sulfide concentrations in gas, the result is 0.375 mg/m3, far more than the provisions of flue gas emission standard value. Mechanism study experiment using batch experiment of hydrogen sulfide on sludge pyrolysis, the pyrolysis products of three phase were determined by XPS on sludge pyrolysis residue analysis, found mainly for sulfur containing substances inorganic sulfide, mercaptan, thiophene, sulfoxide and sulfone and sulfuric acid, with the increase of temperature reduction and inorganic sulfide aliphatic mercaptan and thiophene content increased; were detected by GC-MS on sludge pyrolysis liquid group, bio oil is mainly composed of -S aliphatic compounds, aromatic compounds and thiophene compounds -S with the temperature of -S. Increased, reduce the bio oil in aliphatic and aromatic -S -S content, and the content of thiophene -S increase; by gas chromatography for detection of biological gas, the hydrogen sulfide concentration in 100 ~500 OC interval increased rapidly, slow growth at 500 DEG ~800 DEG, 800 DEG C reached the maximum value, through the analysis of inorganic hydrogen sulfide, -S and aliphatic aromatic -S released hydrogen sulfide in different stages. The experiment using Cao co pyrolysis of adding 5% sludge, removal of hydrogen sulfide on Ca O mechanism, i.e. Cao and Ca S to form hydrogen sulfide, sulfur containing substances into solid residue, so as to achieve the removal of sulfur species in the biogas, run in continuous microwave experiment of sludge lime common heating, lime adding amount is higher, while the hydrogen sulfide removal rate is high, the concentration of lime is 15% when the adding amount of hydrogen sulfide determination for 0.091 mg/m3, the removal rate reached 75.6%, with significant removal effect of residual hydrogen sulfide removal and further through three kinds of desulfurization methods to produce biogas, three desulfurization method, selection As a suitable desulfurization method, the removal rate of hydrogen sulfide can reach more than 94.8%, and biogas can be used directly.

【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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