本文選題：低溫SCR脫硝　切入點(diǎn)：成型催化劑　出處：《浙江大學(xué)》2015年碩士論文

【摘要】：氮氧化物(NOx是主要的大氣污染物,對環(huán)境造成了嚴(yán)重影響。選擇性催化還原(SCR)技術(shù)是脫除固定源排放煙氣中氮氧化物(NOx)的有效手段,對NOx污染的控制具有重要意義。我國水泥行業(yè)NOx排放量大,隨著我國對NOx的排放標(biāo)準(zhǔn)日益提高,水泥行業(yè)NOx的進(jìn)一步深度減排勢在必行,但現(xiàn)有成熟有效的高溫SCR技術(shù)對水泥爐窯的煙氣適應(yīng)性不佳。因此,開發(fā)一種適用于水泥爐窯尾氣特點(diǎn)的低溫SCR煙氣脫硝技術(shù)具有非常重要的意義。目前,低溫SCR成型催化劑在實(shí)際應(yīng)用中仍面臨低溫條件下抗水和抗硫性差、易潮解以及機(jī)械強(qiáng)度不佳等問題。針對以上問題,本文對低溫SCR成型催化劑的機(jī)械性能和抗性的提升展開優(yōu)化研究,并在此基礎(chǔ)上確立了低溫SCR脫硝中試系統(tǒng)的設(shè)計(jì)方案。本文首先研究了催化劑的載體組分對抗水性和機(jī)械性能的影響。結(jié)果表明Ti02與分子篩對抗水性的影響相當(dāng),但Ti02對機(jī)械性能提升作用優(yōu)于分子篩；在優(yōu)化的Ti02添加量條件下,催化劑具有最優(yōu)的抗水性和較強(qiáng)的機(jī)械性能。在此基礎(chǔ)上,本文對催化劑的活性組分進(jìn)行抗水和抗潮解正交實(shí)驗(yàn)分析,分別計(jì)算得到最優(yōu)組合。經(jīng)過綜合極差比較和分析,選取5×5孔的綜合最優(yōu)組合催化劑。該催化劑在120℃,8%H20煙氣條件下反應(yīng)27h后,催化劑活性可以穩(wěn)定在82%左右。此外,本文還考察了金屬摻雜對成型催化劑在水、硫共存的低溫?zé)煔鈼l件下脫銷活性的影響。發(fā)現(xiàn)未摻雜的成型催化劑在同時(shí)含H2O和SO2的氣氛中會快速失活,主要是由于活性組分和載體的硫酸化以及硫銨鹽沉積堵塞孔道和覆蓋活性位點(diǎn)所造成。而Co的摻入可以有效抑制成型催化劑表面的載體和活性組分的硫酸化以及硫銨鹽的沉積,從而可以大大提高催化劑在同時(shí)含H2O和SO2氣氛中的耐受性。最后,本文在實(shí)驗(yàn)室研究基礎(chǔ)上,對水泥爐窯工況120℃,10000m3/h煙氣量的中試工程進(jìn)行了設(shè)計(jì),中試系統(tǒng)的設(shè)計(jì)方案主要包括SCR脫硝反應(yīng)器系統(tǒng)、煙道系統(tǒng)和氨供應(yīng)、制備及噴射系統(tǒng),并對該系統(tǒng)進(jìn)行了相應(yīng)的經(jīng)濟(jì)性評價(jià)。
[Abstract]:The selective catalytic reduction (SCR) technique is an effective method to remove no _ x from flue gas from stationary sources. It is of great significance to control NOx pollution. China's cement industry has a large amount of NOx emissions. With the increasing emission standard of NOx in China, it is imperative to further reduce the emission of NOx in cement industry. However, the existing mature and effective high temperature SCR technology is not suitable for the flue gas adaptability of cement kiln. Therefore, it is very important to develop a low temperature SCR flue gas denitrification technology suitable for the characteristics of cement kiln exhaust gas. The low temperature SCR forming catalyst is still faced with the problems of poor water and sulfur resistance, easy moisture solution and poor mechanical strength under low temperature conditions. In this paper, the mechanical properties and the improvement of resistance of low temperature SCR forming catalyst were studied. On this basis, the design scheme of low-temperature SCR denitrification pilot-scale system was established. Firstly, the effects of the support components of the catalyst on the water resistance and mechanical properties were studied. The results showed that the effects of Ti02 and molecular sieve on water resistance were equal to those of molecular sieve. However, the effect of Ti02 on mechanical performance is better than that of molecular sieve, and the catalyst has the best water resistance and strong mechanical property under the optimized Ti02 content. In this paper, the optimum combination of the active components of the catalyst was analyzed by orthogonal experiments of water resistance and moisture resistance, and the optimum combination was obtained by comprehensive range comparison and analysis. A 5 脳 5 pore composite catalyst was selected. After 27 h reaction at 120 鈩，

本文編號：1665784