發(fā)布時間：2019-01-10 15:37

【摘要】：HCN是一種典型的“非常規(guī)”有毒有害污染氣體,是一種有苦杏仁味的劇毒物質(zhì)。黃磷生產(chǎn)過程中會產(chǎn)生大量污染氣體,氣體成分復(fù)雜,其中就包括HCN,其濃度為400-1000mg/m3。本文在對比國內(nèi)外研究凈化HCN方法的基礎(chǔ)上,針對改性活性炭催化水解-氧化耦合法凈化黃磷尾氣中的HCN展開研究�；钚蕴烤哂芯薮蟮谋砻娣e和復(fù)雜的孔隙結(jié)構(gòu),其來源豐富、成本低廉、改性方法多種多樣,是一種良好的催化劑載體。因此,本論文以活性炭為載體,進(jìn)行了HCN催化水解-氧化耦合催化劑的研究。首先考察了單一過渡金屬改性活性炭(AC)的耦合催化性能,結(jié)果表明：過渡金屬改性的活性炭顯著提高了對HCN的去除能力,其中Cu改性的AC-Cu催化劑表現(xiàn)出最好的催化活性,在250-350℃,HCN去除率大于98%。N2選擇性在300℃達(dá)到48.8%。因此,本文重點(diǎn)選取Cu作為后續(xù)研究的活性組分。反應(yīng)溫度、氧含量、相對濕度以及催化劑焙燒溫度都明顯影響對HCN的催化活性,其中反應(yīng)溫度的影響最為明顯。為拓寬活性炭的反應(yīng)溫度窗,提高HUN轉(zhuǎn)化率與N2選擇性,利用具有儲氧活性的磺化酞菁鉆及稀土金屬元素Ce進(jìn)一步改性負(fù)載Cu氧化物的改性活性炭催化劑。并對改性后的活性炭進(jìn)行多角度表征,最后考察比較了AC-Cu與AC-Cu-CoPcS-Ce的活性穩(wěn)定性,持續(xù)運(yùn)行48小時,催化劑一直保持較高的活性沒有受到任何影響,HCN的轉(zhuǎn)化率均維持在98%以上,結(jié)果表明兩種催化劑都具有較好的活性穩(wěn)定性。由于AC-Cu-CoPcS-Ce的催化活性溫度相比AC-Cu低,所以AC-Cu-CoPcS-Ce催化劑更具有優(yōu)勢。采用X射線衍射(XRD)、電感耦合等離子體-原子發(fā)射光譜(ICP-AES、N2吸脫附(BET、X射線光電子能譜(XPS)、傅里葉紅外(FT-IR)、程序升溫還原(H2-TPR)以及程序升溫脫附(TPD)等手段對催化劑進(jìn)行多角度表征,研究了催化劑的晶體結(jié)構(gòu)、孔結(jié)構(gòu)、形貌以及催化劑可能的催化反應(yīng)原理。通過以上活性評價及表征結(jié)果,推測了可能的反應(yīng)機(jī)理。根據(jù)推理,催化水解-氧化耦合過程中,HCN水解反應(yīng)與HUN氧化反應(yīng)相互關(guān)聯(lián)相互促進(jìn),HUN水解過程產(chǎn)生NH3與CO, HCN氧化過程產(chǎn)生N2、NOx、N2O等,NH3進(jìn)一步與反應(yīng)系統(tǒng)中存在的O2反應(yīng)選擇性生成N2；同時,水解過程產(chǎn)生NH3與HCN氧化過程產(chǎn)生的NOx進(jìn)一步發(fā)生反應(yīng)生成N2,從而比較徹底的轉(zhuǎn)化HCN廢氣。
[Abstract]:HCN is a typical "unconventional" toxic and harmful pollutant gas, and it is a highly toxic substance with bitter almond flavor. Yellow phosphorus production can produce a large amount of polluting gas, the gas composition is complex, including HCN, concentration of 400-1000 mg / m3. On the basis of comparing the domestic and foreign methods of purifying HCN, the HCN purification from yellow phosphorus tail gas by the coupling method of catalytic hydrolysis and oxidation of modified activated carbon was studied in this paper. Activated carbon has a large surface area and complex pore structure, which has rich sources, low cost and various modification methods, so it is a good catalyst carrier. Therefore, in this paper, HCN catalytic hydrolysis-oxidation coupling catalyst was studied with activated carbon as the carrier. First, the coupling catalytic performance of single transition metal modified activated carbon (AC) was investigated. The results showed that the modified activated carbon could significantly improve the removal capacity of HCN. The Cu modified AC-Cu catalyst showed the best catalytic activity, and the removal rate of HCN was higher than that of 98%.N2 at 250-350 鈩，

本文編號：2406490