【摘要】：發(fā)展新型、綠色、環(huán)保、資源化的污水污泥處理技術(shù),是我國國民經(jīng)濟(jì)發(fā)展要求和順應(yīng)歷史發(fā)展潮流的大勢所趨。我國城市污水污泥中有機(jī)物含量和熱值日漸增高,使其具備熱化學(xué)轉(zhuǎn)化等能源化處理的潛力。本文主要針對污泥水蒸氣、水蒸氣-空氣混合氣化合成氣生成特性及其預(yù)測模型等展開研究,旨在全面分析高產(chǎn)出、低污染的污泥氣化工藝特性,為污泥能源化處理裝置的工程設(shè)計和工業(yè)運行提供有價值理論指導(dǎo)。主要研究工作和結(jié)論如下:(1)通過污泥水蒸氣氣化實驗研究,著重分析了溫度和水蒸氣質(zhì)量與污泥含碳量比(S/C比值)等對氣化合成氣生成特性以及污泥能源轉(zhuǎn)化效率的影響規(guī)律,可以發(fā)現(xiàn):溫度對氣化合成氣特性影響是絕對性的,提高氣化溫度有利于高品質(zhì)合成氣的生成和污泥能源轉(zhuǎn)化效率的提高。隨著溫度從650℃增加至1050℃,合成氣中H2和CO含量分別增加了12.1%和6.2%,CO2和CH4含量分別降低了4.8%和3.2%;污泥氣化冷煤氣效率ηl、碳轉(zhuǎn)化效率ηc以及有機(jī)相轉(zhuǎn)化效率ηv分別增加了近40%、18%和34%;綜合考慮氣化過程的能耗和產(chǎn)氣效率,污泥氣化制取富氫合成氣最佳溫度是850℃左右。S/C比值對合成氣生成特性影響是雙重的,過大和過小的S/C比值將造成合成氣品質(zhì)和能源轉(zhuǎn)化效率降低,當(dāng)S/C值為4.74時,合成氣產(chǎn)率及熱值、氫氣含量及其產(chǎn)率、氣化冷煤氣效率ηl均達(dá)到最優(yōu)值。(2)基于污泥空氣氣化與水蒸氣氣化工藝的各自優(yōu)勢,實驗分析了污泥空氣-水蒸氣混合氣化合成氣生成特性。研究發(fā)現(xiàn):與水蒸氣氣化相比,不同溫度下混合氣化H2產(chǎn)率、CO+H2產(chǎn)率、合成氣熱值及冷煤氣效率ηl的最佳值分別為0.38 m3/kg、0.46 m3/kg、6.24 MJ/m3和59%,顯著低于水蒸氣氣化合成氣的相應(yīng)最佳值,但前者能耗低于后者近5 MJ/kg;與熱解相比,混合氣化合成氣品質(zhì)仍較高,尤其H2產(chǎn)率、合成氣熱值及冷煤氣效率ηl顯著高于相同溫度下熱解氣的相應(yīng)各值。另外,混合氣化氣化過程中氣化介質(zhì)與污泥樣品量比值(Agent/SS)和H2O/O2質(zhì)量比應(yīng)嚴(yán)格控制。(3)污泥氣化過程主要是自由基生成反應(yīng)、含氧官能團(tuán)分解反應(yīng)、脂肪側(cè)鏈斷裂反應(yīng)、裂解反應(yīng)、脫氫反應(yīng)、加氫反應(yīng)、縮合等綜合熱化學(xué)反應(yīng)過程;隨著氣化溫度增加,污泥殘渣表面化學(xué)結(jié)構(gòu)發(fā)生了顯著變化,O-H鍵和N-H鍵、-CH2和-CH3基團(tuán)、C=O基團(tuán)及C-O和C-Har鍵逐漸消失,而原樣污泥中其它基團(tuán)或鍵結(jié)構(gòu)在650℃時已基本分解。(4)建立污泥高溫水蒸氣氣化和水蒸氣-空氣混合氣化特性的BP神經(jīng)網(wǎng)絡(luò)模型,其中污泥水蒸氣氣化模型預(yù)測精度較高,相對誤差小于9%;混合氣化預(yù)測模型預(yù)測精度較差,可通過增加樣本量、改善網(wǎng)絡(luò)等方法提高預(yù)測精度。
[Abstract]:The development of new, green, environmentally friendly and resource-based sewage sludge treatment technology is the trend of the development of our national economy and conforms to the trend of historical development. The content and calorific value of organic matter in municipal sewage sludge in China are increasing day by day, which makes it have the potential of energy treatment such as thermochemical conversion. In this paper, the characteristics of sludge steam, steam / air mixture gasification syngas and its prediction model are studied in order to analyze the characteristics of sludge gasification process with high yield and low pollution. It provides valuable theoretical guidance for the engineering design and industrial operation of sludge energy treatment plant. The main research work and conclusions are as follows: (1) through the experimental study of sludge steam gasification, the effects of temperature, water vapor mass and sludge carbon content ratio (S / C ratio) on gasification syngas generation characteristics and sludge energy conversion efficiency are analyzed. It can be found that the influence of temperature on gasification syngas characteristics is absolute, and the increase of gasification temperature is beneficial to the production of high quality syngas and the improvement of sludge energy conversion efficiency. As the temperature increases from 650 鈩，

本文編號：2242347