【摘要】：本論文以資源廣泛,燃燒清潔的毛竹廢棄物為原料,采用正交實(shí)驗(yàn)優(yōu)化熱壓成型工藝,制備優(yōu)質(zhì)毛竹成型顆粒燃料;采用水熱炭化技術(shù)制備優(yōu)質(zhì)毛竹水熱炭燃料,基于無模式函數(shù)多重掃描速率法,研究了毛竹及水熱炭燃燒特性及動(dòng)力學(xué);同時(shí)為探索毛竹水熱炭化原理,以模化物微晶纖維素為原料,探究pH值對(duì)生物質(zhì)水熱炭化的影響規(guī)律。(1)采用熱壓成型工藝制備毛竹成型顆粒燃料,研究了粒徑、含水率、預(yù)熱溫度、成型壓力對(duì)毛竹成型顆粒燃料的影響,并以松弛密度、耐久度為指標(biāo),在單因素實(shí)驗(yàn)基礎(chǔ)上,采用正交試驗(yàn)對(duì)毛竹成型顆粒燃料制備工藝參數(shù)進(jìn)行了優(yōu)化。結(jié)果表明:當(dāng)粒徑小于0.38 mm,含水率為15%,預(yù)熱溫度為125℃,成型壓力為20 MPa時(shí),成型效果最好,此時(shí)成型顆粒的松弛密度為1.110 g/cm3,耐久性為0.955,可達(dá)到歐美國家成型顆粒燃料的標(biāo)準(zhǔn)。該工藝的優(yōu)化設(shè)計(jì)為毛竹廢棄物制備成型顆粒燃料工藝參數(shù)的選擇提供了參考。(2)對(duì)毛竹進(jìn)行水熱炭化處理制備水熱炭,對(duì)毛竹原料及其水熱炭進(jìn)行燃燒實(shí)驗(yàn),采用升溫速率為10、20、40 K/min,基于無模式函數(shù)多重掃描速率法(FWO、KAS、FR法),研究了毛竹及水熱炭燃燒特性及動(dòng)力學(xué)。結(jié)果表明:升溫速率提高,樣品揮發(fā)分燃燒和固定碳燃燒階段均向高溫區(qū)轉(zhuǎn)移,著火性能下降,燃盡溫度提高;水熱炭較原料揮發(fā)分含量降低,固定碳含量升高;水熱溫度越高,熱值越大,能量產(chǎn)率越低,水熱溫度為260℃,水熱時(shí)間為30 min的水熱炭燃料燃料性能最佳。FWO、KAS法活化能結(jié)果相近,FWO法模型最優(yōu)。采用大于230℃水熱溫度制備的燃料,燃燒時(shí)反應(yīng)能力增強(qiáng),反應(yīng)速率增大。(3)為初步探索毛竹水熱炭化原理,以生物質(zhì)模化物微晶纖維素為原料,以檸檬酸、碳酸氫鈉和氫氧化鈉配置pH值為3.0、4.0、5.0、6.0、7.0、8.0、9.0、10.0、11.0的溶液,在溫度220℃,時(shí)間4 h條件下研究反應(yīng)溶液pH值對(duì)微晶纖維素水熱炭化的影響規(guī)律。通過元素分析分析了pH值對(duì)水熱炭理化特性的影響,并結(jié)合范式圖綜合分析pH值對(duì)微晶纖維素水熱炭化反應(yīng)進(jìn)程的影響,利用掃描電子顯微鏡觀察水熱炭表觀形貌。結(jié)果表明:水熱炭產(chǎn)率和固碳率隨酸性的增強(qiáng)而減弱,pH為3.0時(shí),產(chǎn)率及固碳率最小,分別為35.5%、41.82%,熱值達(dá)到最大,為19.11 MJ/kg,pH為3時(shí)制備的水熱炭的芳香性最好,pH為11時(shí)制備的水熱炭的親水性最強(qiáng),堿性和中性水熱炭芳香性、親水性相似,不同pH條件的炭化進(jìn)程均以脫水反應(yīng)為主;掃描電鏡結(jié)果顯示酸性水熱炭炭微球粒徑隨酸性增強(qiáng)而逐漸變小,纖維素在堿性條件下炭微球粒徑均勻度較好。
[Abstract]:In this paper, high-quality bamboo pellet fuel was prepared by optimizing hot pressing process by orthogonal experiment, which was made from bamboo wastes with extensive resources and clean combustion. Hydrothermal carbonization technology was used to prepare high quality bamboo hydrothermal carbon fuel. The combustion characteristics and kinetics of Phyllostachys pubescens and hydrothermal carbon were studied based on the modeless function multiple scanning rate method. At the same time, in order to explore the principle of hydrothermal carbonization of Phyllostachys pubescens, the effect of pH value on biomass hydrothermal carbonization was studied by using microcrystalline cellulose as raw material. (1) the particle size and moisture content of bamboo pellet fuel were prepared by hot pressing molding process. The influence of preheating temperature and forming pressure on the pellet fuel of bamboo molding was studied. Based on the single factor experiment, the parameters of preparation technology of bamboo pellet fuel were optimized by orthogonal test, taking the relaxation density and endurance as the index. The results show that when the particle size is less than 0.38 mm, the moisture content is 15%, the preheating temperature is 125 鈩，

本文編號(hào)：2325632