【摘要】：高爐渣是鋼鐵生產(chǎn)過程的主要副產(chǎn)品,是一種多元金屬熔體,具有大量顯熱并能促進焦油及甲烷等低分子碳氫化合物的催化轉(zhuǎn)化。本研究提出采用干法離心�；夹g(shù)將液態(tài)爐渣制備成液-固過渡態(tài)的高溫爐渣顆粒,作為生物質(zhì)氣化熱載體,同時利用爐渣中多種金屬礦物對大分子的解構(gòu)、斷鍵和分解的催化作用,提高氣化反應(yīng)的選擇性,實現(xiàn)對爐渣顯熱的回收和轉(zhuǎn)換,將低品位的液態(tài)爐渣余熱轉(zhuǎn)換成高品位的氫能。為此,在總結(jié)前期課題組研究工作基礎(chǔ)上,圍繞該工藝的構(gòu)建,開展高爐渣熱載體催化氣化生物質(zhì)的機理研究,提出了本研究主要內(nèi)容:以干法離心�；椒ㄖ苽涞母郀t渣顆粒作為生物質(zhì)催化氣化制氫的熱載體和催化劑,以移動床氣化裝置為實驗平臺,對高爐渣和生物質(zhì)異質(zhì)混合顆粒的在移動床氣化爐內(nèi)的運動狀態(tài)和傳熱規(guī)律進行探討,結(jié)果表明:異質(zhì)顆粒在移動床反應(yīng)器內(nèi)的運動分為密相堆積流動和充分混合流動兩個階段;可采用球殼傳熱模型對顆粒間的傳熱過程進行描述,分別建立了平推流動階段和充分混合流動階段的傳熱計算方程;對高爐渣的催化性能進行評價,明確提高生物質(zhì)燃氣中氫氣含量和產(chǎn)率的最佳工藝條件,結(jié)果表明:高爐渣在促進焦油分解和碳氫化合物重整方面表現(xiàn)出良好的催化性能,增加熱載體爐渣顆粒溫度,減小顆粒粒徑能夠減小爐渣表面積碳,降低氣化產(chǎn)物中焦油產(chǎn)率和提升富氫氣體品質(zhì),在最佳工況下(選用粒徑小于2mm,溫度為1200℃的高爐渣顆粒作為熱載體),氣化產(chǎn)物中焦油含量僅為2.52%,氣體產(chǎn)率達到1.65Nm3/kg,富氫氣體中H2含量可達53.22%;通過分析反應(yīng)過程中各種原料、和主、副產(chǎn)品(焦油和灰分)成分及產(chǎn)量的數(shù)據(jù)建立質(zhì)量平衡;以物料平衡計算為基礎(chǔ),結(jié)合能量守恒定律,對進出系統(tǒng)的物料的焓差或熱力學(xué)能進行計算,推導(dǎo)出能量平衡關(guān)系。結(jié)果表明:研發(fā)的以高爐渣為熱載體的生物質(zhì)氣化系統(tǒng)能源回收效率約為51.44%,能耗比約為1.86。
[Abstract]:Blast furnace slag is a kind of polymetallic melt which is the main by-product of iron and steel production. It has a lot of sensible heat and can promote the catalytic conversion of low molecular hydrocarbons such as tar and methane. In this paper, a dry centrifuge granulation technique is proposed to prepare liquid slag particles from liquid to solid transition state as heat carrier of biomass gasification, and to destruct macromolecules by using a variety of metal minerals in slag. The catalytic action of broken bond and decomposition can improve the selectivity of gasification reaction, realize the recovery and conversion of sensible heat of slag, and convert the waste heat of low-grade liquid slag into high-grade hydrogen energy. Therefore, on the basis of summarizing the previous research work, the mechanism of biomass gasification catalyzed by heat carrier of blast furnace slag was studied around the construction of the process. The main contents of this study are as follows: the blast furnace slag particles prepared by dry centrifugal granulation are used as the heat carrier and catalyst for hydrogen production from biomass catalytic gasification, and the moving bed gasification unit is used as the experimental platform. The moving state and heat transfer law of mixed particles of blast furnace slag and biomass in moving bed gasifier are discussed. The results show that the motion of heterogeneous particles in a moving bed reactor can be divided into two stages: dense stacking flow and fully mixed flow, and the spherical shell heat transfer model can be used to describe the heat transfer process between particles. The calculation equations of heat transfer in the phase of flat-push flow and the stage of full mixing flow were established, the catalytic performance of blast furnace slag was evaluated, and the optimum technological conditions for increasing hydrogen content and yield of biomass gas were determined. The results show that the blast furnace slag has good catalytic performance in promoting tar decomposition and hydrocarbon reforming. Increasing the particle temperature of heat carrier slag and reducing the particle size can reduce the carbon surface area of slag. Reducing the tar yield in gasification products and improving the quality of hydrogen rich body, Under the optimum conditions (using blast furnace slag particles with diameter less than 2mm and temperature of 1200 鈩，

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