CAJ | 학술논문

为了探究分子筛催化剂对精制生物油理化特性的影响和在线催化提质机理，HZSM-5分子筛在固定床反应器上对油菜秸秆真空热解产生的热解蒸气进行在线催化提质试验，研究了催化剂质量、催化剂硅铝比和催化温度等参数对精制油产率和理化特性的影响，并通过气相色谱-质谱联用仪对提质前后生物油的化学组成进行了分析，初步探讨了HZSM-5分子筛在线催化提质机理。研究结果表明，油菜秸秆用量约为150 g，当催化剂质量为60 g，HZSM-5硅铝比为50，催化温度为500℃时，获得的精制油具有较低的氧元素质量分数（27.97%）、较高的高位热值（30.14 MJ/kg）以及较高的氢碳比（0.121）。在该条件下，醛、酸和酮类等非理想产物质量分数分别由提质前的13.71%、11.75%和13.59%降低至3.38%、1.68%和4.48%，而低含氧量的酚类由31.99%大幅增加至65.47%，表明HZSM-5具有良好的催化提质功能。研究结果为生物质的转化利用和在线精制热解蒸气技术的发展提供可靠的试验及理论依据。
위료탐구분자사최화제대정제생물유이화특성적영향화재선최화제질궤리，HZSM-5분자사재고정상반응기상대유채갈간진공열해산생적열해증기진행재선최화제질시험，연구료최화제질량、최화제규려비화최화온도등삼수대정제유산솔화이화특성적영향，병통과기상색보-질보련용의대제질전후생물유적화학조성진행료분석，초보탐토료HZSM-5분자사재선최화제질궤리。연구결과표명，유채갈간용량약위150 g，당최화제질량위60 g，HZSM-5규려비위50，최화온도위500℃시，획득적정제유구유교저적양원소질량분수（27.97%）、교고적고위열치（30.14 MJ/kg）이급교고적경탄비（0.121）。재해조건하，철、산화동류등비이상산물질량분수분별유제질전적13.71%、11.75%화13.59%강저지3.38%、1.68%화4.48%，이저함양량적분류유31.99%대폭증가지65.47%，표명HZSM-5구유량호적최화제질공능。연구결과위생물질적전화이용화재선정제열해증기기술적발전제공가고적시험급이론의거。
Catalytic upgrading of the vapors from rape straw vacuum pyrolysis was conducted over HZSM-5 zeolite in a fixed bed reactor. Univariate analysis was employed in this study to investigate the effects of the operating parameters, including catalyst quality, Si/Al ratio of catalyst, and catalyzing temperature, on the product yields and the composition of upgraded bio-oil. Based on the univariate analysis, the preliminary operating parameters of catalytic reactor were optimized. The results showed that, when the catalyzing temperature was 500℃and HZSM-5 (Si/Al=50) quality was 60 g, a lower oxygen content (27.97 percent), higher heating value (30.14kJ/kg-1), and a lower hydrogen-to-carbon ratio (0.12) were obtained. Moreover, the components of the obtained bio-oil contained a small amount of high oxygen contents, such as aldehydes, acids, and ketones. Meanwhile, phenols and aromatic hydrocarbons obviously increased. Product distribution and yield between upgraded bio-oil and crude bio-oil was also compared to study the catalytic refining effects and catalytic deoxygenation performance of HZSM-5 zeolite. This capacity of HZSM-5 zeolite was the key to make up for the two shortcomings of crude bio-oil, which were corrosivity and instability. The catalyst quality had significant effects on the properties of the upgraded bio-oil. Catalytic upgrading of pyrolysis vapors was incomplete when the catalyst quality was not high enough. However, when the catalyst quality was excessive, a decreased yield of upgraded oil resulted due to excessive secondary cracking reactions. In this study, the quality ratio of the catalyst to biomass was about 0.4. Catalyzing temperature also had an important effect on the properties of upgraded oil. When the catalyzing temperature was lower, the activation energy could not meet the needs of cracking reactions, and the catalytic effect was poor. When the catalyzing temperature was higher than optimal value, deactivation of the catalyst resulted because the structure of the catalyst was destroyed. Accordingly, the upgraded bio-oil with a higher gross heating value and lower oxygen content was obtained when the catalyzing temperature was about 500℃. The Si/Al ratio of the catalyst, which determined its density of acid sites and acid strength, had a great impact on catalytic product distribution. Four different Si/Al ratios of HZSM-5 were investigated. Upgraded bio-oil with a higher gross heating value and lower oxygen content was obtained when the Si/Al ratio of HZSM-5 was 50. Also, there were significant differences between upgraded bio-oil and crude bio-oil in product distribution and yield. The yield of crude bio-oil was 43.98 percent while the yield of upgraded bio-oil was 36.12 percent. Oxygenated components in the upgraded bio-oil, such as aldehydes, carboxylic acids, and ketones, which were 13.71 percent, 11.75 percent, and 13.59 percent, dropped significantly to 3.38 percent, 1.68 percent, and 4.48 percent, respectively. However, phenols containing lower oxygen and non-oxygenated hydrocarbons increased observably. These results showed that the HZSM-5 catalyst had a strong catalytic refining and catalytic deoxygenation capacity. Based on the results of this study, a catalytic reaction mechanism of HZSM-5 was proposed by comparing non-catalytic and catalytic bio-oil compositions. HZSM-5 was highly active in catalytic deoxidation. However, the online catalytic upgrading mechanism of bio-oil vapors was complex and it needs to be further studied in the future.