QQ客服 官方微博 反馈留言

题名	生物质热解油临氢催化酯化改质的研究; Upgrading the Liquid products of Biomass Pyrolysis by Hydrotreating and Esterification
作者	徐莹
学位类别	博士
答辩日期	2009-04-26
授予单位	中国科学院广州能源研究所
授予地点	广州能源研究所
导师	马隆龙研究员
关键词	生物油 改质提升 催化酯化 固体碱 临氢催化酯化
其他题名	Upgrading the Liquid products of Biomass Pyrolysis by Hydrotreating and Esterification
中文摘要	With the development of the world economy and the globalization, the demand of fossil fuel reserves and the energy are increasing. Concerns about the pollution caused by continuously increasing in the energy demands of the world make biomass an attractive alternative energy source. In the case that biomass is utilized to as an energy resource, the emission of carbon dioxide caused by its use is absorbed by newly grown biomass and this is called as carbon-neutral. Moreover, for the negligible sulfur, nitrogen and metal contents comparing with fossil fuels, biomass is a clean energy source. In China, there is abundance of biomass. Therefore the development and utilization of biomass energy is significative to the energy security of China. Biomass pyrolysis is an efficient process of biomass conversion with high yield of liquid fuel, which makes biomass the most promising renewable energy to substitute the convertional fossil fuel. But the negative properties of bio-oil, such as the high viscosity, instability, severe corrosiveness and complicated composition put a lot of obstacles for its replacing process consequently, and have become a bottle-mech in its full applications. An urgen necessity to upgraded bio-oil is demanding. At present, the common method for bio-oil is the fast pyrolysis of biomass. Among the bio-oil upgrading techniques, hydrodeoxygenation process needs complicated equipments, superior techniques and excessive cost and usually is halted by catalyst deactivation and reactor clogging. Although catalytic cracking is regarded as a cheaper route by converting oxygenated feedstocks to lighter fractions, the results seem to promising due to high coking and poor quality of the fuels obtained. Emulsification does not demand redundant chemical transformations, but the high cost and energy consumption input cannot be neglected. The accompanying corrosiveness to the engine and the subassemblies is inevitably serious. The upgrading bio-oil by esterification over solid acid can make the bio-oil less visicosit and more stability but increase the acidity for the catalyst present. Based on the characteristic of high acidity, low pH value and high total amount and multi-organic existence, solid base catalysts, solid base and hydrotreating catalysts were used for the upgrading bio-oil by esterification. The novel method was investigated for upgrading bio-oil by esterification under the atmosphere of hydrogen. First, the novel method for bio-oil was investigated. In the article, the bio-oil was prepared from pine sawdust by fast pyrolysisi and vacuum pyrolysis. The conditions of vacuum pyrolysis, just like temperature and the feedstock size were investigated. When the pyrolysis temperature was 500℃ and the size of the particle was in the mesh of 40-60 mesh, the most yield of liquid product was obtained (52.60%). By the comparison of the properties and the gas product of the two kinds of bio-oils, the difference and common ground were found. Bio-oil prepared from the same material in different pyrolysis ways had different properties is mainly because of the difference pyrolysis process. However, the bio-oils shared the common characteristics, such as low pH value, strong acid and complicated compositions. Based on the characters of bio-oils, in this article, the solid base catalyst was developed, aiming at the adoption of solid base catalyst for esterification, which could improve the pH value of bio-oil and reduce the acidity. Acetic acid was chosen as the model compound and the esterification with ethanol for evaluating the activity of solid base catalysts. The solid base catalyst with the highest activity was screened out for the application of upgrading bio-oil. In this chapter, the solid base catalysts were prepared by different carriers and different precursor. The activity of the solid base catalyst with γ-Al2O3 carrier, loading 15% of K2CO3 was the relative best, which was applied for the uptrading of bio-oil. After upgrading, the pH value increased from 2.60 to 5.35, the viscosity decreased by 86.2% and the calorific value increased by 45.78%. The ester content had a marked increase, and the acid content decrease. In this article, the novel method is explored and developed. The ruthenium and nickel-based catalysts were chosen as the main active site, using acetic acid as a model compound to evaluate the two types of catalysts for the activity of esterification under the atmosphere of hydrogen. For ruthenium-based catalysts, the catalytic activity of esterification under the atmosphere of hydrogen was studied by the addition of different metals as a promoter. The catalyst with 0.5% Ru loading, Co promoter had the highest activity for acetic acid conversion (30.98%), which was applied on the upgrading of self-made fast pyrolysis bio-oil. For nickel-based catalyst, the nickel loading on the catalyst activity was discussed. The Mo promoter and catalyst reduction temperature were also investigated on catalyst activity. XRD and TPR showed that the addition of Mo promoter benefited to the uniformity of nickel species on the catalysts and inhibited the formation of NiAl2O4 spinel. The catalyst with 10% Ni loading, 0.06g/g addition of molybdenum, 600 ℃ of the catalyst reduction temperature had the highest activity for acetic acid conversion, which was applied on the upgrading of self-made fast pyrolysis and vacuum pyrolysis bio-oil. After the upgrading of bio-oils under the atmosphere of hydrogen, both the physical and chemical properties were enhanced. The results of GC-MS spectrometry analysis showed that the content of esters increased and the content of acids decreased. Both hydrotreatment and esterification happened during the upgrading of the raw bio-oils. Results indicate that it is possible to improve the properties of bio-oils by hydrotreating and esterificationg carboxyl group compounds in the bio-oils.
语种	中文
公开日期	2011-07-14 ; 2011-07-15
页码	116
内容类型	学位论文
源URL	[http://ir.giec.ac.cn/handle/344007/5832]
专题	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	徐莹. 生物质热解油临氢催化酯化改质的研究, Upgrading the Liquid products of Biomass Pyrolysis by Hydrotreating and Esterification[D]. 广州能源研究所. 中国科学院广州能源研究所. 2009.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。