生物质流化床快速热解中除尘和分馏冷凝研究

论文总字数：23328字

摘 要

随着人类社会的发展，化石能源危机和环境污染日益严重，开发和利用可再生能源势在必行。在可再生能源中，生物质是唯一的有机碳来源，可以通过催化热解的方法代替煤、石油等化石燃料。在生物质快速热解中，得到的生物油往往冷凝不充分，焦炭含量比较高，造成生物油品质不高。为了解决这个问题，本文针对生物质流化床快速热解中除尘和分馏冷凝环节，在自行设计的连续进料流化床上进行生物质快速热解实验研究，并获得以下研究结果。

对生物质流化床快速热解中除尘环节进行了试验研究。分别改变除尘装置中颗粒层粒径、颗粒层厚度、金属网孔径，通过研究不同条件下金属网、颗粒层除尘率的变化，生物油中固体颗粒物含量的变化，和除尘装置压差的变化，从而确定最佳除尘装置设计方案。结果表明，随着颗粒层粒径的减小、颗粒层厚度的增加、金属网孔径的减小，得到的生物油中固体颗粒物的含量逐渐减小，再结合除尘装置压差等因素综合考虑，最终确定当颗粒物粒径为0.8-1 mm，颗粒层厚度为30 mm，金属网孔径为48 μm时，除尘效果最佳。

对生物质流化床快速热解中分馏冷凝环节进行了试验研究。依据成分复杂的生物质热解气露点不同，利用分级冷凝的方法，通过控制冷凝温度，实现生物油的分组富集。研究了生物油在不同冷凝温度（0℃、50℃、120℃和 260℃）下液体产物分布特性。生物质热解气经过分级冷凝处理后得到四组生物油样品，其中0-50 ℃时得到的生物油产率最大，超过液体总量的55.33 %，pH为2.31；其次是50℃时的冷凝产物，为深褐色油状物质，pH为2.25，生物油产率较高；120℃冷凝得到的产物深褐色的固液混合物，黏度较高，生物油产率很低；260℃时冷凝产物为无流动性的黑色固体，生物油产率很低；结合各组分GC的分析结果，对各温度下冷凝产物生物油中典型有机组分的分布特性进行探寻，得到各类物质在分级冷凝过程中的富集规律：随着冷凝温度的升高，组分停留时间逐渐变长，成分逐渐增加，说明物质结构逐渐变复杂，分子量和沸点逐渐变高，C原子个数也越来越多。

关键词：生物质；快速热解；除尘；分级冷凝

Abstract

With the development of human society, the fossil energy crisis and environmental pollution is increasingly serious, the development and utilization of renewable energy is imperative.In renewable energy, biomass is the only source of organic carbon, which can instead of fossil fuels such as coal and oil by catalytic pyrolysis method .During biomass fast pyrolysis, bio-oil often inadequated condensation, coke content is higher, causing biological oil's quality is not perfect. In order to solve this problem, this article in view of the fluidized bed biomass fast pyrolysis in the shaker and fractional condensation link, in the design of continuous feed on fluidized bed biomass fast pyrolysis experiments, and obtain the following results.

Biomass fluidized bed dust removal link in fast pyrolysis were studied.Respectively in granular layer dust removal device particle particle diameter, layer thickness, metal mesh aperture, metal under different conditions by studying the change of the network layer, particle collection coefficient, the change of solid particles in biological oil content, and the dust removal device the change of pressure difference, thus the optimum design of dust removal device.Results show that with the decrease of the particle size of the granular layer, granular layer thickness increases, the decrease of the metal mesh aperture, the biological oil decreases, the content of solid particles in the comprehensive consideration, coupled with dust removal device pressure factors finally confirmed when the particle size is 0.8 1 mm, granular layer thickness of 30 mm, metal mesh aperture of 48 microns, dust removal effect is best.

Biomass fractionation in the fluidized bed fast pyrolysis condensation segment were studied.According to the complicated composition of biomass pyrolysis gas dew point is different, the method of using fractional condensation, by controlling the condensation temperature, realize the grouping enrichment of bio-oil.Bio-oil was studied at different condensing temperature (0 ℃, 50 ℃, 120 ℃ and 260 ℃) under the liquid product distribution characteristics.Biomass pyrolysis gas after dealing with the fractional condensation by four groups of bio-oil samples, where 0-50 ℃ when the bio-oil yield is the largest, more than 55.33% of the total liquid, pH 2.31;Followed by the condensation product when 50 ℃, for the dark brown oily substances, pH 2.25, biological oil production rate is higher;The product of 120 ℃ condensation get dark brown solid-liquid mixture, high viscosity, biological oil production rate is very low;260 ℃ when the condensation product of no liquidity black solid, biological oil production rate is very low;Based on the component analysis result of GC, condensation products to various temperatures typical organic components in biological oil exploring the characteristics of distribution, for all kinds of material in the process of fractional condensation enrichment regularity: with the increase of condensation temperature, component longer on retention time, composition is gradually increasing, the material structure become complex gradually, molecular weight and boiling point get higher, C atomic number is also more and more.

Key words: Biomass; Fast pyrolysis; Dust removal; Fractional condensation

目录

摘要

Abstract

目录

第一章 绪论

1.1研究背景 1

1.2国内外研究现状 2

1.2.1生物质快速热解技术 3

1.2.2热解液体生物油 3

1.2.3除尘 4

1.2.4分馏冷凝 5

1.3本课题的研究内容和技术路线 6

1.3.1研究目的 6

1.3.2研究内容 6

第二章 深度除尘系统设计与研究

2.1引言

2.2深度除尘系统设计

2.3实验部分 9

2.3.1实验用料 9

2.3.2实验装置 9

2.3.3实验操作步骤 10

2.3.4数据处理 10

2.4实验结论与分析

2.4.1颗粒层粒径对除尘效果的影响 11

2.4.2颗粒层厚度对除尘效果的影响 14

2.4.3金属网孔径对除尘效果的影响 16

2.5本章小结

第三章 分馏冷凝系统设计与研究 20

3.1引言 20

3.2分馏冷凝系统设计 20

3.3实验部分 21

3.3.1实验用料 21

3.3.2实验装置 21

3.3.3实验操作步骤 22

3.3.4数据处理 23

3.4实验结论与分析 24

3.4.1热解温度对各级生物油产率的影响 24

3.4.2热解油理化性质 24

3.4.3各级液体化学组分分析 24

3.4.4结论 26

3.5本章小结 26

第四章 总结与展望 28

5.1结论 28

5.2展望 28

参考文献 30

致谢 31

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