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以桉木为原料,对1.5 t/h生物质混流式固定床气化炉运行特性进行了测试分析与评价,与文献报导报道的相关炉型包括上吸式、下吸式、两段式等炉型运行结果进行了比较。实验以气化炉空气通入量作为主要控制变量,对有或无水蒸气条件下的气化炉温度及压力分布、燃气组成、焦油与飞灰含量、气体产率等参数进行了较长周期的测试,结果表明:气化炉运行效果符合设计要求,各项指标相当于或优于传统的下吸式气化炉;气化炉运行温度与压力比较稳定;以冷燃气计算的燃气热值一般约为4 900 ~ 5 500 kJ/Nm3;气化效率约为70% ~ 78%;燃气焦油含量约600 ~ 3 500 mg/Nm3,运行负荷在50%以上时,焦油含量一般低于1 500 mg/Nm3。研究结果有望为混流式气化炉的改进和操作提供优化建议,同时可为其他气化工艺设计提供参考依据。 相似文献
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在蒸汽锅炉进行生物质能源改造中,生物质气化燃气代替煤、油具有成本、环保、政策方面的优势,但必须解决焦油的二次污染问题。本文提出以改进型即中部出气固定床上吸式气化炉生产生物质可燃气,及焦油成分随燃气直接在锅炉炉膛燃烧的技术路线,并以2 T/h蒸汽锅炉为例对气化炉的主要结构参数进行设计计算。采用基于锅炉输出蒸汽压力的气化炉鼓风自适应控制方法实现系统的闭环控制。最后通过实际应用案例实测数据的热能计算证明生物质气化燃气在蒸汽锅炉中代替煤、油燃烧的可行性。 相似文献
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以松木木屑和水稻秸秆作为生物质原料,在自制小型气流床气化炉上开展CO_2/空气混合气化焦油析出特性实验研究,考察CO_2/C比、温度和生物质种类对焦油产率、组分和露点温度的影响。结果表明,相比于纯空气气化,CO_2/空气混合气化能降低焦油产率,促使焦油组分发生改变,特别是杂环化合物和重多环芳烃组分。随着CO_2/C比升高,松木和秸秆的焦油露点温度总体先升高后下降。不同种类的生物质添加相应量的CO_2能有效控制焦油析出,改善产气品质。 相似文献
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在流化床气化炉中生物质与煤共气化的研究(Ⅰ)以空气-水蒸汽为气化剂生产低热值燃气 总被引:2,自引:0,他引:2
在600kW流化床气化炉工业示范装置上以空气.水蒸汽为气化剂,将生物质/煤按不同比例进行了共气化的实验研究.在实验研究的运行条件下,得到了生物质/煤混合比例对气化炉工作温度、燃气热值、气体产率和气化效率等重要技术参数的影响.对玉米芯/煤的比例为81/19时的典型实验结果表明:气化炉工作温度869℃,空气当量比ER=0.21,S/B=0.20时,气体产率1.96m3/kg,燃气热值6.4MJ/m3,气化效率71.3%,燃气中焦油含量小于10mg/m3,该炉经过连续运行考核,运行平稳,工况稳定. 相似文献
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生物质气化技术在国内的应用,目前主要有两个方面:一是产出的可燃气用于供热;二是可燃气用来发电。本讲结合实例介绍生物质气化的热利用情况。1户用生物质气化供热装置 图1所示为生物质气化供热装置,其工作情况如下。 (1)工作过程 该装置多以树枝、废木料、锯末及农业副产物(秸秆、稻壳、果皮、柴草等)作原料,混合加入气化炉的燃料仓内,产出的可燃气经过滤后,再通过输气管道、分气箱送到炊事灶和水加热器等用气装置,以提供炒菜、做饭及室内取暖等生活用能。 (2)使用效果 该装置的气化效率为70%左右,产出的可燃气的低… 相似文献
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生物质气化焦油脱除过程参数优化方法 总被引:1,自引:1,他引:0
焦油是生物质气化过程中的有害产物,它会降低燃气品质,对气化设备及后续用气设备产生危害.本文通过对生物质气化过程中影响焦油生成量的因素进行分析,依据最小二乘曲线拟合原理和目标规划理论建立了生物质料木屑气化过程焦油脱除的参数优化模型,在此基础上采用遗传算法对焦油脱除过程优化模型进行参数寻优.计算结果表明,当气化温度为796.6℃、当量比为0.203时,木屑气化的焦油生成量最小. 相似文献
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Effect of design and operating parameters on the gasification process of biomass in a downdraft fixed bed: An experimental study 总被引:2,自引:0,他引:2
The main objective of this paper is to study the effect of design and operating parameters, mainly reactor geometry, equivalence ratio and biomass feeding rate, on the performance of the gasification process of biomass in a three air stage continuous fixed bed downdraft reactor. The gasification of corn straw was carried out in the gasifier under atmospheric pressure, using air as gasifying agent. The results demonstrated that due to the three stage of air supply, a high and uniform temperature was achieved in the oxidation and reduction zones for better tar cracking. The designing of both the air supply system and rotating grate avoided bridging and channeling. The gas composition and tar yield were affected by the parameters including equivalence ratio (ER) and biomass feeding rate. When biomass feeding rate was 7.5 kg/h and ER was 0.25–0.27, the product gas of the gasifier attained a good condition with lower heating value (LHV) about 5400 kJ/m3 and cold gas efficiency about 65%. An increase in equivalence ratio led to higher temperature which in turn resulted in lower tar yield which was only 0.52 g/Nm3 at ER = 0.32. Increasing biomass feeding rate led to higher biomass consumption rate and process temperature. However, excessively high feeding rate was unbeneficial for biomass gasification cracking and reforming reactions, which led to a decrease in H2 and CO concentrations and an increase in tar yield. When ER was 0.27, with an increase of biomass feeding rate from 5.8 kg/h to 9.3 kg/h, the lower heating value decreased from 5455.5 kJ/Nm3 to 5253.2 kJ/Nm3 and tar yield increased from 0.82 g/Nm3 to 2.78 g/Nm3. 相似文献
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In the present study, hydrogen-rich syngas production via integrated configuration of pyrolysis and air gasification processes of different algal biomass is investigated at relevant industrial condition. A comprehensive steady state equilibrium simulation model is developed using Aspen Plus software, to investigate and evaluate the performance of pyrolysis and air gasification processes of different algal biomass (Algal waste, Chlorella vulgaris, Rhizoclonium sp and Spirogyra). The model can be used as a predictive tool for optimization of the gasifier performance. The developed process consists of three general stages including biomass drying, pyrolysis and gasification. The model validation using reported experimental results for pyrolysis of algal biomass indicated that the predicted results are in good agreement with experimental data. The effect of various operational parameters, such as gasifier temperature, gasifier pressure and air flow rate on the gas product composition and H2/CO was investigated by sensitivity analysis of parameters. The achieved optimal operating condition to maximize the hydrogen and carbon monoxide production as the desirable products were as follows: gasifier temperature of 600 °C, gasifier pressure of 1 atm and air flow rate of 0.01 m3/h. 相似文献
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Biomass gasification has been a viable alternative for decentralized electricity generation in developing countries. The efficiency of the biomass gasification process for operation of the engine‐generator set is mapped in terms of quality and quantity of the producer gas. In this study, we have attempted to devise generalized correlations for four principal parameters that form the benchmark for the performance of the gasifier. These parameters are lower heating value and net yield (per unit biomass) of producer gas, and volume fractions of CO and CO2 in the gas resulting from biomass gasification process. The correlations have been constituted using simulations of gasification of three common biomass feedstocks (viz. rice husk, saw dust and corn cobs) using semi‐equilibrium non‐stoichiometric thermodynamic model. The independent variables used in the simulations are air ratio, carbon conversion, gasification temperature and three elemental ratios in the gasification mixture, viz. H/C, O/H and O/C. As many as eight expressions of linear and non‐linear type have been evaluated to best fit the simulations data for each performance parameter. On the basis of statistical indicators, the compatibility of the correlations for best fit of the data has been assessed. Finally, the predictions of the correlation have been tested against experimental data on gasification of different biomass. The best correlation for each performance parameter was chosen on the basis of least average absolute error and highest (absolute) regression coefficient. It was found that the set of best correlations could predict the values of performance parameters within engineering accuracy of ± 10–20%. The correlations proposed in this work are independent of the type of biomass gasifier. These correlations can form a useful tool for design and optimization of fixed or fluidized bed gasifier for any biomass feedstock. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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《International Journal of Hydrogen Energy》2023,48(66):25635-25644
The byproduct tar from biomass gasification process had seriously impeded development and applications of this technology, thus novel path for biomass tar valorization is had been continuously pursued. Given its high carbon content, this work attempted to convert biomass tar into hierarchically porous carbon by thermal activation with acetate potassium. The optimal product produced with mass ratio of biomass tar to acetate potassium of 1:3 and activation temperature at 800 °C was revealed as excellent electrode material for high-performance supercapacitor, which demonstrated electrochemical capacitance up to 310.4 F/g at 0.2 A/g, whilst preserved 91% of initial capacitance after 5000 charge-discharge circles at current density of 5 A/g. These excellent properties had arisen from the open and hierarchical porosity and large surface area. This work disclosed the great potential of biomass tar as sustainable and competent candidate for fabricating high-performance electrode material for electrochemical energy devices, and may bring up new opportunities to development of biomass gasification technologies. 相似文献
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《International Journal of Hydrogen Energy》2021,46(59):30559-30580
Syngas production from biomass gasification is a potentially sustainable and alternative means of conventional fuels. The current challenges for biomass gasification process are biomass storage and tar contamination in syngas. Co-gasification of two biomass and use of mineral catalysts as tar reformer in downdraft gasifier is addressed the issues. The optimized and parametric study of key parameters such as temperature, biomass blending ratio, and catalyst loading were made using Response Surface Methodology (RSM) and Artificial Neural Network (ANN) on tar reduction and syngas. The maximum H2 was produced when Portland cement used as catalyst at optimum conditions, temperature of 900 °C, catalyst-loading of 30%, and biomass blending-ratio of W52:OPF48. Higher CO was yielded from dolomite catalyst and lowest tar content obtained from limestone catalyst. Both RSM and ANN are satisfactory to validate and predict the response for each type of catalytic co-gasification of two biomass for clean syngas production. 相似文献