Simulation Study of Biomass Gasification

生物质气化是生物质利用过程中热效率较高的一种方法，同时也是一种十分重要的可再生能源利用方式。本文采用AspenPlus模拟软件，结合吉布斯自由能最小原理，建立了生物质气化反应器模型，模拟研究了不同操作参数对气化结果的影响，同时对三种气化剂下的气化结果进行了对比分析。 在三种气化剂的模拟结果中，同一操作参数对气化结果的影响有一定共通性：（1）随着气化温度的升高(600～900℃)，一氧化碳体积分数升高，二氧化碳和甲烷体积分数降低，但氢气体积分数变化不大；气体的热值升高（700℃以上），气体产率先升高后降低，气化效率略微升高。（2）随着S/B的增大(0.2～1.2)，氢气和二氧化碳体积分数升高，...Biomass gasification is considered as one of the most promising technologies because it can convert renewable biomass resources into producer gas. In this study, based on Aspen Plus of process simulation software and the minimization principle of Gibbs free energy, a model for gasifier was developed. The effects of different reaction conditions on gasification performance were studied, and the res...学位：工学硕士院系专业：能源学院_能源化工学号：3242013115229

Simulation of Pine Sawdust Gasification with Oxygen, Steam and Carbon Dioxide as Gasifying Agents

以氧气-水蒸气-二氧化碳作为气化介质,松木屑为原料,采用Aspen Plus软件,结合自建模型,对生物质气化进行了模拟研究。首先,利用文献中的数据对模型进行了验证,模拟结果与文献中的数据基本吻合,证明了该模型的正确性。接着,考察了气化温度、氧气用量（c_（ER））、水蒸气与生物质质量比（m_S/m_B）、二氧化碳与生物质质量比（mCO2/mB）对产气组成、气体热值、气体产率、气化效率和产气氢碳比（n_（H2）/n_（CO））的影响。结果表明：在850℃、101.325 k Pa、c_（ER）=0.2、m_S/m_B=1、mCO_2/m_B=0.6的条件下,气化产物特性为气体热值7.45 MJ/m~3、气体产率1.78 m~3/kg、气化效率73.3%、氢碳比1.79。适当提高气化温度有利于气化。c_（ER）的增大使气体热值、产率和气化效率均迅速降低;但对产气中氢碳比的影响较小。此外,气化剂中水蒸气的适量增加有利于氢气的产生并能明显提高其体积分数,二氧化碳的适量增加有利于一氧化碳的产生并能在一定程度上提高其体积分数,二者均能有效调节产气的氢碳比。Using Aspen Plus software, a model was developed to simulate the gasification of pine sawdust with steam-oxygencarbon dioxide as gasifying agent. At first, the model was verified by the data of literature and the results showed that the model was reliable. And then,the effects of gasification temperature, oxygen equivalence ratio（ CER ） , the mass ratio of steam to biomass （ms/roB） as well as the mass ratio of carbon dioxide to biomass （mco2/mB ） on gas composition, low heating value, yield, gasification efficiency and H/C ratio （n.2/nco） in the produced gas were studied. The low heating value, yield, gasification efficiency and H/C ratio of the produced gas reached 7.45 M）/m3 , 1.78 m3/kg, 13.3 %, 1.79 respectively under the optimum reaction conditions of 850 ℃, 101.325 kPa, CER = 0.2, ms/mB = 1, mco2/mB = 0.6. Higher gasification temperature was favorable to the process of biomass gasification. With the increased CER, the low heating value, gas yield and gasification efficiency decreased rapidly,while H/C ratio was basically keeping stable. The amount of steam added into gasification agent enhanced H2 content in the produced gas ; while appropriate amount of CO2 added would improve the CO content. Therefore, either of the above two measures could effectively adjust the H/C ratio in the produced gas.福建省科技厅高校产学合作项目（2016H61010067

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies