油页岩微波干燥过程分析及模拟  

Analysis and simulation of the microwave drying of oil shale

作　　者：柏静儒[1] 孙灿辉[1] 张亮[1] 王擎[1] 

机构地区：[1]东北电力大学油页岩综合利用教育部工程研究中心,吉林吉林132012

出　　处：《化学工程》2017年第2期26-32,共7页Chemical Engineering(China)

基　　金：吉林省重点科技攻关项目(20140204004SF);长江学者和创新团队发展计划(IRT13052)

摘　　要：以柳树河油页岩为原料,分别在100℃热风温度和不同的微波功率的干燥条件下进行试验;用Weibull分布函数对油页岩的干燥曲线进行拟合分析,结合尺度参数估算水分有效扩散系数。结果表明:加速干燥阶段脱除的是油页岩颗粒的表面水;前期存在预热过程,温度升高,水分析出很少;随后干燥速率显著增大。恒速阶段析出的也是表面水,受物理脱附作用的影响;功率越大,恒速段时间越短。降速第一阶段主要是大孔隙中水分的脱除,降速第二阶段主要是中孔和微孔中水分的汽化。临界水分比随功率的增加而升高。Weibull分布函数准确模拟了油页岩微波干燥曲线;尺度参数α值随功率增加而减小,功率大于550 W后减小幅度降低;微波干燥的形状参数β>1,即升速段出现在干燥前期;估算的水分有效扩散系数随功率增加而增大。微波干燥和热风干燥时相比,油页岩颗粒形态并没有发生显著变化。Liushuhe oil shale was adopted as the raw materials to achieve drying test, the drying experiments were carried out at different microwave power and 100 degrees Celsius hot air temperature. Weibull distribution function was used to simulate and analyze the drying kinetics curves, and the effective diffusion coefficient of water was estimated with scale parameters. The results showed that the rising-rate drying stage removal of oil shale particle surface water, there was a pre heating process in this dry period, with the temperature increase, the moisture removal was less; then the drying rate increased significantly. The removal of water of constant-rate drying stage was also the surface water, which was affected by physical desorption, and the time of constant velocity stage decreased with the increase of the power. In the first falling-rate phase, the removal of water from large pores, the second falling-rate stage, the removal of water from the middle pores and micro holes. The critical moisture content increased with the increase of power. Weibull distribution function was good at simulating the process of microwave drying of oil shale. The scale parameter decreased with the increase of power, but the decrease rate of the scale parameter reduced after the power was larger than 550 W. The shape parameter fl 〉 1 in microwave drying, there was a rise rate stage in the drying pre-period. Based on weibull model, the estimated moisture effective diffusion coefficient increased with the increase of the power. The oil shale particle morphology in the microwave drying had no significant change when compared to hot air drying.

关 键 词：油页岩 微波干燥 干燥速率 临界水分比 有效水分扩散系数 

分 类 号：TE662[石油与天然气工程—油气加工工程]