【作者】 邵守言；

【导师】 王辅臣；

【作者基本信息】 华东理工大学 ， 化学工艺， 2012， 博士

【摘要】 发酵法生产酒精会产生大量的酒精废液,直接排放将产生严重的环境污染,其已成为制约酒精工业可持续发展的瓶颈。基于酒精发酵废液的特点和现有处理方法的不足,结合作者企业建有水煤浆气化装置的实际,借鉴较成熟的水煤浆气流床气化技术,提出将酒精废液和煤混合制浆共气化的工艺思想。论文通过对酒精发酵废液与煤的成浆特性、废液煤浆浆滴的雾化性能、废液煤浆的气化特性及磷在气化系统内的分布规律的研究,以及根据气化结果所做的经济和环境效益分析,得主要研究结果如下：1.研究了粗细颗粒比、分散剂种类和用量一定时,5种煤样和酒精发酵废液的成浆性,结果表明：玉米和木薯酒精发酵废液煤浆均表现出剪切变稀或假塑性流体的特征,且煤浆固含率越高,浆体的剪切变稀行为或假塑性行为越明显；制浆其他条件相同时,用酒精发酵废液全部或部分代替去离子水制浆,所得合格废液煤浆的固含率均低于水煤浆,并且酒精发酵废液高的粘度和低的pH值使废液煤浆的稳定性变差；用玉米及木薯酒精发酵废液制水煤浆在工业应用上是可行的。2.利用高速摄像仪,研究了水煤浆和不同废液煤浆浆滴在高速气流中的运动、变形与破裂情况及其规律,结果表明：当水煤浆和酒精发酵废液煤浆具有较低粘度和较好流动性时,从雾化性能考虑,废液煤浆在破裂时间和破裂粒径两方面都表现出比水煤浆更好的雾化效果。酒精发酵废液煤浆浆滴的破裂模式均可分为拉伸破裂和剪切破裂两种,且与水煤浆相比,废液煤浆更易发生拉伸和剪切破裂模式。在拉伸破裂模式下,玉米和木薯粗馏塔后发酵废液煤浆的破裂时间较短,总特征时间在2.0～4.0左右；在剪切破裂模式下,玉米一次厌氧后和木薯粗馏塔后废液煤浆的破裂时间较短,总特征时间在1.5～2左右。木薯粗馏塔后发酵废液煤浆浆滴在较低的We数下即能破裂,破裂临界气速较低；且在60 m/s和90m/s喷嘴出口气速下,其浆滴破裂平均粒径SMD较小。说明该煤浆易于工业雾化,工业应用价值较高。3.借助内窥式工业电视、高温热偶、质谱仪等在四喷嘴对置式气化炉小型热模实验平台上,研究了废液煤浆气化撞击火焰稳定性、气化温度分布、各气体浓度分布等,结果发现：在给定的实验条件下,各废液煤浆均能顺利气化,撞击火焰形状和稳定性无明显区别；撞击火焰集中在气化炉的中心区域；相对于两喷嘴撞击,四喷嘴撞击火焰更加集中,也更加稳定；气化撞击火焰的稳定性主要与煤质特性有关,短时间内,各废液煤浆自身特点对气化的影响不明显。4.采用Aspen Plus过程模拟软件对水煤浆和酒精发酵废液煤浆的气化过程进行了模拟,并据此对酒精发酵废液与煤成浆共气化的经济和环境效益进行了分析评价,结果表明,随着成浆时酒精发酵废液掺入比例的增加,合成气中CO的含量略降低、H2和CO2的含量均略增大,有效气含量略降低,比氧耗略增大、比煤耗降低；与日处理2000吨煤(干基)的水煤浆气化相比,在产生等量有效气的情况下,玉米和木薯发酵废液煤浆气化,每年可分别节煤0.20万吨和0.08万吨,节水2.15万吨和3.47万吨,减排CO20.56万吨和0.23万吨。5.对木薯发酵废液与煤混合制浆后气化系统内磷的分布规律研究表明,进入气化炉的磷主要转化为PH3,其他磷的化合物的量非常少；气化炉生成的PH3主要存在于废水中排出气化装置,出水洗塔合成气中几乎不含PH3。更多还原

【Abstract】 The process of alcoholic fermentation will produce large amounts of alcohol fermentation wastewater(AFW). The direct discharge of untreated AFW will cause serious environment pollution and huge waste of the resources, which has became the bottleneck restricting the sustainable development of alcohol industry. Based on the characteristics of AFW and the shortage of the existing processing method, the craft idea of co-gasification and slurrying of AFW and coal has been put forward according to more mature coal water slurry (CWS) entrained-flow gasification technology. The slurryability of AFW and coal, the atomization performance of slurry droplet, the gasification characteristic of coal AFW slurries(CAFWS) and the distribution laws of Phosphorus in the gasification system were researched, meanwhile, the environmental and economic benefits of CAFWS gasification were analysed. The principal conclusions obtained are as follows:1. The slurryabilities of five kinds of coal and AFW have been investigated respectively as the mass ratio of coarse particle to fine particle, the variety and amount of dispersing agents are given. It is showed that it is feasible for industrial application to prepare coal slurry with maize AFW(MAFW) and cassava AFW(CAFW). The coal MAFW and coal CAFW slurries exhibited shear-thinning behavior. The higher solid concentration in coal slurry was, the more significant shear-thinning or pseudo-plastic behavior was. The solid concentration in the qualified CAFWSs which were prepared by totally or partly substituting AFW for deionized water is lower than that in CWS. At the same time, the stabilities of CAFWSs become poor due to high viscosity and low PH of AFW.2. The movement, deformation and rupture of slurries droplets in high speed air were researched with high speed camera. The results showed that when CAFWSs and CWS are of lower viscosity and better fluidity, CAFWSs have the better atomization performance in rupture time and particle size than CWS does. The rupture of slurry droplets of CAFWS has two patterns:elongating rupture pattern and shear rupture pattern. Compared with CWS, the two rupture patterns of CAFWS droplets occur more easily. In elognating rupture pattern, the rupture time of the slurry droplets of maize and cassava fermentation wastewater from crue distillation tower is shorter, and the total dimensionless time is about 2.0-4.0s. While in shear rupture pattern, the rupture time of the slurry droplets of maize wastewater from once anaerobic and cassava wastewater from crue distillation tower is shorter, and the total dimensionless time is about 1.5-2.0s. The critical rupture velocity of the slurry droplets of the cassava crude distillation tower wastewater which can breakup in lower We number is low. At 60m/s and 90m/s (nozzle exit velocity), the average breakup diameter (SMD) is smaller. From the above discussion, the CCAFWS can be easily atomized, and be of good value for industrial applications.3. On bench-scale hot-model experimental platform of opposed multi-burner gasifier, impinging flame stability, gasification temperature distribution, gas concentration distribution were studied by using endoscopic industrial TV, high temperature thermocouples, mass spectrograph. The results show that all CAFWSs can be gasified successfully, and there are no significant differences in shape and stability of impinging flame between CAFWS and CWS. The impinging flame is concentrats in the central area of gasifier. Compared with two-nozzle impinging, the flame of four-nozzle impinging is much more concentrated and stable. The stability of impinging flame is mainly related to coal characteristics, the effects of CAFWS characteristics on gasification aren’t significate in short time.4. Based on Aspen Plus software, the gasifications of CWS and CAFWS were simulated, and according to the simulation results, the economic and environmental benefits of slurrying and co-gasification were analysed and evaluated. The results showed that with increasing blending ratio of AFW, the contents of CO and effective gas in syngas and specific coal consumption slightly decrease, while the contents of H2 and CO2 in syngas, and specific oxygen consumption slightly increase. Compared with CWS gasification handling 2000 ton/d of coal(by dry basis), in the case of producing equivalent effective gas, each year CCAFWS and CMAFWS gasifications can save 2.0 and 0.8 thousand ton coal respectively,21.5 and 34.7 thousand ton water each year, and reduce the emissions of CO2 5.6 and 2.3 thousand ton.5. The distribution of Phosphorus in CCAFWS gasification system were investigated. The results show Phosphorus entering into the gasifier primarily is converted into PH3, the amount of other compounds of phosphorus is very little. PH3 produced from gasification exists primarily in wastewater and is eventually discharged from the gasification system, while there is almost no PH3 in the syngas out of the water scrubber.更多还原