【作者】 王洪海；

【导师】 李春利；

【作者基本信息】 河北工业大学 ， 化学工艺， 2010， 博士

【摘要】 发酵法丙酮-乙醇-丁醇溶剂生产是丙酮和生物丁醇(丙丁)的主要生产方式之一,其过程中的蒸馏系统工艺复杂,能耗高,改造和优化困难,所以一直沿用老的四塔流程或五塔流程。本文对发酵法丙酮-丁醇生产的四塔流程蒸馏系统进行了深入研究。针对该系统工艺复杂、参数多、流股之间耦合严重、计算难收敛的特点,利用解耦算法对其进行解耦,将整个蒸馏系统划分为醪塔子系统、丁塔子系统和乙丙子系统三部分,建立了算法的数学模型。通过分析发酵醪液中主要成分及其相互间作用特性,利用PRO/Ⅱ流程模拟软件,对该系统进行了模拟计算,并以某工厂实际生产数据为计算基础,对计算模型进行了修正。在此基础上,通过详细分析模拟计算结果,提出了该蒸馏系统中存在的不足。以节能减排为最终目标,提出了新工艺。新工艺主要包括侧采工艺、热泵回收工艺、塔顶回流工艺、热量综合利用工艺及丁醇分离器的重新设计等。以醪塔为研究对象,对所建立的新工艺进行了实验研究。实验数据和模拟数据吻合良好,证明了新工艺的可行性。为了对所提出的新工艺进行全面优化,引入统计学方法——响应面优化法(RSM),以塔顶含水量或塔釜残余溶剂含量最小为响应值,对蒸馏系统中的醪塔、1#丁醇塔和丙酮塔的多个操作参数进行了综合优化,建立了影响因素与优化目标之间的数学模型,得到了最优的参数组合。对所得到的最优参数组合,重新利用PRO/Ⅱ流程模拟软件进行模拟计算,得到综合优化后的最优值。结果表明,所建立的数学模型是正确的,综合优化后的计算结果较单参数优化后的结果更优。为了考察RSM优化结果的可靠性,以1#丁醇塔和丙酮塔为研究对象,对综合优化结果进行了实验研究。实验结果与RSM优化结果一致,验证了RSM用于精馏塔多参数综合优化的可靠性。将优化后的新工艺在某工厂的节能项目改造中进行了实际应用,生产运行数据与优化计算数据吻合良好,节能减排效果明显。与原工艺相比,节能达到40%,降低排放达到75%以上,证明了新工艺的先进性和可靠性。该论文的研究对复杂蒸馏系统的综合优化提供了理论支持。更多还原

【Abstract】 Acetone and bio-butanol were mainly produced by acetone-butanol-ethanol (ABE) fermentation process, which uses bacterial fermentation to produce acetone,1-butanol and ethanol from starch. The traditional four-column or five-column distillation process is still in use because the distillation system in the fermentation process is very complex and difficult to modify and optimize, with high energy consumption.In this thesis, the four-column distillation system was studied for the fermentation production of acetone-butanol. Considering the system’s complexity, multi-parameters, severe coupling between streams, and non convergence during calculation, the whole distillation system was divided into three subsystems using the decoupling algorithm: prefractionator subsystem, butanol subsystem and ethanol acetone subsystem. And a mathematical model was built based on the subsystems. By using PRO/II process simulation software, the distillation system was simulated by analyzing the main components in the fermentation broth as well as their interactions, and then the mathematical model was modified based on the actual production data collected in a real factory.Through a detailed analysis of the simulation results, the distillation system deficiencies were found and a new process was proposed with the ultimate goal of energy saving and emission reduction. The new distillation process mainly included the side withdrawal technology, heat pump recovery process, reflow process, and comprehensive utilization of heat as well as a re-design of the butanol separator. Experimental data were collected in the prefractionator. Experimental data and simulated data agreed well, which proved the feasibility of the new process.One statistical method, response surface methodology (RSM), was introduced in order to optimize the new process completely. By minimizing the water content in the top or the solvent content in the bottom, many parameters were optimized together in the distillation system including prefractionator, 1#butanol column, and acetone column; mathematical models were built to correlate the factors and the objectives and then the optimized groups of parameters were obtained. Based on the obtained optimal parameters, PRO/Ⅱprocess simulation software was reused to obtain the integrated optimal value. The results showed that the mathematical models were correct and the integrated optimized results were more accurate than the results from single-parameter optimization.In order to investigate the reliability of RSM optimization results, experimental data were obtained from the 1#butanol and acetone columns. The results agreed well with the integrated optimal values, which verified that RSM was reliable when used for multi-parameter optimization for the distillation system.The optimized new process has been applied in a project of energy-saving and consumption-reducing technological transformation. Run data and the calculated data agreed well. Compared to the traditional process, the effect of energy saving and consumption-reducing can reach 40% and 75% individually. That proved the advanced nature of this new technology and its reliability. The studies in this thesis provided a theoretical support on integrated optimization of the complex distillation system.更多还原