Investigating the Phase Equilibria of Branched Alcohol/Water/Salt Mixtures

研究支链醇/水/盐混合物的相平衡

• 批准号: RGPIN-2022-03196
• 负责人: RamosPallares, Francisco
• 金额: $ 2.4万
• 依托单位: Lakehead University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=747181
• 关键词: Investigating; Phase; Equilibria; Branched; Alcohol

Branched alcohols are more suitable to produce fuel additives and biofuels than methanol and ethanol because their properties are similar to those of gasoline. However, their production at large scale in biorefineries is currently not economically viable because of the higher cost of purification through distillation. The addition of some salts to the fermentation broth reduces the affinity of the alcohol with the broth, facilitating the purification. Therefore, the phase behaviour of these electrolyte systems is required for designing cost-efficient purification operations. The proposed research has the following objectives, which aim to address critical gaps in the fundamental understanding of the thermodynamics of branched alcohols/water/salt mixtures to advance in the development of modelling tools for the design and simulation of purification operations in biorefineries. Objective 1-Develop a Data-Validated Activity Coefficient Model Using Data Collected from Liquid- Liquid Equilibrium (LLE) Studies: The addition of some salts to an alcohol/water mixture forces the alcohol to separate off the mixture. However, the LLE data required to shed light on the thermodynamics of the mixture are scarce and available models are correlative rather than predictive. It is proposed to collect LLE data for branched alcohol/water/salt mixtures over a range of temperatures and pressures to investigate its thermodynamics, and to incorporate it into an activity coefficient-based model. Objective 2- Develop a Data-Validated Hybrid Model Using Data Collected from Vapor-Liquid Equilibrium (VLE) Studies: The addition of some salts to an alcohol/water mixture increases the relative volatility of the alcohol facilitating its separation from the mixture by distillation. However, VLE data for branched alcohol/water/salt mixture are scarce. It is proposed to investigate the effect of the salt on the VLE of these mixtures and to develop a Cubic Equation-of-State/Activity Coefficient hybrid model. Objective 3- Propose an Equation-of-State-Based Modelling Methodology: The electrolyte version of the Cubic Plus Association (e-CPA) equation of state (EoS) has the potential to be applied to model the phase behaviour of branched alcohol/water/salt mixtures across the phase diagram. However, this EoS does not produce accurate phase compositions for LLE and has not been tested on data at high pressure. It is proposed to develop a suitable e-CPA based methodology suitable for biorefinery applications. The results from this research will allow biorefinery operators to design cost-effective purification operations to produce fuel-grade branched alcohols. Canada will benefit from more competitive and greener biorefineries. In addition, two M.Sc. and one Ph.D. students will receive background and training suitable for careers in the industry and academia.

支链醇比甲醇和乙醇更适合用于生产燃料添加剂和生物燃料，因为它们的性质与汽油相似。然而，由于通过蒸馏提纯的成本较高，目前在生物精炼厂大规模生产它们在经济上是不可行的。在发酵液中加入一些盐可降低酒精与发酵液的亲和力，有利于纯化。因此，这些电解质系统的相行为是设计成本效益的净化操作所必需的。拟议的研究有以下目标，旨在解决对支链醇/水/盐混合物热力学基本理解的关键空白，以推进用于生物精炼厂净化操作设计和模拟的建模工具的开发。目的1-利用从液-液平衡（LLE）研究中收集的数据建立数据验证的活度系数模型：在酒精/水混合物中加入一些盐会迫使酒精从混合物中分离出来。然而，揭示混合物热力学所需的LLE数据很少，可用的模型是相关的，而不是预测的。本文建议在一定温度和压力下收集支链醇/水/盐混合物的LLE数据，以研究其热力学，并将其纳入基于活度系数的模型。目标2-利用从汽液平衡（VLE）研究中收集的数据建立数据验证的混合模型：在酒精/水混合物中加入一些盐会增加酒精的相对挥发性，从而促进酒精通过蒸馏从混合物中分离出来。然而，支链醇/水/盐混合物的VLE数据很少。研究了盐对这些混合物的VLE的影响，并建立了三次状态方程/活度系数混合模型。目标3-提出一种基于状态方程的建模方法：电解质版本的Cubic Plus Association （e-CPA）状态方程（EoS）有可能应用于模拟支链醇/水/盐混合物在相图上的相行为。然而，这种EoS不能为LLE产生准确的相组成，也没有在高压下的数据上进行测试。建议开发一种适合生物炼制应用的基于e-CPA的方法。这项研究的结果将使生物精炼厂经营者能够设计出具有成本效益的净化操作，以生产燃料级分支醇。加拿大将受益于更具竞争力和更环保的生物精炼厂。此外，两名硕士和一名博士学生将接受适合工业界和学术界职业的背景和培训。