双碳目标的提出对化工生产中精馏塔的节能提出了新要求。本文以N,N-二甲基乙酰胺-水二元混合体系为例,采用Aspen Plus V 11化工模拟软件对普通精馏技术和双效精馏技术进行模拟与优化,并对两种不同精馏技术的能耗和环境进行评价。模拟计...双碳目标的提出对化工生产中精馏塔的节能提出了新要求。本文以N,N-二甲基乙酰胺-水二元混合体系为例,采用Aspen Plus V 11化工模拟软件对普通精馏技术和双效精馏技术进行模拟与优化,并对两种不同精馏技术的能耗和环境进行评价。模拟计算结果表明,在相同的设计基础和分离要求下,采用双效精馏可明显降低分离能耗近40%且环境友好,具有较强的节能优势和较少的二氧化碳排放。另外,两种不同的双效精馏技术中,逆流双效精馏技术稍优于顺流双效精馏技术。展开更多
以Aspen Plus 10.1为计算工具,评价了16个热力学模型对氨-水体系气液平衡预测的适用性。在中低压下,适宜的模型有LK-PLOCK、PR、RKS和PSRK等状态方程模型以及WILS-RK、NRTL-RK、UNIQUAC-RK和ELECNTRL等活度系数模型。各模型预测的准确...以Aspen Plus 10.1为计算工具,评价了16个热力学模型对氨-水体系气液平衡预测的适用性。在中低压下,适宜的模型有LK-PLOCK、PR、RKS和PSRK等状态方程模型以及WILS-RK、NRTL-RK、UNIQUAC-RK和ELECNTRL等活度系数模型。各模型预测的准确性有如下顺序:PSRK>NRTL-RK>PR>LK-PLOCK>RKS,各模型对液相的预测准确性要明显高于气相。展开更多
Ulexite dissolution in water has been studied in the wide temperature range from 10℃ to 93 ℃ and two higher temperatures at 120 ℃ and 240 ℃. The analytical results showed that ulexite dissolved congruently from 10...Ulexite dissolution in water has been studied in the wide temperature range from 10℃ to 93 ℃ and two higher temperatures at 120 ℃ and 240 ℃. The analytical results showed that ulexite dissolved congruently from 10 ℃ to 35 ℃ and incongruently from 40 to 68 ℃. The solid component of ulexite, NaCaB5O6(OH)6·5H2O was dehydrated to form NaCaB5O6(OH)6·H2O from 50 to 68 ℃ and finally amorphous solid at 68 ℃. This amorphous solid converted into priceite at 71 ℃ and then converted completely to priceite at the boiling point(93 ℃) of the solution. At both 120 and 240 ℃, the dissolution of ulexite was an incongruent process. Above 120 ℃, ulexite became amorphous solid and then transformed into priceite. In addition to the solid to solid transformation, crystallization of priceite from the solution has also been observed. Based on our experimental results, mechanisms of dissolution, transformation, and crystallization of borate in ulexite-water system are discussed.展开更多
文摘双碳目标的提出对化工生产中精馏塔的节能提出了新要求。本文以N,N-二甲基乙酰胺-水二元混合体系为例,采用Aspen Plus V 11化工模拟软件对普通精馏技术和双效精馏技术进行模拟与优化,并对两种不同精馏技术的能耗和环境进行评价。模拟计算结果表明,在相同的设计基础和分离要求下,采用双效精馏可明显降低分离能耗近40%且环境友好,具有较强的节能优势和较少的二氧化碳排放。另外,两种不同的双效精馏技术中,逆流双效精馏技术稍优于顺流双效精馏技术。
文摘以Aspen Plus 10.1为计算工具,评价了16个热力学模型对氨-水体系气液平衡预测的适用性。在中低压下,适宜的模型有LK-PLOCK、PR、RKS和PSRK等状态方程模型以及WILS-RK、NRTL-RK、UNIQUAC-RK和ELECNTRL等活度系数模型。各模型预测的准确性有如下顺序:PSRK>NRTL-RK>PR>LK-PLOCK>RKS,各模型对液相的预测准确性要明显高于气相。
文摘Ulexite dissolution in water has been studied in the wide temperature range from 10℃ to 93 ℃ and two higher temperatures at 120 ℃ and 240 ℃. The analytical results showed that ulexite dissolved congruently from 10 ℃ to 35 ℃ and incongruently from 40 to 68 ℃. The solid component of ulexite, NaCaB5O6(OH)6·5H2O was dehydrated to form NaCaB5O6(OH)6·H2O from 50 to 68 ℃ and finally amorphous solid at 68 ℃. This amorphous solid converted into priceite at 71 ℃ and then converted completely to priceite at the boiling point(93 ℃) of the solution. At both 120 and 240 ℃, the dissolution of ulexite was an incongruent process. Above 120 ℃, ulexite became amorphous solid and then transformed into priceite. In addition to the solid to solid transformation, crystallization of priceite from the solution has also been observed. Based on our experimental results, mechanisms of dissolution, transformation, and crystallization of borate in ulexite-water system are discussed.
