超重力精馏回收果胶沉淀溶剂的应用

同时应用超重力精馏连续与间歇操作分离回收果胶沉淀溶剂中的乙醇,并以不锈钢波纹丝网为填料,在原料乙醇质量分数x_f=55%、回流比R=4、超重力因子β=63.16～252.67、原料流量F=15～50L/h、1.01×10⁵Pa和室温进料下操作,研究了四级超重机在连续精馏过程中的传质性能;并在β=161.71、R=2.5～7及1.01×10⁵Pa操作条件下,考察了间歇精馏过程中不同回流比R对塔顶和塔底乙醇浓度x_d和x_w的影响.结果表明,在连续精馏过程中,理论塔板数N_T随β和F的增大而增加,设备的等板高度HETP为41.12～58.21mm,x_d=93%,x_w=35%;在间歇精馏过程中,x_d随着R的增大先增高后降低,x_w随着R和t的增大而下降,所得产品x_d为92.5%,x_w为1.05%;乙醇分离回收效果良好,回收率为91.28%,单位回收乙醇产品成本为0.644元/L,充分表现出超重力精馏工艺应用于果胶沉淀溶剂的回收再利用的优势.

Application of higee distillation for pectin precipitation solvent recovery

The continuous and intermittent processes of higee distillation separation were used in recycling ethanol in the solvent of pectin precipitation at the same time. With stainless steel wave thread packing,mass transfer of four-stage higee distillation continuous process was studied,under the conditions of atmospheric pressure and ambient temperature,feedstock mass fraction x_f of 55%,reflux ratio R of 4,average high gravity factor β of 63.16—252.67,feedstock flux F of 15—50 L/h. Different operating conditions impacting on the tower top ethanol mass fraction x_d and tower bottom ethanol mass fraction x_w were also studied in the four-stage higee distillation batch process,under the conditions of atmospheric pressure,R of 2.5—7,β of 161.71. Under the operation of continuous process,the number of theoretical plate N_T of four-stage higee distillation equipment increased with increasing β and F; the height equivalent of theoretical plate HETP was 41.12—58.21mm; x_d was 93% and x_w was 35%. Under the operation of batch process,x_d increased first then decreased with increasing R,while x_w decrease with R and t; x_d is 92.5% and x_w is 1.05%. The separation effect of Ethanol recycling is good,and recovery rate was 91.28%. The cost of unit ethanol recovery was 0.644 yuan/L,showing advantage of higee distillation in recycling ethanol in the solvent of pectin precipitation.