超滤-反渗透组合膜分离偶联真空浓缩鸡骨素中试

该研究以鸡骨素为原料,中试条件下对比分析了真空浓缩与2种膜组合偶联真空浓缩工艺的优劣。通过测定真空浓缩工艺的浓缩速率和水分去除率,微滤-反渗透和超滤-反渗透组合膜的膜通量、物料损失率、干物质损失率和蛋白损失率,研发了梯度膜分离与真空浓缩偶联的新型骨素浓缩工艺并进行了中试研究。结果显示:真空浓缩前期60 min内可溶性固形物含量升高缓慢,浓缩速率低,耗能大;微滤、超滤、纳滤和反渗透膜分离的物料损失率为0.5%、6.25%、4%、7.1%,干物质损失率为1.6%、19.4%、22.4%、20%,蛋白质损失率分别为35.8%、25.7%、22%、16%,膜通量衰减速率与膜孔径呈现负相关;膜组合结果表明超滤-反渗透膜组合能够提高反渗透膜通量,显著减少物料损失和干物质损失(P0.01)。中试结果表明,超滤-反渗透-真空浓缩工艺耗时110 min,耗资27.85元,耗煤11.018 8 kg,污染气体SO2和NOx的排放量分别为0.010 1 kg和0.014 6 kg。超滤-反渗透-真空浓缩新型工艺缩短了浓缩时间,降低了生产成本,污染气体的排放显著(P0.01)减少,一定程度上实现了节能减排,可以作为一种新型工艺用于鸡骨素浓缩生产。

Pilot-plant test of ultrafiltration-reverse osmosis membrane separation coupling with vacuum concentration technology of chicken bone extract

Abstract: In this study, the concentration technologies of chicken bone extract (Brix=4%), involving vacuum concentration technology and other two membrane combination concentration technologies, were investigated with the pilot scale production. Firstly, the conventional vacuum concentration (VC) technology was studied by determining the concentration rate and the water removed rate, and then the properties of different single osmotic membrane were analyzed by detecting the changes of membrane flux and the loss rates of material, dry matter and protein. After that, we also studied the membrane combination separation technologies that included the microfiltration-reverse osmosis combination (MF-RO) technology and ultrafiltration-reverse osmosis combination (UF-RO) technology. Ultimately, we developed a new concentration technology of chicken bone extract that was, a kind of gradient membrane combination coupling with the vacuum concentration technology, and ultrafiltration-reverse osmosis-vacuum concentration (UF-RO-VC) technology. Simultaneously, the advantages and disadvantages of the traditional VC technology were compared with the reverse osmosis-vacuum concentration (RO-VC) technology and UF-RO-VC technology. Results suggested that, as for the conventional VC technology, the Brix increased very slowly prior to 60 min of the concentration, which resulted in decreasing the rate of concentration and much more energy consumption. And the results of single membrane concentration indicated that the membrane fluxes of microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) were all decreased with the proceeding of concentration, and the membrane flux showed the negative correlation with the membrane diameter. Besides that, these four different membrane separation technologies could contribute to some losses of the chicken bone extract, which included the materials loss (the loss rates were 0.5%, 6.25%, 4% and 7.1%, respectively), the dry matter loss (the loss rates were 1.6%, 19.4%, 22.4% and 20%, respectively) and the protein loss (the loss rates were 35.8%, 25.7%, 22% and 16%, respectively). For the membrane combination separation technologies, results indicated UF-RO technology was able to decrease dramatically the materials and dry matter loss (P<0.01), and meanwhile the membrane flux of the reverse osmosis membrane was increased 2 - 3 times, which was compared with the MF-RO technology. The chicken bone extract of 360 kg, as the pilot-plant test, was concentrated through the technologies that included the VC technology, RO-VC technology and UF-RO-VC technology. As for these three concentration technologies, the results suggested that the time-consuming was 120, 105 and 110 min, respectively; power consumption was 1.62, 2.81and 3.57 kW·h, which was concerted into standard coal consumption being 0.199 1 kg, 0.345 3 kg and 0.438 8 kg, respectively; standard burning coal converting from steam consumption was 63.46 kg, 23.8 kg and 10.58 kg, respectively; emission of pollution gas SO2 was 0.057 6 kg, 0.021 9 kg and 0.010 1 kg, and NOx was 0.068 2, 0.0278 5 and 0.014 6 kg, respectively. Eventually, the total cost was 33.03, 50.78 and 27.85 yuan, and total standard coal consumption was 63.659 1 kg, 24.145 3 kg and 11.018 8 kg. Taken together, the UF-RO-VC technology can be considered as an optimal concentration technology to obtain the chicken bone extract. Comparing with the conventional VC technology, this new kind of concentration technology could be recognized to be much more friendly to environment as it is capable of concentrating the chicken bone extract with decreasing the cost, saving concentration time, reducing the consumption of standard coal and emission of pollution gases significantly (P<0.01).