【作者】 李陶陶；

【导师】 许加超；

【作者基本信息】 中国海洋大学 ， 水产品加工及贮藏工程， 2011， 硕士

【摘要】 本文主要研究了褐藻胶生产节能减排关键技术及褐藻胶含量脱羧检测方法,对现有褐藻胶生产工艺中的冲稀漂浮及絮凝两个主要步骤进行了改进,并研究了关键技术对褐藻胶的得率、质量、耗水量、过滤程度及成本的影响,以减少褐藻胶生产用水,提高褐藻胶质量,达到节能减排的目的,并为褐藻胶的生产及应用提供可靠的理论依据。1.研究了脱羧法的反应条件并对褐藻胶含量测定方法进行了比较,确定了脱羧法的反应条件为6mol/L的盐酸溶液。探讨了四种方法的线性相关性,实验结果显示脱羧法、咔唑比色法、醋酸钙法的线性相关性很好,重量法的线性相关性较差一些。对四种褐藻胶含量测定方法的稳定性研究发现,脱羧法的稳定性较好,四种方法中醋酸钙法的稳定性最好。2.研究了冲稀漂浮工艺的节能减排技术。单因素实验确定了壳聚糖添加工艺的最佳漂浮时间为6h,最佳壳聚糖添加量为7.5ppm,最佳稀释倍数为110倍,最佳pH为原始pH。正交试验得壳聚糖添加工艺最优组合条件为漂浮时间为5h、壳聚糖添加量为9ppm、稀释倍数为100倍,此条件下,耗水量降低了25.19%,时间缩短了50%以上,得率提高了2.58%,达到了节能减排的目的。单因素实验确定稀释倍数为80倍和90倍时壳聚糖最佳添加量均为15ppm,并比较了稀释80倍和稀释90倍在其最佳壳聚糖添加量条件下与传统工艺的褐藻胶得率及过滤时间。若不将褐藻胶得率作为第一评定标准,而以耗水量的减少量为评定标准,在不增加过滤难度的前提下,稀释倍数为90倍、漂浮时间为6h、壳聚糖添加量为15ppm、pH为原始pH将是壳聚糖添加工艺最佳组合条件。该条件下,耗水量减少了30.68%,褐藻胶得率提高了1.39%。3.研究了絮凝工艺的节能减排技术。采用钙析法和酸析法两种方法制得褐藻胶,并比较了褐藻胶的水分、粘度、灰分含量、透明度、水不溶物含量、凝胶强度、含钙量、纯度这八个主要质量指标,结果表明,酸析法与钙析法所得褐藻胶在水分、灰分含量、透明度、含钙量和纯度指标上没有显著差异,但酸析法所得褐藻胶的水不溶物含量较钙析法低,粘度及凝胶强度均高于钙析法,且差异显著,这说明酸析法所得褐藻胶的质量优于钙析法所得褐藻胶,而且酸析法成本低,耗水量低,耗时短,两种方法制备褐藻胶的得率无显著性差异,可达到节能减排的目的。更多还原

【Abstract】 This study is to investigate the key technologies of energy saving and emission reduction in alginate production and decarboxylation method for alginate quantification. The process is improved mainly through altering the steps of dilute floatage and flocculation. The influence of the technologies on yield, quality, water consumption, filtration time and costs of alginate production is also conducted, in order to decrease the water consumption and provide reliable references for alginate production and applications.1. The reaction condition of decarboxylation method is studied, and four determinations for alginate quantification are compared. The reaction condition of decarboxylation method is 6mol/L hydrochloric acid solution.The linear correlation of four determinations is discussed. The results show that the linear dependence of decarboxylation method, colorimetry of carbazole and calcium acetate method is perfect. Besides, the study on the stability of four determinations indicates that the stability of decarboxylation method is good, and calcium acetate method gets the best stability.2. The technology of energy saving and emission reduction in dilute floatage process is discussed. Single factor experiment shows that the optimum floating time is 6h, the optimum chitosan addition is 7.5ppm, the optimum dilution multiple is 110 and the optimum pH is original pH. The optimum conditions obtained by the orthogonal test are as follows:floating time is 5h, chitosan addition is 9ppm and the dilution multiple is 100. Under these conditions, the water consumption reduces 25.19% and the time decreases above 50% while the yield of alginate increases 2.58%, which suggests the new technology could save energy and reduce emission.The optimum chitosan addition is 15ppm with the dilution multiple is 80 or 90 through single factor experiment. And the alginate yield and filtration time are compared with the traditional process. If the reduction of water consumption is the first assessment standard and the filtration time is not increased,90 dilution multiple with 15ppm chitosan addition will be the best process conditions. Under these conditions, the water consumption reduces 30.68% while the alginate yield increases 1.39%.3. The technology of energy saving and emission reduction in flocculation process is studied. There are two methods, calcification precipitation and acidulation precipitation, to extract alginate in production. The water content, viscosity, ash content and transparency are measured of alginate collected from the above two methods. The water-insoluble content, gel strength, level of calcium and purity are also detected.The results indicate that there are no significant differences in water content, ash content, transparency, level of calcium and purity between the alginate samples extracted by the two methods. However, the water-insoluble content of the alginate extracted by acidulation precipitation is lower with significant difference, while the viscosity and the gel strength are higher with extremely significant differences. All the above show that the quality of alginate extracted by acidulation precipitation is better than that extracted by calcification precipitation. In addition, the acidulation precipitation consumes much shorter time, fewer water and raw materials than calcification precipitation with no significant difference in alginate yield. So acidulation precipitation was of great significance for energy saving and emission reduction.更多还原