铬革渣资源化处理研究Ⅶ.蛋白质的水解及其测定

铬革渣在碱性介质中脱鞣提取蛋白质的过程中,当反应体系的ｐＨ＝１３,反应压力为１．４ｋｇ／ｃｍ＾２,１１ｈ后出现蛋白质水解产物氨基酸,随反应时间的延长,水解度随之增大。这种水解,随体系的ｐＨ值升高而加快。实验表明,用改进的甲醛滴定法可测定铬革渣在碱性介质中蛋白质的水解度。     

Tracking effective measures for closed-loop recycling of automobile steel in China

Closed-loop recycling of steel in automobiles is particularly difficult because of the low tolerance for impurities and the use of composites of various types of steel products. Technologies that reduce impurities or increase impurity tolerance must be developed and introduced to the steel recycling system at the appropriate time. This study evaluated the feasibility of closed-loop recycling in the automobile industry in China. Material pinch analysis combined with dynamic modeling of the life cycle of steel sheets used in the manufacture of automobiles was employed to estimate the amount of steel sheet scrap available for closed-loop recycling and the amount of copper contamination in the scrap. The results indicate that by 2050, more than half of the old steel sheet scrap generated annually will have to be down-cycled because of its high copper contamination. However, scenario analyses of three types of technologies for mitigating the problem of copper contamination showed the potential for increasing the amount of old scrap used in closed-loop recycling. In particular, improving copper tolerance in the steel production process could be effective both now and in 2050.