公开(公告)号：US20220234993A1

公开(公告)日：2022-07-28

申请号：US17603846

申请日：2020-06-03

申请人： Dow Global Technologies LLC ,  Dow Silicones Corporation

发明人： Deboleena Chakraborty ,  Edward D. Daugs ,  Kenneth E. Stockman ,  Ronald Peterson

IPC分类号： C07C227/02 ,  C07C255/25

摘要： Provided is a method of making ethylenediaminetetraacetic acid (EDTA) comprising the steps: (a) providing a reaction mixture (a) comprising ethylenediamine (EDA) and glycolonitrile (GN), wherein reaction mixture (a) comprises 0% to 0.1% by weight, based on the weight of reaction mixture (a), of any base having pKa of the conjugate acid (PKaH) of 13 or higher; (b) causing or allowing reaction mixture (a) to react to form a dinitrile (DN) compound; (c) bringing the DN into contact with aqueous solution of a base having pKaH of 11 or higher, and causing or allowing the resulting mixture to react to form a diacid compound (DA); (d) causing or allowing the DA to react, either sequentially or simultaneously, with additional GN to form products (Pd); (e) causing or allowing products (Pd) to react with a base having pKaH of 11 or higher, to form EDTA. Also provided is a composition comprising a diacid/dinitrile compound (DADN) wherein each —R has the structure:

公开(公告)号：US20240336495A1

公开(公告)日：2024-10-10

申请号：US18577434

申请日：2022-09-19

申请人： Dow Global Technologies LLC

发明人： Deboleena Chakraborty ,  Ronald R. Peterson ,  Reza Hagh Panah ,  Erich Molitor ,  Mark A. Robertson

IPC分类号： C02F1/28 ,  B01J20/20 ,  C02F101/38 ,  C07C227/40

CPC分类号： C02F1/283 ,  B01J20/20 ,  C07C227/40 ,  C02F2101/38

摘要： The present invention provides simple methods for treating aqueous chelating agent compositions containing one or more nitrilotriacetic acid (NTA) salts with one or more adsorbents, such as activated carbon, two or more activated carbon adsorbent in sequential treatments, to remove the NTA without removing more than 5 wt. %, or more than 3 wt. % or, preferably, more than 1 wt. % of the chelating agent in the aqueous chelating agent compositions. The methods comprise treating aqueous chelating agent compositions having a pH of from 7 to 12 and can be carried out at from 10 to 110 C. The methods can be used to treat a wide range of aqueous chelating agent compositions having, for example, from 700 to 6000 ppm of NTA, such as waste streams.