Patent GB-497928-A (GB)
Title: Improvements relating to the exchange or elimination of anions in liquids and the absorption of gases
IPC: B01J41/04
Filed: 1937-06-23
Abstract: Insoluble organic materials containing one or more amino groups or other basic radicles are used as absorption agents for acidic gases. Albuminoids of amine origin, such as horn, hoofs, wool, hair or leather, which have been treated so as to increase their basicity, may be used.  Wool, which has been esterified or of which the fibre has been diazotized and then coupled with aromatic di- or poly-amines is suitable.  Another suitable material may be obtained by dyeing cotton fibre with direct colours, which are diazotized on the fibre and coupled with amino-groups.  Synthetic plastics, such as glyptals or polystyrolenes can be used, if their condensation is carried out with nitro-derivatives of the components and the nitro-groups afterwards reduced to amino-groups.  Some artificial fibres containing oxycellulose may, with the help of this component, fix substituted aryl-hydrazines and give aryl hydrazones or oxazones or their nitro- and substituted nitro-derivatives, which will act as anion absorbents after the reduction of their nitro-groups. Oxycellulose itself and insoluble carbohydrates, such as starch, aldehydes or ketones, also yield insoluble aryl hydrazones or oxazones or derivatives.  After use the absorbent material is regenerated by treatment with an alkaline solution. Specification 490,704, [Group I], is referred to.ALSO:In order to eliminate or exchange free or combined anions from liquid or gas the fluid is brought into contact with insoluble organic material containing one or more amino-groups or other basic radicles.  Albuminoids of animal origin, such as horn, hoofs, wool, hair or leather, which have been treated so as to increase their basicity, may be used.  Wool, which has been esterified or of which the fibre has been diazotized and then coupled with aromatic di- or poly-amines is suitable.  Another suitable material may be obtained by dyeing cotton fibre with direct colours, which are diazotized on the fibre and coupled with amino-groups.  Synthetic plastics, such as glyptals or polystyrolenes can be used, if their condensation is carried out with nitro-derivatives of the components and the nitro-groups afterwards reduced to amino-groups.  Some artificial fibres containing oxycellulose may, with the help of this component, fix substituted aryl-hydrazines and give arylhydrazones or oxazones or their nitro- and substituted nitro - derivatives, which will act as anion-fixers after the reduction of their nitro-groups. Oxycellulose itself or insoluble carbohydrates, such as starch, aldehydes, or ketones, also yield insoluble arylhydrazones or oxazones or derivatives which serve as anion fixers or exchangers. The process of the invention can be used in the preparation and purification of salts, the separation of salts, and the purification of water, particularly water which has been previously treated with a hydrogen cation exchanged.  After use the exchange material is regenerated by treatment with an alkaline solution.  Specification 490,704 is referred to.