Components Analysis And Optimization Of Green Oxygen

In this thesis, the qualitative and quantitative analysis of new type cooking additive green oxygen was carried on by chemical, infrared, ultraviolet spectroscopy and X-ray. Results showed that the green oxygen is composed of anthraquinone, fatty alcohol ethoxylates and Na2SO3. The content of these three ingredients were30.3%,8.8%, and59.3%respectively.Results revealed that the catalytic component of the Green Oxygen during the cooking process was anthraquinone. It can oxidized aldehyde end group of cellulose and hemicelluloses to carboxyl group and generated anthracene hydroquinone. Moreover the anthracene hydroquinone can generated strong nucleophiles under alkaline conditions which was good for lignin degradation. A small amount of sodium sulfite in the cooking process was benifical to cook. In addition, as a strong nucleophile SO32-can broke and sulphonated lignin effectively and increased the removal of lignin. Therefore the existant of anthraquinone and sodium sulfate in green oxgen was favour of cooking significantly in cooking process. The abilities of strong wetting and penetration was received for the existant of fatty alcohol ethoxylates surfactants in green oxgen. These surfactants made soda quickly wet fiber surface and penetrate fiber internal. All that shortened the cooking time grealy. In addition complex reactions between the hydrophilic group of surfactant and metal irons in raw materials made the pulp color become shallow and easy to bleach and wash. Moreover the pulp with higher brightness after washed was received.The green oxygen played a significant role on cooking process of grass raw materials, but the effect of that on wood raw material cooking was not very clear. As the proposed of "The Integrated Forest-Paper", the demand for the cooking additive for wood will be more and more large. The heating stage of cooking process was simulated in this paper. Before heating, the chip was reacted with kraft cooking liqour which was added different surfactants for about20min first. Then the volume of the cooking liquor into chip and the concentration of dissolved substances in residual liquid was determined during heating process from20℃to100℃. In order to defined the composition of dissolved substances, the IR specta of dissoved substances was analyzed and compared with that of organic solvent extraction of poplar. Results showed that the dissolved substances in atmospheric pressure was the same with the organic solvent extraction of poplar, which was fatty acids and fatty acids of partly esterification.Studies presented that the fatty acids and fatty acids of partly esterification dissoved from cooking liquid which was added different surfactants was different in quantity. The effects of sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate and NP-40were better than that of the green oxygen. During the early cooking stage, the dissolution of the organic material was good for the increase of penetrate rate of cooking liquid to the raw materials. However the dissolution of organic matter opened the channel for the dissolution of lignin. So the results of the penetration test can be used as the selection of surfactants for cooking additive.Kraft pulp cooking was proceeded in a certain concentration of alkali solution. While the cooking liqor was difficult to penetrate into the fiber interior for the high surface tension of NaOH. The addition of surfactant in cooking process was benefical for the decrease of surface tension and the increase of wetting ability of cooking liqor. All that accelerated the penetration and diffusion of cooking liquor and the swelling of raw materials. At the same time, the surface tention of the surfactants which were selected in penetratino experiment was determined. Results showed that the surface tension of the cooking liqor adding green oxygen and SDBS was45.2mN/m and45.4mN/m respectively. The results was close to the cellulose surface tension of45mN/m.After the component optimization of cooking additive, the cooking liquor was built with30%the anthraquinone,10%surfactant and60%Na2SO3. Then poplar was cooking with this built cooking liquor. Results revealed that when the pulp Kappa number was close to viscosity, the yield of screened pulp with green oxgen was higher2.04%than that of with SDS.