Coal Black Liquor Slurry Preparation And Convertion It To Hydrogen In A Continuous Supercritical Water Reactor

Black liquor is black waste, which is generated in the process of pulp and paper industry. The black liquor of in China is accounted for 10% of the total industrial waste water, is one of the main environmental pollution sources. Forced by environmental pressures, the comprehensive management of the black liquor is imperative. Lignin, hydroxy organic acids and sodium of the blacd liquor have the function of surface-active agent, so we can directly use the black liquor instead of water to make the coal slurry, and then in supercritical water gasification, which can convert harmful organisms of the black liquor into clean hydrogen. Moreover, it will effectively deal with the black liquor to reduce the environmental pollution and can reduce the production cost of coal-water slurry to achieve the reuse of black liquor and bring good economic and social benefits.This paper aims to treat and utilize black liquor. First, the characteristic of black liquor was analyzed to provide a data reference for the preparation of coal slurry. Then the black liquor which is made of different dilution times and Hangjinqi Hangjinq lignite were made into the coal black liquor slurry with excellent performance, and then the maximum slurry concentration, rheology, static stability, and additives on the properties of black liquor coal slurry were investigated. Finally, using special physical and chemical properties of supercritical water, the effect of temperature, pressure, coal-water slurry concentration and different raw materials on continuous hydrogen production process in supercritical water from the coal black liquor slurry were investigated. The main conclusions are summarized as follows:1. Determination of black liquor characteristics preparation of black liquor slurrySolids of black liquor were high compared with literature values, organics and inorganics were accounted for 66.79%,33.21%of the total of solids, organic matter content was the inorganic 2.011 times. Recovery of lignin from black liquor of paper-making by acidulation method was 0.375g/ml, as the solid content of 21.82%. Total alkali content was 39.68g/l, while the effective alkali content was 27.16 g/l. S2- and SO42-content were 1.83% and 0.41%. Correspondding to the production targets of the paper mill, the measured data of black liquor were in the normal range production targets.Black liquor and lignite could make a good performance of slurry. The slurry prepared by dilutiple multiple of 5 have the best comprehensive performance, slurry concentration of it was up to 62.8% with a yield pseudoplasticity, and could be stable more than 15 days. Moreover, with the addition of dispersant and stabilizing agent, the viscosity of slurry decreased substantially. 2. Continuous hydrogen production from coal black liquor slurry in supercritical water.Temperature and pressure were two main factors affecting the characteristics of supercritical water. Concentration of the coal sluury had a direct impact on large-scale hydrogen production. The temperature had a significant influence on the continuous hydrogen production process, while the pressure has little effect. The concentration of coal-water slurry affected large-scale hydrogen produce. With the increasing of the coal-water slurry concentration, the hydrogen yield decreased gradually.3. Temperature on the different materials in a continuous supercritical water gasification of HydrogenTemperature was conducive to individual lignite and black liquor gasification, especially for the improvement of hydrogen yield. By comparing and connecting the results of two separate weighted average and co-gasification, it had a significant synergistic effects in the presence of the black liquor during continuous hydrogen production from lignite in supercritical water, as the temeperature are elevated, the synergistic effect increased.