Preparation Of Biomass Additive And Study Of Slurry Ability Of High Concentration CWS

Coal water sllury (CWS) is a late-model and clean coal fuel technology developed in the 70s of the 20’s century because of globle oil cresis, part of clean coal technologies. Clean coal technology aims at reduce discharge of pollutant and improve efficiency in the use of the coal. Compared with others, CWS has advantages of cleaning、efficiency and cost. Additive is one of core technologies of high quality CWS, so cheap material and additive with wide applicability are the keys that CWS plays to the advantage of economizing coal and replacing oil.This experiment separates lignin from maize straw and sulfonated lignin (GXL) with better solubility is synthesized to lower surface tension of solution through Step Sulfomethylated Methed (SSM). Compared with the traditional High Temperature Sulphonated Method (HTSM), SSM has gentler temperature、 simpler craft and lower cost, etc. GXL is used for the study of slurry ability of CWS as a dispersant, concentration of CWS is up to 70wt%, compared with business CWS, CWS has lower viscosity、better liquidity and stability than before adding GXL, the concentration of CWS increases by 2～5%.The parameters of dissolving lignin through alkaline process:alkalinity is 10%, the reaction time is 4 hours; the optimal pH of extracting lignin through acid process is 3, the optimal holding temperature is 80℃, the optimal holding time is 30 minutes; when the reaction temperature range of SSM is 90～95℃, the optimal mass ratio of Na2SO3 and lignin is 2:1, the optimal volume fraction of 37% formaldehyde is 16.67%, the reaction time is 6h.The ultraviolet and infrared indicate that two substances both appear characeristic obsorptions peak of lignin; GXL has novel and pointed peak at 979cm-"1 and 633cm-1, corresponding to S=O and C-S; the surface tension of 1% GXL is 36.806mN·m-1, critical micelle concenreation(cmc) is 0.25%, γcmc≈46.333 mN·m-1.When the dosage of GXL is 1%, the MAX concentration of Lishi CWS is less than 68.3wt%, apparent viscosity is 1400mPas, the concentrations of Linfen、Jinyang and Taiyuan CWS are 800、710�'�1010 mPa·s. Except Lishi CWS, liquidity of the rest is grade A, stability is around 25d.By contrast, the apparent viscosity of CWS is sharply reduced after adding GXL, this indicates that GXL can effectively fall viscosity and increase concentration of CWS. GXL is an anion surfactant, the hydrophobic groups can adsorb on coal surface, the hydrophilic groups are outward and obsorb hydrone to form hydration shell, hydration shell could reduce friction and hinder aggregation among particals, these interactions could drop viscosity and enhance stability of CWS.