Phase Separation Of Biomass Power Plants Straw Ash And Its Utilization

The straw ash of biomass power plant is rich in K, Si and C. If those useful elements in the straw ash can be separated and be made most use of, then not only can we reduce the environmental pollution, but also can bring a better economic benefit. With the increasing of straw power generation, it’s straw ash is paid more and more attention.The experiment extract the potassium by using once leaching method of distilled water, We studied the effects of the leaching time, the ratio of ash and water,leaching process and other factors on extraction efficiency. The experimental results show that, in the water to ash ratio was1:4, soaking temperature was60℃, immersion time was60min, the maximum extraction rate of potassium was80.74%. The extrat solution dried to get its powder, and then did a XRD test, from the test we know the main components of the extract solution is KCl. On this basis, the addition of H2SO4in the extract, at the same time by using organic amine extraction, not only can effectively remove the Cl-in the solution, but also the preparation of potassium magnesium fertilizer. By orthogonal experiment we know the optimum test process of potash fertilizer preparation:V organic phase:inorganic phase=1:2, V tri-n-butylamine:n-butanol=1:2:5, time2h, temperature60℃; The product is meet GB/T20937-2007.The filter residue after extract potassium is mainly Si and C. In order to separate the two, we studied the effect of the concentration of sodium hydroxide, reaction temperature, sodium hydroxide dosage and reaction time on the modulus of water glass and silicon dissolving rate, the optimum experimental conditions of soluble silicon was obtained:sodium hydroxide solution was200ml (per10g), the concentration of sodium hydroxide was2mol/L, filter residue reaction of3hours at90℃, can make the dissolved silica rate reached89.6%, and the modulus of water glass was1.3123.The filter residue after dissolved silica is C, we studied the effect of wash method of alkali-soluble residue, the activation time, the activation temperature and the amount of activator on the size of the methylene blue adsorption, activated charcoal ash and carbon rate influence, the results show that:using two washing method can greatly reduce the activated carbon ash.Experiments show that the activation temperature was600℃, the amount of activator is24g (per8g residue), the activation time was80min,the carbon prepared under the condition is better than the best of LY/T1281-1998.