Study On The Slurryability And Co-gasification Characteristics Of Sludge-coal-water Slurry

Two kinds of sludge containing lots of water and with higher calorific value, from sewage disposal work in Huainan city, and two kinds of coal sample Shenhua and Panyi coals, were choosed to carry out experiments aiming to deal with the problems of environmental pollution. Proximate analyses, ash chemical composition analysis and mineral components analysis were analyzed to investigate the differences between coal samples and sludge samples. It studied stressly the effects of different kinds of sludge and their additive amount on the concentration, rheological properties, stable performance of coal water slurry. The effect of sludge on coal fusion temperatures was studied as well by using the coal ash melting instrument. Besides, the effect of sludge additive amount on Shenhua coal ignition temperature, devolatilization temperature, burnout temperature, carbon reaction rate, and the gas products after reaction were analyzing by TG-FTIR technology. On the basis of the present work,, the following conclusions can be reached:The slurryability of CWS mixed with two kind of sewage sludge (A and B) was studied with different dosage. The result shows that:when S-CWS was prepared with the adding dosage in the limit of1%～15%, compared with common CWS, the rheological properties of S-CWS were the shearing and diluting feature. However, the apparent viscosity increased and the maximum solid concentration reduced as the sludge adding dosage increased, and that can reduce the rate of water, improving its stability. Nevertheless, two kinds of sludge change the slurryability on different levels, because of their different properties. Among them, sludge B has a bigger impact on the slurryability of S-CWS, the maximum solid concentration reduced and apparent viscosity increased further mixed with sludge B than sludge A.After the addition of sludge, the coal ash flow tests show that two kinds of sludge can decrease ash fusion temperature, and it will be lowest with two kinds of sludge ratio of2%, but when the sludge dosage was beyond2%, ash fusion temperature display have the different trend with two kinds of sludge dosage.Thermogravimetric analysis-Fourier transform infrared spectrometer(TG-FTIR) is used to analyse the co-gasification characteristics of coal added sludge B. Both Shenhua coal and sludge B contained CO2、H2O and a little of CO during the heated process, Compared to the ShenHua coal, The gases after reaction of sludge contained a small amount of hydrocarbon, and the carbon monoxide level was lower. In addition, the more proportion of sludge, the closer initial temperature of S-CWS, the quicker gasification rate.B as alkali index and Rs as gasification reaction index of S-CWS were analyzed to find out that the alkali index B of sewage sludge was above1, and the activation energy of Shenhua coal was more than sludge. Also, with sludge dosage increased, Rs increased and the activation energy of S-CWS reduced, it indicated that adding sludge was beneficial to gasfication of S-CWS.