Study On Interfacial Photothermal Evaporation And Salt-differential Power Generation Of Carbonized Wood

With the rapid expansion of the global economy and the rapid growth of population,people's demand for fresh water resources is increasing,but the supply capacity of fresh water resources is obviously insufficient.In recent years,researchers have found that the technology of solar interface photothermal evaporation to treat brine and wastewater to produce fresh water has the advantages of green,high efficiency and low cost compared with traditional methods.Because of its high mechanical strength,high hydrophilicity,low raw material cost and environmental protection,wood has a good performance in the field of solar interface photothermal evaporation.However,wood photothermal evaporator floats on the water surface in the evaporation process of seawater,and part of the energy radiated by sunlight on the evaporation surface is absorbed by water,which restricts the evaporation rate of wood evaporator,and the salt difference energy formed in the evaporation process is seldom used.Therefore,this paper uses sylvestris sylvestris as the evaporator material to carry out the following research:(1)A Mild Carbonized Wood(MCW)photothermal material was prepared by the reaction kettle Mild carbonization method.By controlling different carbonization temperature,carbonization time and water supply height,MCW8 with the best performance was screened according to the results of solar photothermal conversion test and water evaporation conversion test.The results show that the evaporation rate of MCW8 can reach 1.48 kg·m^-2·h^-1 and the evaporation efficiency is 66.2%under the condition of water supply height of 15 mm.The optimum reaction conditions are as follows:the carbonization temperature is 200?,the carbonization time is 8 h and the water supply height is 15 mm.After comparing the micromorphology,element distribution,spectral absorption capacity,water transport capacity,contact Angle,thermal stability and antibacterial properties of MCW8 and log,it was found that the performance of MCW8 was significantly better than that of log.(2)In order to increase the carbonation degree of Pinus sylvestris wood block,toluene-4-sulfonic acid monohydrate(Ts OH·H2O)was used as catalyst and reaction kettle catalyst carbonation method was adopted.A Catalyst Carbonized Wood(CCW)was prepared.Five samples were prepared by controlling different concentrations of Ts OH·H2O solutions.The best sample CCW5 was screened according to the results of solar thermal conversion test and water evaporation conversion test.The results show that the evaporation rate of CCW5 can reach 1.59 kg·m^-2·h^-1 and the evaporation efficiency is 69.0%under the condition of water supply height of 15 mm.The optimal mass concentration of Ts OH·H2O solution was 45%.(3)The salt tolerance of CCW5 was investigated in 3.5%brine.Under the condition of 15 mm water supply height,the evaporation rate and evaporation efficiency of CCW5 are 1.44 kg·m^-2·h^-1 and 65.2%,respectively,under one solar light intensity,and there is no salt accumulation in the evaporation process,indicating that CCW5 also has excellent evaporation performance in seawater.CCW5 and Nafion117membrane were assembled into a mixed evaporative power generation device.When the concentration of evaporating brine was 1 mol/L and the intensity of sunlight was double,the maximum voltage of CCW5 could be 167.54m V during the evaporation of brine.The results show that CCW5 has good evaporation performance,salt resistance and power generation performance in brine evaporation process.