Abstract:Annual production of straw is 600~800 million tons in China. The advanced solidstate fermentation technology (ASSF) and solidstate fermented crushed straw material had been developed to acquire ethanol and increase the economical utilization level of straw. However, the high cost of ethanol separation from fermented material is the biggest problem unsolved. Planar thermal source (PTS) was used to separate ethanol from solidstate fermented crushed straw material (SSFM) instead of water steam. In order to facilitate the study, fermented material and dry material uniformly added with ethanol solution were heated on thermal balance under the same environmental condition. The mass, wet content, ethanol concentration in wet of control group and test group were the same. The mass loss curve of them was familiar. As a result, from the macro view, dry material uniformly added with ethanol solution (called prepared material) can be used on study instead of fermented material, which made it easier to study quantitatively. Complete thermogravimetric test was done on prepared material to study the material wet change rules. Factors considered were heating temperature T(20~100℃), wet content θ (10%~90%), ethanol concentration in wet ω (3%~11%). The weight order of factors on material wet change speed Vloss,e in descending trend was T, θ and ω, and ω can be ignored for that was an order of magnitude less important than the other factors. Vloss,e was linearly increased with the increase of T, and increased by power function with the increase of θ. Vloss,e model with T and θ was regressed. As there was no chemically combined water in prepared material, heating material can be considered as heating ethanol solution in materialshaped electric heating device. According to multi data, equations for ethanol solution evaporation coefficient K were derived. Above all, model of ethanol separation from SSFM by PTS was derived. The cost model was added at last. Software was programmed to calculate the separation process and its cost. The result showed that the cost of PTS method was obviously lower than that of the current water steam method. The new method would significantly promote the ASSF technology to produce renewable energy. The study can also be used as reference on drying process of other crushed plant material. In the end, a set of production equipment for continuous ethanol separation from fermented material by PTS was given. The design formulas were given and a sample set of industrial level equipment was calculated.
