| The increasing demand for energy and serious environment pollution forced the countries to seek environment friendly energy as substitutions for fossil fuels. Biomass is considered as a promising resource of global fuel production due to the advantages of its reproducibility and materiality of carbon source. Biomass fast pyrolysis offers an effective way to convert solid biomass feedstock into liquid fuel by thermolchemical technology. In this paper, based on the technology of biomass heated by ceramic balls, an originally demonstrative installation of biomass pyrolysis for bio-oil production was built, which has a throughout of over 300kg/h biomass feedstock. The demonstrative installation mainly consists: a furnace of biomass particle combustion, a heat exchanger of solid carriers, a the control valve of ceramic balls, a material feeding apparatus, a the casing tube reactor of gas heating, a gas/solid separation device, a ceramic balls elevator, two cyclones, bio-oil quenching system, water cooling system and data acquisition and monitoring system.The overall technological process, structures and working principles of the industrial demonstration were simply introduced and its key components were analyzed in detail. Then, the installing process, and test running of the demonstrative installation were carried out. Furthermore, to test the feasibility of the demonstrative installation, pyrolysis experiments for bio-oil production of corn stalk and sawdust waste were performed using a fluidized bed and demonstrative installation, at 450、500 and 550℃,respectively. The pyrolysis products yield, physical properties and chemical characteristics of bio-oils obtained from two reactors are compared and analyzed, respectively. Moreover, economic analysis of the industrial demonstration was analyzed by dynamic evaluation index method. The results are as follows:1. The yield of bio-oil increases with the temperature rising and the yields obtained from sawdust waste are obvious higher than that of cornstalk on both of the two kind reactors. With respect to sawdust waste, at the temperature of 500℃, the highest bio-oil yield is 54% from fluidized bed and the highest yield is 47.5% obtained from the industrial demonstration.2. According to the analysis of the bio-oils obtained in fluidized bed and industrial demonstration, the results show that the contents of acid、phenols and ketones are affected significantly by temperatures. The content of acid increases, but the content of phenols decreases with the temperature rising. The content of ketone is about 15wt% in corn stalk pyrolytic bio-oil, while its content is only 5wt% in sawdust waste pyrolytic bio-oil. The content of saccharides in the sawdust waste pyrolytic bio-oil is much higher than in the corn stalk bio-oil.3. The analysis of the physical properties of bio-oils obtained at the temperature of 500℃ indicated that the p H of bio-oil is 2-4, the heating value of synthesized is 17-18MJ/kg, the density is 1100-1200kg/m3 and the dynamic viscosity is 30-45 Mpa.s at 40℃. These physical properties indicate that the bio-oil need to be modified and upgraded before used as fuel or applied to the specific burner as fuel used directly.4. The study of economic analysis of the industrial demonstration installation showed that the internal rate of return, net present value and payback period including construction period of the industrial demonstration is 34.2%, 1.349 million yuan RMB and 4.44 years, respectively. When the throughput of industrial demonstration reaches 840.73 t a year, the balance of profit and loss is achieved. Compared the influence of five factors on the internal rate of return, net present value and payback period, it is found that the price of the pyrolysis products are the key factor, followed by the price of material. The impact of the other three factors is very less. Therefore, the price of the products and biomass feedstock are the key factors which for the profit during the operation of the biomass pyrolysis demonstrative installation. |
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