The Economyic And Environmental Benefit Analysis Of Biomass Gasification/Direct Combustion Heating System

With the development of economy and society,the way of heat supply in rural area is becoming cleaner and renewable.Biomass as a new renewable energy has been paid more and more attention.Today,biomass heating technology can be broadly divided into Gasification technology and biomass direct combustion technology,both of which heating economy,environmental benefits are uncertain.Therefore,this paper aims at two kinds of technical design two sets of plans to carry on the economic and the environmental benefit appraisal.The paper takes the rural buildings in Tianjin as the heating object,selects a natural village of about 300 households in Tianjin,each household heating area is about 90m2,the heating design heat load of the building is estimated to be 1728kw,the annual heat consumption is 12076.65GJ.Based on the annual heat consumption and the design heat load,the equipment selection and initial investment estimate of the heat source,heat medium pipe and radiator were made,and the initial investment of the Gasification heating scheme were calculated to be 2.020.8 million yuan and1.240.8 million yuan respectively,the income of heating is 1.2461 million yuan,and the operating cost of the two schemes is 702,000 yuan and 511,000 yuan respectively.The study shows that the total cost of the Gasification heating scheme is 3.2984million yuan higher than that of the direct biomass heating scheme.The present value method（5%annual interest rate）is used to calculate and analyze various economic structures.The results show that the total life cycle profit of the Gasification heating system is 5.162.8 million yuan and 8.461.2 million yuan,and the payback period is 3.18 years and 1.50 years,respectively Investment returns were28 per cent and 62 per cent,respectively,while internal rates of return were 29.9 per cent and 66.55 per cent.Direct biomass heating is more economical than Gasification heating.Considering the environmental cost,the CO₂ emission inventory of the two schemes is prepared,and the CO₂ emission is quantified and calculated as the environmental cost economically.The results show that the total life cycle profit of the Gasification heating system is 3.951.9 million yuan and 5.318 million yuan,the payback period is 5.46 years and 2.67 years,and the return on investment is 16%and34%respectively The internal rate of return was 13.25%and 36.63%,respectively.Although the environmental cost of the Gasification scheme is low,the Gasification scheme is still economically disadvantaged.Using the technology economy method,this paper analyzes the data of the two heating schemes,and investigates the influence of the data of the Gasification heating schemes on the total difference between the two schemes.The results show that the environmental cost and initial investment of the two schemes are the main factors that affect the economic difference between the two schemes,and the cost of electricity and depreciation of equipment are relatively low,it is also one of the main reasons that lead to a large gap between the total costs of the two programmes;although the amount of material collection fees is huge,the impact on the gap between the total costs of the two programmes is relatively small.