531 / 2018-09-19 16:36:49

Technical, economic and environmental analysis for biomass moving-bed pyrolytic polygeneration system: a net negative-carbon technology in China

全体主题 > 生物质政策与战略

Showed in Paris Agreement is that developing the negative emission technologies (NETs) will be likely to restrict global warming less than 2℃ by the end of this century. Being the country with high air pollution and huge carbon emission, it is necessary for China to employ NETs from the first half of the century. Given the status of immature development for most NETs, the biomass pyrolytic polygeneration system can achieve negative carbon emission via sequestering carbon-rich biochar in soil. To allow earlier deployment of biochar technology, this study analyses the technical, economic and environmental performances of the biomass moving-bed pyrolytic polygeneration system. We evaluate the net present value (NPV) with biomass load of feedstock varying from 2 to 12 ton/h in different temperature from 250 to 650℃. The results show that when the temperature is higher than 550℃, meanwhile biomass input is larger than 7.5 ton/h, the NPV is always positive. Whilst the carbon mitigation and air pollution abatement of pyrolytic systems are considered via the life-cycle assessment method in the event that the NPV is positive. If 7.5 ton/h biomass input was provided in a pyrolysis plant, the largest negative-carbon emission can reach 2.25E+03 ton CO2-eq per year when temperature is 600℃. In addition, employing the pyrolysis plants with largest carbon emission around China, the maximum SO2 emission can be reduced by 4353 kt in East China, yet with maximum reduction of NOx, particulate matter (PM2.5) and BC by 13145, 43581 and 1728 kt respectively in Northeast. The analysis for the biomass moving-bed pyrolytic polygeneration systems can provide guidance for curbing air pollution and designing China’s NETs strategy in near future, making contribution on the realization of the goal of limiting global warming in the long run.