Carbon footprint analysis of straw collection, transportation, and storage system for power generation in China based on emergy evaluation

Carbon footprint analysis method was employed to evaluate the ecological benefits of the straw collection, transportation, and storage system based on the case of Laifa Straw Recycling Company, and the emergy-based carbon emission indicator system was also set up to assess the relationship between input resource and carbon emission. In the condition of collecting 2 x 10(8) kg of straw production, the carbon emission of the artificial model (7.26 x 10(3) t CO2eq) and mechanical model (6.11 x 10(3) t CO2eq) was greatly lower than that of the straw burned in the field (2.78 x 10(5) t CO2eq). According to the emergy-based carbon emission indicator system, the carbon emission of straw recycling system was mainly triggered from labor input, which could be reduced by adjusting the resource structure. The ratio of carbon emission to environmental loading rate (ELRCO2) and ratio of carbon emission to emergy sustainability index (ESICO2) of the artificial model were 90.75E+6 kgCO(2eq) and 1.52E+6 kgCO(2eq), respectively, which were higher than that of the mechanical model, 55.55E+6 kgCO(2eq) and 1.22E+6 kgCO(2eq). It was obviously that the mechanical model had weaker influence on environmental loading than that of the artificial model and presented promising sustainable development ability in the case of mitigating carbon emissions.