Selection of the cold logistics model based on the carbon footprint of fruits and vegetables in China.

To reach the goal of becoming carbon neutral, there is a necessity to optimize the cold logistics due to its huge energy consumption and waste. Here, the life cycle assessment method was used to calculate the carbon emissions at each step of the fruit and vegetable cold chain. Based on the energy balance equation, the refrigerated transportation methods and carbon emissions under different transportation times was studied. The results show that the carbon emission of 1 kg of fruits and vegetables in the cold logistics is 0.098 kg: In this carbon emission, the transportation step accounts for 82%, while the emission of the pre-cooling step, storage (sales) step and consumption (abandonment) step account for 7%, 6% and 5%, respectively. If the transportation time is within 5 h, the pre-cooled fruits and vegetables are best to be transported by insulated transportation. If the transportation time is between 5 and 60 h, the preferable transportation method is the cold storage transportation. Moreover, 70 kg of cold storage agent is needed per cubic meter when the latent heat of the cold storage agent is 270 kJ/kg. Comparing the cold storage transportation with the mechanical refrigerated transportation, the transportation time is less than 87 h (1.5tons) and 98 h (10tons), that is the cold storage transportation has lower carbon emission. We also found that the driving carbon emission of a 1.5tons small refrigerated truck is three times that of a 10tons heavy refrigerated truck. In order to reduce the carbon emission in the transportation step, a smaller shape factor H, a cold storage agent with a large phase change latent heat and a thicker insulation layer have been suggested. ● The CO 2 emission of three different transportation types was calculated during the cold chain. ● The time used to decide on the transportation type was provided during the cold chain based on the CO 2 emission ● The method to reduce the CO 2 emission of the transportation step has been suggested. [ABSTRACT FROM AUTHOR]