Evaluation Of The Life Cycle Carbon Emissions Of Litchi Supply Chain

With global warming,sea level rise,and various extreme weather events,carbon emissions have become a growing concern for the international community.The food system as a high carbon emission area brings a heavy burden to the environment.As the world’s largest food producer and consumer,China,on the one hand,generates high carbon emissions due to food loss in the process of food distribution;on the other hand,cold chain logistics consumes a lot of energy while ensuring food quality and safety.Under the pressure of global warming,it is necessary for the food cold chain logistics industry to spend more efforts to achieve green and sustainable development.Based on this,this paper is guided by the whole life cycle approach,combined with modeling analysis and experimental research,to study the carbon footprint of the cold chain logistics system of Litchi,a characteristic fruit of southern China,as an example.The main work is as follows:（1）A kinetic model of Litchi quality change was constructed.The quality of lychee is continuously degraded by time and temperature during the circulation process after production.This paper detects the changes of Litchi browning index,good fruit rate,quality loss rate,soluble solids and p H index under different temperature conditions by experimental method;secondly,through linear fitting analysis of experimental data,the browning index is selected as the key index to evaluate the change of Litchi quality;finally,the kinetic equation of zero-level reaction and Arrhenius equation are used to construct the kinetics of Litchi quality change model,and then the model was validated,the relative error were within 10%,within the acceptable range,the model can quantify and predict the quality changes of Litchi when circulating under different temperature conditions.（2）A life cycle carbon footprint evaluation model of Litchi supply chain was constructed.In this paper,we focus on the carbon emission of Litchi supply chain,under the guidance of the life cycle assessment method,according to the life cycle evaluation process of defining system boundary,target list analysis and impact evaluation,the life cycle carbon footprint evaluation model of Litchi supply chain is divided into seven sub-models of Litchi production,production storage,trunk transportation,distribution storage,urban distribution,super retail and household consumption,and the relationship between production carbon emission and circulation carbon emission and other influencing factors in the Litchi supply chain is comprehensively considered to provide a basis for the effective measurement of the life cycle carbon emission of food supply chain.（3）Evaluation and analysis of the life cycle carbon footprint of cold chain circulation of Litchi.Using 1 kg of Litchi as the functional unit of calculation,the life cycle carbon emissions of the cold chain circulation scenario of Litchi is 0.699 kg CO₂eq.which accounts for 33.19%of the life cycle carbon emissions,followed by refrigerated transportation with 0.232 kg CO₂eq,accounting for 33.19%of the life cycle carbon emissions,followed by Litchi production with 0.221 kg CO₂eq,accounting for 31.62%of the life cycle carbon emissions,and finally Litchi retailing and household consumption with 0.008 kg CO₂eq,accounting for 1.14%of the life cycle carbon emissions.（4）Evaluation of the life cycle carbon footprint of Litchi in different contexts.Taking the cold chain circulation of Litchi as the benchmark and 1 kg of Litchi as the functional unit of calculation,we compare the life cycle carbon emissions of Litchi under the scenarios of without pre-cooling,ambient sales and ambient circulation.First,the without pre-cooling scenario:the life cycle carbon emissions of the Litchi supply chain is 0.656 kg CO₂eq;as the Litchi is picked without pre-cooling,which leads to the production of 1 kg of Litchi only 0.669 kg into home consumption,the effective utilization of production carbon emissions is only 63.9%.Secondly,ambient sales scenario:the life cycle carbon emissions of the Litchi supply chain is 0.725 kg CO₂eq;due to the end of the sale of Litchi after not taking insulation measures,thus leading to the production of 1 kg of Litchi only 0.181 kg into home consumption,the effective utilization rate of production carbon emissions is only 18.1%.Lastly,under the ambient circulation scenario:the life cycle carbon emission of Litchi supply chain is 0.562 kg CO₂eq;due to the uncirculated process are in a high temperature environment,the production of 1 kg of Litchi only 0.241 kg into home consumption,the effective utilization of production carbon emissions is only 24.1%.However,when consumers get 1 kg of Litchi,the production of 1.759 kg under the circulation of ambient temperature,the cold chain circulation under the production of1.073 kg to meet the demand for consumption of 1 kg of Litchi.At this point,the life cycle carbon emissions of Litchi cold chain circulation decreased by 34.8%compared to ambient temperature circulation.In summary,this paper,guided by the life cycle assessment,constructs a life cycle carbon emission evaluation model for Litchi supply chain,and the research results can provide reference for energy saving and emission reduction in the food supply chain,and provide decision support for achieving the carbon neutral target in 2060.