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[Display omitted] • GHG emissions from an industrial-scale AD plant were assessed. • The AD process before digestate treatment achieved carbon offset. • Electricity consumption caused the major GHG emissions. • Waste oil recovery and biogas reuse are pivotal for offsetting GHG emissions. • Net GHG emissions from digestate process varies with different final disposal ways. Anaerobic digestion (AD) has been widely applied for treating organic waste and is known as a carbon-offsetting process. However, most studies relied on laboratory-scale experiments or literature to calculate carbon emissions from AD process, and the impact of digestate processing was overlooked. This study assessed the carbon footprint for an industrial food waste co-digestion plant with operational data. The results indicated that carbon emission before digestate treatment is −88.5 ± 4.4 kg CO 2 -eq/t. The major source of carbon emission is electricity provision, followed by fuel combustion, unburned biogas, and fugitive gas emissions, while waste oil recovery and biogas utilization offset the carbon emissions. Considering digestate treatment and disposal options, the plant's net carbon emissions are as follows: −86.1 ± 6.2 kg CO 2 -eq/t (incineration) < -80.7 ± 6.5 kg CO 2 -eq/t (land application) < 6.7 ± 12.2 kg CO 2 -eq/t (landfilling). This work aims at providing a roadmap for making site-specific calculations of the carbon footprint for AD process. [ABSTRACT FROM AUTHOR]

• Evaluation parameters Q , COP , and R d of buried pipe heat transfer are discussed. • Factors and corresponding levels affecting heat transfer in buried pipe are analyzed. • Optimal level of factors at same weight of Q , COP , and R d is D4, G1, T in 3, GG4, k4. • Ranking of contribution rate at same weight of Q , COP , and R d is D, G, T in , GG, k. For building heating systems with a deep-buried coaxial double-pipe, its heat transfer performance was studied using three evaluation parameters in five heating periods under five factors and the corresponding four levels. The three evaluation parameters are time-averaged heat transfer per meter Q L-a , time-averaged performance parameter COP -a of heat pump unit, and five-year decay rate of heat exchange rate R d-5. The five factors are buried pipe depth, water flow rate, inlet water temperature, geothermal gradient, and thermal conductivity of ground. The levels for each factor were selected in combination with practical problems. Sixteen sets of orthogonal simulation conditions (L 16 45) with five factors and four levels were designed following the Taguchi method. Using signal-to-noise ratio and analysis of variance, Q L-a , COP -a , and R d-5 were evaluated under various factors and levels. The optimal combination of various factors for the best heat transfer performance of buried pipe and the contribution rate of each factor to the heat transfer performance of buried pipe were obtained. [ABSTRACT FROM AUTHOR]