The mechanism of environmental regulation on energy conservation and carbon reduction in the petrochemical industry through directed technological progress remains uncertain due to the directional characteristics of technology. This paper develops a mechanism framework and employs a panel two-way fixed-effects model to clarify the impact of environmental regulation on directed technological progress and energy conservation, while uncovering its underlying mechanisms. Subsequently, a dynamic Kaya model is constructed, using the Monte Carlo method to determine the required intensity of environmental regulation for China's petrochemical industry to actualize the SSP1-CHN, SSP1, and SSP2 scenarios. The model also simulates the future bias of technological progress, energy utilization, and potential carbon emissions under each scenario. The findings indicate that increasing the intensity of environmental regulation drives technological progress toward energy conservation, thereby enhancing energy-saving biased technological progress, improving energy productivity, and optimizing the energy structure. Furthermore, to actualize the carbon peak by 2030 and carbon neutrality by 2060 under the SSP1-CHN scenario, the annual growth rate of environmental regulation intensity in China's petrochemical industry should be no less than 8 % before 2030 and should be strengthened to 20 % after 2030.This study not only extends the application of directed technological progress theory in the energy field but also provides innovative and practical environmental policy recommendations for the low-carbon development of the global petrochemical industry.

Decarbonising the transport sector is crucial, yet selecting the most suitable alternative fuels remains challenging. This study applies life cycle assessment to evaluate six alternative fuels, such as hydrogen, compressed natural gas, methanol, ethanol, Fischer-Tropsch gasoline, and diesel, against conventional gasoline, diesel, and grid electricity, focusing on global warming potential and acidification potential. Emissions were analysed using the Greenhouse gases, Regulated Emissions, and Energy use in Technologies model under two scenarios: current technologies (2025) and projected advancements (2050). The results indicate that, compared to gasoline, compressed natural gas reduces global warming potential and acidification potential by 27% and 23% in the short term, while gaseous hydrogen achieves reductions of 63% and 46% in the long term, respectively. These findings reinforce the theoretical foundation for transport sector decarbonisation and contribute to its sustainable development. Future research will broaden the assessment framework by incorporating complete vehicle life cycle analysis, evaluating additional alternative fuels, and integrating a wider set of indicators.

Social impacts in packaging supply chains remain underexplored compared to environmental and economic aspects, despite their growing relevance in sustainability decision-making. This study applies Social Life Cycle Assessment (S-LCA) to evaluate the social sustainability of three carrier bag types: low-density polyethylene (LDPE) plastic, polylactic acid (PLA) bioplastic and kraft paper. The assessment is conducted using OpenLCA by integrating primary data with the SOCA V2 database, and focuses on four stakeholder groups, including Local Communities, Society, Value Chain Actors, and Workers. Social impacts are quantified across life cycle stages and stakeholder categories. Results are expressed as “medium risk hours,” a relative indicator used for comparative hotspot identification. The results indicate that Society and Value Chain Actors face high to very high risks (>40%) across all materials, highlighting potential areas for improvements. The PLA bioplastic bag exhibits the highest social impacts during raw material production, while the kraft paper bag performs worst in manufacturing and end-of life treatment. Overall social impacts rank PLA bioplastic highest (95.79 medium risk hours), followed by kraft paper (54.45), and LDPE plastic (35.15), a ranking that challenges common assumptions about the sustainability of bioplastics and paper alternatives. This quantitative social impact analysis provides clear, data-driven insights into social risk hotspots and improvement opportunities.