Life cycle assessment and optimization scenario of solid wood composite doors: A case study in the east of China.

The large scale of the Chinese wooden door market has resulted in a slew of environmental issues that must be addressed. This paper evaluated a solid wood composite door using life cycle assessment (LCA). Field research was used to obtain production data for the wooden door. The production stages were divided into the raw material stage, the transportation stage, the woodworking workshop stage, and the painting workshop stage in order to identify potential environmental improvements and analyze the underlying causes to offer some suggestions for improvement. Four service lives were considered in the use stage, and three disposal methods were considered in the disposal stage to explore their environmental impacts. The functional unit was defined as a solid wood composite door using the "cradle-to-grave" system boundary. Using a 20-year service life as an example, the results revealed that the production stage was the most crucial stage, with a contribution ratio of 49 % to 72 % to all impact categories, regardless of waste disposal method. The main reasons for this were the production of density boards and the consumption of electricity. By replacing straw-density boards and hydropower, the global warming potential (GWP) was reduced by 46 % and 67 %, respectively. If a wooden door can be used for 20 years, the use stage will account for 26 % to 51 % of the environmental impact contribution, owing primarily to wood wax oil. Recycling was recognized as the most environmentally friendly method of waste disposal. This research can be used as a reference for evaluating solid wood composite doors in China as well as providing optimization recommendations for production improvement.