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other countries. Under the consumer responsibility principle, CO 2 emissions from the export transportation of paper and paperboard should be borne by the importing country of paper and paperboard, and this part of CO 2 emissions is not included in the transportation phase of paper products. Due to the availability of data, CO 2 emissions from the export transportation of the product to the consumer are difficult to calculate, and the part of the production process that involves transportation from the workshop is neglected. (4) The transportation stage. China’s waste paper disposal mainly has three ways: landfill, incineration, and recycling [23]. Waste paper recycling and utilization is an important part of the closed-loop material flow of “resource consumption-products-renewable resources” in the papermaking industry, and the CO 2 generated from recycling is included in the transportation stage. For the convenience of estimation, it is assumed that the waste paper is landfilled or incinerated in the open air without fixed concen- tration points, and methane recovery is not considered in the landfilling process, so theCO 2 released in the landfilling or incineration process is mainly accounted for in the waste paper disposal stage.
Table1. Three sources of raw materials and definition of CO 2 emissions.
Raw Materials
Origins
Notes
The proportion of foreign imported wood used for furniture manufacturing is high, and only a small portion of it is used for pulp and paper making, so the CO 2 generated from the transportation of this part of imported wood is negligible. The CO 2 generated in the process of forest plantation can be absorbed by its own photosynthesis, so we do not calculate CO 2 emissions from forest plantation, but only calculate CO 2 emissions from domestic harvesting of wood for pulp and paper production. Wood pulp imported from abroad is mainly involved in transportation distance and transportation volume, so CO 2 generated from imported wood pulp is included in the transportation phase for calculation. Among non-wood pulp, rice-wheat straw pulp has always accounted for the highest percentage [6], so we mainly calculate theCO 2 emissions from the rice-wheat straw pulp feedstock acquisition process, and then estimate the CO 2 emissions from the non-wood pulp feedstock acquisition process based on the percentage of rice-wheat straw pulp. Both domestic waste paper recycling and foreign waste paper import mainly involve transportation, so this portion of CO 2 emissions are included in the transportation phase.
Domestic timber harvesting and transportation
Woodpulp
Foreign wood pulp import
Non-wood pulp
Domestic production
Domestic recycling and foreign import of waste paper
Waste paper pulp
2.2. Calculation Method 2.2.1. Accounting for CO 2 Emissions in the Raw Material Acquisition Stage Timber Harvesting Process The acquisition of wood pulp raw materials (wood harvesting process) involves three processes: logging for timber, skidding, and transportation. The accounting of CO 2 emissions from this process is based on the carbon emission factor method of the National Greenhouse Gas Emissions Inventory Guidelines. The formula is as follows.
Logging and timbering operations:
1
(1)
C h = e d × E h = e d × W h × W ah
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