# Assessing the Techno-Economic Feasibility of Bamboo Residue-Derived Hard Carbon
## 4 Discussion  
This study provides the first techno-economic assessment of bamboo residue-derived hard carbon production at a national scale in China. By integrating LCI data, spatially resolved feedstock distribution, and process-specific cost modeling, our results demonstrate that, even with only 10% utilization of bamboo processing residues in ten major bamboo-producing provinces, over 1 million tons of hard carbon could be produced annually within a price range from 14.47 to 18.15 CNY/kg. This is highly significant when compared to  
Figure 6: One-way sensitivity analysis of minimum selling price (MSP) for the Fujian case. Parameters are detailed in Table 3; corresponding numerical results are presented in Table 5.  
the global natural graphite production is approximately 1.3 million tons, while synthetic graphite production reaches approximately 3 million tons [34]. Our findings suggest that bamboo-based hard carbon alone could provide a scalable and renewable domestic substitute for a substantial share of China's current and future anode material supply. The MSP translates to 14,470-18,150 CNY/ton, which is highly competitive in the current global market. For reference, commercial hard carbon from leading Japanese suppliers such as Kuraray is priced from 150,000 to 200,000 CNY/ton [35]. This price advantage suggests that bamboo-derived hard carbon has strong potential not only to displace fossil-derived graphite but also to expand sodium-ion battery production by lowering material cost thresholds. It should be noted that wastewater treatment costs were not included in the rigorous MSP calculation due to the lack of reliable data. To provide a rough estimation of its potential impact, we referenced typical treatment costs for acidic industrial wastewater, which range from 5 to 80 CNY per ton depending on acid concentration and local environmental regulations [36; 37]. According to the LCI source, the production of 1 kg of hard carbon generates approximately 14 kg of wastewater [17]. Based on this, the additional cost attributable to wastewater treatment would be between 70 and 1120 CNY per ton of hard carbon. This increase remains acceptable, as the adjusted MSP will still be around 20,000 CNY/ton. This value remains well within the range between synthetic graphite (up to 20,000 USD/ton) and activated carbon (around 2000 USD/ton), which are functionally and structurally related materials [38; 39]. Another critical implication of this study is the geographical concentration and maturity of bamboo supply chains. Unlike many other lignocellulosic biomass types that are dispersed or seasonal, bamboo residues are generated year-round from well-established industries (e.g., construction, pulp and paper), often in centralized clusters. This enables efficient feedstock collection, reduces transportation cost, and enhances long-term investment feasibility. As shown in our results, the MSP differences between provinces are relatively modest, highlighting a robust economic profile even under varying local conditions. Furthermore, the capital investment needed to construct a large-scale 2000 t/ day facility was within reasonable bounds (<6 billion CNY) compared to other emerging bio-carbon technologies, indicating attractive scale-up opportunities. The sensitivity analysis revealed that electricity efficiency, product yield, and electricity price are the dominant drivers of MSP. These results point to critical leverage points for further cost reduction. For example, future efforts to develop low-temperature graphitization technologies or renewable-powered carbonization systems could directly improve energy efficiency and decouple production from fossil-based grid electricity. Similarly, process optimization to improve carbon yield--e.g., through feedstock pretreatment or process control--can significantly reduce cost per unit output.