## 3 Results and Discussion
### Life Cycle Assessment Results  
Impact scores established in the LCIA stage represented the quantified potential environmental impacts of the cellulosic extraction process. They were derived from the LCI data and subsequently categorized into specific (and identified) environmental impact categories. By employing characterization factors, the raw data from the LCI stage are converted into these impact scores, which reflect the magnitude of potential environmental burdens associated with each category. Table 1 lists the impact scores for the entire cellulose extraction process in the current study. The impact categories identified using the ReCiPe method are _fossil resource scarcity_, _terrestrial ecotoxicity_, _freshwater ecotoxicity_, _water consumption_, _human carcinogenic toxicity_ and _marine ecotoxicity_, while categories identified using the ILCD method are _freshwater  
Figure 2: Scanning electron micrograph of cellulose extracted from date palm biomass using NaDES and microwave-assisted process. ectoxicity, water resource depletion, mineral, fossil and resource depletion, human toxicity and cancer effects._ The differences in identified impact categories for both ILCD and ReCiPe arise from their distinctive methodological frameworks. The ILCD method, developed by the European Commission, is created to provide comprehensive impact assessment categories that align with European regulatory contexts, while the ReCiPe method emphasizes incorporating impact categories to complement scientific robustness with practical applicability. It is our opinion that their methodological differences are manifested in ILCD, identifying more on specific impact categories, while ReCiPe exhibits a more consolidated set and possibly overlooks some specific impacts highlighted by ILCD. Consequently, the difference in identified impact categories reflects the diverse objectives, local considerations and aggregation levels innate in each Midpoint assessment method. It can be observed that _fossil resource scarcity_ from the ReCiPe method shows the highest impact in the cellulose extraction process, as indicated by its raw impact score of 0.21367 kg oil eq., though the comparison between categories at this stage is moot given that their scores are not normalized. The numerous identified toxicity and ecotoxicity categories are unsurprising, given the amount of wastewater and residual chemicals emitted from the cellulosic extraction process. It can be argued that, however, the use of NaDES-based chemicals mitigates the toxicity impact as they are reported to exhibit low toxicity [16; 17]. It can be seen that the category of global warming is conspicuously missing from the table; this is expected as energy is being consumed from an external source (energy generator) rather than being generated from on-site fossil fuel combustion (i.e., non-Scope 1 emission according to GHG protocol) [18]. The normalization stage serves the purpose of affording context and comparative significance to the impact category scores obtained from the ILCD and ReCiPe methods. In essence, the normalization process compares the impact category scores to reference values that characterize the average environmental impacts caused by activities associated with the cellulosic extraction process within a specific region (in this case, Saudi Arabia). This comparison facilitates the evaluation of the significance of the impacts in relation to broader environmental burdens. On a broader scale, normalization allows stakeholders to recognize that the environmental issues associated with the NaDES-microwave extraction of cellulose from biomass process are comparatively more or less important compared to other process activities. By affording a relative scale, normalization assists in decision-making and prioritization of environmental improvement strategies. Figure 3 shows comparative normalized impact category scores by using ReCiPe 2016 Midpoint (H) and ILCD 2011 Midpoint assessment methods for the cellulosic extraction process.