Evaluation of unbleached pulps from Miscanthus x giganteus and Miscanthus cultivars for tissue paper production

Lexa, A., and Zollner, H. (2026). "Evaluation of unbleached pulps from Miscanthus x giganteus and Miscanthus cultivars for tissue paper production," BioResources 21(4), 9893–9909.

Abstract

This study assessed the suitability of four Miscanthus cultivars as alternative raw materials for pulp and paper production. A field evaluation revealed that cultivars 1 and 6 achieved the highest biomass yield ratios, at 2.4 and 2.0, compared to Miscanthus x giganteus. Chemical characterization identified cultivar 6 as favorable for pulping, exhibiting low extractives (1.35%), Klason lignin (14.5%) and moderate ash contents (1.37%). Pulp yields of up to 61.5% were achieved by soda pulping at 160 °C for 90 min and the addition of 15% NaOH by weight of the raw material. Cultivar 23 had the lowest residual lignin content at 1.1%. After refining to 500 PFI revolutions, sheets (30 gsm basis weight) produced from cultivar 6 achieved a tensile index of 43.9 N·m/g. The same tensile index as eucalyptus (44.0 N·m/g) was exhibited after 3000 rotations in the PFI mill. Overall, the results demonstrated that the selected Miscanthus cultivars, especially cultivar 6, is a promising source of fiber, particularly for products that require high absorbency and strength.

Download PDF

Full Article

**Evaluation of Unbleached Pulps from Miscanthus x giganteus and Miscanthus Cultivars for Tissue Paper Production**

Anna Lexa * and Helga Zollner

DOI: 10.15376/biores.21.4.9893-9909

Keywords: Miscanthus x giganteus; Cultivars; Soda pulping; Fiber properties; Paper; Pulp yield

Contact information: University of Applied Sciences Munich, Faculty of Technical Systems, Processes, and Communication, Lothstr. 34, 80335 Munich, Germany; *Corresponding author: [email protected]

Graphical Abstract

INTRODUCTION

Current State

Over the past decades, economic growth and rising living standards have been accompanied by a steadily increasing demand for energy and raw materials, resulting in a strong dependence on fossil resources (Ghatak 2011). In response, renewable biomass has gained increasing attention as a sustainable source for energy and chemicals (Alexopoulou 2018; Świątek et al. 2020; Cabrera-Jiménez et al. 2022; Lopez et al. 2023; Daimary et al. 2025), as well as for material applications (Henniges et al. 2014; Lavrič et al. 2021; Kapun et al. 2022; Tofani et al. 2024; Ganesh et al. 2025). Biomass feedstocks are commonly categorized into first- and second-generation energy crops. First-generation crops, such as maize, sugarcane, soybeans, and rapeseed, have been widely used for bioenergy and bioproducts. However, their cultivation competes with food production and is associated with high energy and resource inputs (Fargione et al. 2008; Allwright and Taylor 2016). In contrast, Miscanthus, switchgrass, poplar, and willow, which are identified as second-generation crops, offer considerable advantages. These include the ability to grow on low-quality land, low fertilizer and irrigation requirements, and high biomass yields with reduced environmental impact (Heaton et al. 2008; Allwright and Taylor 2016).

These advantages have led to the development of new applications. For Miscanthus, for instance, these include the construction and building sector as demonstrated in the works of Beck et al. 2004; Kursawe 2006; Ferrández-García et al. 2012; Dias et al. 2021; Schulte et al. 2021), or as mulch for fruit trees (Pude et al. 2006). Chemical pathways such as the synthesis of 5-hydroxymethylfurfural (HMF) (Światek et al. 2022) and bioethanol (Lask et al. 2021) have been investigated. What is more, Miscanthus is contributing to biodiversity and providing essential habitats for various species (Fritz and Fromowitz 2009)

At the same time, growing environmental consciousness and government regulations aimed at reducing plastic waste have led to a renewed focus on paper-based products. Paper and paperboard are attractive alternatives to petroleum-based packaging materials within a recycling-focused economic model, since they are biodegradable, recyclable, relatively low in density, and mechanically resilient (Oloyede and Lignou 2021). However, the limited availability of wood resources has increased the need to identify alternative fibrous raw materials for pulp and paper production (Danielewicz and Surma-Ślusarska 2019). In this context, annual non-wood plants such as Miscanthus have emerged as promising feedstocks, particularly as resource efficiency, environmental performance, and regional availability become increasingly important criteria for sustainable material selection (Fiedler et al. 2023).

Among paper products, the tissue and hygiene paper sector represents an attractive application for alternative fiber resources. According to recent market projections, the global tissue and hygiene paper market is expected to reach a value of USD 325.22 billion in 2026. A growth of 3.34 % is predicted for the market by 2030. Toilet paper remains the largest market segment, with an anticipated value of USD 104.61 billion in 2026. Per capita, global consumption is projected to reach approximately 16.9 kg per person per year, equivalent to an average revenue of USD 41.30 per person (Statista 2025). The steadily increasing demand for tissue products makes this sector suitable for the integration of novel fiber sources such as Miscanthus.

Miscanthus as a Renewable Biomass Resource

Miscanthus, a perennial grass, belongs to the Poaceae family and is classified as a C4 plant. Native to East Asia, the genus comprises approximately 17 to 20 species (Fritz and Fromowitz 2009). Miscanthus was introduced to Europe in the early 20^th century, and the genotype later known as Miscanthus × giganteus originated from a clone collected in Japan and cultivated in Denmark (Clifton-Brown et al. 2015). Based on morphological characteristics, the genotype was later recognized as a natural cultivar between Miscanthus sacchariflorus and Miscanthus sinensis (Greef and Deuter 1993). Miscanthus has gained considerable attention as a biomass crop due to its high productivity and efficient use of water and nutrients. Its C4 photosynthetic pathway enables high biomass yields with relatively low inputs, while a single annual harvest and long lifetime allow low-maintenance cultivation (Lewandowski et al. 2003).

Despite these advantages, the widespread use of Miscanthus x giganteus has been limited by its narrow genetic base, as it originates from a single sterile clone. This genetic uniformity restricts adaptability to different environments and may increase vulnerability to pests and diseases (Sang and Zhu 2011; Hodkinson et al. 2015). The narrow genetic base underscored the need for the development of new, site-adapted cultivars to ensure long-term productivity and ecological resilience (Lewandowski et al. 2003; Sang and Zhu 2011; Hodkinson et al. 2015). Genetic diversity within the genus enables growth across a wide range of climatic and soil conditions (Heaton et al. 2008; Kalinina et al. 2017).

Beyond its established role as an energy crop, Miscanthus has attracted increasing interest as a renewable raw material for industrial applications. Its fast growth, relatively low lignin content, and adaptability to various climatic conditions could enable energy-efficient pulping processes. In addition, decentralized cultivation of Miscanthus can lower transportation-related emissions while providing new income opportunities for farmers, thereby supporting regional bioeconomy concepts and rural development (Lewandowski et al. 2003; Gupta et al. 2022; Neelisetty et al. 2024).

In the last years, a lot of investigations have been carried out, testing the potential of Miscanthus for different pulp and paper applications. A comparison of the current literature reveals that many publications on pulp and paper production use Miscanthus x giganteus as the primary raw material (Danielewicz et al. 2018; Bocianowski 2019; Danielewicz and Surma-Ślusarska 2019; Barbash et al. 2020; Tsalagkas et al. 2021; Singh et al. 2022; Neelisetty et al. 2024). The article addresses the current research gap concerning the use of different Miscanthus cultivars to expand the genetic diversity for industrial applications and to identify the most suitable Miscanthus plants for pulp and paper production. Thus, the quality of the final product could be improved by selecting a different Miscanthus cultivar as the raw material. It integrates biomass characteristics, pulping performance, fiber properties, and paper-related quality parameters. In addition, the paper properties are to be compared with those of commercially available eucalyptus pulp in order to classify the properties. In doing so, this research advances the understanding of Miscanthus as a versatile lignocellulosic feedstock and the strategic selection of cultivars for specific applications.

EXPERIMENTAL

Miscanthus Cultivars

The raw material was provided by H. Gallin-Ast from “Landwirtschaftliches Technikum F&E – Energiepflanzen”. The study compared several Miscanthus cultivars with Miscanthus x giganteus as reference material. The plant material was obtained from a small Miscanthus trial field located near Dachau (Germany). The cultivation of the plants was initiated in a greenhouse in 2011.

Fig. 1. Comparison of the heights of various Miscanthus plants. The red lines indicate the location of the individual plants. From left to right: Miscanthus x giganteus, Cultivar 1, Cultivar 2, Cultivar 3, and Cultivar 4.

The plants are cultivars of the species Miscanthus sacchariflorus, Miscanthus sinensis, and Miscanthus lutarioriparius. The seeds used for cultivation were collected in various regions of China. Subsequent to the initial planting in the greenhouse, the seedlings were transferred to the trial field. Consequently, the cultivars have been in the field for 13 years. It can be assumed that they have reached their maximum yield potential. As they develop in close proximity to one another, they are subject to uniform climatic and soil conditions, and site-related variability is minimized.

A representative view of the cultivar trial field is shown in Fig. 1, illustrating the pronounced differences in plant height and morphology. Miscanthus x giganteus (G) is positioned on the left, followed by cultivar 1 (1) and the remaining cultivars in ascending numerical order, highlighting the substantial phenotypic diversity present within the Miscanthus population. Each plant is rendered by red lines.

**Preparation of Miscanthus for Research**

The sample collection took place on 10 September 2024. The material used for the experiments consisted of dried culms from the 2023 growing season that had not been harvested during the typical spring harvest period. The plants were left standing in the field to enable a direct comparison between the 2023 biomass and the 2024 actively growing plants. This provides insight into morphological differences. Based on the morphological survey, four Miscanthus cultivars were selected for detailed analysis, along with Miscanthus x giganteus as the reference species. The selected cultivars were designated as cultivar 1, cultivar 6, cultivar 23, and cultivar 50. The samples were harvested as they were found on the field. Leaves were not observed on the culms of any of the Miscanthus cultivars, which is a good basis for even sample collection. Therefore, only the dried culms of the plants were used for the experiments. They were harvested manually using pruning shears. The collected biomass served as raw feedstock for all subsequent experiments and was stored in paper bags at room temperature in a dry room.

Fig. 2. Comparison of the dried culms and chopped stalks of different Miscanthus plants used in this investigation. From left to right: Miscanthus x giganteus, Cultivar 1, Cultivar 6, Cultivar 23, and Cultivar 50.

In order to determine the chemical composition of the plant material, the size of the dried culms needed to be reduced. The initial fragmentation was performed using an SM 300 cutting mill (Retsch GmbH, Germany), which was operated at a speed of 1000 rpm and equipped with a 6 mm sieve. In order to carry out the extraction process, the sample was pulverized. The precut material was therefore milled to a particle size of approximately 80 μm using a ZM 300 ultra centrifugal mill (Retsch GmbH, Germany). Figure 2 shows the dried culms and chopped stalks of different Miscanthus plants used in this investigation.

An overview of the applied methods is provided in Table 1. The determinations were carried out in duplicate.

Table 1. Overview of the Analytical Methods for the Plant Characterization

Pulp Production and Characterization

The samples were evaluated for their suitability for chemical pulping. A soda pulping process was applied with an autoclave (Büchi Switzerland) and a volume of 5 L in combination with a Lauda oil heating device. For each cooking process, 350 g of oven-dried biomass was processed at 160 °C for 90 minutes. This corresponds to an H-factor of 740. A NaOH content of 15%, based on the raw material, and a dry-to-liquid ratio of 1:5 were applied. After cooking, the autoclave was opened at approximately 80 °C, and the pulp and black liquor were removed. First, the black liquor was separated from the pulp by washing with water in a screen frame fitted with a nickel-plated sheet-forming screen from a Rapid-Köthen sheet former. Then, the pulp was washed with water using a Rapid-Köthen sheet former to remove residual chemicals and neutralize the pH to 7. Subsequently, the pulps were characterized. Table 2 provides an overview of the applied methods and relevant standards. One pulp cooking was carried out for each Miscanthus sample, and the resulting material was used for further testing. All tests were carried out in duplicate. The residual lignin values were calculated from the Kappa number determination by multiplying the Kappa number with the factor 0.12.

Table 2. Overview of Analytical Methods for Pulp Characterization

Fiber Processing and Paper Characterization

The pulps were processed to evaluate their suitability for paper making. Before refining, all pulp samples were prepared according to ISO 5263-1 (2004) to ensure consistent samples. The refining was performed using a PFI mill (Frank PTI GmbH, Germany) described in ISO 5264-2 (2011). Afterwards, sheets were produced using a Rapid-Köthen sheet former (ISO 5269-2 2005). The basis weight was reduced to 30 gsm in order to simulate tissue-relevant conditions. After formation, the sheets were air-dried for 24 h in a controlled climate room (DIN EN ISO 187 2022), with one side exposed to the environment, as described by Prinz (2022). This prevents distortion of the softness of the sheets during the drying process. Additionally, the properties of the sheets of unbleached Miscanthus pulps were compared with those of a commercially available bleached eucalyptus pulp. In Table 3 the testing methods are shown. For the paper testing, 10 measurements were taken per sample for tensile strength, softness, and capillary rise. The water absorption capacity was tested in duplicate.

Table 3. Overview of the Paper Testing Methods

RESULTS AND DISCUSSION

Plant Characteristics

The initial differentiation of the Miscanthus cultivars was based on observable morphological traits. From the larger cultivar population, four cultivars and the reference species Miscanthus x giganteus were selected for a detailed laboratory analysis. The main morphological parameters are summarized in Table 4. Among the plants investigated, cultivar 50 stood out for reaching the greatest culm height (4.3 m) and for its thick-walled, brown culms with a wood-like structure. In addition to visual classification, biomass productivity was evaluated. A 0.5 m² area was used for the measurements, and the number of stalks was counted. Then, the number of stalks per square meter was calculated. The biomass could be determined by combining the weight per stalk with the number of stalks.

For comparison, the yield of Miscanthus x giganteus was defined as a reference value of 1.0, and the yields of the cultivars were expressed as relative ratios.

Table 4. Plant Characteristics of cultivars from the Testing Field

Cultivars 1 and 6 exhibited the highest relative biomass yields of 2.4 and 2.0. This indicates that, under identical site conditions, up to twice the amount of biomass could be harvested compared to Miscanthus x giganteus. These elevated yields highlight the potential of these cultivars for large-scale cultivation and industrial utilization.

The chemical composition was analyzed to evaluate the suitability for pulping applications (Table 5). The inorganic content of Miscanthus x giganteus was 0.94%. Similar values were observed for cultivars 1, 23, and 50, ranging between 0.71% and 1.0%. Cultivar 6 showed the highest inorganic content among the Miscanthus plants investigated, with 1.37%. In literature inorganic content for Miscanthus typically ranges from 0.9 to 2.95% (Neelisetty et al. 2024) or even 1.6 to 4.0% (Bergs et al. 2020), confirming that the cultivars examined in this study exhibit comparatively low inorganic content. Nevertheless, these values remain low compared to other annual lignocellulosic feedstocks, such as 12.4% for banana (Melesse et al. 2022), 8.9% for wheat straw (Sheoran 2020), or up to 20% for rice straw (Sinha and Sanjay 2021).

Table 5. Comparison of Plant Components

The Klason lignin represents a key parameter for the suitability of plants for pulping, as the primary objective of chemical pulping is the separation of cellulose fibers from the lignin matrix (Bajpai 2018). A lower initial lignin content is therefore advantageous. Miscanthus x giganteus showed a Klason lignin content of 15.5%, while all investigated cultivars exhibited lower values. Cultivar 23 showed the lowest lignin content with 11.5%. Kim and Um (2020) reported a Klason lignin content of 20.9% for Miscanthus. The lower lignin contents observed in the present study could not be fully explained within its scope, but they indicate favorable conditions for efficient delignification.

Pulp Production

The suitability of the selected Miscanthus cultivars for chemical pulping was evaluated using a soda pulping process. A key parameter for assessing the pulping performance is the pulp yield (Fig. 3). Miscanthus x giganteus exhibited a yield of 53.5%. In contrast, cultivar 6 and cultivar 23 achieved the highest pulp yields, each reaching 61.5%, corresponding to an increase of approximately eight percentage points relative to Miscanthus x. giganteus. These yields are within the expected range for annual plants. Pulp yields between 45% and 55% are reported for Miscanthus x giganteus (Danielewicz et al. 2018).

Together with the biomass productivity of the plants, these results reveal clear differences in overall feedstock suitability. Miscanthus x giganteus, defined as a reference with a relative biomass yield of 1.0, showed both low field biomass productivity and a low pulp yield. In contrast, cultivar 6 combined a high relative biomass yield (2.0) with a high pulping yield (61.5%), indicating a higher potential pulp output per unit area.

Fig. 3. Pulp yield comparison of Miscanthus x giganteus and different Miscanthus cultivars

Fiber morphology was further assessed to evaluate the pulp quality. The length-weighted average fiber length, Lc(l) ISO, ranged from 0.89 mm to 0.93 mm for all investigated samples (Table 6). The fiber length differences between the samples were minor, indicating comparable fiber dimensions across the investigated plants. Neelisetty reports a fiber length of 0.656 mm for Miscanthus sinensis that was treated with a steam explosion process (Neelisetty et al. 2024). Danielewicz and Surma-Ślusarska (2019), on the other hand, show numbers between about 1.0 and 1.13 mm. The cited authors reported that fiber length also depends on the adjustments to the pulping method used.

In addition, the fines A content was analyzed. Fines A represents small, rounded particles below 200 μm, which can increase drainage resistance and negatively affect strength properties when present in high proportions (Niskanen 1998). Cultivar 6 exhibited the lowest fines A content (25.5%), whereas cultivar 23 showed the highest value (30.1%), which is a difference of 4.6 percentage points. Although both cultivars achieved similarly high pulp yields, the substantially higher fines content of cultivar 23 suggests inferior pulp quality compared to cultivar 6.

Table 6. Fiber Characteristics

The effectiveness of the delignification during the soda pulping was assessed by comparing the initial Klason lignin content of the raw material with the residual lignin content after cooking (Fig. 4). The residual lignin values were calculated from the Kappa number determination by multiplying the Kappa number with the factor 0.12. The residual lignin indicates the amount of lignin that remains in the pulp after the chemical treatment. A greater reduction suggests a more efficient pulping process.

For Miscanthus x giganteus, the Klason lignin content decreased from 15.5% to 1.9%, corresponding to a reduction of 13.6 percentage points. Cultivar 6 showed a comparable reduction, with a lignin decrease from 14.5% to 1.2%. Cultivar 23 achieved the lowest residual lignin content with 1.1%. For all the plants investigated, the lignin content could be greatly reduced, demonstrating effective lignin removal. The results indicate that soda pulping is an effective method for Miscanthus.

Fig. 4. Comparison of Klason lignin and residual lignin contents after the pulp cooking of Miscanthus x giganteus and different Miscanthus cultivars

Paper Properties

The paper properties were evaluated and compared with sheets made from industrial reference pulps to assess their suitability for tissue applications. As a reference point, bleached eucalyptus kraft (BEK) was used and refined with 1000, 2000 and 3000 rotations in the PFI mill. The eucalyptus pulp results were obtained from Prinz (2022). The reference material provided a relevant framework for comparison. The Miscanthus results presented in this section refer to sheets produced from pulps refined at 500 revolutions in the PFI mill.

Figure 5 illustrates the correlation between the tensile index and the Schopper–Riegler (SR) results. The eucalyptus-based samples start in the lower-left region of the diagram, indicating comparatively low drainage resistance and moderate tensile strength. After refining in the PFI mill at 2000 rotations, the eucalyptus showed a tensile index of 37.1 N·m/g, which was a little high in comparison to Miscanthus x giganteus (35.6 N·m/g) and cultivar 23 (35.9 N·m/g). The Miscanthus cultivars in total were shifted towards higher SR values, reflecting a reduced drainage but generally enhanced strength development. Within the Miscanthus group, differences in tensile performance were observed. Cultivar 6 achieved the highest tensile index of 43.9 N·m/g, indicating superior bonding potential and fiber interaction. Cultivar 6 exhibited the same tensile index at 500 rotations in the PFI mill as eucalyptus (44.0 N·m/g) did after 3000 rotations. This demonstrates its great potential for paper production. Moreover, the influence of refining on tensile strength is particularly pronounced for cultivar 6. Without refining, the tensile index of cultivar 6 was 13.8 N·m/g, whereas refining to 500 revolutions increased the value to 43.9 N·m/g. Considering that these measurements were performed on sheets with a basis weight of 30 gsm, this result highlights the strength potential of cultivar 6, making it a promising candidate for tissue paper products.

Fig. 5. Tensile index to Schopper-Riegler at 500 revolutions in the PFI mill for Miscanthus x giganteus and different Miscanthus cultivars, compared to bleached eucalyptus kraft refined at 0, 1000, 2000 and 3000 revolutions in the PFI mill.

In addition, the tensile index was evaluated in combination with softness, as both parameters are critical for assessing the suitability of pulps for tissue paper applications (Fig. 6). From an application-oriented perspective, an optimal tissue pulp combines high tensile strength with high softness, which corresponds to the lower right region of the diagram. In general, an increasing tensile index is accompanied by a reduction in softness, expressed by higher TS7 values. Miscanthus x giganteus is located near the center of the plot, achieving a tensile index of 35.6 N·m/g. However, this higher strength is associated with reduced softness, limiting its direct applicability for tissue production. A similar trend was observed for the other Miscanthus cultivars. Cultivar 6 reached the highest tensile index among all tested samples but simultaneously exhibited a comparatively rough surface. These results highlight that, although Miscanthus cultivars have promising strength properties, they cannot be used for tissue production without blending with softer raw materials, such as eucalyptus, to achieve a balanced property profile.

Fig. 6. Tensile Index to Softness at 500 revolutions in the PFI mill for Miscanthus x giganteus and different Miscanthus cultivars, compared to bleached eucalyptus kraft refined at 0, 1000, 2000 and 3000 revolutions in the PFI mill.

Comparable trends have been reported by Prinz (2022), who investigated the correlation between tensile index and softness for pulps from various non-wood raw materials. Unrefined bagasse exhibited a tensile index of approximately 14 N·m/g with a TS7 of 43 dB, while wheat straw showed a tensile index of 16 N·m/g and a TS7 of 55 dB (Prinz 2022). The unrefined cultivar 6 showed a tensile index similar to that of bagasse. At the same time, a TS7 of 31.0 dB was reached. Miscanthus x giganteus even underscored this value with a TS7 of 27.5 dB. Compared to other annual fiber sources, Miscanthus x giganteus and cultivar 6 were in the lower TS7 range, which indicates that they have comparatively softer surfaces. Overall, the results confirm that no single alternative fiber can fully substitute eucalyptus for tissue paper production without property trade-offs.

The water absorption behavior was evaluated using the capillary rise and water absorption capacity as complementary indicators of the liquid uptake. The capillary rise represents the capillary-driven vertical water uptake in a paper stripe, while the absorption capacity reflects the total amount of water retained after full immersion. The results are presented in Fig. 7.

Fig. 7. Capillary rise to water absorption capacity at 500 revolutions in the PFI mill for Miscanthus x giganteus and different Miscanthus cultivars, compared to bleached eucalyptus kraft (all own data).

The commercial eucalyptus pulp is located in the upper right region of the diagram and exhibited the highest capillary rise (18.0 cm) combined with high absorption capacities of about 6.4 g/g. Miscanthus x giganteus and cultivar 6 are located in the central region. They demonstrated a moderate capillary rise, yet their absorption capacities were comparable to those of the reference materials. Miscanthus x giganteus reached an absorption capacity of 6.7 g/g, while cultivar 6 achieved 6.3 g/g. This property combination suggests potential suitability for absorbent tissue applications such as kitchen towels.

In addition to the quantitative results, distinct differences in wettability were observed during testing. Unrefined sheets initially floated on the water and required manual force for immersion, indicating limited wettability. This effect was particularly pronounced for unrefined Miscanthus x giganteus and cultivar 6, which showed low absorption capacities of 1.9 g/g and 2.2 g/g. Refining markedly altered this behavior. After 500 PFI revolutions, both materials exhibited an increase in absorption capacity, exceeding the values of the commercial references. This improvement is likely due to the increased accessible surface area of the fibers resulting from refining. The newly exposed surfaces may contain fewer hydrophobic substances, thereby enhancing fiber wettability and water absorption capacity.

CONCLUSIONS

Initial field analysis provided insights into the agronomic behavior of various Miscanthus cultivars cultivated in a single harvest location. Distinct growth patterns and structural differences among the cultivars were identified. In terms of harvest yield, cultivars 1 and 6 were the most efficient, with promising yield ratios of 2.4 and 2.0, which indicates their superior biomass potential.
Further, the material characterization was used to classify each plant. Cultivar 6 exhibited favorable chemical characteristics for pulping, such as low extractives (1.35%), low Klason lignin (14.5%), and moderate ash content (1.37%). In comparison, Miscanthus x giganteus had a higher extractive (1.45%) and lignin content (15.5%).
Among all Miscanthus plants, cultivar 6 was judged to be the most promising source of fiber under the given pulping conditions. Despite its slightly shorter fibers, reflected in a Lc(l) ISO of 0.89 mm, it offered the highest yield of the investigation. In particular, its lower fines A content (25.5%) and residual lignin of 1.2% after pulping indicate a high processing efficiency. Although cultivar 23 achieved a comparable yield and the lowest residual lignin content (1.1%), it exhibited a higher fines A content (30.1%), which may impact its mechanical properties and processability.
Comprehensive paper testing revealed that Miscanthus pulps performed well in key papermaking parameters. After 500 revolutions of refining, cultivar 6 reached a tensile index of 43.9 N·m/g, demonstrating a high strength potential. It exhibited the same tensile index as eucalyptus (44.0 N·m/g) after 3,000 rotations in the PFI mill. Its water absorption capacity of 6.3 g/g indicates its suitability for tissue and hygiene applications. However, due to its lower softness values, it must be blended with other pulps to meet the comfort expectations of tissue products.
Overall, the findings of this study highlighted the potential of Miscanthus cultivars, especially cultivar 6, as a potential sustainable alternative to wood-based fibers. Nevertheless, this study is the beginning of further research. To evaluate the Miscanthus cultivar further, harvests from different years must be compared to assess their stability. Additionally, the soda pulping process must be optimized for Miscanthus to achieve the best possible yield and fiber quality. It is also important to consider black liquor and its potential uses. The blending of Miscanthus pulp with other types of pulp also needs further investigation. To validate the laboratory results on a larger scale, further validation at the pilot or industrial scale is required. Based on this work, the questions are to be clarified within a doctoral dissertation.

ACKNOWLEDGMENTS

The results used for this article are part of a master’s thesis written at Munich University of Applied Sciences, supported by WEPA Hygieneprodukte GmbH.

The authors would like to thank H. Gallin-Ast from “Landwirtschaftliches Technikum F &E – Energiepflanzen” for the supply of Miscanthus cultivars.

Conflict of Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

REFERENCES CITED

Alexopoulou, E. (2018). Perennial Grasses for Bioenergy and Bioproducts: Production, Uses, Sustainability and Markets for Giant Reed, Miscanthus, Switchgrass, Reed Canary Grass and Bamboo, Academic Press.

Allwright, M. R., and Taylor, G. (2016). “Molecular breeding for improved second generation bioenergy crops,” Trends in Plant Science 21(1), 43-54. https://doi.org/10.1016/j.tplants.2015.10.002

Bajpai, P. (2018). Biermann’s Handbook of Pulp and Paper: Raw Material and Pulp Making, Vol. 1, Elsevier, Amsterdam, The Netherlands.

Barbash, V. A., Yashchenko, O. V., and Vasyliev, O. A. (2020). “Preparation and application of nanocellulose from Miscanthus × giganteus to improve the quality of paper for bags,” SN Appl. Sci. 2, article no. 727. https://doi.org/10.1007/s42452-020-2529-2

Beck, A., Schwab H., and Fricke J. (2004). “Wärmeleitfähigkeiten von Bauteilen mit Miscanthus, ” in: Anbau, Verwertung und Erfolgsaussichten von Miscanthus in Europa: 3. Internationale Miscanthus – Tagung, R. Pude (ed.), p. 57.

Bergs, M., Do, X. T., Rumpf, J., Kusch, P., Monakhova, Y., Konow, C., Völkering, G., Pude, R., and Schulze, M. (2020). “Comparing chemical composition and lignin structure of Miscanthus × giganteus and Miscanthus nagara harvested in autumn and spring and separated into stems and leaves,” RSC Advances 10, 10740-10751. https://doi.org/10.1039/C9RA10576J

Bocianowski, J. (2019). “NSSC pulping of Miscanthus x giganteus and birch wood part 2: A comparison of papermaking potential and strength properties,” Wood Res. 64, 281-291.

Cabrera-Jiménez, R., Mateo-Sanz, J., Gavaldá, J., Jiménez, L. and Pozo, C. (2022). “Comparing biofuels through the lens of sustainability: A data envelopment analysis approach,” Applied Energy 307, 118201. https://doi.org/10.1016/j.apenergy.2021.118201

Clifton-Brown, J., Schwarz, K.-U., and Hastings, A. (2015). “History of the development of Miscanthus as a bioenergy crop: From small beginnings to potential realisation,” Biology and Environment: Proceedings of the Royal Irish Academy 115B(1), 45-57. https://doi.org/10.3318/BIOE.2015.05

Daimary, N., Deb, B., Roy, B., Ranjan, R.K. and Mukherjee, A. (2025). “Sustainable biorefinery approach for the transformation of biowaste into biofuels and chemicals for the circular economy: A review,” Sustainable Energy Technologies and Assessments 82, article 104457. https://doi.org/10.1016/j.seta.2025.104457

Danielewicz, D., Dybka-Stępień, K., and Surma-Ślusarska, B. (2018). “Processing of Miscanthus × giganteus stalks into various soda and kraft pulps. Part I: Chemical composition, types of cells and pulping effects,” Cellulose 25, 6731-6744. https://doi.org/10.1007/s10570-018-2023-9

Danielewicz, D., and Surma-Ślusarska, B. (2019). “Miscanthus × giganteus stalks as a potential non-wood raw material for the pulp and paper industry: Influence of pulping and beating conditions on the fibre and paper properties,” Industrial Crops and Products 141, article 111744. https://doi.org/10.1016/j.indcrop.2019.111744

Dias, P., Jayasinghe, L.B. and Waldmann, D. (2021). “Investigation of Mycelium-Miscanthus composites as building insulation material,” Results in Materials 10, article 100189. https://doi.org/10.1016/j.rinma.2021.100189

DIN 54357 (1978). “Testing of pulp—Determination of Kappa number,” Deutsches Institut für Normung (DIN), Berlin, Germany.

DIN EN ISO 187 (2022). “Paper, board and pulps—Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples,” Deutsches Institut für Normung (DIN), Berlin, Germany.

DIN EN ISO 638-2 (2022). “Paper, cardboard, and pulp—Determination of dry content—Oven method,” Deutsches Institut für Normung (DIN), Berlin, Germany.

DIN ISO 8787 (1994). “Paper and board—Determination of capillary rise (Klemm method),” Deutsches Institut für Normung (DIN), Berlin, Germany.

Fargione, J., Hill, J., Tilman, D., Polasky, S., and Hawthorne, P. (2008). “Land clearing and the biofuel carbon debt,” Science 319(5867), 1235-1238. https://doi.org/10.1126/science.1152747

Ferrández-García, C.E., Andreu-Rodríguez, J., Ferrández-García, M. T., Ferrández-Villena, M., and García-Ortuño, T. (2012). “Panels made from giant reed bonded with non-modified starches,” BioResources 7(4), 5904-5916

Fiedler, M., Tech, S., and Lindner, M. (2023). Schaffung von Wertschöpfungsketten für den Einsatz von Miscanthusfasern aus nachhaltig bewirtschafteten Grenzflächen und Bergbaufolgeflächen, Papiertechnische Stiftung (PTS), Heidenau, Germany.

Fritz, M., and Fromowitz, B. (2009). Miscanthus als Nachwachsender Rohstoff: Ergebnisse aus Bayerischen Forschungsarbeiten, Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe, Straubing, Germany.

Ghatak, H. R. (2011). “Biorefineries from the perspective of sustainability: Feedstocks, products, and processes,” Renewable and Sustainable Energy Reviews 15(8), 4042-4052. https://doi.org/10.1016/j.rser.2011.07.034

Greef, J. M., and Deuter, M. (1993). “Syntaxonomy of Miscanthus × giganteus,” Angewandte Botanik 67, 87-90.

Gupta, N., Mahur, B. K., Izrayeel, A. M. D., Ahuja, A., and Rastogi, V. K. (2022). “Biomass conversion of agricultural waste residues for different applications: A comprehensive review,” Environmental Science and Pollution Research 29, 73622-73647. https://doi.org/10.1007/s11356-022-22802-6

Heaton, E. A., Dohleman, F. G., and Long, S. P. (2008). “Meeting US biofuel goals with less land: The potential of Miscanthus,” Global Change Biology 14(9), 2000-2014. https://doi.org/10.1111/j.1365-2486.2008.01662.x

Henniges, U., Veigel, S., Lems, E.-M., Bauer, A., Keckes, J., Pinkl, S. and Gindl-Altmutter, W. (2014). “Microfibrillated cellulose and cellulose nanopaper from Miscanthus biogas production residue,” Cellulose 21, 1601-1610. https://doi.org/10.1007/s10570-014-0232-4

Hodkinson, T. R., Klaas, M., Jones, M. B., Prickett, R., and Barth, S. (2015). “Miscanthus: A case study for the utilization of natural genetic variation,” Plant Genetic Resources 13(3), 219-237. https://doi.org/10.1017/S147926211400094X

ISO 12625-4 (2022). “Tissue paper and tissue products—Part 4: Determination of tensile strength, stretch at maximum force and tensile energy absorption,” International Organization for Standardization, Geneva, Switzerland.

ISO 12625-8 (2011). “Tissue paper and tissue products—Part 8: Water-absorption time and water-absorption capacity, basket-immersion test method,” International Organization for Standardization, Geneva, Switzerland.

ISO 5263-1 (2004). “Pulps—Laboratory wet disintegration—Part 1: Disintegration of chemical pulps,” International Organization for Standardization, Geneva, Switzerland.

ISO 5264-2 (2011). “Pulps—Laboratory beating—Part 2: PFI mill method,” International Organization for Standardization, Geneva, Switzerland.

ISO 5267-1 (1999). “Pulps—Determination of drainability—Part 1: Schopper-Riegler method,” International Organization for Standardization, Geneva, Switzerland.

ISO 5269-1 (2005). “Pulps—Preparation of laboratory sheets for physical testing—Part 1: Conventional sheet former method,” International Organization for Standardization, Geneva, Switzerland.

Kalinina, O., Nunn, C., Sanderson, R., Hastings, A. F. S., van der Weijde, T., Özgüven, M., Tarakanov, I., Schüle, H., Trindade, L. M., Dolstra, O. (2017). “Extending Miscanthus cultivation with novel germplasm at six contrasting sites,” Frontiers in Plant Science 8, article 563. https://doi.org/10.3389/fpls.2017.00563

Kapun, T., Zule, J., Fabjan, E., Hočevar, B., Grilc, M., Likozar, B. (2022). “Engineered invasive plant cellulose fibers as resources for papermaking,” Eur. J. Wood Prod. 80, 501-514. https://doi.org/10.1007/s00107-021-01779-y

Kim, G.-H., and Um, B.-H. (2020). “Fractionation and characterization of lignins from Miscanthus via organosolv and soda pulping for biorefinery applications,” International Journal of Biological Macromolecules 158, 443-451. https://doi.org/10.1016/j.ijbiomac.2020.04.229

Kursawe, K.-W. (2006). “Vorwand-Schallschutzelemente für das Verkehrswesen, ” in: Miscanthus – Potentiale und Perspektiven – regionale und überregionale Anbau- und Verwertungskonzepte: 4. Internationale Miscanthus-Tagung, Pude R. (ed), pp. 54-55.

Lask, J. Rukavina, S., Zoric, I., Kam, J., Kiesel, A., Lewandowski, I., and Wagner, M. (2020). “Lignocellulosic ethanol production combined with CCS—A study of GHG reductions and potential environmental trade‐offs,” GCB Bioenergy 13, 336-347. https://doi.org/10.1111/gcbb.12781

Lavrič, G., Zamljen, A., Juhant Grkman, J., Jasiukaitytė-Grojzdek, E., Grilc, M., Likozar, B., Gregor-Svetec, D., and Vrabic-Brodnjak, U. (2021). “Organosolv lignin barrier paper coatings from waste biomass resources,” Polymers (Basel) 13, article 244443. https://doi.org/10.3390/polym13244443

Lewandowski, I., Scurlock, J. M. O., Lindvall, E., and Christou, M. (2003). “The development and current status of perennial rhizomatous grasses as energy crops in the US and Europe,” Biomass and Bioenergy 25(4), 335-361. https://doi.org/10.1016/S0961-9534(03)00030-8

Lopez, G., Keiner, D., Fasihi, M., and Koiranen, T. (2023). “From fossil to green chemicals: sustainable pathways and new carbon feedstocks for the global chemical industry,” Energy Environ. Sci. 16, 2879-2909. https://doi.org/10.1039/D3EE00478C

Melesse, E. Y., Bedru, T. K., and Meshesha, B. T. (2022). “Production and characterization of pulp from banana pseudo stem for paper making via soda anthraquinone pulping process,” Journal of Engineering Research and Reports 58, 63-76. https://doi.org/10.4028/www.scientific.net/JERA.58.63

Nagaraja Ganesh, B., Rekha, B., Krishna, M. G., and Ferozdheen, S. I. S. M. (2025). “Ascertaining the anatomical parameters and chemical composition of Luffa cylindrica cellulosic fibers for their plausibility in pulp and paper production,” Polymers (Basel) 17, article 192643. https://doi.org/10.3390/polym17192643

Neelisetty, S. S. B., Ahuja, A., Kleinert, R., Wagenführ, A., Miletzky, F., and Rastogi, V. K. (2024). “Potential of sustainable non-woody Miscanthus sinensis fibers in paper-making,” Cellulose 31, 8863-8879. https://doi.org/10.1007/s10570-024-06143-w

Niskanen, K. (1998). Paper Physics, in series: Papermaking Science and Technology, Vol. 16, J. Gullichsen and H. Paulapuro (eds.), Fapet Oy, Helsinki, Finland. ISBN 9525216000.

Oloyede, O., and Lignou, S. (2021). “Sustainable paper-based packaging: A consumer’s perspective,” Foods 10(5), article 1035. https://doi.org/10.3390/foods10051035

Prinz, M. (2022). The Influence of Fibre Characteristics and Papermaking Processes on the Softness of Tissue Paper Products. Doctoral Dissertation, Graz University of Technology (TU Graz), Austria.

Pude, R., Beeck, C., and der Blanke, M. M. (2006). “Eignung von Miscanthus-Mulch im Obstbau,” in: Miscanthus – Potentiale und Perspektiven – regionale und überregionale Anbau- und Verwertungskonzepte: 4. Internationale Miscanthus-Tagung, R. Pude (ed.), pp. 39-43.

Sang, T., and Zhu, W. (2011). “China’s bioenergy potential,” GCB Bioenergy 3(2), 79-90. https://doi.org/10.1111/j.1757-1707.2010.01064.x

Schulte, M., Lewandowski, I., Pude, R. and Wagner, M. (2021). “Comparative life cycle assessment of bio‐based insulation materials: Environmental and economic performances,” GCB Bioenergy 13, 979-998. https://doi.org/10.1111/gcbb.12825

Sheoran, M. (2020). “Pilot-scale soda pulping of wheat straw using continuous pulp digester,” Journal of the Indian Chemical Society 2020, 403-408.

Singh, S., Zaitoon, A., Sharma, S., Manickavasagan, A., and Lim, L.-T. (2022). “Enhanced hydrophobic paper-sheet derived from Miscanthus × giganteus cellulose fibers coated with esterified lignin and cellulose acetate blend,” Int. J. Biol. Macromol. 223, 1243-1256. https://doi.org/10.1016/j.ijbiomac.2022.11.066

Sinha, A., and Sanjay, K. (2021). “Formic acid pulping process of rice straw for manufacturing of cellulosic fibers with silica,” Tissue Journal 20(8), 489-496. https://doi.org/10.32964/TJ20.8.489

Statista (2025). “Tissue & hygiene paper – Worldwide,” (https://www.statista.com/outlook/cmo/tissue-hygiene-paper/worldwide), Accessed 26 May 2026.

Świątek,K., Gaag, S., Klier, A., Kruse, A., Sauer, J., and Steinbach, D. (2020). “Acid hydrolysis of lignocellulosic biomass: Sugars and furfurals formation,” Catalysts 10, article 437. https://doi.org/10.3390/catal10040437

Świątek, K. Olszewski, M. J., and Kruse, A. (2022). “Continuous synthesis of 5‐hydroxymethylfurfural from biomass in on‐farm biorefinery,” GCB Bioenergy 14, 681-693. https://doi.org/10.1111/gcbb.12938

TAPPI T204 (2007). “Solvent extractives of wood and pulp,” TAPPI Press, Atlanta, GA, USA.

TAPPI T211 (2007). “Ash in wood, pulp, paper and paperboard: Combustion at 525 °C,” TAPPI Press, Atlanta, GA, USA.

TAPPI T222 (2006). “Acid-insoluble lignin in wood and pulp,” TAPPI Press, Atlanta, GA, USA.

Tofani, G., Jasiukaitytė-Grojzdek, E., Grilc and M., Likozar, B. (2024). “Organosolv biorefinery: Resource-based process optimisation, pilot technology scale-up and economics,” Green Chem. 26, 186-201. https://doi.org/10.1039/d3gc03274d

Tsalagkas, D., Börcsök, Z., Pásztory, Z., Gogate, P., and Csóka, L. (2021). “Assessment of the papermaking potential of processed Miscanthus × giganteus stalks using alkaline pre-treatment and hydrodynamic cavitation for delignification,” Ultrason. Sonochem. 7, article 105462. 10.1016/j.ultsonch.2021.105462

Article submitted: June 22, 2026; Peer review completed: July 11, 2026; Revised version received and accepted: August 6, 2026; Published: August 19, 2026.

DOI: 10.15376/biores.21.4.9893-9909