Zusammensetzung und Eigenschaften von Zuckerrohrbagasse

Technisches Team von Sheeon Pulp | Technisches Team des Unternehmens | Veröffentlicht: September 2026

Sugarcane bagasse is the fibrous residue left after sugarcane stalks are crushed to extract juice. Like any lignocellulosic material, it’s made up mainly of cellulose, hemicellulose, and lignin, plus a non-fibrous pith fraction that behaves differently from the fiber during processing, which is why raw bagasse composition matters before it ever reaches a pulping step.

What Bagasse Actually Contains

Published chemical analyses of raw sugarcane bagasse generally place cellulose in the roughly 42–56% range of dry weight, hemicellulose around 22–27%, and lignin around 19–26%, with ash typically low, often under 3.5%. A Brazilian bagasse chemistry study from the Escola de Engenharia de Lorena reported cellulose values between 42.5% and 46.8% depending on the extraction method used, alongside hemicellulose around 25–27% and lignin around 19–21%, illustrating how much the reported figures shift depending on how a given lab measures them. These aren’t fixed constants; they vary by cane variety, growing conditions, and how the sample was processed before testing, which is one reason a mill’s own testing matters more than a single published average.

Fiber vs. Pith: The Structural Split That Matters Most

Raw Bagasse isn’t a uniform material. It’s a mix of two structurally different particle types: fiber, found in the rind and the vascular bundles running through the stalk, and pith, the softer parenchyma tissue that fills the interior. Research published by the South African Sugarcane Research Institute (SASRI) puts the split at roughly 50–55% fiber and 30–35% pith by weight in raw bagasse, with the remainder made up of fines and other residual material.
This split isn’t incidental to papermaking. Fiber is what contributes to sheet strength; pith is not. Pulp mills routinely depith bagasse, mechanically separating the pith fraction, before cooking, because pith consumes cooking chemicals without contributing useful fiber to the finished pulp and adds to screening load downstream.

Why Pith Content Is Usually the Bigger Story Than People Expect

A common assumption is that leftover pith in unprocessed bagasse is essentially harmless filler that gets sorted out somewhere in the pulping line regardless. The SASRI research points to a more specific reason pith needs deliberate removal rather than incidental screening: pith has a lower lignin content and a more porous, higher-surface-area structure than fiber. That porosity means pith absorbs cooking liquor disproportionately to its fiber contribution, which is part of why depithing efficiency, not just total pith percentage, affects how consistently a given batch of bagasse cooks.

For a buyer or mill evaluating raw bagasse rather than finished pulp, that makes depithing quality, not just gross composition percentages, one of the more practical things to ask a supplier about.

Fiber Length and Why It’s Reported Separately From Composition

Chemical composition (cellulose, hemicellulose, lignin) describes what bagasse fiber is made of; fiber length describes its physical dimensions, and the two are measured and reported separately. A BioResources-published study on bagasse pulping for corrugating board reported an average fiber length around 1.6 mm for the fiber fraction tested, alongside separate measurements for fiber diameter and cell wall thickness. Composition percentages alone don’t indicate fiber length, so a buyer comparing bagasse sources on cellulose content alone is missing a variable that affects sheet strength independently of chemical makeup.

How Composition Translates Into Pulping Suitability

• Higher cellulose relative to lignin generally supports easier delignification. Lignin is what cooking chemicals need to break down to free the cellulose fibers, so a lower lignin starting point can mean less chemical and processing time needed to reach a given pulp brightness or purity target.
• Low ash content is generally favorable. High mineral content can interfere with chemical recovery processes at the mill and isn’t a contributor to fiber strength.
• Pith percentage affects both chemical consumption and yield. A batch with a higher pith fraction, or with pith that wasn’t efficiently separated before cooking, tends to consume more cooking chemical per ton of usable fiber recovered.
• Extractives content affects processing but isn’t part of the fiber itself. Non-fiber compounds removed during water or solvent extraction can represent a meaningful share of raw bagasse’s dry weight and are typically washed out before the fiber composition figures above are even measured.

What to Ask a Bagasse Supplier Before Ordering

• Request the fiber-to-pith ratio for the specific batch, not a general industry average, since this varies by cane variety and harvest conditions.
• Ask how depithing was performed and to what tolerance. Mechanical vibration screening and pneumatic separation are both used industry-wide, and the two methods vary in how completely they remove pith.
• Check moisture content and storage duration. Bagasse holds high moisture at the point of sugar extraction and is prone to degradation if stored wet for extended periods before delivery.
• Ask whether composition figures are supplier-reported or come from independent lab testing. Composition ranges vary enough between studies and batches that a specific test result carries more weight than a general reference range.

Häufig gestellte Fragen

Q: What percentage of bagasse is usable fiber?

A: Published research puts the fiber fraction at roughly 50–55% of raw bagasse by weight, with the remaining 30–35% as pith and the rest as fines and residual material, though exact figures vary by source and cane variety.

Q: Does higher cellulose content always mean better pulp quality?

A: Not on its own. Cellulose content is one factor in pulping suitability, but lignin content, pith percentage, and fiber length all affect how a given batch of bagasse behaves in cooking and what strength properties the resulting pulp has.

Q: Why does bagasse composition vary between sources?

A: Cane variety, growing region, harvest timing, and how the sugar-extraction process was run all affect the resulting bagasse’s fiber-to-pith ratio and chemical composition, which is why published ranges are ranges rather than fixed values.

Q: Is raw bagasse the same thing as bagasse pulp?

A: No. Raw bagasse is the unprocessed residue from sugar extraction; bagasse pulp is the fiber product that results after depithing, cooking, washing, and (for bleached grades) bleaching. Composition figures for raw bagasse describe the starting material, not the finished pulp’s specification sheet.

Depithing efficiency is the variable that’s easiest to overlook when comparing bagasse sources on composition percentages alone, and it’s worth a direct question to any supplier before committing to a bulk order.