From Biomass to Fiber Performance

The Pulping and Bleaching Laboratory supports research and industry work across the fiber processing workflow—from biomass preparation and pulping to bleaching, refining, and fiber characterization.

These capabilities allow researchers and industry partners to evaluate how raw materials and processing conditions influence pulp quality and paper-making performance.

Core Capabilities

  • Raw materials preparation
  • Kraft and chemi-mechanical pulping
  • Recycling and recovered fiber studies
  • Bleaching processes
  • Refining and handsheet formation
  • Pulp fiber characterization
  • Black liquor evaporation studies

 

Raw Materials Preparation

Before pulping begins, feedstocks must be prepared and evaluated to support consistent processing.

Capabilities include:

  • Woodchip size analysis using a size classifier
  • Preparation and evaluation of non-wood biomass feedstocks

 

Pulping Processes

The laboratory supports pulping studies across multiple feedstocks and process approaches, allowing researchers and industry partners to evaluate how materials respond under different pulping conditions.

Capabilities include:

  • Kraft pulping of hardwood, softwood, and non-wood agricultural residues
  • Chemi-mechanical pulping of hardwood, softwood, and non-wood agricultural residues

Equipment includes:

  • M/K digesters
  • Rotary digesters
  • Sprout-Waldron disk refiner

 

Recycling and Recovered Fiber

The laboratory also supports studies focused on paper recyclability and the behavior of recovered fiber streams.

Capabilities include:

  • Paper and paperboard repulpability
  • Recycled fiber characterization

Equipment includes:

  • Benchtop pulper (8 liter)
  • Lamort pulper (15 gallon)
  • British disintegrator
  • Somerville Screen

 

Bleaching

The laboratory supports several bleaching and delignification processes used to study lignin removal, brightness development, and changes in pulp properties.

Capabilities include:

  • Oxygen delignification
  • Chlorine dioxide delignification/bleaching
  • Hydrogen peroxide bleaching
  • Hypochlorite bleaching

 

Refining and Handsheet Formation

After pulping and bleaching, fibers can be refined and formed into laboratory handsheets to evaluate papermaking performance.

Capabilities include

  • Canadian Standard Freeness (CSF)
  • Drainage measurement using Britt Jar
  • Hollander Beater and PFI mill refining
  • Standard TAPPI handsheet forming
  • Water retention value

 

Pulp Fiber Characterization

The laboratory provides tools for examining fiber morphology and cellulose properties, helping connect process conditions to fiber performance.

Capabilities include:

  • FQA fiber morphology analysis
  • Bauer-McNett fiber classifier
  • Pulp fiber viscosity
  • Degree of cellulose polymerization
  • Content of alpha cellulose, beta cellulose, and gamma cellulose in pulp fibers

 

Black Liquor Evaporation Studies

The laboratory also supports studies related to black liquor behavior during evaporation, an important part of recovery operations.

Capabilities include:

  • Black liquor viscosity
  • Black liquor boiling point rise during evaporation
  • First critical solid determination

Our Equipment

By combining pulping, bleaching, refining, recycling, and fiber characterization in one place, the laboratory supports work across the pulp and paper process—from feedstock preparation to measurable fiber performance. Please see our listing of specific capabilities and tests below and contact us about your project needs.

Pilot digester system with liquor vessels for modified cooking

Pilot digester system with liquor vessels for modified cooking

Multi-unit digester with 6 one-liter vessels and individual electric heaters

Multi-unit digester with 6 one-liter vessels and individual electric heaters

Close up of vessels

Close up of vessels

High-shear bleaching mixer with ozone injection capabilities

High-shear bleaching mixer with ozone injection capabilities

Screen for pulp contaminant analysis

Screen for pulp contaminant analysis

Computer controlled handsheet press with heated platens for wet-pressing studies

Computer controlled handsheet press with heated platens for wet-pressing studies

Corona discharge unit for paper surface modifications

Corona discharge unit for paper surface modifications

Pulper for pulp and wastepaper defibering

Pulper for pulp and wastepaper defibering

Specific Capabilities

Raw Material Preparation

  • Chip classifier

Pulp Quality

  • Canadian Standard Freeness
  • Valley, Sprout Waldron, Somerville flat screens
  • Bauer-McNett Fiber Classifier
  • Fiber Quality AnalyzerTM
  • Valley Beater
  • PFI Mill
  • TAPPI Handsheets
  • Standard TAPPI Strength Testing
  • PULMACTM Shive Analyser 

Pulping

  • Sprout refiners – 12" diameter
  • Multi-unit digester with individual electric heating
  • Three M/K digesters with indirect heating - approximate volume10 L
  • Two batch digesters with direct or indirect heating - approximate volume 2 ft
  • Automatic titrator for liquor analysis 

Bleaching

  • Water baths and sealed bags
  • CRSTM high shear mixer with gas and liquid injection - 2 L volume
  • Pressurized pig mixer 

Contact

Rallming Yang

Research Scientist II
Renewable Bioproducts Institute
rallming.yang@rbi.gatech.edu
(404) 894-7862

To Request Testing

  1. Send e-mail to rallming.yang@rbi.gatech.edu with details regarding the nature of the request, the tests required and the problem or issue that is to be resolved. Provide billing contact name and address.
  2. Samples via courier (UPS, FedEx, DHL, etc.) may be sent to the attention of:
    Rallming Yang
    RBI at Georgia Tech
    500 10th St. NW
    Atlanta, GA 30318-5794
    If sending by U.S., mail, replace the ZIP code with 30332-0620
  3. A Purchase Order for an amount to cover the costs for the requested testing is required.
    Georgia Institute of Technology Bursar’s Office/ A/C Receivables
    225 North Avenue NW
    Lyman Hall Suite #111
    Atlanta, GA 30332-0257
    A copy of the Purchase Order sent via fax to 404-894-4778 is requested. 
  4. The sender should have the name of the appropriate RBI contact and phone number on their invoices/P.O.s
  5. Receipt of samples coupled with e-mail detailing testing requirements, and any background information initiates the generation of an internal project and officially starts the project.
  6. The work request is queued with others in order of time of receipt of samples.  Work requests may be expedited under special circumstances.
  7. A report will be issued within the agreed turnaround time.
  8. Bills are sent separately by mail through the GT accounting system.