Rallming Yang

Research Scientist II
(404) 894-7862

In May 2000, Dr. Yang earned his doctorate degree in environmental and resource engineering from the College of environmental science and forestry, State University of New York. He also held M.S. degree and B.Sc. degree in pulping and paper. He first joined IPST, the former of RBI at Georgia Tech, in 2000 as a post doctor fellow. Soon he was hired as research scientist I. In 2006, he was promoted to be research scientist II. In 2013, he was appointed to be the manager of pulping and bleaching lab. Beginning from 2016, Dr. Yang has been teaching Pulp & Bleaching Lab (ChBE4873).  In 2019, he was assigned additional duty in managing chemical analysis lab.

With strong educational background in wood chemistry, coupled with the acquired skills and experience in chemical analysis., Dr. Yang’s main area of interest was utilizations of natural resources, especially biomass, in a sustainable way. He also interested in the development of novel online detection and monitoring in chemical process, and providing technical services to the industries and research communities. His teaching, research and technical services are summarized as following:  

  • Course taught: Pulp & Bleaching Lab, ChBE4873
  • Wood Chemistry: Cellulose Chemistry, Lignin Chemistry
  • Analytical Chemistry
  • Cellulose derivatives: regenerated cellulose, cellulose esters
  • Pulping and Paper: Chemical and chemi-mechanical Pulping of Woody and Non-woody Materials, TCF bleaching and ECF Bleaching
  • Biomass extractives characterization using GC/MS
  • Biomass hydrolysate characterization using HPLC and HPLC/MSn;
  • Lignin characterization through nitrobenzene oxidation, permanganate oxidation, cupric oxide oxidation, methoxyl group content measurement and phenolic hydroxyl group content determination
  • GPC characterization of cellulose
  • Pulping black liquor total analysis: organic degradation products characterization using GC/MS, inorganic species characterization using capillary ion electrophoresis
  • Volatile chemicals analysis using SPME-GC/MS
  • Carbon content determination using coulometer titration
  • High molecular weight degradation products and polymer characterization using Nicolet FTIR and GC/MS Coupled with CDS Pyroprobe 2000
  • Protein content and nitrogen content determination using Kjeldahl Method
  • Hazardous air pollutants analysis using gas phase FTIR


Ph.D. in Environmental and resource engineering, SUNY-College of Environmental Science and Forestry, New York, Syracuse, USA, May 2000          
M.S. in Pulping and Paper Engineering, South China University of Technology, Guangzhou, P, R China, May 1987.
B.Sc. in Pulping and Paper Engineering, South China University of Technology, Guangzhou, P.R. China, December 1982.

Peer-reviewed journal publications:

R. Yang and C. Luettegen.  ”Repulping of Wet Strength Paper Towel with Potassium Monopersulfate”. TAPPI Journal,19(9):463-470 (2020)

S. Banerjee, R. Yang and L. A. Lucia.  “Polysulfide Distribution during Kraft Pulping”.    Ind. Eng. Chem. Res., 49(8):3983-3985 (2010)

H. Tan, R. Yang, W. Sun and S. Wang. “Peroxide-Acetic Acid Pretreatment to Remove Bagasse Lignin Prior to Enzymatic Hydrolysis”. Ind. Eng. Chem. Res., 49(4):1473-1479 (2010)

S. Banerjee, R. Yang, C. E. Courchene and T. E. Conners.  ”Scanning Electron Microscopy Measurements of the Surface Roughness of Paper”.  Ind. Eng. Chem. Res., 48(9):4322-4325 (2009)

S. Banerjee, R. Yang and R. D. Haynes.  “Aggregation of Colloidal Material in Recycling Process Water”.   Tappi Journal, 8:19 – 23(2009)

R. Yang, S. Banerjee and R. W. Sackellares. “Effect of Soap Spills on the Treatability of Pulp Mill Effluents”.  Appita, 62(2):110-117 (2009)

R. Yang and Y. Z. Lai. “Characterization of the Residual Kraft Lignin in situ by Sulfite Treatments”. J. Wood Chem. Technol., 29(2):164-177 (2009)

R. Yang, He Tan, F. Wei and S. Wang. “Peroxidase Conjugate of Cellulose Nanocrystals for the Removal of Chlorinated Phenolic Compounds in Aqueous Solution”. Biotechnology, 7(2):233-241 (2008)

K. Knutson, Y. Pu, T. Elder, G.B Buschle-Diller, R. Yang, C. Thomson, D. H. Kim, Z. Dang and A. J. Ragauskas “Effect of Photolysis on 17th/18th Century Paper”. Holzforschung, 61:131-137 (2007)

S. Banerjee, K. Pendyala, M. Buchanan, R. Yang, and M. Abu-Daabes. “Process-Based Control of HAPs Emissions from Drying Wood Flakes”.  Environ. Sci. Technol., 40(7):2438-2441(2006)

J. Jacobson, G. D. Smith, R. Yang and S. Banerjee. “Diffusion of Sulfide into Southern Pine and Sweetgum Particles and Chips”. Holzforschung, 60:498-502, (2006) 

Q. X. Hou, . S. Chai, R. Yang, T. Elder and A. J. Ragauskas. “Characterization of Lignocellulosic-Poly(lactic acid) Reinforced Composites?”.  J. Appl. Poly. Sci., 99:1346-1349 (2006)

R. Yang, L. Lucia,  A. J Ragauskas and H. Jameel.  “Oxygen Delignification Chemistry and Its Impact on Pulp Fibers”.  J. Wood Chem.  Technol., 23(1):13-17 (2003)

R. Yang, L. Lucia and A. Ragauskas. “Oxygen Degradation and Spectroscopic Characterization of Hardwood Kraft Lignin”. Ind. Eng. Chem. Res., 41(24):5941-5948 (2002)

Conference presentations

R. Yang.  “Research on regenerated cellulose fibers in RBI at Georgia Tech”,  4th International Symposium on Materials from Renewables, The University of Georgia, New Materials Institute, Athens, GA, October 9 to 10, 2019.

R. Yang. “Effect of blended-bed stacker/reclaimer systems on pulping”. FMW Technology and Innovation Symposium, FMW, Charlestone, SC, November 8 to 9, 2018.


Research interests are mainly in two areas: 1. utilizations of natural resources, especially biomass, in a sustainable way. 2. chemical analysis in pulping and paper. Research Project in the past three years,

  1. Use of electrolytic generated alkali peroxide in enhancement of alkali extraction stage to bleach chemical wheat straw pulp. This was a subcontract funded by NSF, and it  was completed in August 2018.
  2. Regenerated cellulose filament through Lyocell process. This was industrial funding project to manufacture regenerated cellulose filament from nanofibrated cellulose.
  3. Effect of blended-bed stacker/reclaimer systems on pulping. This was an industrial funded project in investigating the effect of wood yard equipment on pulping quality.
  4.  Repulping of Wet Strength Paper Towel with Potassium Monopersulfate. This was an industrial funded project in the application of chlorine-free reagent in repulping of recycled papers.

Academic Courses Taught

Pulp & Bleaching Lab, ChBE4873.

The purpose of this course is to acquaint students with practices and procedures in the paper industries, specifically in pulping and bleaching processes.  Students will begin with bags of raw woodchips, and eventually make and test their own hand sheets as the class proceeding. By the end of the class, students will have the overall knowledge about paper making from raw materials to final products. They will also familiarize the basic testing procedures, analyze and interpret experimental data, communicate their results and analyses in written and spoken forms. 

The course consists of three modules: kraft pulping, bleaching and papermaking. Each module is outlined as following:

Module I: Kraft Pulping

  • Wood Chip Solids Content
  • White Liquor Preparation
  • Digester Operation
  • Residual Alkali
  • Screening Yield & Rejects
  • Pulp Characterization: Kappa Number, Viscosity

Module II: Bleaching

  • Oxygen Delignification
  • Hypochloride Bleaching
  • Chlorine dioxide bleaching
  • Hydrogen peroxide bleaching
  • Brightness measurement

Module III: Papermaking

  • Refining & CSF measurement
  • Hand sheet formation
  • Physical Properties: Tensile, Burst and Tear

Technical Services


Raw materials preparation and characterization

  • Woodchip size analysis: size classifier
  • Chemical composition analysis: lignin, holocellulose, hemicellulose, extractives


  • Kraft pulping
  • Chemimechanical pulping
  • Equipment includes: M/K digesters, Aurora rotary digesters, Sprout-Waldron disk refiner

Recycling of Paper Products

  • Paper and paper board recyclability
  • Recycled fiber characterizations
  • Equipment include: Benchtop pulper (8 liter), Lamort pulper (15 gallon), British disintegrator, Somerville Screen


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

Refining and hand sheet:

  • Canadian Standard Freeness (CSF)
  • Drainage measurement using Britt Jar
  • Holand Beater, PFI mill for refining
  • Standard Tappi hand sheet forming
  • Water retention value

Pulp fiber characterization:

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

Black liquor evaporation:

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



  • Anion determination using capillary electrophoresis ( SO4-2,  SO3-2, S2O3-2,  Cl-1, Formate, Acetate, propanoate, butyrate, Oxalate) in black liquor, green liquor, white liquor, salt cake, ash and other process materials
  • Element determination using inductively coupled plasma optical emission spectrometry (ICP-OES) in in various sample matrices. Samples such as black liquor, green liquor, white liquor, salt cake and ash from pulping and paper industries are routinely analyzed
  • Carbon content determination using Coulometeric Titrator. Inorganic carbon (such as carbonate), organic carbon and total carbon are determined. Carbon content in black liquor, green liquor, white liquor, salt cake, ash and other process materials are analyzed with this instrument
  • Heating value determination using adiabatic oxygen bomb calorimeter. The unit is routinely used for heating value determination for black liquor samples
  • Alkaline, hydrogen sulfide and sulfide determination using Mettler Toledo Titrator. This unit is widely used in determination of residual alkaline and other active species in pulping process liquors
  • Process degradation products, extractives, deposits and organic contaminants in pulping and paper process are analyzed with GC/MS system
  • High molecular weight degradation products, extractives, deposits and organic contaminants in pulping and paper process are analyzed with FTIR system
  • Sugar profile of biomass and pulping process materials are determined using the HPLC system equipped with amperometric detector