Prepared by

Michael T. Rains

Theodore H. Wegner

Alan Rudie

Forest Products Laboratory

July 2015

Implementation Plan of the 

Yreka, California, Feasibility Analysis

Cellulose Nano- and Micromaterial 

Production Study
2

INTRODUCTION

Forest Service Research and Development (Forest Products 

Laboratory and Northern Research Station), the National Forest 

System (Pacific Southwest Region), and the U.S. Endowment for 

Forestry and Communities are collaboratively initiating a feasibility 

study for cellulose nanomaterial and micromaterial production in 

Northern California. The Yreka, California, site is characterized 

by wood species availability and water use constraints typical of 

western U.S. Government public lands and much of the Rocky 

Mountain region where forest product utilization options are 

limited. 

T H E U LT I M AT E G OA L of the project is to develop 

a product option that can help fund forest management 

activities. A high-value product would support 

delivered timber costs sufficient to pay for harvesting 

and transportation costs for trees removed in forest 

restoration and hazardous fuel reduction operations. 

OVERALL PROJECT GOALS

• Compare quality and particle characteristics for cellulose 

nanomaterials and cellulose micromaterials made directly from 

wood using six production methods

• Produce quantities of cellulose nano- and micromaterials 

sufficient to evaluate four applications

• Identify production site requirements (such as water use, water 

treatment) and evaluate these requirements relative to the Yreka 

location

• Determine production costs (capital and operating) for the 

cellulose nano- or microparticle intermediates

This Public–Private Partnership will evaluate cellulose nano- and 

microparticle production options provided by one university, three 

private-sector companies, and the Forest Products Laboratory 

(FPL). Engineering evaluation referred to as AACE Class 5 (–30% 

to +40% capital costs) will be performed on each option and used 

to select one option for further analysis.

Klamath National Forest, California.

Supervisory Research Chemist Alan Rudie (left) 

tours Secretary of Agriculture Tom Vilsack (right) 

through FPL’s nanocellulose pilot plant and shows 

nanocellulose samples.

Technical

Alan Rudie, PhD

Supervisory Research Chemist

Fiber and Chemical Sciences Research

Forest Products Laboratory

arudie@fs.fed.us

608–231–9496

Media/Public Relations

Douglas Clawson

Assistant Director

Communications and Science Delivery

Forest Products Laboratory

dsclawson@fs.fed.us

608–231–9325

For more information, contact
BACKGROUND

Northern California and 

Southern Oregon are 

home to five National 

Forests (Klamath, Six 

Rivers, Rogue–Siskiyou, 

Shasta–Trinity, and 

Modoc National Forests) 

covering about seven 

million acres of U.S. 

Forest Service land. 

Yreka falls within 

Siskiyou County, 

currently a Federally designated HUB zone 

(Historically Underutilized Business zone) with a 

current unemployment of 12% and most recent job 

growth measure at –1.88%.

 Ranging from very dry (average annual rainfall of 13 

inches in the Medicine Highlands of the Modoc NF) 

to ample rain (80 inches in parts of the Six Rivers NF), 

the five forests represent a broad range of forest types 

and management needs. As with much of California 

and the Rocky Mountain states, few forest product 

options are available within reasonable transportation 

distance from the forests, and nearly all removals for 

fuels reduction and other management efforts have 

been funded from taxpayer dollars. This severely 

restricts the pace of the work needed to maintain 

forest health and protect communities from wildfire.

Cellulose nanomaterials have been known to 

exist for a half century but have received renewed 

attention because the tools and technologies to 

effectively measure, characterize, and utilize these 

and other nanodimensional materials have become 

commonly available only in the past 10 years. 

Cellulose nanomaterials are surprisingly strong 

(strength of steel at one-sixth the weight) and are 

expected to be affordable by competing material 

standards. The largest potential product volume is 

in composite products, including applications as 

varied as lightweight armor for military vehicles to 

car body panels to 100% renewable and compostable 

food storage containers. Other possible applications 

include support films for flexible electronics; very 

low density aerogel supports (to collect oil from 

environmental spills, provide high-surface-area 

support for chemical catalysts and battery electrodes, 

and for high-performance insulation products), and 

photo-electric applications (such as liquid crystal and 

piezo-electric applications).

The science surrounding production and use of 

cellulose nanomaterials has benefited greatly from 

technical interest in carbon nanotubes and similar 

inorganic nanoparticles, which have paved the way in 

terms of developing imaging techniques and surface 

compatiblization for composite applications. The two 

classic forms of cellulose nanoparticles—cellulose 

nanocrystals (CNCs) and cellulose nanofibrils 

(CNFs)—have different potential uses. CNCs are 

chemically resistant nano-sized crystals of cellulose 

that exist in all cellulose products, including paper 

pulps and cotton. Although known since 1949, 

methods for larger scale production and industrial 

use have just been developed in the past decade and 

are not yet at a commercial level of readiness. CNCs 

are rigid rod-shaped particles and when produced 

from wood are about 6 nm in diameter and 100–150 

nm long. They are the strongest form of cellulose 

nanoparticle and the form that exhibits both liquid 

crystal and piezo-electric properties. CNFs are 

string-like particles. A chemically produced form 

referred to as TEMPO oxidized cellulose nanofibrils 

(TOCNs) are particles 6–10 nm in diameter and 1–2 

μm long, in linear or single-chain form. A variety 

of mechanical grades vary principally by type of 

chemical pretreatment and amount of subsequent 

mechanical energy required; this type is also long 

and filamentous, but the particles are cross-linked 

or branched, and particle diameters are in a broad 

range that can be as small as 6 nm and range up to 

100 nm or more. Experience has shown that the 

benefits of smaller particle size usually plateau in the 

microparticle size range, and refining/grinding is 

usually terminated before true nano-scale (<100 nm) 

is achieved.

Research and development efforts to date have 

generally focused on materials produced from 

relatively pure cellulose sources or on processes 

that have first utilized a known laboratory cellulose 

isolation process before preparing the nanoparticles. 

The Yreka project intends to evaluate six cellulose 

nanoparticle production methods including CNCs 

(two methods), chemically prepared fibrils (two 

methods), and mechanically prepared fibrils (two 

methods), all produced directly from wood.

Yreka

Rogue River – 

Siskiyou NF

Klamath NF

Six Rivers NF

Modoc NF

Shasta-Trinity NF

CALIFORNIA

OREGON

3
PRODUCTION METHODS

Cellulose nanocrystals utilizing the traditional 

sulfuric acid method

Forest Service R&D, Forest Products Laboratory

The basis for this method was discovered 

in 1949; current methods are based on a 

modified approach from 1953. A cellulose 

source is mixed into a sulfuric acid solution. 

The sulfuric acid dissolves and hydrolyzes 

the noncrystalline (amorphous) portion of 

the cellulose, leaving the crystalline regions 

as separate nano-scale particles that are 

decorated with sulfuric acid half-ester groups, 

which help to keep the particles apart and 

suspended in water. The method has about 

a 50% yield when starting from cellulose 

and is expected to have about a 25% yield 

starting from wood. The remaining cellulose 

(50%) and hemicellulose (25% of wood 

mass) will be hydrolyzed to simple sugars 

and abandoned in the process to simplify 

recovery of spent acid. Lignin will be an 

insoluble and nondispersed byproduct that 

can be isolated for other applications. The 

sulfuric acid production method is being 

commercially used by CelluForce in a 1-ton/

day scale pilot plant in Windsor, Quebec, 

Canada, starting from bleached wood pulp.

Cellulose nanocrystals utilizing a peroxide radical 

chemical approach 

Blue Goose Biorefineries, Saskatoon, Saskatchewan, and 

Pure Lignin Environmental Technology, Kelowna, B.C.

The process has two major components. 

First, the wood is converted to brown pulp 

with Pure Lignin Environmental Technology’s 

patented two-step process of dilute nitric acid 

and ammonium hydroxide impregnation followed by alkaline extraction at atmospheric 

pressure. The washed pulp is then treated by 

the Blue Goose Biorefineries (BGB) process, 

which uses hydrogen peroxide and transition 

metal ions to both delignify wood and depolymerize cellulose. The crystalline regions are 

more resistant to the radicals produced by 

this chemical approach and remain after the 

other wood chemicals are rendered soluble by 

the treatment. Yield from wood is expected 

to be 25% to 35%. Lignin and hemicellulose 

side streams result from this process; among 

other market uses, Pure Lignin Environmental 

Technology has demonstrated their lignin as 

a polyethylene strength enhancer and their 

hemicellulose as a fertilizer and soil enhancer.

Cellulose nano-fibrils using a sulfur dioxide procedure

American Process Inc. 

The American Process (API) production 

method involves both delignification of wood 

and carbohydrate hydrolysis using sulfur dioxide in ethanol, similar in some respects to 

the sulfite pulping process. The product can 

be either rod-shaped particles similar to the 

traditional cellulose nanocrystal, or stringlike particles—cellulose nanofibrils. A unique 

advantage of the API process is that the lignin 

removed is recovered and can be used as an 

unreacted lignin, or can be re-deposited on the 

CN product to provide an interface between 

the CN particles and resin used in a composite 

product. API has recently started up a 0.5 ton 

per day facility in Thomaston, Georgia. 

4
Cellulose nanofibrils using the TEMPO chemical pretreatment 

Forest Service R&D, Forest Products Laboratory

Several research groups have evaluated the 

TEMPO treatment of wood particles, typically 

thermomechanical pulp. The processing 

conditions are nearly the same as required for 

TEMPO treatment of bleached wood pulp, but 

the sodium hypochlorite required are about three 

times what is needed for cellulose oxidation. 

Product yield is about 40% to 50% because nearly 

all the lignin and hemicellulose becomes soluble 

during the reaction. This reaction process offers 

no byproduct possibilities because both lignin and 

hemicellulose are highly degraded by hypochlorite 

and TEMPO oxidations. Effluent properties raise 

some concern because hypochlorite can produce 

polychlorinated phenols and other problematic 

chlorinated hydrocarbons. Oji Paper and Nippon 

Paper in Japan are currently pursuing small-scale 

demonstration of the TEMPO process starting 

from bleached wood pulp.

Cellulose microfibrils using mechanical pulping refiners 

University of Maine

This process involves recirculating a wood pulp 

slurry through one or more modified disk refiners, 

similar to those conventionally used in the 

production of paper and paperboard. The process, 

which requires 20–30 passes though the refiner and 

at least one change in refiner plates, is normally 

continued until 90% of the fiber particles are less 

than 0.2 μm. Fibrils produced using this method 

are characterized by broader fiber diameter and 

length distributions than chemical-based methods. 

The fibrils appear to be branched in structure. The 

process is expected to work well with wood if the 

initial size of the wood particles is small enough so 

that they can be suspended in water and pumped 

through the refiner. Wood particles will be 

screened to remove dirt and reduce bark content. 

Overall yield from wood should be greater than 

90%. The final product will be thickened to about 

10% solids to minimize transportation costs and 

fresh water usage. This process has been piloted 

at the University of Maine using bleach kraft 

market pulp at the 1-ton/day scale. Southworth/

Paperlogic has recently commissioned a 2-ton/day 

CNF production facility based on this technology 

at its specialty paper mill in Turners Falls, 

Massachusetts.

Microfibrillated cellulose/mineral composite material

FiberLean IMERYS

IMERYS has a proprietary process to manufacture 

commercial volumes of microfibrillated cellulose 

(MFC) suitable for use in a wide range of industrial 

applications. FiberLean is a composite product 

of MFC and mineral, with MFC content ranging 

widely depending on the application. The mineral, 

typically calcium carbonate or kaolin, plays an 

essential role in the transfer of mechanical energy 

to the cellulose fiber. The efficiency in processing 

allows the transformation from cellulose to MFC 

at a lower energy demand and with no additional 

chemicals compared with other processes. 

Any water removed during the process can be 

reused with little to no treatment. Losses in the 

production process are extremely low, and the 

mineral portion of the product may offer some 

unique advantages to the end-use application, 

where downstream economies of manufacturing 

may be achievable; for example, kaolin and 

calcium carbonate are often used as components 

for reinforcing composite products.

5
A N C I L L A R Y P R O D U C T 

DEVELOPMENT ACTIVITIES

This project focuses on methods for producing cellulose nanoparticles as intermediates to be used in final products, so there will also 

be an emphasis on final product opportunities appropriate to the 

region. 

The Yreka site raises specific local production constraints that need 

to be better understood and accounted for in Forest Service planning. The rural siting also raises specific product concerns. 

The project will evaluate the six process nanomaterial types in 

four potential product applications: 

• reinforcing cement/concrete, 

• a coating applied to preserve foods for shipping, 

• a reinforcing fiber in polylactic acid, and 

• the insulation core of structural insulated panels (SIPs). 

To the extent necessary and appropriate, these evaluations will 

be built into the scope of work with the various participating 

cooperators.

O P E R A T I O N A N D 

GOVERNANCE

An operating board consisting of designated representatives from 

the Forest Service (Forest Products Laboratory, Northern Research 

Station, and Pacific Southwest Region) and the U.S. Endowment 

for Forestry and Communities will oversee and approve the work, 

approve budget allocations, review results, and make strategic 

decisions to achieve project goals. The operating board will meet 

regularly (no less than quarterly) via teleconference until the project 

is completed.

The Forest Service is providing the bulk of the funds, and several 

participants are also supplying resources. 

The U.S. Endowment for Forestry and Communities will serve as a 

contractor to help manage funds, provide administrative support, 

and carry out subcontracting under the direction of the Forest 

Service.

6

Cellulose nano-fibrils.

Cellulose nanocrystals.
7

PROJECT EXECUTION

Each participating organization will be provided with 

one or more wood sources from the Yreka area. They 

will each conduct necessary laboratory evaluations 

and then perform a large-scale experiment—preferably at pilot scale—that will be attended by a Forest 

Service engineer and a second industrial engineer 

contracted for this purpose. 

At the end of the trial, the organization will submit a 

report that includes a detailed experimental description, with all chemicals and quantities used, and a 

block mass-balance diagram. Details will be sufficient 

to enable an engineering firm to develop an AACE 

Class 5 cost analysis of the method for a 100-ton/

day plant located in the Yreka area and including all 

services needed by the proposed plant. The contract 

engineering company will provide a detailed list of 

what should be included in the report.

Organizations that are concerned about intellectual 

property and confidential business information will 

attach an appendix to their report identifying all 

intellectual property and business information in 

the report that they require to be held confidential. 

Although the initial reports are confidential, because 

public funds are being used, the Forest Service has a 

TASK RESPONSIBILITY

TARGET

COMPLETION

PRODUCTION

CNC (clean and slash chips) FPL

CN (rods) (clean chips) BGB

TEMPO CNF (clean chips) FPL

Mechanical CNF (clean wood particles) Univ. of Maine

Co-ground CNF (clean wood particles) Imerys

CNC and CNF (clean chips) API

ENGINEERING

AACE Class 5 Harris Group* 1st quarter, 2016

Process selection FPL/Harris Group* 1st quarter, 2016

AACE Class 4 Harris Group* 2nd quarter, 2016

Project decision FPL 2nd quarter, 2016

AACE Class 3* Harris Group* 3rd quarter, 2016

goal of publishing significant portions of each report 

and the Class 5 outcomes. The FPL will work with 

all cooperators to ensure that no confidential business information is disclosed. Forest Service R&D 

recognizes that corporate intellectual property and 

confidential business information must be preserved 

and that this may preclude publishing reports on some 

of the methods.

After the Class 5 studies are completed, one method 

deemed to be most appropriate for a more detailed 

analysis (AACE Class 4) will be selected by the Forest 

Service in consultation with the engineering company that performed the six Class 5 analyses. The 

Forest Service intends that the Class 4 outcome be 

made available to the public without disclosing any 

confidential business information that can be legally 

withheld. Should one of the corporate-sponsored 

methods be selected for the Class 4 analysis, intellectual property issues and publication concerns will be 

agreed to before initiating the Class 4 study. 

If sufficient funds are available and a promising outcome results from the Class 4 analysis, a more detailed 

Class 3 analysis may be contracted. 4th quarter, 2015
The USDA prohibits discrimination in all its programs and activities on the basis of race, color, 

national origin, age, disability, and where applicable, sex, marital status, familial status, parental 

status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because 

all or a part of an individual’s income is derived from any public assistance program. (Not all 

prohibited bases apply to all programs.) Persons with disabilities who require alternative means 

for communication of program information (Braille, large print, audiotape, etc.) should contact 

USDA’s TARGET Center at (202) 720–2600 (voice and TDD). To file a complaint of discrimination, 

write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, 

D.C. 20250–9410, or call (800) 795–3272 (voice) or (202) 720–6382 (TDD). USDA is an equal 

opportunity provider and employer.

The Forest Products Laboratory’s nanocellulose pilot plant in Madison, 

Wisconsin, is the first of its kind in the United States, situating FPL as the 

leading producer of domestic, renewable, forest-based nanomaterials. The 

plant can produce semicommercial-scale batches of cellulose nanofibrils and 

cellulose nanocrystals from renewable, wood-based sources.

This cellulose nano- and micromaterial production study is the next step 

toward using these materials in a more sweeping commercial basis.