ww

w.in

l.gov

Characterizing Biomass Within the Supply Chain

Getting the right information at the right time

Advanced Bioeconomy Feedstocks ConferenceJune 10, 2015

William A Smith, Ian Bonner, Lynn Wendt, & Garold L Gresham—Idaho National Laboratory Energy Systems & Technologies

Biomass Feedstock Supply Logistics

• Resources: Regionally, temporally, and compositionally diverse with low energy density

• Herbaceous residues harvested seasonally

• Conversion occurs year-round

• Feedstock: Available supply, suitable composition, predictable performance in supply chain and within conversion processes

• Storage of native herbaceous biomass is necessary for first-generation biorefineries, co-firing applications, and future feedstock formulation operations

What Are You Buying?• Biomass, BTUs, Glucan, Xylan, Water, Soil, Sand?• How much is it worth? How much represents “product”? How much will

it cost to convert?• What can you or the producer do to collect, preserve, and deliver

quality feedstock?

Raw Feedstocks are Variable• Spatial & Temporal Variations

– Composition: carbohydrates, lignin, ash– Moisture: “native” & atmospheric– Contaminants: soil, rocks, weeds, “trash”

• Anatomical Fractions– Cut height/lower vs upper stalk, leaves– Bark, limbs, tops, leaves

• Harvest Practices– When, where, and how?

• Storage– Where? How? How long?

Atchison, 2004 NREL/SR-510-33893

Sampling is Required• Sampling relies on statistical methods (how many/how big?) and can

only tell you what you have at that time– Results of sampling are a function of history:

• Where, when, and how was it harvested, stored, and transported?

– Results represent a single point in time:• What comes out of harvest may not be what comes out of

storage or what’s delivered to the biorefinery.– Results are only as “good” as your sampling methods.

Analyses Are Costly• Most analyses require sample preparation

– Drying, grinding, and splitting (sub-sampling) are usually necessary.

• Results take time to acquire and analyze– Even “simple” moisture measurements take minutes to hours.– Composition can take 2 weeks and require 40-80 hours of labor.

• Analytical equipment, lab space, & skilled staff add operational expense

What you need to know and when…• Focus on key operations and exchange points

Harvesting and Collection• Soil contamination & ash

– Variability of samples

• Sample more of the bale– X-ray radiography

6% 12%

Storage—Moisture & Dry Matter Loss

• High storage moisture leads to biodegradation

• DML measurements are simple but error prone

• Storage conditions vary• Time…

• Laboratory storage reactors:– Control moisture, airflow,

and temperature– Measure CO2 for DML– Reaches extent of

degradation in ~1/3 the time compared to field

Storage Stability is a Feedstock Property• Rate & extent of corn stover degradation are proportional to moisture

content…

• …And, internal temperature from self-heating is a good indirect measure of dry matter loss over time.

Feedstock Composition

• NREL—Laboratory NIRS of prepared feedstocks– Corn stover, mixed herbaceous, sorghum, & pre-treated materials– Complete compositional characterization

• BALES—NIRS research in baled corn stover– Preliminary models for moisture, glucan, and ash

Courtesy of Bonnie Hames & BALES

NIRS Bale Probe Shows Impacts of Storage

• Saturated layer 3”-4”• Enrichment in ash and glucan

– Consistent with HC loss• Results for bale in 10 minutes

Moisture Profile New Bale

Moisture Profile Stored Bale

Glucan and Ash % Dry Weight

Stored Bale

Courtesy of Bonnie Hames & BALES

What Are Our Near-Term Options

• IR– Temperature, self-heating, &

fire• NIRS

– Moisture, composition• Conductivity

– Moisture• Microwave

– Moisture• X-ray Radiography

– Foreign matter, ash• Hyperspectral Imaging

– Moisture, composition• Prompt Gamma Neutron Analysis

– Elemental analysis, heating value

• “Electronic Nose”– Multiple sensor array for

various compounds– Detect degradation or fire

• Acoustics– i.e. grain loss sensors for

detecting foreign matter

Questions?