Biomass Conversion: Moving Advanced Carbon Materials to Market

NRRI is experimenting with a variety of pellet shapes and binders to create enhanced BTU output biomass-based fuel products.
By June Breneman | April 01, 2019

As demand for composites in automotive, construction, aerospace and electronics sectors expands, there will be an increasing need for advanced carbon materials from biobased resources. But there are hurdles to moving new materials to market. Is your business ready to address this market opportunity?

The Natural Resources Research Institute, an applied research arm of the University of Minnesota in Duluth, has a pilot demonstration-scale biomass conversion lab specifically designed to deliver industry-relevant production capabilities, support commercialization efforts and reduce private sector capital investment risk. An on-site, pilot-scale hydrothermal carbonization unit can process high moisture content biomass, eliminating the need to dry the biomass materials before conversion to higher carbon products.

The NRRI Biomass Conversion Lab produces carbon-based, natural feedstocks using a rotary dryer and high-temperature kiln combined with compaction equipment. The unique drying and roasting capacity at the lab can convert a variety of biomass species, from wood chips and forest residuals to agricultural byproducts like corn stover or switchgrass. Carbon-based, sustainable feedstocks include activated carbon, charcoal briquettes and pellets, agglomerated biochar, solid biofuel briquettes and pellets, advanced inoculant carriers and biobased fertilizers, advanced plastics compounding fillers, biochar powders, and other value-added, high-carbon products.

Market, Testing Opportunities
The carbonization of raw biomass feedstock to desired fixed carbon content allows for the creation of a variety of agglomerated structures, from such as 2-4 millimeter (mm), free-flowing spherical beads to 0.25-1.5-inch solid biofuel briquettes. Depending on the application, very fine powder material to well-compacted agglomerated products can be routinely produced. Advanced products for battery and electronic applications can be derived from the processed biomass.

NRRI’s lab has rotary briquetting machines and pellet mills to densify enough carbonized feedstock to allow industrial evaluations for testing the produced solid fuels. On-site analytics are available to validate and document fuel specifications and chemical content to meet international and domestic fuel standards. NRRI has technical expertise in creating advanced agglomerates to meet targeted or desired product specifications. A variety of binders can be tested for efficacy. Laboratory facilities can take gram quantity formulations to barrel quantities for trial sales or performance testing and validation. NRRI partners with industry in a variety of R&D applications and contract service work.  Nonfuel products can be developed for field testing or for use in industrial markets such as plastic compounding.

Equipment Overview
The equipment in NRRI’s lab includes the following.

Torrefaction Kiln: A 2-foot by 24-foot rotary kiln capable of generating up to 6 tons of woody biomass chips daily into high-energy content, torrefied feedstocks at temperatures spanning 250 to 950 degrees Celsius.  NRRI has demonstrated the ability to deliver uniform, dry solid products that meet targeted fuel specifications similar to western coal. In addition, chars and activated carbon are new products that can be produced with the established capabilities. The kiln has the capability to process materials to temperatures as high as 1,150 degrees.

Hydrothermal Carbonization: A semi-continuous, 20 kilogram-per-day hydrothermal pipe reactor capable of transforming wet, grassy or fibrous biomass feedstocks into a variety of forms and shapes, from pellets to briquettes to 2-3 mm spherical agglomerate, to finely divided biochar powders and fillers.


Densification Equipment:
• Komarek B220: 15 horsepower, 12-inch rotary briquetter with multiple-sized pockets and dies capable of up to 300-pounds-per-hour output.

• CPM 40 horsepower pellet mill: Capable of up to 500 pounds per hour, equipped with a variety of die configurations spanning from one-eighth to one-fourth-inch pellets or even three-fourth-inch cubes.
• Hobart extruder: 5-inch screw equipped with 3-4 mm die plates. Transforms wet, pasty feed stocks into 3-4 mm extrusions.

• 30-inch coating spheronizer: Capable of transforming wet biochar or biocoal extrudate into 3-4 mm spherical, coated beads such as those used in the fertilizer sector.

NRRI’s lab has a rotary briquetting machine and pellet mills to densify enough carbonized feedstock to conduct a burn trial at a power plant. On-site analytics are available to validate and document fuel specifications and content to meet international and domestic fuel standards. NRRI has technical expertise in creating advanced agglomerates to meet targeted or desired solid fuel specifications. A variety of binders can be tested for efficacy, and laboratory facilities can take gram quantity formulations to barrel quantities for trial sales or performance testing and validation. NRRI partners with industry in a variety of R&D applications and contract service work.

Future processing equipment includes a demonstration-scale, moving-bed carbonization system that is currently being installed at the facility to complement the kiln-based process. In late 2019, a new, steam-based boiler system will be implemented, capable of producing 100 kilowatts of electricity using biomass-based fuels with a direct grid connection.

The current technologies at NRRI’s Biomass Conversion Lab, along with the new torrefaction system and advanced generator coming in late 2019, can accelerate the transition of biomass to new market opportunities and reduce industry risk.

 
Contact: Don Fosnacht
Director, NRRI Energy Initiative Director
 dfosnach@d.umn.edu
218-788-2682