SequesChar — Pyrolysis for Brewers' Spent Grain

38.6Mt

Wet brewers' spent grain produced globally each year.

85%

Of all physical waste from beer production is spent grain.

2–3days

Disposal window before in-house decomposition starts.

1.1Gt

Annual CO₂ biochar can sequester at scale.

01 / Problem

A waste stream brewers can't get rid of fast enough.

Beer is the third most-consumed beverage on earth. The grain it leaves behind is heavy, wet, and decomposes in days. Today, most of it gets trucked to a landfill, farm, or compost pile. Every option leaks methane and money.

Hands holding a heap of wet brewers' spent grain — Brewers' Spent Grain · BSG

Decomposes in 48 to 72 hours.

Wet grain has to leave the brewery fast. Miss the window and it ferments in-house, releasing methane and odors that make it nobody's friend.

Hauled, not processed.

Brewers ship spent grain to farms, composters, or landfills. Each route adds transport emissions, and without nearby farmland, real disposal fees.

Energy and carbon, hauled away.

Each dry kilogram of BSG carries roughly 11 MJ of recoverable chemical energy and ~50% usable carbon. Trucked off as feed, compost, or landfill, none of it stays at the brewery.

Methane, every step of the way.

Transportation, anaerobic digestion in livestock, decomposition in compost. The same kilogram of grain emits across multiple pathways.

02 / Process

Heat the grain. Skip the oxygen.

Pyrolysis is thermal decomposition of biomass in an oxygen-free chamber. Heat breaks the chemical bonds; the volatile fraction comes off as flammable vapor, and the carbon backbone stays behind as solid biochar.

INPUT · 01

Spent Grain

Wet BSG from the brewery's mash tun, transferred straight into the SequesChar feed hopper.

~75% moisture · cellulose, hemicellulose, lignin

REACTOR · 02

Pyrolysis

Augered through an oxygen-deprived chamber at around 450 °C. The grain dries, devolatilizes, then carbonizes.

T_target ≈ 450 °C · O₂ → 0

OUTPUT · 03

Three Streams

Solid biochar, combustible pyrolysis vapors (syngas + bio-oil), and the process heat released as they combust. All useful, all on-site.

char · syngas · bio-oil

03 / Cycle

Same carbon. Different ending.

When biomass decomposes or burns, 99% of its carbon goes back to the atmosphere. Pyrolysis bends the loop: roughly half the carbon stays locked into biochar, and the volatile half does useful energy work on the way out.

Diagram comparing the natural carbon cycle to the biochar cycle, where pyrolysis diverts half the biomass carbon into stable biochar and yields syngas or bio-oil as a 50%-less-CO2 energy stream — The carbon cycle vs. the biochar cycleNet effect: 50% less atmospheric return

01 · Status quo

Decompose or burn.

Spent grain rotting in a compost heap or a landfill releases nearly all of its carbon back into the atmosphere within months.

02 · The detour

Pyrolyze it instead.

Half the carbon comes out as biochar, a porous solid that won't break down. The other half drives a syngas burner, displacing fossil heat.

03 · Outcome

Carbon, parked.

Plowed into soil, BSG biochar has a mean residence time of 100 to 1,000 years. We're targeting at least 250. It also makes the soil better at growing the next crop.

04 / Impact

Biochar isn't a niche. It's the second-largest land-based carbon sink we have.

Soils get healthier, sandy ground holds water, dense clay aerates, chemically damaged land recovers. And the carbon stays underground.

A soil amendment and a carbon sink, in the same pile.

Biochar's porosity gives it a surface area in the hundreds of square meters per gram. That structure lets it hold water, nutrients, and beneficial microorganisms, restoring soils that synthetic agriculture has depleted.

Mixed into the ground, it doesn't break down. The carbon that biomass pulled out of the atmosphere stays sequestered, indefinitely.

1.2Gt

CO₂ / yr · Reforestation + avoided conversion

1.1Gt

CO₂ / yr · Biochar sequestration potential

05 / Machine

Two prototypes. From senior capstone to brewery-ready.

Built first as a UMass senior capstone on a $500 budget. Won the UMass Innovation Challenge, used the prize and an EDA grant to build the production unit, and went from concrete-and-pipe to stainless-and-PLC.

Generation 01 · Capstone$500

The Cylinder

2022 · UMass senior capstone

Capstone pyrolysis reactor — steel cylinder mounted on a hand-poured concrete base in the lab

A salvaged steel cylinder on a hand-poured concrete base, wrapped in ceramic blanket, fed by an off-the-shelf temperature controller. Crude, but it cracked biomass and won the UMass Innovation Challenge.

Cylinder wrapped in ceramic insulation, temperature controller reading 400 °C

Insulated

Auger

Winner

ReactorSteel pipe

InsulationCeramic fiber

ControlPID, single-zone

FundingSenior capstone

Generation 02 · Funded$36,000

The Production Prototype

2023–25 · EDA-backed build

Generation 02 prototype — stainless steel reactor on extruded aluminum frame with HMI and emergency stop

Engineered for a brewery floor. Continuous-feed auger, multi-zone thermal control, sealed pyrolysis chamber, integrated syngas return. Built from real grant funding after the Innovation Challenge win.

HMI showing target temp 500 °C, motor speed, residence time

HMI

Industrial control box — Arduino Pro, RS485, terminal blocks

Wiring

SolidWorks CFD simulation of reactor airflow

CFD

ReactorStainless, sealed

FeedContinuous auger

ControlArduino Pro, 3-zone PID

FundingEDA + UMass

06 / Team

Built by two engineers who spent a year welding their own reactor.

We started this as classmates in mechanical engineering at UMass Amherst. We've been at it ever since.

Co-founder

Ethan Gorman

B.S. Mechanical Engineering, UMass Amherst

Co-founder

Megan Anderson

M.S. Mechanical Engineering, UMass Amherst

07 / Backing

Grant-funded. University-backed.

SequesChar began as a capstone, won the UMass Innovation Challenge, and grew up with support from the U.S. Economic Development Administration and UMass Amherst.

UMass Innovation Challenge2022 · Winner

EDA + UMassGrant · Gen 02 build

The brewery's wettest waste,
turned into stable carbon.