Biomass system selection – start with the fuel

3 October 2023

The number of possible biomass fuels and fuel mixes utilizing waste “opportunity” fuels for a biomass energy system is large and continues to change and grow.  When you include the variabilities imposed by varying soil and climate conditions for agricultural wastes and varying feed for animals that results in changing animal waste fuels, the variability is almost limitless. 

One approach that is consistently tried is to take a combustion technology and try to make that combustion technology work for all fuels.  This “one solution fits all” approach often results in unsatisfactory results.  We would argue that the best way to design and optimize biomass energy systems is to start with the fuel and then to smartly apply the best fuel conversion technology.

Successful conversion of biomass fuels includes all of the elements that go into an efficient and smoothly functioning plant, including but not limited to, the areas of fuel receiving, sizing, possible densification, storage, reclaim, delivery to the boiler and metering into the boiler followed by controlled combustion or gasification, ash handling including disposal or sale, and finally air emission controls.  These separate systems make up a unified system where if any one of them is failing to perform it usually means the plant is down.

In order to design these systems, one needs to know as much information as possible about the fuel itself, including its size distribution (dust to large pieces), shape (evenly shaped particles to strings, sticks or leaves), structure (crystalline, amorphous), bulk density and chemical analysis, as well as information about where it was produced.

Analysis of the fuel including proximate and ultimate analysis that includes elements and compounds often not reported such as chlorine and detailed mineral analysis of the ash.  These results should also be reported in both “as-received” and “dry” condition.  While published information is very useful as a general guide and for initial discussions of possible energy conversion projects, it should be noted that standard published information is not adequate for initial feasibility studies, and certainly not for final design.  The possibility for wide variations from standard published information is vast.  For example, biomass fuels grown in the lateritic soils of West Africa will vary significantly from the same species of plant grown in Europe or Asia.

A recent example would be East Energy Renewables in North Carolina.  The challenge here was to convert hundreds of thousands of annual tons of poultry litter from numerous North Carolina poultry growers into steam, renewable energy and heat. 


Moisture and Heating Value – Conservative sized single pass furnace with lower heat release and furnace exit gas temperature, along with heated air for combustion

Size Distribution – Effectively proven stoker grate combustion and individual feeders

High Alkali (Na + K) – Fouling considerations including wide tube pitch on heat recovery surface components, low flue gas velocities, and strategically placed sootblowers

High Ash Content and Characteristics – Traveling grate, oversized bottom ash chute and collection conveyors, and some design considerations as high alkali

The effects of fouling and corrosion influence – all facets of the boiler design, including the furnace sizing, flue gas velocities, tube spacing and materials


Included for two (2) separate locations in NC, design and supply a conservatively sized grate stoker furnace for combustion with wide tube spacing for cleaning, and waste heat capture for adjacent waste water treatment plant.

Boiler Capacity (per site)85,000 PPH
Steam Pressure300 psig
Steam Temperature422 deg F Saturated
FuelsPoultry Litter (Chicken & Turkey)
Combustion TechnologyTraveling Grate Stoker
Emissions ControlsSNCR, Mechanical Dust Collector, Dry Sorbent Injection (DSI), Baghouse
ScopePower Island EPC Project
Schedule21 months
CODApril 2024

Wellons is proud to provide East Energy Renewables with a successful thoughtfully-considered solution.

Read More

Kea Aerospace achieves milestone in autonomous flight

Kea Aerospace has successfully completed a landmark BVLOS (Beyond Visual Line of Sight) flight, demonstrating the capabilities of their advanced autonomous flight technology. The milestone UAS (Unmanned Aircraft System) flight, conducted within Kea Aerospace’s Special Use Airspace, marks significant growth ...
Read more

€100 m investment in wood-based EV batteries

Stora Enso Oyj is preparing to invest about €100 million in a pioneering project to use wood in electric vehicle batteries and offer an alternative to components currently made in China, according to its chief executive officer. The funds would ...
Read more

First long-range electric trucks to New Zealand

Windrose Technology will work with Auckland based Etrucks® to bring the first long-range electric trucks to New Zealand. The Windrose E1400 6×4 semi tractor features extreme aerodynamic efficiency, with an industry low coefficient of drag of 0.2755. Combined with the ...
Read more

DC Equipment Canada return Madill to B.C.

DC Equipment has announced the opening of its new manufacturing facility in Prince George, marking the return of Madill equipment production to British Columbia. The first machines to be produced at this facility will be the Madill 3000B Log Loaders, ...
Read more

QLD budget weak on future timber material needs for housing

Queensland’s peak body for the forest and timber industry is warning of a looming building materials crisis by a lack of policy and budget measures for increasing future timber supply to help meet the state’s rising housing demand. “While we ...
Read more

Kenworth unveils futuristic SuperTruck 2

Kenworth showcased its SuperTruck 2 demonstrator vehicle at the Advanced Clean Transportation (ACT) Expo in Las Vegas last month, a project developed over six years in collaboration with the US Department of Energy’s (DOE) SuperTruck programme. The aim of the project ...
Read more

Key drivers to decarbonise heavy transport fleets

The industry was buzzing once again for the Wood Transport & Logistics 2024 event that ran last week in Rotorua, New Zealand. Well over 200 forestry and log transport companies from across Australasia, America and Europe, came to Rotorua to ...
Read more

Rocket Lab launches climate science satellites

Rocket Lab, a global leader in launch services and space systems, today launched the first of two back-to-back launches for NASA’s PREFIRE (Polar Radiant Energy in the Far-InfraRed Experiment) climate change-focused mission. ‘Ready, Aim, PREFIRE’ lifted-off from Rocket Lab Launch ...
Read more

Hiringa launches hydrogen refuelling network

Taranaki-based green hydrogen developer Hiringa Energy has marked the opening of New Zealand’s first zero-emission green hydrogen refuelling network set to service heavy freight across the North Island. The initiative is the first of its kind in Australasia and was officially ...
Read more