A clean alternative to coal
Biocoal, or torrefied pellets, produced by Airex's CarbonFX system is a clean and readily available drop-in replacement for coal.
- Biocoal has an energy content similar to that of coal, which enables a generating unit to operate at full load.
- It can also be co-fired with coal in any proportion, or replace coal completely - turning a coal-fired plant into a 100% renewable energy plant.
Biocoal pellets provide superior performance compared to conventional wood pellets, making them the fuel of choice in existing coal-fired facilities.
- Biocoal's unique properties allow it to be easily integrated into existing systems for handling storing and grinding coal, without major changes or expensive conversion.
- Torrefied pellets are weather resistant allowing them to be stored outside in a pile where they can withstand the elements whereas wood pellets easily deteriorate under wet conditions.
- Wood pellets are difficult to grind and require the addition of specially designed grinding and handling systems while biocoal is easily friable.
| PROPERTY | INDUSTRIAL PELLETS | BIOCOAL PELLETS | PRB COAL |
|---|---|---|---|
| Conversion to biomass | Major | Minor | - |
| Conversion Costs | $ 150M - 500M | < $ 5M | - |
| Net Calorific Value* (GJ/metric ton) | 16 - 17 | 20 - 22 | 20 - 23 |
| Bulk Density (kg/m³) | 600 - 650 | 700 - 750 | 675 - 900 |
| Energy Density (GJ/m³) | 9.6 - 11 | 14 - 16.5 | 13.5 - 20.7 |
| Dust | Limited | Limited | Limited |
| Water Resistance | Poor | Good | Good |
| Biological Degradation | Yes | No | No |
| Grindability | Poor | Good | Good |
| Handling | Special | Good | Good |
* as received
Source: ISO-TS 17225-2 Graded Wood Pellets; IEA Bioenergy Task 32; U.S. Department of Energy (NETL-401/012111)
Benefits of BiocoalFX
Extend useful life of assets
A conversion to torrified pellets enables power producers to extend the useful life of existing assets in jurisdictions where coal-fired power plants are being phased-out.
Lower emmission and pollution
Compared to coal, torrefied pellets can reduce the greenhouse gas emissions by 90% per GWh. Biomass combustion also reduces nitrogen oxides (NOX) emissions by 50% to 70% and sulfur dioxides (SO2) emissions by 90%, while generating no toxic mercury emissions.
Sustainable and renewable fuel
There is no net addition to the atmosphere when biomass is used as a fuel to produce energy. The amount of carbon dioxyde released during combustion is the same as was captured by trees during their growth phase. The carbon dioxide circulates in a renewable, carbon-neutral cycle.
Dispatchable base load power
Biocoal-fired power plants can easily and quickly adjust output to fluctuations in demand. Weather-dependent, intermittent renewable energy sources lack the flexibility and reliability of biocoal to provide dispatchable base load power.
Low transportation costs
Biocoal pellets have superior energy density, reducing supply chain and logistics costs by 25% to 30% compared to conventional wood pellets. Biocoal pellets can be produced in Canada, from certified forests, and be exported anywhere in the world by sea, rail and trucks.
Specifications
Airex Energy’s torrefied pellets meet or exceed ISO Technical Specification ISO‑TS 17225‑8‑Graded thermally treated biomass.
| PROPERTIES | UNIT | TW2H |
|---|---|---|
| Origin and source |
1.2 : By‐products and residues from wood processing industry 1.3.1 : Chemically untreated used wood |
|
| Diameter (D) ; Length (L) | mm | 5 ≤ D ≤ 7 ; 3,15 < L < 40 |
| Moisture (M) | w‐% as received wet basis | < 8 |
| Ash (A) |
w‐% dry | < 1,2 |
| Mechanical Durability (DU) |
w‐% as received | > 96,0 |
| Fines (F) | w‐% as received | ≤ 2,0 |
| Net Calorific Value (Q) |
MJ/kg as received | ≥ 19,13 |
| Bulk Density (BD) |
kg/m3 as received | > 650 |
Test Burn
Airex Energy operates an industrial-scale biocal plant in Quebec, Canada where woody biomass is abundant and certified.
In order to help power producers gain a better understanding of the advantages of biocoal, Airex can supply torrefied pellets to perform test burns at any coal-fired generating units.
Airex Energy was recently awarded a contract to supply Portland General Electric's (PGE) Boardman coal-fired power plant in Portland, Oregon, which is planned to be converted to torrefied biomass. The 100% biomass test burn required 5,000 tons of torrefied pellets. Three tests on three separate days were successfully performed in December 2016, for a total of 16 hours of operations. More tests are planned this year.