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About SIRF pellets

The waste journey begins at the WKE depot, when Solid Recovered Fuel (SRF), derived from a mix of commercial and industrial waste and collected from various regulated sources, arrives on site. Upon arrival at WKE’s sorting facility, the material undergoes a meticulous process to categorise the waste before it continues on its journey to become Solid Improved Recovered Fuel (SIRF).

To become superior SIRF, the analysed SRF undergoes further metal extraction and is dried to achieve a 5% moisture content. Additional heavies such as stone, glass and rigid plastics are also removed through the refining process.

The waste is then put through a hammermill system and pelletised, which makes it much easier to transport, store and use in various industrial settings, for example cement, steel power, gasification, paper mills and lime kilns.

WKE’s port-side storage facility accommodates up to 10,000 tonnes of SIRF Pellets, from which it embarks on the final leg of its journey via bulk shipments, rail and road.

SIRF yields numerous benefits, including reduced costs, decreased CO2 emissions, improved storage and handling, a homogenised, reliable end product and stable costs. It’s a sustainable and resourceful way to use what was once considered fit only for landfill

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Advantages

WKE SIRF pellets are consistent and have a high net calorific value, and so are an ideal solution for helping high-energy-using industries on their decarbonisation journeys. They also provide the answer to our national fuel security problem by reducing the UK’s reliance on expensive imported fossil fuels.

Bespoke fuels

Thanks to their high specification and customisable content, WKE SIRF pellets are suitable for a wide range of bulk industrial applications. We have the ability to vary specifications to meet individual client requirements, allowing for multi-burner injection and fuels for waste-to-energy facilities.

Production process

The SIRF pellets have more than 50% biomass content and are made from a mix of dry waste materials such as wood, paper, card and non-chlorinated plastics that are carefully processed to produce a clean, highly specified and consistent alternative fuel that’s a strong contender for high-energy users. It’s also cleaner, and with less dust contamination.

Technical data

Pellet spec

Value

Pellet diameter
9mm
Net Calorific value
18-22MJ/kg
Moisture
4%-9%
Bulk density
500kg/m3 - 650kg/m3
Durability
96% - 98%
Ash
12% - 19%
Chlorine
0.3% - 0.9%

Ash specification

Value

Spherical C
1150°
Hemispherical C
1320°
Flow C
1360°
SiO2
2.07%
Al2O3
51.00%
Fe2O3
2.48%
CaO
5.00%
MgO
0.45%
K2O
0.41%
Na2O
0.17%

NCV - MJ/kg

2020

Coal (anthracite) 29
€2.40
Pet coke 29.5
€2.47
WKE fuel pellets (21)
€2.21
Wood pellets (17)
€8.11

NCV - MJ/kg

2022

Coal (anthracite) 29
€17.68
Pet coke 29.5
€31.44
WKE fuel pellets (21)
€3.24
Wood pellets (17)
€17.67

FAQs

WKE has an ambitious growth plan – security of supply is critical for our customers, and we aim to produce more than two million tonnes per annum. WKE sites have been planned in locations to take advantage of local transport hubs. These sites have been identified in both the UK and Western Europe. This maximises transport efficiency, minimises transport costs and reduces the carbon footprint of transport into and out of WKE sites. The first site at the port of Middlesbrough is on the North Sea Supply Base and is ideally located to enable transportation by land, sea or rail.

Due to the low cost per tonne and high energy content, the price per gigajoule (GJ) is significantly lower than for traditional fuels.