Products
SkyClean delivers modular pyrolysis systems for industrial carbon removal and renewable energy projects. From the core pyrolysis module to complete plant deployments, SkyClean solutions combine feedstock preparation, slow pyrolysis, energy integration, and site-specific balance-of-plant systems.
SkyClean systems to fit your project and site
SkyClean designs and delivers modular pyrolysis systems for industrial carbon removal and renewable energy projects.
The modular design of the SkyClean system enables projects to be configured around available feedstock, energy integration opportunities, and site conditions.
Serving as the core conversion technology, the SkyClean pyrolysis module can be deployed as a standalone process unit or as part of a complete SkyClean plant with feedstock preparation, energy integration, and balance-of-plant systems.
Explore the SkyClean pyrolysis module and the complete plant concept.
SkyClean pyrolysis
SkyClean pyrolysis is the core conversion module at the centre of every SkyClean system.
It converts prepared biomass into stable biochar and energy-rich pyrolysis gas through a self-sustaining slow pyrolysis process. The module consists of three integrated components:
- The reactor
- The gas filter
- The heat exchanger
Together, they enable efficient biomass conversion, internal energy recovery, and consistent biochar production.
1. The reactor
This is where conversion happens. Pelletised feedstock enters at the top and moves through three thermal zones: drying, torrefaction, and active pyrolysis, under controlled oxygen-free conditions.
Process temperatures and residence times are managed to ensure consistent carbonisation. Stable biochar exits the bottom of the reactor, while pyrolysis gas exits the top.
2. The gas filter
Before further use, pyrolysis gas passes through the SkyClean gas filter.
The filter removes particulates such as dust to protect downstream components. The resulting gas stream is suitable for combustion or other post-processing.
3. The heat exchanger
Pyrolysis gas is combusted in a boiler to generate heat.
A portion of the hot exhaust gas is routed back through the heat exchanger, transferring thermal energy to the reactor and thus fuelling the pyrolysis process.
This closed energy loop is central to how SkyClean systems operate: the process fuels itself, and external energy demand is minimised.
Industrial performance
High throughput, high carbon retention, and efficient energy recovery are central to the SkyClean design.
The figures below show expected SkyClean pyrolysis performance using straw pellets as feedstock.
- Capacity: 4.7 tons of biomass per hour at 10% moisture content
- Energy production: 8.5 MW heat
- Carbon capture: 0.8 tons CO₂e per hour
- Biochar production: 1.2 tons of biochar per hour
- Power consumption: 0.1 MW
- Nominal duty: 0.1 MW
- Design basis: 200,000 hours
- Minimum service area: 25 m × 15 m
Assumed Lower Heating Value (LHV) of feedstock is 17 MJ/kg, dry basis
Flexible feedstocks
Pelletisation enables consistent processing of a wide range of biomass resources.
Industrial-scale throughput
More feedstock processed. More carbon removed. More renewable energy produced.
Stable carbon storage
The process produces stable biochar for durable carbon storage while breaking down organic contaminants.
The SkyClean plant
Loading 360° viewer…
The Feedstock Preparation Module
SkyClean modules are designed for pelletised biomass with controlled moisture content, particle size, and density. Drying and pelletisation prepare agricultural residues, wood waste, and other biomass streams for efficient conversion.
Consistent feedstock supports stable operation and reliable biochar quality.
The SkyClean Pyrolysis Module
The pyrolysis module is the core conversion technology at the heart of every SkyClean deployment.
It converts prepared biomass into stable biochar and energy-rich pyrolysis gas through a self-sustaining slow pyrolysis process.
The Energy Integration Module
The energy released during pyrolysis can be used internally to sustain the process or supplied to industrial facilities, greenhouses, district heating networks, and other heat consumers.
The result is an integrated system that combines durable carbon removal with renewable energy production.
Flexible deployment
No two projects are identical.
SkyClean offers flexible deployment models ranging from the core pyrolysis module to complete pyrolysis plants including feedstock preparation, energy integration, and site-specific balance-of-plant solutions.
The modular architecture allows each plant configuration to be adapted to the available feedstock, site conditions, and desired project outcomes.
Why slow pyrolysis?
At SkyClean, slow pyrolysis is the foundation of our product offering, combining high carbon retention with efficient energy recovery in a fully continuous, industrial process.
The SkyClean updraft fixed-bed reactor with recirculation of pyrolysis gas was developed at The Technical University of Denmark (DTU) and industrialised by Stiesdal SkyClean. Unlike combustion, nothing burns during the process. Instead, recirculated pyrolysis gas transfers heat directly to the biomass, creating a highly uniform carbonisation temperature.
The result is a feedstock-flexible process with simple process control, high biochar yields, and consistent biochar quality suitable for durable carbon removal.
Today, this technology forms the core of every SkyClean system and powers the world’s largest operating pyrolysis plant in Vrå, Denmark.
Frequently asked questions
Can pyrolysis form heavy metals?
No. Pyrolysis cannot create new chemical elements, including heavy metals.
When returning biochar produced from crop residues to a farm, no additional or more heavy metals are introduced to the farmland than would have been added by mulching crop residues without prior conversion to stable biochar.
Can pyrolysis of agricultural residues form other pollutants?
Yes, other pollutants can be formed by pyrolysis of agricultural residues, and active process control is necessary to ensure that the levels of such pollutants remain below all relevant threshold values.
Stiesdal SkyClean has no issues implementing the necessary process control for certification of sufficient purity in the biochar.
Numerous analyses conducted by independent laboratories have demonstrated that the content of pollutants in biochar from the Stiesdal SkyClean plant is far below all relevant limits for products that can be used in agriculture.
SkyClean biochar also meets the limits for the constituents in fertilisers.
Is pyrolysis a highly energy-intensive process?
The pyrolysis process in a SkyClean plant uses approximately 5% of the energy content in the biomass used to drive the process.
The remaining energy content in the biomass is preserved in the two products from the plant: biochar and renewable energy.
In light of this, pyrolysis cannot be considered a highly energy-intensive process.
Planning a pyrolysis project?
SkyClean supports projects from early concept and business case development to system delivery, integration, and operation.