Clean Fuels B.V.
Clean Fuels - Scale-Up Condensing Retort Pyrolysis (Carbonisation)


WO Bachelor 3, WO Master, WO Afgestudeerd





Vereiste talen

Engels OF Nederlands




Chemie, Engineering


2, 3

Functie omschrijving

Phase 1: Basic Engineering

Clean Fuels has developed an innovative process for the slow-pyrolysis of biomass. It is suitable for a large variety of biomass types ranging from wood chips and nut shells to log wood. A true-scale test and demonstration unit has been built at its lab facility in Oldenzaal, and a first commercial unit is currently being installed in Germany (1300 kg dry biomass/h, 400 kg charcoal/h). The unit produces charcoal, gas and pyrolysis oil. Clean Fuels is starting the development of a scaled-up version of the same technology by a factor of 5. The purpose of the assignment is to contribute to this development.

The first phase is a Basic Engineering study. This study provides an estimate of performance and costs. Combined with a market evaluation, it enables the investors to finalise their feasibility study and take an informed decision about the further realisation of the project (Detailed Engineering, followed by Construction).

Objective: The process is analysed to provide a mass and energy balance. Material Inputs (biomass) and Outputs (charcoal, pyrolysis liquid), their quantities and qualities, are defined. Also the Energy Balance (inputs and outputs), electricity and heat, is analysed. The models that Clean Fuels developed for the German plant are available, and should be updated and adapted. A Process Flow Diagram (PFD) and a piping and instrument diagram (P&ID) are made. The PFD and P&ID form the basis of an equipment list with major dimensions that is also to be prepared. The results of the technical analysis are used to estimate costs (investments, maintenance, operating), unit costs (€/kg, €/kWh).

Approach: The activities include:

  • Review and adaptation of existing thermo-dynamic models, concerning major unit operations:
    • batch-wise pyrolysis, at three scaling levels: solid particle, reactor, entire processing system.
    • charcoal cooling.
    • gas scrubber & pyrolysis oil condensor.
  • Review and adaptation of gas burner basic design (2 capacities: 10 MWth, 1 MWth). • P&ID and PFD preparation. Flow analysis in view of operation and safety. Quantification (mass flow, volume flow, pressure, temperature, gas composition).
  • Equipment review with major dimensions, followed by
  • Cost estimation. 

Functie eisen

Required Skills: The activities require University level of Mechanical Engineering, or Chemical Process Engineering (last phase of studies or graduated). 


The new employee works in a team of 3 persons, one mechanical engineer and one process engineer, with a wide and long-term international technical experience.

Some laboratory activities may become part of the assignment (small-scale pyrolysis, ultimate and proximate analyses).

Clean Fuels is a small technology firm with a focus on the pro­duction of sustainable energy carriers made of biomass. Its markets are both in industrialised world and developing countries. Pyrolysis for bio-oil, and charcoals are among the core technologies developed. Clean Fuels has vested several patents.