Renewable residential heating with fast pyrolysis bio-oil

Short description

Residential heating systems have the potential to contribute significantly in the challenges Europe faces to make its energy system clean, secure and efficient. For residential heating systems it is vitally important to use a standardized fuel, to allow optimization of the heating systems and create an economically viable value chain. To meet the fluctuating heat demand encountered in residential heating it is advantageous when the produced heat can be rapidly adjusted, which is easily achievable with liquid or gaseous fuels.

So called wet heating systems are mainly oil and gas fired, allowing rapid start-up and a typical 2-20 turn-down ratio of the thermal power. The total CO2 equivalent emissions for boilers and water heaters count up to 25% of the total CO2 in EU15. The market potential for residential oil-fired heating systems in Europe adds up to about 28 million units throughout Europe, mostly in Germany, the UK, Belgium, Austria, France, Spain and Italy. Most of these heating systems use Domestic Heating Oil (DHO), derived from crude oil. Heating systems using 1st generation renewable biofuel such as vegetable oils and bioethanol are available as well, however with the food-for-fuel and indirect land use change (ILUC) aspects these fuels are considered as undesirable from social and environmental point of view.

The overall objective of this project is to enable the utilization of various biomass residue streams in residential heating applications in a sustainable manner. Even the most advanced residential heating systems are currently unable to handle the difficult, inconsistent properties of agricultural and forestry residue streams. Within Residue2Heat, a two-step approach is followed in which biomass residue streams are first converted into a uniform, 2nd generation liquid biofuel via fast pyrolysis. Secondly, existing residential heating systems are tailored and optimized to allow the use of this standardized biofuel.

Residue2Heat aims not only to enable use of 2nd generation biofuel for residential heating, but to maximize the combustion efficiency. At the moment, only about 10 % of the residential heating units classify as a high efficient condensing boiler (labeling class A). A so called blue flame burner is suitable to be installed on condensing boilers of multiple manufactures. These blue flame burners maximize the combustion efficiency and comply with the most stringent emission regulations in Europe. The blue flame burner/boiler system provides an excellent starting point for the envisaged development within Residue2Heat. Because the properties of the 2nd generation fast pyrolysis bio-oil (FPBO) deviate from conventional fuels, available systems need to be modified to deal with this type of biofuel.

Working objectives of the project

Widening the biomass feedstock base: The overarching target of this work is to enable the use of different types of sustainable, non-food lignocellulosic biomass as renewable energy source for residential heating. In this project the approach is to produce FPBO from various agricultural- and forestry residues as intermediate fuel for heat generation.

High ash content biomass: One of the benefits of using the fast pyrolysis process as intermediate step is that ashes and minerals are removed in the process. The recycling of ashes and minerals from the pyrolysis process is an important objective of the project

Improving efficiency: The development is based on condensing boilers providing a high efficiency (class A). Since FPBO fuel contains a significant amount of water use of a condensing boiler allows recovery of the energy required for water evaporation;

Low-Emissions: The applicability of FPBO for residential heating purpose is closely related to low emissions as maximum emissions are regulated in the European standards. The starting point is a blue flame type of oil burner complying with the latest European regulations with respect to NOx, CO and particles.

Working Tasks OWI

OWI will take care of the technical coordination and hence monitor the progress of the project. Moreover, OWI is responsible for development and optimization of FPBO fired burner system with respect to atomization of fuel, spray characterization and possible firing strategies. Furthermore, OWI will set up a test environment to be able to test essential components of the burner such as oil pump, oil preheater, nozzle / atomizer and evaluate its suitability with FPBO. Finally, a prove of concept will be provided by means of long term combustion tests under realistic conditions.Â

Project partners

  • Rheinisch-Westfaelische Technische Hochschule Aachen (RWTH) (University)
  • Biomass Technology Group B.V. (BTG) (SME)
  • VTT Technical Research Centre of Finland Ltd. (VTT) (Research organisation)
  • MEKU Energie Systeme GmbH & Co.KG (MEKU) (SME)
  • Istituto Motori; Consiglio (Research organisation)
  • Politecnico Milano (PTM) (University)
  • BTG BioLiquids B.V. (BTL) (SME)
  • University of Innsbruck, Institute of Microbiology (UIBK) (University)
  • OWI Oel-Waerme-Institut GmbH (OWI) (Research organisation)

Project promotion

The Residue2Heat project receives funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No. 654650.

Project duration

January 2016 until December 2019


Dr.-Ing. Sangeetha Ramaswamy
Phone: 02407/ 9518-143