The Residue2Heat project aims to enable residential heating with Fast Pyrolysis Bio-Oil (FPBO). This report presents the results of a screening Life Cycle Assessment (LCA) of the environmental performance of FPBO residential heating in comparison with natural gas, heating oil, and wood pellet residential heating. It provides quantitative insight in the environmental performance and possible environmental risks of FPBO combustion in residential heating systems.
For this screening LCA, the ISO 14040:2006 standard on LCA and the International Reference Life Cycle Data System (ILCD) handbook were used as guidelines. These guidelines divide an LCA in four stages: the determination of the goal and scope, a life cycle inventory (LCI), the life cycle impact assessment (LCIA) and finally the interpretation of the results.
This LCA has several goals that determine the scope. These goals can be summarized as:
- To identify the sources of greenhouse gas emissions of pyrolysis oil heating in small domestic boilers and their environmental impacts in order to obtain insight in major and minor emitters of greenhouse gases throughout the supply chain
- To quantify the greenhouse gas emission reduction of heating with pyrolysis oil in small scale domestic boilers (20-200 kW) compared with oil fired boilers using fossil fuel as reference case
- To compare the impacts of the different feedstocks on the greenhouse gas emissions per unit of produced pyrolysis oil
- To identify other environmental impacts, beside greenhouse gas emission reduction, of pyrolysis oil combustion compared to other fuels, with special attention to the impacts of the emissions of dust and nitrogen dioxides
- To form a basis for a future, more in depth life cycle inventory in compliance with the ISO 14040:2006 norm and ILCD handbook
The target audience of this report are policy makers, investors, scientists and pyrolysis oil combustion technology developers. However, since the report is publicly available, it should be emphasised that it concerns a screening LCA that provides the basis for a full-fledged LCA. The results of this screening LCA are subject to change as further research can provide more detailed insight in all sources of emissions.
The functional unit of this screening LCA is 17.8 GJ of heat, which is the average per capita domestic energy consumption for heating and hot water within the EU. Following the methodology of JRC’s ILCD handbook it can be derived that the LCA is a “situation A” LCA providing “micro level decision support”, meaning that changes in the structure of the heating sector due to the introduction of FPBO on the market for residential heating are not taking into account. As a consequence, attributional modelling was chosen. Using an attributional model over a consequential model allows the allocation of environmental impacts between produced pyrolysis oil and its by-products steam and electricity, instead of integrating the (positive and negative) environmental impacts of the by-products within pyrolysis oil as main product, as would be the case in consequential modelling. In this screening LCA processes that contribute less than 5% of the GHG emissions of the production of pyrolysis oil in CO2 eq. were not investigated in detail. The software Simapro (version 8.4.0) was used to perform the LCA, with both IPCC 2013 and ReCiPe 2016 as impact assessment methods. The foreground data for the pyrolysis process and the pyrolysis oil factory are based on first-hand knowledge within BTG.
For the life cycle inventory (LCI) of this screening LCA, the data for natural gas, heating oil and wood pellets were directly obtained from the Ecoinvent database. No data are available in the EcoInvent database for FPBO as a fuel for residential heating. As a result, an LCI was set up for each of the four FPBO feedstocks used within the Residue2Heat project, i.e. forestry residues (chips), bark, Miscanthus and straw. Moreover, a theoretical fifth FPBO supply chain was setup using the same feedstocks as used for wood pellets production (a mixture of sawdust, shavings and wood chips, furthermore referred to as “pellet wood mix”)
|D6.2 Environmental impact evaluation|