Purpose: Peat extraction rapidly removes carbon from the peatland carbon store and furthermore leads to substantial losses of carbon from the extraction site by stimulating decomposition and erosion. Aim of this study is to evaluate whether the Product Environmental Footprint (PEF) approach is suitable for assessing the environmental impacts of white and black peat used in growing media as well as to provide generic data collected from growing media producers and the scientific literature. It is not the aim of this study to compare different land use options for peatlands. Method: PEF is developed in order to make environmental product declaration claims more reliable, comparable and verifiable across the EU, and to increase consumer confidence in eco-labels and environmental impact information. For PEF-compliant studies all land use activities must be considered. For peat extraction either pristine peatland or previously drained peatland used for forestry or agriculture has to be transformed. Hence, the suitability of land use-related PEF indicators is also investigated. Results: Diesel consumed for peat extraction, electricity used for peat processing and transport are the main contributors to acidification. Fuel production and consumption are the main contributors to human toxicity, with heavy metals to air and freshwater the contributing emissions. Ionising radiation, ozone depletion and resource depletion of minerals and metals are mainly caused by the electricity used. Climate change increased from 26 kg CO_2eq per m³ processed white peat to 51 kg CO_2eq per m³ processed black peat. The use of peat causes substantially higher GHG than the previous life cycle stages combined; white peat causes approximately 183 kg CO_2eq per m³ and black peat 257 kg CO_2eq per m³. Conclusions: Environmental impacts caused by peat are variable and depend on a number of spatial and temporal factors. Although most indicators used for PEF are suitable for assessing peat systems, that does not apply for the land use indicator and is at least questionable for the water use indicator, respectively, its weighting factor. Consequently, it is neither possible to identify the most relevant impact categories based on normalised and weighted results nor to calculate an overall single score for peat containing growing media. Since normalisation and weighting are mandatory steps for PEF conform impact assessment, the current PEF approach is not suitable to assess peat as intermediate product without adaptation of the land use indicator.

To achieve sustainable development, the transition from a fossil-based economy to a circular economy is essential. The use of renewable energy sources to make the overall carbon foot print more favorable is an important pre-requisite. In this context, it is crucial to valorize all renewable resources through an optimized local integration. One opportunity arises through the synergy between bioresources and green hydrogen. Through techno-economic assessments, this work analyzes four local case studies that integrate bio-based processes with green hydrogen produced via electrolysis using renewable energy sources. An analysis of the use of webGIS tools (i.e., Atlas of Biorefineries of IEA Bioenergy) to identify existing biorefineries that require hydrogen in relation to territories with a potential availability of green hydrogen, has never been conducted before. This paper provides an evaluation of the production costs of the target products as a function of the local green hydrogen supply costs. The results revealed that the impact of green hydrogen costs could vary widely, ranging from 1% to 95% of the total production costs, depending on the bio-based target product evaluated. Additionally, hydrogen demand in the target area could require an installed variable renewable energy capacity of 20 MW and 500 MW. On the whole, the local integration of biorefineries and green hydrogen could represent an optimal opportunity to make hydrogenated bio-based products 100% renewable.

Life cycle assessment (LCA) of waste treatment processes is often associated with considerable uncertainties. The aim of this study is to estimate the total uncertainty in the modelled composting system and the influence of material and process parameters on the uncertainty. Four composting combinations with fresh (FC) and mature substrate compost (MSC) from partially enclosed (PEC) and open composting (OC) were investigated. Perturbation analysis was used to determine the effect of parameters on the result and Monte Carlo simulation was used to estimate the total uncertainty. This study showed that the production of MSC using PEC had the lowest overall impacts across all impact categories except ozone depletion. Results of the Monte Carlo simulation showed that comparing composting options was challenging. The sensitivity ratios obtained from the perturbation analysis showed that the process parameter percentage of carbon fraction degraded was the most influential for FC. In MSC, the moisture content in the input material and the substitution factor used for peat were the most influential. Monte Carlo simulations demonstrated the overall uncertainty of the model and its relevance when comparing results between combinations. The perturbation analysis identified the parameters that required more accurate data to reduce the uncertainty in the model. Graphical abstract