Life Cycle Assessment and Environmental Valuation of Biochar Production: Two Case Studies in Belgium

Mauro Villarini,Tom Kuppens,Sara Rajabi Hamedani,Robert Malina,Andrea Colantoni,Enrico Bocci

doi:10.3390/en12112166

Abstract

It is unclear whether the production of biochar is economically feasible. As a consequence, firms do not often invest in biochar production plants. However, biochar production and application might be desirable from a societal perspective as it might entail net environmental benefits. Hence, the aim of this work has been to assess and monetize the environmental impacts of biochar production systems so that the environmental aspects can be integrated with the economic and social ones later on to quantify the total return for society. Therefore, a life cycle analysis (LCA) has been performed for two potential biochar production systems in Belgium based on two different feedstocks: (i) willow and (ii) pig manure. First, the environmental impacts of the two biochar production systems are assessed from a life cycle perspective, assuming one ton of biochar as the functional unit. Therefore, LCA using SimaPro software has been performed both on the midpoint and endpoint level. Biochar production from willow achieves better results compared to biochar from pig manure for all environmental impact categories considered. In a second step, monetary valuation has been applied to the LCA results in order to weigh environmental benefits against environmental costs using the Ecotax, Ecovalue, and Stepwise approach. Consequently, sensitivity analysis investigates the impact of variation in NPK savings and byproducts of the biochar production process on monetized life cycle assessment results. As a result, it is suggested that biochar production from willow is preferred to biochar production from pig manure from an environmental point of view. In future research, those monetized environmental impacts will be integrated within existing techno-economic models that calculate the financial viability from an investor’s point of view, so that the total return for society can be quantified and the preferred biochar production system from a societal point of view can be identified.

Highlights

Biochar is the stable, carbon-rich substance obtained from the pyrolysis of biomass materials such as wood, manure, or leaves [1]
The results show that ionizing radiation, non-renewable energy, and global warming impacts were reduced in willow biochar production compared with pig manure biochar production ((−9500 vs. 22,392 Bq C-14 eq t−1 )
Since the willow biochar process results in a higher amount of natural gas and electricity being avoided, related impacts are greatly reduced compared with pig manure biochar

Summary

Introduction

Carbon-rich substance obtained from the pyrolysis of biomass materials such as wood, manure, or leaves [1]. The application of this pyrogenic black carbon can have substantial advantages from a social, economic, and environmental point of view, such as (1) job creation (social),. Life cycle assessment (LCA) has been applied several times to quantify the environmental impacts of biochar production systems. In the sustainability framework, a comprehensive assessment involves not just the quantification of the financial impact of biochar technology and issues such as global warming, and the broader, societal, cultural, political, and environmental impacts. Review of Existing Weighting Approaches in Life Cycle Impact Assessment (LCIA); European Union: Luxembourg, 2011.

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