Assessment of biochar potential as a land-based emission mitigation measure in Colombia

Abstract: There is an urgent need to mitigate carbon emissions to the atmosphere to reduce the negative effects of climate change. Countries have pledged national strategies to reach their climate change mitigation goals in their Nationally Determined Contributions (NDC). In the case of Colombia, the country envisions becoming carbon neutral by 2050.  A pathway to reach this goal is emission reduction through nature-based solutions (NBS). Biochar is an NBS with the potential to be used as a land-based emission mitigation technology. Records indicate that it was first used by indigenous communities in the Amazon about a thousand years ago. Biochar can be obtained through thermochemical conversion by slow pyrolysis of residual biomass. The original organic carbon present in the biomass is sequestered in the biochar as it is pyrolyzed and thus, CO2 emissions are prevented. Biochar is not yet considered in Colombia´s carbon neutrality strategy. The aim of this thesis project is to investigate the potential of biochar production in Colombia as a land-based mitigation technology (LMT). Therefore, a comprehensive assessment is performed with the purpose of identifying the status of biochar in the country. The motivation behind the assessment is to gain an understanding of the variables involved in biochar production. Factors such as the production sectors involved, feedstocks, production technologies, project costs and emission mitigation are of interest. The study explores these factors by following five methodological steps. First, the current research on the technology is mapped to understand biochar’s status at a national level. Second, experts are interviewed to collect their views regarding biochar and a PESTEL (Political, Economic, Social, Technological, Environmental & Legal) analysis is employed based on their point of view on the technology. Third, the potential sources of residual biomass which could be used to produce biochar in the agricultural sector are quantified. The approach to biochar’s potential is enriched with a focused in-person case study of biochar production from oil palm residues. Fourth, these residual biomass sources are subsequently employed to estimate the emissions sequestered in their biochar production. Lastly, project feasibility implementation is evaluated through a techno-economic to identify the project’s main cost drivers. The results are then discussed using a SWOT (Strength, Weaknesses, and Opportunities & Threats) analysis. The existing studies and the local experts’ opinion indicate that biochar potential is in the agricultural sector and that it can be thought of for soil adaptation. Biochar’s emission mitigation is considered an added value. In 2021, the agricultural sector produced near 73 million tonnes of agricultural products. The residues from agriculture could be used for biochar production. If the residues from the most produced agricultural products are transformed into biochar, about 1 to 2,2 tonne of CO2 per tonne of biochar could be avoided. The published literature and the in-person study visit confirmed that the largest advance in biochar production and use in Colombia is in the oil palm sector. Palm kernel shell, fibre and empty fruit bunches are the oil palm residues that could be used to produce biochar. From 1 tonne of these three oil palm residues, about 60 kg of biochar can be obtained. The results show that currently there is no market for trading with biochar in Colombia. High investments, transport and feedstock costs are identified obstacles. An Advanced Technology pyrolizer cost can cost around 330.000 USD while a Basic Technology one can be around 100 USD. Taxes associated with revenue from the biochar trade can negatively impact a biochar project’s feasibility. In this study, a price for biochar is estimated using break-even analysis. Under the assumptions used, the biochar price per tonne is around 200 to 1.000 USD. Price variability is explained in the technologies used for production, feedstock biomass availability and variable revenues from biochar sales.