Researchers at the Leibniz Institute for Agricultural Engineering (ATB) have one explanation for the rapid growth of their biochar research program: Biochar is viral. As researcher Jan Mumme tells it: “Biochar is contagious and self-spreading. At ATB we became infected in 2008. Interestingly, the black stuff almost simultaneously arrived from three very different angles. While a biogas researcher was looking for a way to upgrade the remaining digestate, a biogeochemist was eager for knowledge about the emission behavior of terra preta and an economist was interested in cost-efficient greenhouse gas mitigation.”

In 2009, driven by the idea of integrated biochar production and in continuation of the ATB’s long history in anaerobic digestion, Jan Mumme formed a new research group called APECS – Anaerobic Pathways to Renewable Energies and Carbon Sinks. Meanwhile, his colleague Jürgen Kern initiated a European Biochar Network and, in 2012, another colleague Andreas Meyer-Aurich created the German-Malaysian network project “Biochar in Agriculture”. Today the Biochar team at ATB counts 10 researchers and follows a highly interdisciplinary approach. This approach highlights the different aspects of biochar and the accompanying research networks. The ATB team works with the following initiatives which are profiled below as part of the ATB story:

  • APECS – Anaerobic Pathways to Renewable Energies and Carbon Sinks
  • European Biochar Research Network
  • Biochar in Agriculture Network Project- Perspectives for Germany and Malaysia
  • 1st International Biochar Summer School


The focus and technical aim of APECS – Anaerobic Pathways to Renewable Energies and Carbon Sinks – is to integrate biochar into the production of biogas. The APECS project and its team of 8 researchers is funded by grants from the German Federal Ministry of Education and Research (BMBF) administered by the project management agency Jülich (PtJ). Ideally, the project will yield an innovative and efficient solution bringing new perspectives to farmers and supply industries. The APECS project wants to answer some specific questions about biochar:  What is biochar really capable of? Can it turn digestate into more? Can it turn sandy sites into fruitful soils? And, not to be forgotten, can it turn struggling farmers into successful pioneers?

Several novel reactor types are being tested. Results are characterized by a broad range of chemical and microbiological methods. Core equipment includes a 20 L pressure reactor for hydrothermal carbonization, an automated rotary kiln for pyrolysis experiments, and a novel pilot-scale high-performance biogas reactor for straw digestion.

A major milestone of APECS is to develop biochar that is specifically optimized for the improvement of sandy soils. This task is connected to various questions about the target properties of biochar and how they interact with soil biota and abiota. The soil and crop effects of biochar are investigated in pot as well as field trials. There they focus on plant growth, biomass yields, and nutrient behavior.

APECS considers the full-extent value chain – from field to field – and assesses the energy and mass efficiency of the process. With the aim to find potential synergies, analysis and optimization of the whole biogas-biochar system is carried out with simulation software. For this purpose they include experimental data from all areas of the project as well as from joint projects.

APECS also conducts research on biochar stability and GHG emissions. Biochars are considered to sequester carbon on a long-term basis within the soil. However, carbon stability of biochars applied to the soil is expected to vary widely with biochar, soil, and climate characteristics. Jürgen Kern and his working group began incubation experiments in 2009 and have studied various carbon substrates – chars and soil substrates. Besides CO2, the investigation also includes the much stronger greenhouse gases CH4 and N2O. The lab scale experiments have been running now for two years. Together with his PhD students, Jürgen Kern will shortly conclude his work on GHG emissions with field experiments. These field trials will help to understand how biochar influences the CHand N2O emissions in more natural conditions.


The COST Action aims at coordinating European biochar research, bringing together researchers, stakeholders and potential users from EU and candidate countries. This will be accomplished by annual Biochar Workshops, Short-Term Missions among EU young, senior and female researchers, Training Schools, and an internet platform to monitor and streamline biochar research and innovation.

Innovative biochar strategies can help the EU in mitigating greenhouse gases, while industries and farmers benefit from new markets, opportunities, and the use of improved soils, e.g. for biofuel production without endangering food supply. However, a risk assessment is necessary to protect the food web and human health.


ATB coordinates the network project “Biochar in Agriculture – Perspectives for Germany and Malaysia” funded by the Leibniz-Association in the context of the Joint Initiative for Research and Innovation. The aim of this project is to analyze potential impacts of biochar use in agriculture to provide a better understanding of economic and environmental potentials of biochar. A special focus is set on the GHG mitigation potential of biochar use and its economic costs. The holistic challenge will be analyzed in a consortium led by the Leibniz-Institute for Agricultural Engineering Potsdam-Bornim e.V. (ATB) in cooperation with the Leibniz-Centre for Agricultural Landscape (Zalf), the German Institute for Economic Research (DIW), Technical University of Berlin (TU), Humboldt-University Berlin (HU) and the University of Putra Malaysia (UPM). In particular, the consortium will analyze the impact of several biochars on soil fertility in terms of yield potential, water holding capacity, nutrient dynamics and soil biology in laboratory and field experiments in the temperate zone and in the tropics (Germany and Malaysia). Some biochars are based on research from the APECS Project. The potential environmental impacts will be estimated together with cost effects at the farm level and welfare effects at the national and international levels to provide the most efficient concepts for biochar use in the tropics and the temperate zone.


The Program will include sessions on biochar production, feedstock availability, system integration, biochar characterization, and soil effects of biochar, with practical workshops and competitions, excursion to the sites of biochar field tests and a public biochar workshop event.

From left to right: Biochar from pyrolysis, liquor from hydrothermal carbonization (HTC), and biochar from HTC; all photos courtey of ATB.

Jan Mumme at a biochar testing site close to Berlin, Germany. “After finishing my PhD thesis on biogas in 2008, I was looking for a solution to make biogas production more soil-friendly. The little organic matter that ‘survives’ biogas production should be returned to the soil in the most effective form. Biochar, as I see it, promises the win-win solution to close the gap between the energetic use of biomass and sustained soil fertility. However, many questions remain.”

APECS group PhD student Maja Werner investigates biochars by laser scanning microscopy. Says Mamadou Diakité, “My PhD thesis in 2010 was focused on the design, operation, control, and optimization of chemical and physical processes using sequential modular and equation based process simulation, generally called process system engineering. Application of this method for biochar processing is for me as an engineering scientist, a promising, yet challenging task for the future.”

Axel Funke loading a 20 L pressure reactor for hydrothermal carbonization experiments. “Biochar promises a potential that could be compared to a third green revolution – enough motivation for me to try hard to make this inspiring idea work! For this to happen an intensive interdisciplinary approach is necessary, and one part of this fascinating research is the investigation of suitable processes and their optimization to enhance product quality. This knowledge will increase the flexibility of biochar application according to individual feedstock availability and existing infrastructure.”

Jürgen Kern and members of his research team with soil incubation bottles designated for gas chromatography. “In 2009, three roads crossed within my field of research: Long-term studies on greenhouse gas emissions, studies on nitrogen cycling in Amazonia and a visit to a small Amazonian village called Terra Preta. This was the motivation to start research on the effects of biochars in soils. My focus is on the stability of biochars applied to the soil and the potential of biochars to mitigate the emission of greenhouse gases such as CO2, CHand N2O.”

Jürgen Kern collecting samples of soil-based gases in  a rye  field.

Andreas Meyer-Aurich at the kick-off meeting for the “Biochar in Agriculture“ project. “Our Biochar in Agriculture initiative brings together interdisciplinary research on biochar use in agriculture. As the coordinator of this network project I bring in expertise on the economic analysis of greenhouse gas mitigation strategies in agriculture, which actually led me to biochar. It is extremely interesting from a scientific point of view, because of its complex impact on soil, plants and environment. I expect various interaction effects of the involved subsystems, which are not yet well understood and need further research to find optimal strategies for biochar use in agriculture.”