New Life for Biowaste as a sustainable Soil Improver

Project Information

FENIX

Grant agreement ID: 101113002

DOI

10.3030/101113002

EC signature date 23 May 2023

Start date 1 June 2023

End date 31 July 2027

Funded under

• Food, Bioeconomy Natural Resources, Agriculture and Environment

Total cost

€ 3 251 511,46

EU contribution

€ 2 894 851,33

Coordinated by

UNIVERSIDAD DE GRANADA
Spain

Periodic Reporting for period 1 - FENIX (New Life for Biowaste as a sustainable Soil Improver)

Reporting period: 2023-06-01 to 2024-11-30

Summary of the context and overall objectives of the project

Soil plays an indispensable role in sustaining life on our planet. However, we are currently facing two inter-related issues that endanger the health of our soils. From one side, conventional agriculture depletes soil nutrients, contributes to land erosion and requires external fertilizers, which are often produced with fossil fuels. On the other hand, there are significant amounts of nutrients that are lost during the agrifood chain. Bio-waste is a source of economically valuable materials and essential nutrients that were once part of the soil. Since bio-waste represents 34% of municipal waste, the lack of sustainable management means that results in the loss of large amounts of nutrients.

However, there might also lie an ember, of opportunity for the bio-waste valorisation and its reintegration into agricultural fields. Recycling bio-waste allows us to harness its untapped potential, and when it applied to agricultural soils, it guarantees nutrients recovery and offers a powerful solution for soil health.

FENIX aims to develop soil improvement products derived from two by-products generated by renewable gas production technologies: biochar and digestates. The mixture of biochar and digestate is a formulation rich in nutrients that can be used as a soil amender, restoring agricultural land, curbing land desertification, and boosting agricultural yields. The resulting mixture will be tested across agricultural fields in Spain, Greece, and France, ensuring comprehensive insights into its agronomic benefits.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

- SO1 Produce and characterise 36 different types of biochar at lab scale and determine the 4 most appropriate as a soil improvement ingredient.
Four types of green waste were collected by Terrawatt and CIRAD. A total of 36 biochars were produced through 9 process treatments for each raw material type, involving different pyrolisis conditions. Characterization of the 36 biochars, according to the European Biochar Certificate (EBC) standards, was conducted by ELGO and CIRAD (D1.1 & D1.2). Based on 6 specific criteria, four types of biochars have been selected for the subsequent research activities (D1.3).

- SO2 Characterise, formulate and test at lab scale the most appropriate biochar-digestate mixture for different poor soil types
The lands for soil sampling were identified, and three different soil types (coarse, medium, fine) were collected and prepared for the greenhouse pot experiment. Physicochemical analyses of the soils are currently underway, focusing on parameters such as C, N, P, K, micro-nutrients, heavy metals, electrical conductivity, pH, and cation exchange capacity (CEC).

- SO3 Characterize gaseous emissions and organic nitrogen mineralization potentials of the soil improvement products at lab-scale and develop computer simulation and decision-making tool
The preparatory phases for experiments on GHG emissions and C humification have been initiated. All biochar-digestate mixtures and soil samples have been prepared and are ready for use. The experimental protocol for GHG measurement has been established and the device is currently undergoing maintenance for its correct functioning during the testing period.

- SO4 Production of soil improver at pilot scale - adding biochar post-digestion in the soil improver mixture
During the first period, TW successfully assembled, installed and commissioned the pilot scale pyrolysis kiln. This kiln is able to process 80kg/h of biomass and to produce ~15 kg of biochar per hour. At M18 the first kilograms of biochar were produced with the pilot equipment. Also, a first calibration was performed to reach the parameters defined by CIRAD for biochar production.

- SO5 Field testing of the soil improver substrate effects in different sites in Spain, Greece and France, with various types of poor soils, demonstrating the safety, efficiency and cost-effectiveness of the soil improver at large scale
Soil characterisation has been carried out initially by UGR for those properties that are more stable and for others that serve as early indicators of changes in the soil. The analyses were started after collecting the samples from the experimental plots in Spain (UGR) and receiving those from Greece (ELGO) and France (INRAE). The work started in M3 until M12 with the submission of deliverable D4.1.

- SO6 Test biochar as an additive to enhance microbiological activity in anaerobic digestion plants and its effect in the quality of the digestate as a soil improver substrate
Different biochars (36 biochars) produced by CIRAD were examined as additive in AD process at DTU. Different lab-scale batch experiments were conducted to evaluate how different biochars produced under different conditions influence methane yield during AD. Different experiments showed that biochars produced under the optimum conditions can improve the methane yield up to 20%.

- SO7 Co-development the soil improver with industry players resulting in precommercial products (TRL 7-8).
During the first reporting period, EAS supported by the input from CIRAD and TW had focused on assessing and frame the conformity of the input materials for the biochar (pyrolysis process) and for the digestate (anaerobic digestion process) targeted to the product function category expected (soil amendment). Additionally, the regulatory framework to obtain marketable products has also been started.

- SO8 Develop appropriate business model that consider different market outlets and marketing strategies for the proposed soil amendment.
Related activities are planned to start on M25 (according to project plan) once the first results of SO1 and SO2 are available.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

FENIX will go beyond the state of the art in several aspects:

SOA Aspect 1 – Soil improvers from biowaste
The project will propose a methodology to optimize the agricultural use of biochar and digestate combination.This includes both the selection and the processing of the feedstocks and the pyrolysis conditions, the formulation of the biochar-digestate mixture and the method of preparation and application of the mixture in the fields. The agronomic and environmental performances of the formulated product will be tested at different scales. Numerical models will be adapted to simulate the long-term agronomic and environmental effects of different scenarios of use of the product.

SOA Aspect 2 – Effects of the addition of biochar in the anaerobic digestor
Currently there is no research that evaluates simultaneously the effect of adding biochar in the digestion process for increased methanogenesis and the effect on the digestate’s soil-improvement qualities. Project FENIX will investigate the impact of the biochar addition to the digestate during the digestion phase on the different soil properties. Different types of biochar will be added (pyrolyzed at different temperatures, biochar metal ion coatings).

SOA Aspect 3 – Biochar production
Project FENIX will advance in scaling-up production of biochar at an industrial environment in a novel setup that integrates pyrolysis with anaerobic digestion, testing a variety of biowaste feedstocks and pyrolizer operating conditions. The work will include measuring the operating parameters in industrial setting and the characterization of biomasses and biochars, and the balance of mass and energy of the top 3 biochar experimental productions.

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