PhD openings

Production of biochar-based organic fertilizers and amendments to improve carbon storage and soil quality 

Project overview 

The project aims at designing, generating and testing sustainable second-generation material-based carbons displaying high efficiency in capturing ammonium from wastewater streams. Materials and processes need external sources of phosphorous to balance stoichiometrically nitrogen. Resulting materials will be designed and tested to comply with the Fertilising Products Regulation (FPR) 2019/1009. The project will build and validate at TRL 3 a system consisting of devices integrated to existing industrial processes and production lines, new materials and circular economy routes to generate functional carbons, to capture, concentrate and transport ammonia from different sources. The production processes should be designed to be not dependent on fossil components and the products increase the soil organic carbon stock and make the overall process CO2-negative. 

The Project in detail 

1 - Thermo-chemical conversion of biomass and dolomite into [material 1] and energy co-production.

Using the synergistic effect of the carbonisation of two residual biomass feedstock and the selective calcination of a carbonate mineral rich in magnesium a carbon-carbonaceous material will be generated [material 1]. The carbonisation process will be performed by intermediate temperature pyrolysis (500-600°C) at a short residence time and a reforming process at 700°C. A pilot plant is available at the Marina di Ravenna Laboratories. 

2 - Wastewater application, nitrogen removal and carbonaceous struvite deposition to generate [material 2]  

[material 1] acts as a seed to promote struvite (NH4MgPO4 6(H2O) and is obtained from NH3-rich wastewater. The system is fed with material at rates to fit the stoichiometric quantities. Bone meal will be used as non-critical phosphorous source, due to its availability, low cost and lack of contaminants like chlorides, Na, K, etc.  That fosters P recovery from secondary sources. After an appropriate contact time necessary for the growth of struvite crystals, the struvite can be separated from the liquid medium through a filter press to obtain  [material 2]. This will be used as such in agronomic tests.  

3 - [material 2] thermolysis and regeneration 

After drying [material 2] will be heated at relatively low T. NH3 and CO2 are liberated and collected for further use in urea production ([urea based material] in the following). In the [urea based material] production reactor, NH3 from thermal regeneration and CO extracted from activity #1 will be fed in a reactor and sulphur added as a catalyser. The solution of [urea based material], sulphur and polysulphides obtained at the end of the process will be concentrated and subsequently dried. 

The PhD candidate will work in a team including experts in agronomy, chemistry, environmental science, environmental management and together with industrial stakeholders. They must propose a project elaborating at least one or more topics among (A-D) and activity E as indicated below: 

Reference to Activity 1, Topic A

Candidates shall contribute to achieve the optimal carbonisation process with respect to feedstock characteristics, carbon-carbonate ratio and process conditions. Energy co-production implies pyrolysis oil and syngas. One of the goal of the Ph.D is to investigate and develop original solution on how to use these energy vectors in industrial applications.  

Reference to Activity 2, Topic B

Candidates shall contribute to designing, planning, execution, checking and monitoring process conditions, engineering solutions, material preparation etc.  

Reference to Activity 3, Topic C

Candidates shall contribute to designing, planning, execution, checking and monitoring process conditions, engineering solutions, material preparation etc.  

Reference to Activities 1, 2 and 3, Topic D

Candidates shall conduct a sustainability and system analysis including hybrid life cycle assessment, techno-economic considerations, planning and fostering supply chains to make possible the production and distribution of materials 1, 2, 3 

Reference to Activities 1, 2 and 3, Topic E 

Candidates shall propose co-creation approaches and outreach activities underpinning their project

Group description and general research lines 

A group of 20 (physics, pedology, microbiology, chemistry, environmental science, environmental management) generating around 0,7M€/year turnover and dealing with soil carbon cycle, soil health, biomass treatment, (bio)remediation, regeneration, reuse and recycling of production waste for the development of new products. Recent activities include: study and modelling of carbon sequestration capacity through the use of vegetable chars (biochar) for carbon farming uses and carbon removal, P and N recovery, Fertiliser Product Regulation CMC 3,4,5,14, PFC 1,3,7 development, generation and application of second generation material-based carbons (also in combination with microbes), industrial microbiomes, study of methods for the mapping of residual biomass and waste, long-term experiments for the agronomic application of biochar and other carbon based substrates, soil quality indicators in a life cycle perspective. The research group operates  in the Ravenna Campus at the Fraunhofer Innovation Platform for Waste and Energy at UniBO.

Flag project: RERCARB0N – Recovering and Regenerating technologies and materials towards net zero CO2 emissions