Periodic Reporting for period 1 - CERESiS (ContaminatEd land Remediation through Energy crops for Soil improvement to liquid biofuel Strategies)
Período documentado: 2020-11-01 hasta 2022-04-30
CERESiS aims to provide a win-win sustainable solution to both issues by facilitating land decontamination through phytoremediation, growing energy crops to produce clean biofuels. In the longer term, this will increase the land available for agriculture, due to removal or stabilisation of contaminants, while at the same time producing non-ILUC biofuels, thus supporting transport decarbonisation.
The project is based on three key objectives. 1. to demonstrate the suitability and effectiveness of various conventional and novel species of energy crops for phytoremediation purposes in contaminated land, against a variety of the most common contaminants globally, considering both inorganic potentially toxic elements (including heavy metals) and organic compounds (including mineral oils, tars, pesticides and persistent organic compounds). 2. to demonstrate the potential of two novel thermochemical processes, i.e. Supercritical Water Gasification (SCWG) and Fast Pyrolysis (FP), for the production of biofuels and key biofuel precursors suitable for further upgrading, from contaminated biomass, while developing beyond state-of-the-art technologies for the conversion of the organic contaminants and the separation or confinement of the inorganic contaminants. 3. to provide decision support to stakeholders and policy makers in order to achieve optimal win-win solutions for site-specific land decontamination through phytoremediation while simultaneously producing clean liquid biofuels.
In terms of phytoremediation-related research, so far 15 field or greenhouse trials were planted using soils from 8 contaminated & brownfield sites in UK, Italy, Ukraine, Brazil. This involved 10 different biomass species, both grassy and woody. Additionally, progress was made towards optimisation of cultivation and harvesting methods of energy crops by developing an experimental design for the cultivation of Phalaris arundinacea to facilitate plant growth and arsenic uptake, which involved nitrogen fertilisation and pre-treatment of the seeds with a Trichoderma spp. Fungus. Collection and processing of biomass has so far provided 19 bulk biomass samples (> 5 kg DM) from 7 field trials & 11 species in UK, Italy, Brazil.
In terms of the processing technology-related research, a biomass sampling scheme for the distribution and prioritization of biomass samples between SCWG and FP has been defined. The process chain of both technological pathways has been thoroughly described by identifying key influential parameters and conditions.
For the SCWG technology pathway, the 24 initial experiments led to a redesign and re-configuration of the lab-scale plant, that was ongoing during M18. A Membrane Gas Absorption (MGA) process for acid gas removal from the SCWG gas effluent has been developed and tests were performed. Also, a hybrid electrocoagulation/electrochemical oxidation lab pilot setup has been constructed. For the reforming stage, the lab-scale experimental setup has been modified, achieving an operational reactor for dry reforming. The Fisher Tropsch Synthesis (FTS) has progressed by having an operational FTS lab-scale experimental setup and by developing a structured catalyst.
For the FP technology pathway, a new experimental plant has been designed. Initial experiments were done in a semi-batch reactor. A microfiltration (MF) laboratory pilot unit was designed and constructed in house
In terms of the phytoremediation research, the focus has been on adopting a strategy of using low-uptake, high productivity grassy energy crop species, so as to optimise the energy production and minimise contamination levels, thereby enabling downstream processing and maximum overall contaminant offtake. Early results are the successful growth and agronomy of Phalaris arundinacea in both Mediterranean and continental European climatic conditions. Furthermore, x-ray computed tomography imaging of lead contaminated Phalaris grown on a former lead mining site has shown that at least some of the contamination is due to persistent adhering dust, which has important implications for downstream processing and phyto-extraction estimates based on plant analysis.
Within CERESiS, several technologies relating to thermochemical processing of biomass that are beyond the current state of the art will be developed. Gasification of contaminated biomass under SCWG conditions will be optimized to reach high gasification rates for biomasses with low humidity. New solutions for cleaning the product gas and the water phases of the process will be developed. A technological breakthrough over currently existing pyrolysis plants and bio-oil decontamination has been achieved and the conditions for producing a clean bio-fuel precursor from contaminated biomass will be optimizing.
Specifically, within M01-M18 progress beyond the state of the art achieved includes:
• The Lab-scale SCWG plant has been reconfigured with respect to increased concentrations of toxic elements in the process effluent streams.
• A Membrane Gas Absorption (MGA) process for acid gas removal from the SCWG gas effluent has been developed.
• A new plant has been developed for Fast Pyrolysis (FP) experiments corresponding to an auger pyrolysis reactor presenting technological innovations.
• An “in-house” microfiltration (MF) laboratory pilot unit has been constructed.
• A detailed kinetic mechanism for SCWG of methanol has been developed and is currently being validated.