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Advanced Carbon Materials from Biowaste: Sustainable Pathways to Drive Innovative Green Technologies

Periodic Reporting for period 2 - GreenCarbon (Advanced Carbon Materials from Biowaste: Sustainable Pathways to Drive Innovative Green Technologies)

Reporting period: 2018-10-01 to 2021-03-31

The energy crisis, environmental pollution and global warming are serious problems that are of great concern throughout the world. Materials as today are mostly derived from fossil fuels, leading to energy and environmental-related issues. Biomass-derived carbon materials are ideal candidates to replace fossil fuels-based ones in a wide range of applications. So far, excluding activated carbons, relatively little research has been conducted on the synthesis and characterisation of carbon materials based on natural resources.

The objectives of the research programme are: (i) developing engineered thermochemical processes (based on pyrolysis and hydrothermal carbonisation from dry and wet biomass sources, respectively) to produce tailor-made biomass-derived carbons (BCs); (ii) developing novel low-cost carbon materials from BCs through a unique set of functionalisation protocols; (iii) using the resulting carbon materials in advanced applications in heterogeneous catalysis for renewable energy (e.g. pyrolysis vapours upgrading) as well as pollutants removal (e.g. CO2 capture in post-combustion and desulphurisation of biogas); and (iv) analysing the feasibility of using BCs as soil enhancers and carbon sequestration agents.

The main goal of GreenCarbon was to empower the early-stage researchers (ESRs) through the provision of a comprehensive and coherent training package that will allow them to take the academic research into industry and to solve societal and industrial problems. The project consortium believes that this objective has been globally reached, since the training programme initially proposed has been implemented with almost 100% compliance. Regarding this, the following points have to be pointed out:
-. A Personalised Training Programme (PTP) was developed for each researcher hired within the network according to her/his initial Career Development Plan (CDP).
-. The PTPs were articulated around four pillars: (a) primary “on the job training”; (b) secondments to other partners within or outside the network; (c) training in complementary skills; and (4) network-wide training events and meetings.
-. Regarding “on the job training”, all the ESRs joined research groups of recognised excellence at international level. All of them have been enrolled in high quality doctoral programmes.
-. Concerning training in complementary skills, the three dedicated network-wide workshops were successfully held and received a very positive feedback from the ESRs.
The research programme of GreenCarbon consisted of four strongly interconnected work packages (WPs 4-7):
WP 4: Pyrolysis Conversion Routes for Dry Feedstocks. With the aim to set the most appropriate slow pyrolysis process conditions, several experimental studies have already been conducted. Regarding the continuous intermediate pyrolysis, experimental studies were also done in order to establish the most appropriate characteristics of such systems at laboratory scale. Finally, a comprehensive and beyond the-current-state-of-knowledge pyrolysis/carbonisation single-particle model has already been developed.
WP 5: HTC Conversion Routes for Wet Feedstocks. The objective of this WP was the assessment of the potential of different wet biomass sources (including lignin from bio-refinery processes) to produce engineered hydrochars or pyrochars through an HTC process or a cascaded HTC-fast pyrolysis process, respectively. A high number of experiments was already conducted at both laboratory and pilot-plant scale in order to set the most appropriate operating conditions in terms of energy efficiency as well as the properties of the produced hydrochars.
WP 6: Refining of BCs and Advanced Applications. This WP was designed for the functionalisation and modification of the biomass-derived carbons (BCs) produced within the previous WPs. Activated carbons (ACs) from corresponding BCs were developed for both CO2 capture and biogas desulphurisation purposes through several synthesis methods (based on hydrothermal treatment + soft templating, and hard templating + chemical vapour deposition). Several pyrochars have been physically and chemically activated to be used as low-cost and sustainable catalysts for cracking and reforming of pyrolysis vapours. Furthermore, metal-based catalysts supported onto activated carbons have been synthetised to evaluate their performance in catalytic upgrading and CO2 methanation in terms of temperature required, conversion, and selectivity towards H2 and CH4, respectively.
WP 7: Sequential Biochar Systems. The objective of this WP was to integrate expertise across the GreenCarbon network, focusing on identifying synergistic sequences for BC uses, spanning engineering, agricultural and horticultural applications, in order to maximise the added-value and minimise carbon footprint across the whole chain. Several experimental studies have been conducted to assess: (a) the effect of biomass feedstock and pyrolysis conditions on the carbon sequestration potential of BCs, and (b) the effect of replacing peat by BCs as growing media. In addition, several uses of biochar as adsorbent and regeneration pathways of spent biochars have been studied in detail in order to propose sequential uses of biochar.
25 scientific papers emanating from GreenCarbon has been published so far in JCR-indexed journals (Q1 and Q2 quartiles in their respective categories). I should be noted that several additional articles are now under progress at different stages (writing; submission, and revision). In any case, the objective initially pursued (at least 20 articles published at the end of the project ) has been reached.
Most of the identified exploitable results are still on a low technology readiness level (TRL), since they represent advanced materials or sophisticated mathematical models. However, all the nodes within the network will continue sharing the Foreground related to these results beyond GreenCarbon. Despite the fact that they are not able to be commercialised in the short-term, further synergistic development (between partners from both within and outside the network) will be able to increase TRL up to the more practical levels.
The originality of GreenCarbon was the proposed multidisciplinary approach, involving studies on all the essential parts needed to develop greener materials from sustainable resources. To the best of our knowledge, there is no other consortium worldwide looking synergistically at all these aspects related to biomass-derived carbons (BCs). Our research programme comprehensively covered all aspects from precursors (the nature of biomass) to processing (thermochemical conversion, porosity development, chemical functionalisation) and application (CO2 capture, adsorption of emerging contaminants, heterogeneous catalysis, chemicals from biomass, and peat replacement in growin media) enabling a unique design of engineered sustainable BC materials. The project consortium is aware that the collaborative and synergistic nature of the research and training done within GreenCarbon should continue in the short-term to consolidate the European research network and expand it to other partners, with the aim at facilitating the direction of research toward other emerging fields as well as the knowledge transfer to the non-academic sector.
Overview of the project's implementation