Developing the next generation of renewable energy technologies: an overview of low-TRL EU-funded research projects.

A cluster of eleven research and innovation projects, funded under the same call of the EU's H2020 programme, are developing breakthrough and game-changing renewable energy technologies that will form the backbone of the energy system by 2030 and 2050 are, at present, at an early stage of development. These projects have joined forces at a collaborative workshop, entitled ' Low-TRL Renewable Energy Technologies', at the 10th Sustainable Places Conference (SP2022), to share their insights, present their projects' progress and achievements to date, and expose their approach for exploitation and market uptake of their solutions.

Kinetic Analysis of Digestate Slow Pyrolysis with the Application of the Master-Plots Method and Independent Parallel Reactions Scheme.

The solid fraction obtained by mechanical separation of digestate from anaerobic digestion plants is an attractive feedstock for the pyrolysis process. Especially in the case of digestate obtained from biogas plants fed with energy crops, this can be considered a lignin rich residue. The aim of this study is to investigate the pyrolytic kinetic characteristics of solid digestate. The Starink model-free method has been used for the kinetic analysis of the pyrolysis process. The average Activation Energy value is about 204.1 kJ/mol, with a standard deviation of 25 kJ/mol, which corresponds to the 12% of the average value. The activation energy decreased along with the conversion degree. The variation range of the activation energy is about 99 kJ/mol, this means that the average value cannot be used to statistically represent the whole reaction. The Master-plots method was used for the determination of the kinetic model, obtaining that n-order was the most probable one. On the other hand, the process cannot be modeled with a single-step reaction. For this reason it has been used an independent parallel reactions scheme to model the complete process.

Hydrothermal liquefaction of organic resources in biotechnology: how does it work and what can be achieved?

Increasing the overall carbon and energy efficiency by integration of thermal processes with biological ones has gained considerable attention lately, especially within biorefining. A technology that is capable of processing wet feedstock with good energy efficiency is advantageous. Such a technology, exploiting the special properties of hot compressed water is called hydrothermal liquefaction. The reaction traditionally considered to take place at moderate temperatures (200-350 °C) and high pressures (10-25 MPa) although recent findings show the benefits of increased pressure at higher temperature regions. Hydrothermal liquefaction is quite robust, and in theory, all wet feedstock, including residues and waste streams, can be processed. The main product is a so-called bio-crude or bio-oil, which is then further upgraded to fuels or chemicals. Hydrothermal liquefaction is currently at pilot/demo stage with several lab reactors and a few pilots already available as well as there are a few demonstration plants under construction. The applied conditions are quite severe for the processing equipment and materials, and several challenges remain before the technology is commercial. In this review, a description is given about the influence of the feedstock, relevant for integration with biological processing, as well as the processing conditions on the hydrothermal process and products composition. In addition, the relevant upgrading methods are presented.