Project Objectives & Scope

Project Objectives and Scope

T he main objective of the project SYNAGRON is to pave the way for the environmentally friendly useful exploitation of the residues of the Chinese and Greek agricultural sectors for the generation of high value bio-products and/or energy. This is accomplished by designing and developing an innovative pyrolysis - anaerobic digestion processing plant for the conversion of agricultural wastes initially into useful bio-products, such as bio-char, bio-oil, syngas and biogas, and then into hydrogen and/or electrical energy. Research focuses on the experimental and/or theoretical design and optimization of each process, on the design and optimization of the overall processing plant, on the development of innovative catalytic systems for the pyrolysis and the biogas and bio-oil reforming for hydrogen (H2) production reactions, and on the utilization of the gaseous products of the processing plant for highly efficient generation of electricity in Solid Oxide Fuel Cells (SOFCs). Through these technological advances the project aims at the optimal exploitation of every available biodegradable and non-biodegradable agricultural residue depending on the needs of the end users (farmers, enterprises, etc.) for specific bio-products and/or energy.

Τhe successful implementation of this project demands the highest possible degree of cooperation between the two Consortia, and also between the Consortiums members. At the strategic level, the close collaboration between the two Consortia will benefit from the already established, harmonious collaboration that the academic partners enjoy. It should be noted that UP and UOWM have already signed Memorandums of Understanding with BUCT that make provisions for student exchange, staff exchange and research collaboration. These MOUs have been signed formally when a delegation from BUCT (that includes BUCT’s President, Prof. Tianwei Tan) visited both UP and UOWM in 14th -16th May 2018. During these visits further discussions were held towards expanding collaboration activities between these Universities. On the other hand, Profs. V.G. Papadakis (UP), M.A. Goula (UOWM) and Dr. N. Charisiou (UOWM) visited BUCT in June 2018, continuing the cooperation. Such actions are a clear demonstration of the faith both Consortia have to each other, but also their strong desire for the project to succeed in a long lasting, mutually beneficial way.

In both China and Greece agricultural residues include: a) the remaining matter of the harvests such as cereal straw, plant part of the tobacco, cotton, sunflower, greenhouse residues etc., b) materials collected during the pruning of fruit trees, olive trees and vineyards, c) the residuals of the agricultural industries such as nut sells, kernels etc., and d) wastes of the agricultural product processing chain such as manure, wastewater etc. For example, it is estimated that Greece produces about 3 million tons of olive trees prunings annually which are burnt releasing about 2.7 millions of CO2 greenhouse gas emissions in the atmosphere. Alternatively, these prunings could annually produce 6.6 ΤWh of thermal energy or equivalently 2.3 TWh of electrical energy covering almost 4.8% of the total country's energy needs. These figures show that the uncontrolled final processing of any of the produced agricultural residues may leave a serious environmental footprint and deprive the opportunity for a sizable contribution in the national energy supply.

Anaerobic digestion (AD) and pyrolysis (Py) are two basic biowaste-degrading technologies and have been studied for decades. In recent years, the integration of these two basic technologies into a single system has been brought up as a new conception. Compared to the individual processes, this integration has the potential to offer great advantages in recovering bioenergy from agrowaste-biomass, reducing digestate management cost, recycling and reutilizing digestate and lowering greenhouse-gas releases. Additionally, enhanced performance of products obtained from the integrated processes has been observed, especially the strongly strengthened biochar’s ability to fix heavy metals and nutrient elements. Each single process plays a key role in the integrated process, accelerating the decomposition rate of biomass and increasing the energy recovery efficiency. The integrated AD-Py concept has been used as leverage in promoting the concept of ‘‘circular economy”, aiming at the improvement of both the exploitation of the resources and operation efficiency. Moreover, the use of an integrated process may overcome defects in each individual process.

The SYNAGRON project proposes a new concept; not only the integration of anaerobic digestion with pyrolysis, but also their combination with the steam reforming reaction (SR) for the production of hydrogen rich mixtures (from biogas and bio-oil), which can pave the way for the commercial exploitation of biomass residues in a highly efficient and effective way.