Project Methodology

A successful example of combining biological (anaerobic digestion) and thermal (pyrolysis) processes to improve the net energy and product yields from further decomposing the residual organic fractions of municipal solid waste has been provided by the "Supergen" Bioenergy Hub launched in 2014.

At the same time, researchers have increasingly focused on thoroughly degrading lignocellulosic biomass through AD-Py as means for the sustainable management of waste biomass. As is well known, biomass can be bio-converted into biogas (a mixture comprising the mainly of CH₄ and CO₂) through anaerobic digestion while after pyrolysis (in the absence of oxygen) biomass can be degraded into syngas (mainly H₂ and CO₂), bio-oil and biochar. Through this combination, resource use efficiency can be significantly improved, as after anaerobic digestion, energy in the raw feedstocks is transferred into pyrolysis volatiles and biogas. On one hand, biochar produced from pyrolysing anaerobic digestate has lower heating value (LHV) than biochar derived from pyrolysing raw feedstocks, but this type of biochar can fix heavy metals and nutrient elements like P, K and Ca in the digestate (preventing them from being released into the aqueous phase). On the other hand, during the AD process, some recalcitrant components of lignocellulose biomass (e.g. lignin) prevent anaerobic micro-organisms from degrading the substrate. Thus, the anaerobic digestate still contains considerable energy. In this case, pyrolysis of solid anaerobic digestate, not only reduces the digestate cost management, but further makes full use of it by recovering higher bioenergy and producing more bio-products like biochar, bio-oil and syngas. Furthermore, the biogas and bio-oil reforming for hydrogen (H₂) production and the utilization of all the gaseous products of the processing plant for highly efficient generation of electricity in Solid Oxide Fuel Cells (SOFCs) proposed, is an innovative concept applied for the exploitation of the agricultural residues.

Agricultural waste biomass is the largest and most sustainable energy source, but its exploitation has not been realized until now. Therefore, technological innovations for the full utilization of renewable bioenergy sources and practical application of recycle-bioenergy technologies are extremely urgent. Anaerobic digestion and pyrolysis are two promising technologies to degrade bio-degradable and non bio-degradable biomass, producing multiple value-added and renewable bioenergy products. It is suggested that the integration of anaerobic digestion and pyrolysis will open up new interesting pathways for combining biological and thermo-chemical processes to obtain higher bioenergy recovery from agro-waste biomass.

The holistic approach in the design and development of an integrated AD-Py process combine with hydrogen production through the main products of biogas and bio-oil. This integration is designed to provide the optimal efficiency gains and the maximum bioenergy yields extracted from a certain amount of biomass. Besides, the effects of significant process factors on the yields and properties of bio-products and/or bio-energy production are introduced, including further optimization for the integrated processes. The project is divided into five (5) Work Packages (WPs), which in turn are divided into a number of tasks. For each task the beneficiaries involved and the expected outputs (Deliverables) are also presented.