ABSTRACT
While renewable energy sources are getting high interest, amounts of biogas plants have visible increases. In addition to energy, these facilities also produce a nutrient-rich organic material called digestate, which can be utilized as a crop fertilizer. Scientific research on digestate usage has increased with the new environmental protection laws for direct discharges, particularly after the 2000s. The nutrient composition of digestate provides a variable range of applications, rendering it a valuable commodity. In this study, the energy production capacity of Turkey and Poland from biogas power plants are compared, and the case study was used to estimate the amount of digestate produced for both countries. Two recovery technologies, such as organomineral fertilizer production and an innovative technology of super-heated steam torrefaction to produce valuable products and energy from digestate, were presented with their energy potentials. The outcomes of the case study indicate that harnessing digestate as an energy source holds the capability to make a 3.64% to 4.26% contribution to the overall energy consumption of Turkey and Poland through torrefied biochar energy. As per the results derived from the fertilizer case study, the application of digested biomass as a source of organomineral fertilizer holds the capacity to yield approximately 16,142,806 tons and 9,648,142 tons of fertilizer for Turkey and Poland, correspondingly.
Highlights
Digestate volarization technologies used in the market were examined.
An innovative technology (super-heated steam torrefaction) has been proposed to volarize digestate to gain biochar, valuable chemicals, and CH4 and H2 gasses.
Energy, digestate, organomineral fertilizer, and biochar production potential of Turkey and Poland are evaluated.
Digestate and BSR amounts for Turkey and Poland are 40,917,529 - 2,728,022 and 24,455,361 - 1,630,469 tons, respectively.
Potential organomineral fertilizer and biochar production are 16,142,806 - 1,745,836 and 9,648,142 -1,043,442 tons for Turkey and Poland, respectively.
Acknowledgements
The authors thank Energrom Energy Production Company from Turkiye, especially Nilufer Gokce Ertugrul and Murat Kuzulcan, for providing support with all valuable information related to the biogas sector in Turkiye.
This work has been completed while the first author and correspondence author was the Doctoral Candidate in the Interdisciplinary Doctoral School at the Lodz University of Technology, Poland.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Data availability statement
The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.
Author contribution
Data collection; H. Unyay, N. A. Perendeci, P. Piersa
Study design and collection; H. Unyay, P. Piersa, S. Szufa, N. A. Perendeci, G. Wielgosinski
Draft manuscript preparation; H. Unyay, S. Szufa, N.A.Perendeci
All authors reviewed the results and approved the final version of the manuscript.
Statement of novelty
This study proposes innovative super-heated steam torrefaction technology, which is currently unavailable in the market, giving another perspective for the utilization of dewatered digestate called biogas solid residue (BSR) from biogas plants compared to digestate usage as fertilizer. Within a short residence time, this technology presents essential benefits such as; torgas production, reduced emissions, the enhancing the recovery rate of by-products from condensate, boosting thermal efficiency through heat recovery during water re-condensation, and employing semi-dry biomass residues with a moisture content of up to 60%.