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•Cascade biorefinery of Gracilaria g., seaweed harvested in Lesina Lagoon performed.•R-phycoerythrin, allophycocyanin, and phycocyanin were primary extracted.•Extraction’s residue ...pyrolyzed for bio-oil and biochar production, at 400–600°C.•High bio-oil yielded (∼65wt%) but not suitable for fuel without de-nitrogenation.•Pyrolytic char (26.5–33wt%) including P, K, Ca, Fe and Mg, suggested as biochar.
Phycobiliproteins extraction (primary refining) from Gracilaria gracilis seaweed, harvested in Lesina Lagoon (Italy) and further valorization of the residual algal via pyrolysis (secondary refining), were investigated with a cascade biorefinery approach. R-phycoerythrin (7mg/g d.w.), allophycocyanin (3.5mg/g d.w.) and phycocyanin (2mg/g d.w.) were the main phycobiliproteins extracted. Pyrolysis of G.gracilis residue followed, aiming to investigate the production of bio-oil and biochar within a pyrolysis temperature range of 400–600°C. Results showed that the bio-oil yield is high (∼65wt%) at pyrolysis temperature ∼500°C, but its high content in nitrogenous compounds prevents its use as a biofuel, unless some further de-nitrogenation takes place. Biochar yield ranged between 33wt% (400°C) and 26.5wt% (600°C). Interestingly, inorganic nutrients including P, K, Ca, Fe and Mg were detected in biochar, suggesting its potential use as recovering system of natural mineral resources from the oceanic reservoir.
In the transition to a sustainable Bioeconomy, pyrolysis-based bioenergy is finding a new impetus within integrated biorefinery concept, which is one of the vehicles of this transition. An integrated ...winery waste biorefinery is proposed in this study. A closed-loop approach was designed, by integrating pyrolysis process, to the primary pomace (winery waste) biorefinery. The results of the experimental study revealed that from 15 t of fresh grapes of the special variety ‘Xinomavro’ harvested per hectare in Northern Greek vineyards, along with the 10.5 t of red wine (main product), 0.27 t of hydrocolloids and 0.06 t of grape-seed oil can be produced, via pomace extraction. By pyrolyzing the remaining solid wastes derived from pomace extraction, in the secondary biorefinery, 0.52 t of biochar, 0.80 t of bio-oil and 0.630 MWh energy, can be produced. It was resulted that pyrolysis of the primary biorefinery wastes brings many benefits: it increases the number of the biorefinery products to 5 by shifting from a mono to multi-product pathway, creates an additional economic benefit of 4470€ ha−1 and avoids 355 kg CO2/t on dry pomace basis. The pyrolysis biochar can be used as a soil improver, because it contains N, P, K, Ca nutrients, significant amounts of K, Na, Mg, Ca, P, Fe, Zn, and negligible amounts of heavy metals. With the present study at TRL 4, protocols for the winery waste-biorefinery processes were created and a pathway for sustainable waste management, in the wine industrial sector, with environmental and socio-economic benefits, was provided. Pyrolysis-based bioenergy production integrated in the biorefinery was studied, as a paradigm for the greater integration of bioenergy into the Bioeconomy. Within the wider Bioeconomy transition, it is important to move from sustainability debate into sustainable solutions, and bridge the gap between research and industrial implementation.
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•The study gives insights into the valorization of grape winery wastes (pomace).•Integrated biorefinery of Xinomavro variety's proof of concept at TRL 4, is provided.•Hydrocolloids, grapeseed oil, biochar, biooil and bioenergy are produced.•Resource efficiency and waste valorization are faced in a circular approach.•Pyrolysis-based biochar system can bring environmental and economic benefits.
The screening of sustainable agro-industrial biorefinery pathways for the production of bio-based products and energy is a complex challenge and needs investigation. Critical tools for predicting the ...commercialization feasibility of biorefining pathway includes laboratory and pilot-scale experimental results, processes modeling, technoeconomic and market analysis. The objective of the present study was the potential pathways experimental proof of concept of the sunflower meal (SFM), by-product in the sunflower oil production process, at TRL3-4 level, in an effort to assist the bio-based industries in evaluating the profitability of different possible production routes and product portfolios. Taking a reflexive approach, various processes and products were investigated, adding insights in the technical feasibility of conversion towards multi-product pathways at lab scale. Many sets of experiments were conducted in two laboratories, investigating SFM biorefining using physical, biological and thermochemical processes (fractionation, fermentation, enzymatic hydrolysis and pyrolysis) for the production of various added-value products, biochar and energy carriers. Product yields, mass balances, Effective Mass Yield (EMY) and Feature Complexity (FC) were estimated for each pathway. The study demonstrated that SFM cascade refining concept is feasible leading to the production of antioxidants, protein isolate, biochar, bioenergy carriers (pyro-oil and pyro-gas) and also poly(3-hydroxybutyrate) and microbial oil with a Feature Complexity (FC): 6-7. The studied pathways were based on the principle of optimised resource utilisation. Pyrolytic chars showed suitable for soil amendment, thus, closing the loop in agriculture (from land-to-land). The study demonstrated at TRL3-4, alternative pathways for sifting from a mono-to-multiple process and product agricultural industry (Grey biotechnology), in the context of Circular Bioeconomy and provided experimental protocols.
•Reflexive TRL2-4 approaches in the content of Circular Bio Economy.•Valorization of sunflower meal through a cascade bio-refinery approach.•Shifting from a mono-to a multiple-product agricultural Industry.•Antioxidants, protein, microbial oil, PHB and bio-char from sunflower meal.
The present study aims to valorise, through fast pyrolysis, the solid residue of microalga Dunaliella tertiolecta, after extraction of added-value compounds (β-carotene, phytosterols and fatty ...acids), which are included in the total lipid fraction, following the “Biorefinery Approach”. This study targets biooil and/or char as pyrolysis end-products. At pyrolysis temperature of 600°C, biooil yield was maximized (45.13wt.%), while char reached 29.34wt.%. Biooil quality was assessed and its potential use as biofuel discussed. In addition, assessment of char composition and properties, either as fertilizer or sorbent for soil remediation, was also discussed. Finally, microalga D. tertiolecta can produce high amounts of lipids which have a high potential application and also renewable fuel/soil amendment by fast pyrolysis of its residue.
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•Dunaliella tertiolecta can produce β-carotene, phytosterols, fatty acids and a residue.•The residue can be valorised through fast pyrolysis for bio-oil and/or biochar production.•Pyrolysis temperature affects the choice of algal residue as feedstock for biofuel or biochar.•The highest bio-oil yield (45.13wt.%) obtained at 600°C is suitable for biofuel.•Char (29.34wt.%) at 600°C can be used as fertilizer or inorganic contaminant sorbent.
The aim of the paper is to investigate the recovery of useful material and energy from waste, in the context of circular economy, by studying pyrolysis of spent coffee grounds, for the production of ...fuels and carbon materials such as biochar, to be further used as fertilizer in arid fields, thus closing loops in agriculture. Pyrolysis was carried out at temperature ranging from 400 to 700 ° C with a heating rate of 50 °C/s, at atmospheric pressure and inert atmosphere. The results have shown that a maximum yield of biooil can be achieved at 540° C (36 wt%) where the gas reached a yield 9 wt% and the char reached the 29 wt%. At 700 ° C, where oxidation reactions mainly take place against of cracking (gasification), gas yield reached 29 wt%, while biooil and char reached 20 wt% and 26 wt%, respectively. These preliminary data can challenge decision making in introducing sustainable food waste management strategies where pyrolysis can be the conversion pathway.
