New feedstocks for bioethanol production

In the last few decades raw material molasses, used in large scale fermentations in the production of bioethanol, citric acid, (baker´s) yeast and yeast extracts, has become more and more expensive. That is why agro-industrial wastes have become an interesting alternative. They are being produced in large volumes every day and represent a serious environmental problem considering its high organic content. The present contribution aims to demonstrate how waste products of wine production can be employed as substrate in bioethanol production. Cultivation of yeast and bioethanol production on molasses and grape pomace extract was studied in flasks in laboratory scale. This work should be regarded as an example of integrated sustainability which demonstrates how the waste from one industrial process is used as feedstock for another

Transformacija problematičnog vinskog otpada u vrijedan supstrat za proizvodnju pekarskog kvasca i čvrstog biogoriva: princip kružnog gospodarstva

Research background. Wine production, which is considered a major sector in food industry, often involves the use of a large amount of resources. Moreover, wine making generates a large amount of grape pomace, which is generally used for low-value applications such as fertiliser and animal feed. The aim of the present research is to explore the possibility of improving the overall sustainability of traditional winemaking. Experimental approach. A zero-waste process was developed. It includes the production of white wine and the substantial valorisation of grape pomace, which is converted into solid biofuel, tartaric acid and concentrated grape extract as feedstock for industrial baker’s yeast production. Results and conclusions. We estimate that a significant surplus of renewable energy of approx. 3 MJ/kg processed grapes can be obtained during this conversion. The suitability of grape extract as a potential substrate for industrial baker’s yeast production was evaluated and the feasibility of a partial replacement of molasses (up to 30 %) was demonstrated. Novelty and scientific contribution. We present a circular economy approach for the conversion of winery biowaste into high-value resources such as feedstock and solid biofuel.Pozadina istraživanja. Proizvodnja vina, koja se smatra važnim sektorom u prehrambenoj industriji, često uključuje korištenje velikih resursa. Osim toga, nakon proizvodnje vina zaostaju velike količine komine grožđa, koja se obično koristi za dobivanje proizvoda niske vrijednosti, poput gnojiva ili stočne hrane. Svrha je ovog znanstvenog rada bila istražiti mogućnost poboljšanja ukupne održivosti tradicionalnog postupka proizvodnje vina. Eksperimentalni pristup. U radu je razvijen postupak koji uključuje proizvodnju bijelog vina i značajnu valorizaciju komine grožđa, koja se pretvara u čvrsto biogorivo, vinsku kiselinu i koncentrirani ekstrakt grožđa kao sirovinu za industrijsku proizvodnju pekarskog kvasca. Rezultati i zaključci. Procjenjujemo da se ovom metodom može dobiti značajan višak obnovljive energije od otprilike 3 MJ/kg obrađenog grožđa tijekom postupka. Istražena je moguća uporaba ekstrakta grožđa kao potencijalne sirovine u industrijskoj proizvodnji pekarskog kvasca, te je dokazana mogućnost djelomične zamjene melase s ekstraktom grožđa (do 30 %). Novina i znanstveni doprinos. U radu predstavljamo princip kružnog gospodarstva pri pretvaranju biološkog vinskog otpada u visokovrijedne resurse, poput sirovina i čvrstog biogoriva

Multidisciplinary approach in industrial baker´s yeast production : from manufacture to integrated sustainability

The present study shows how industrial baker´s yeast manufacture can be turned into multipurpose bioprocess by combining multidisciplinary developments into innovative strategic concept. It demonstrates additional roles given to this manufacture; besides producing yeast, as waste discharger and as supplier of valuable biomolecules and energy

Bridging the Implementation Gap between Pomace Waste and Large-Scale Baker’s Yeast Production

The objectives set in the European Green Deal constitute the starting point of this review, which then focuses on the current implementation gap between agro-industrial wastes as resources for large-scale bioprocesses (e.g., baker’s yeast, bioethanol, citric acid, and amino acids). This review highlights the current lack of sustainability of the post-harvest processing of grapes and apples. In light of the European Green Deal, industrial biotechnology often lacks sustainability as well. We reviewed the recent progress reported in the literature to enhance the valorization of grape and apple pomace and the current failure to implement this research in technical processes. Nevertheless, selected recent papers show new perspectives to bridge this gap by establishing close collaborations between academic teams and industrial partners. As a final outcome, for the first time, we drew a circular flow diagram that connects agriculture post-harvest transformation with the industrial biotechnology and other industries through the substantial valorization of apple and grape pomace into renewable energy (solid biofuels) and sugar extracts as feedstock for large-scale bioprocesses (production of baker’s yeast industry, citric acid, bioethanol and amino acids). Finally, we discussed the requirements needed to achieve the successful bridging of the implementation gap between academic research and industrial innovation

A Batch Reverse Osmosis Process to Recover and Recycle Trivalent Chromium from Electroplating Wastewater

Electroplating generates high volumes of rinse water that is contaminated with heavy metals. This study presents an approach for direct metal recovery and recycling from simulated rinse water, made up of an electroplating electrolyte used in industry, using reverse osmosis (RO). To simulate the real industrial application, the process was examined at various permeate fluxes, ranging from 3.75 to 30 L·m−2·h−1 and hydraulic pressures up to 80 bar. Although permeance decreased significantly with increasing water recovery, rejections of up to 93.8% for boric acid, >99.9% for chromium and 99.6% for sulfate were observed. The final RO retentate contained 8.40 g/L chromium and was directly used in Hull cell electroplating tests. It was possible to deposit cold-hued chromium layers under a wide range of relevant current densities, demonstrating the reusability of the concentrate of the rinsing water obtained by RO

State-of-the-art review of porous polymer membrane formation characterization—How numerical and experimental approaches dovetail to drive innovation

Porous polymer membranes substantially contribute to an acceleration of sustainability transformation based on the energy efficient separation of liquid and gaseous mixtures. This rapid shift toward sustainable industrial processes leads to an increased demand for specifically tailored membranes. In order to predict membrane performance factors like permeability, selectivity and durability, the membrane formation process by film casting and phase inversion needs to be understood further. In recent years, computational models of the membrane formation process have been studied intensely. Their high spatial and temporal resolution allows a detailed quantitative description of phase inversion phenomena. New experimental techniques complement this development, as they provide quantitative data, e.g., on compositional changes of the polymer solution during membrane formation as well as the kinetic progression of the phase separation process. This state-of-the-art review compiles computational and experimental approaches that characterize the phase inversion process. We discuss how this methodological pluralism is necessary for improving the tailoring of membrane parameters, but that it is unlikely to be the way to the ultimate goal of a complete description of the evolution of the membrane structure from the initial demixing to the final solidification. Alternatively, we formulate an approach that includes a database of standardized and harmonized membrane performance data based on previously publicized data, as well as the application of artificial neural networks as a new powerful tool to link membrane production parameters to membrane performance

Reshaping Apple Juice Production Into a Zero Discharge Biorefinery Process

In the last decade, the utilization of waste by-product apple pomace has been extensively researched (due to its difficult disposal) and currently finds beneficial usage in various industries; as substrate for microbial growth or recovery of pectin, xyloglucan and polyphenols. In this research apple juice was produced at pilot scale. Furthermore, apple pomace was employed as substrate for the production of pectin, biofuel (pellets) and concentrated apple pomace extract. Extensive mass and heat balances were conducted to evaluate the feasibility of this approach on industrial scale. The produced pellets had very similar characteristics to wood pellets (net calorific value of 20.3 MJ/kg). Dried apple pomace contained 11.9% of pectin. Fed-batch cultivation of baker´s yeast with apple pomace extract demonstrated a potential for partial substitution of molasses in industrial bioprocesses. This concept shows how a zero discharge biorefinery process converts waste from apple juice production into three valuable products enabling connections between different industries