Abstracts:Biodegradable polymers such as polyhydroxyalkanoates (PHAs) can reduce pollution caused by the increasing global polymer demand. Although industrial production of PHAs grew rapidly in the past years, their total market share is still marginal. While this is often attributed to their higher price, which is mainly caused by high production costs, the industrial success of PHAs can also depend on policy framework. Environmental assessment tools such as life cycle analysis and the product environmental footprint showed that PHAs can contribute to greenhouse gas emission reduction targets, waste reduction as well as green jobs and innovation in the biotechnology sector. As many countries aspire to these targets under the umbrella of bioeconomy concepts, inclusion into the respective policies can stimulate industrial PHA production. With a high variability in the industrial production of PHAs in terms of feedstock, energy source, polymer properties etc., the choice of optimization criteria influences the design of new production processes. Considering the political targets for bioeconomy products is therefore useful to direct the technical design of sustainable PHA production, for example in integrated lignocellulose biorefineries.

Abstracts:Increasing global energy demands are leading towards the production of bio-alcohols from food crops, subsequently posing detrimental consequences in terms of food insecurity. Selection of suitable energy crops and availability of land for their cultivation are the leading concerns. Although cellulosic feedstocks are believed to have positive environmental impact and can make up a remarkable proportion of future energy portfolios yet they cannot be produced on arable lands due to social, environmental and economic concerns. A promising alternative is to grow cellulosic crops (traditionally called energy crops) on “marginal lands”. Low productivity and profitability make marginal lands puny for agricultural practices either due to intrinsic climatic limitations or they are susceptible to erosion and other environmental risks. However, marginal lands may be practically suitable either to grow short-rotation grasses or perennial vegetation, native to these lands which are better adapted to poor soils. Energy crops grown on marginal lands will not only provide cellulosic biomass without competition with food crops, but also help to reclaim those lands along with substantial mitigation of greenhouse gases (GHG) without posing any risk of food security. Nonetheless, the user-friendliness of such lands for cellulosic biomass production on commercial scale, and the corresponding GHG emissions, still remain indeterminate. This review describes the potential of marginal lands to produce ample amounts of biomass, also discusses the suitable crops cultivable on marginal lands for energy purpose, management practices of crop production on marginal lands and their economic and environmental perspectives.

Abstracts:In this work, a holistic exergetic-based framework was developed to assess the sustainability and productivity of a batch bioreactor used for ethanol production by ethanolic fungus Mucor indicus. Analyses were carried out in order to identify the most exergetically-sustainable concentration of phosphorous compound to produce ethanol and biomass. The microorganisms were aerobically cultivated using glucose as carbon source at various phosphate concentrations ranging from 0.0 to 7.5 g/L. The results obtained showed that the exergetic parameters of the fermentation process were remarkably influenced by the concentration of phosphate. Generally, the findings achieved revealed 3.5 g/L phosphate concentration as the most optimal fermentation condition from the exergetic point of view. Under this condition, the process exergetic efficiency and normalized exergy destruction as decision making parameters were found to be 53.42% and 0.48 kJ/kJ product, respectively. Moreover, the rational and process sustainability indexes for this concentration were determined at 3.92 and 2.15, respectively. The developed framework could be easily transplanted to evaluate the renewability of various lab-scale biofuel production processes to meet the goals laid forth for sustainable development.

Abstracts:In the USA, approximately 6 million tons of nitrogen and 1 million tons of phosphorus are being produced as a waste stream from the dairy operations. The main aim of this research was to estimate the potential of algal biofuel production, using waste nutrients present in the dairy waste, as well as performing a life cycle assessment to estimate the energy requirement of produced algal biofuel. Four different scenarios for algal biofuel production were simulated using different combinations of the following processes (i) algal-biodiesel-production, (ii) anaerobic-digestion (AD), (iii) pyrolysis and (iv) enzymatic-hydrolysis. Scenario 1 consists of AD and algal biodiesel production. Introduction of pyrolysis in the second scenario decreased biofuel production by ∼6% in the initial cycle and gradually increased to 25% in the later cycles. In the third scenario, biomass liquefaction through enzymatic hydrolysis was introduced to recover nutrients and sugars from the sludge generated from the AD process. Recovered nutrients and sugars were used for additional algal biodiesel production. Remaining sludge after the biomass liquefaction was applied on the agricultural land. As compared to the 1st scenario, further processing of the sludge through liquefaction increased the overall bioenergy production marginally. In the fourth scenario, biomass left after liquefaction was further processed through pyrolysis. In the fourth scenario, a 38% increase in the energy production was observed versus the 1st scenario. Additional energy production (compared to 1st scenario) through pyrolysis (Scenario 2) required additional 1.5 GJ of energy per GJ of energy produced and showed little variability. Additional energy production through the 3rd and the 4th scenario is not energetically favorable as compared to the 1st scenario. With respect to the 3rd scenario, energetically favorable additional energy can only be produced by the 4th scenario. Life-cycle energy-demand of the produced biofuel was varied from 0.35 to 0.68 GJ/GJ of energy produced. This study estimated that using dairy waste at a maximum of 3.14 billion GJ bioenergy could be produced.

Abstracts:The global textile fiber production, consumption of textiles and amounts of textile waste are constantly growing. The increase of textile waste has also been demonstrated in sorting studies performed for the municipal solid waste, where the share of textiles has grown. Ideally, recycling and, even more so, reusing textiles can reduce the production of new textiles from virgin materials and hence reduce the use of water, energy and chemicals in the production chain. The aim of the study was to ascertain the flows of textiles and textile waste currently in Finland and assess the environmental performance of the current system. In addition, the possible consequences of a significant increase in the reuse or recycling of discarded textiles were analyzed. Finally, an assessment on the policy measures available for increasing textile circulation was performed.

Abstracts:The processing and commercialization of fruits and vegetables produces considerable amounts of by-products, the disposal of which can be a problem for the industry, but can also provide a valuable source of bioactive compounds. The aim of this research was to evaluate the potential of different by-products generated in Central Mayorista de Antioquia to serve as a source of biocompounds for their possible use as functional ingredients for animal feed or human consumption. The ten by-products with the highest production per day were selected for analysis of the total carotenes, polyphenols and antioxidant capacity by ORAC. Acceptance Quality Limit (AQL) tables were used at the special inspection level S2, considering the amount of by-products produced (kg/day) as a lot to determine the sample size for analysis. To further characterize the carotene content, bell pepper, carrot, tomato, cabbage and lettuce with the highest carotene values (16.16, 10.36, 8.37, 7.36 and 4.41 mg $\beta$-carotene/100g, respectively), were selected to determine their specific carotene composition by HPLC with regard to $\beta$-carotene, lycopene and lutein. HPLC analysis showed the presence of $\beta$-carotene in all of the by-products analyzed: lycopene in tomato and lutein in cabbage, lettuce, tomato and carrot. Thus, the study showed that the biocompounds found in those five by-products suggest that they can be used as a raw material in the development of functional foods for human consumption and animal feed, offering an alternative way to add value to by-products in food supply chains.