Environmental prospective of valorizing corn processing effluent to produce ferulic acid grafted chitosan polymer.

The food industry requires new production models that include more environmentally friendly waste management practices, considering that the environmental loads of solid waste and wastewater associated with this sector cause damage to the receiving ecosystems. The approach considered in this study focuses on the design and environmental assessment of an enzymatic process for the valorization of ferulic acid present in the effluent of a corn tortilla plant. The ferulic acid can be immobilized on chitosan so that the ferulic acid grafted chitosan can be used as a bioactive film with enhanced antioxidant properties with potential applications in the biotechnology sector. Its real projection approach requires the evaluation of its environmental and economic performance, trying to identify its benefits and potential in the value chain, using the Techno-Economic Analysis (TEA) as a phase for the conceptual design of the process and the Life Cycle Assessment (LCA) methodology for the environmental evaluation. It should be noted that the TEA indicators are promising, since the values of the financial indicators obtained are representative of the economic profitability, which makes the ferulic acid valorization a viable process. In terms of the environmental impact of the process, the buffer dose and the chitosan production process are identified as the main critical points. This double benefit in environmental and economic terms shows that the valorization of ferulic acid for chitosan functionalization is a promising alternative to improve the sustainability performance of corn processing.

Evaluation of Starch as an Environmental-Friendly Bioresource for the Development of Wood Bioadhesives.

The environment is a very complex and fragile system in which multiple factors of different nature play an important role. Pollution, together with resource consumption, is one of the main causes of the environmental problems currently affecting the planet. In the search for alternative production processes, the use of renewable resources seeks a way to satisfy the demands of resource consumption based on the premises of lower environment impact and less damage to human health. In the wood sector, the panel manufacturing process is based on the use of formaldehyde-based resins. However, their poor moisture resistance leads to hydrolysis of amino-methylene bonds, which induces formaldehyde emissions throughout the lifetime of the wood panel. This manuscript investigates the environmental profile associated with different wood bioadhesives based on starch functionalization as a renewable alternative to formaldehyde resins. Considering that this is a process under development, the conceptual design of the full-scale process will be addressed by process modeling and the environmental profile will be assessed using life cycle assessment methodology. A comparative study with synthetic resins will provide useful information for modify their development to become real alternatives in the wood-based panel industry. The results obtained show the enormous potential of starch bioadhesives, as their environmental impact values are lower compared to those based on petrochemicals. However, certain improvements in the energy process requirements and in the chemical agents used could be developed to provide even better results.

Techno-environmental and economic assessment of color removal strategies from textile wastewater.

The textile industry is one of the most chemical-intensive processes, resulting in the unquestionable pollution of more than a quarter of the planet's water bodies. The high recalcitrant properties of some these pollutants resulted on the development of treatment technologies looking at the larger removal efficiencies, due to conventional systems are not able to completely remove them in their effluents. However, safeguarding the environment also implies taking into account indirect pollution from the use of chemicals and energy during treatment. On the other hand, the emerged technologies need to be economically attractive for investors and treatment managers. Therefore, the costs should be kept under control. For this reason, the present study focuses on a comparative Life Cycle Assessment and Life Cycle Costing of four scale-up scenarios aiming at mono and di-azo reactive dyes removal from textile wastewater. Two reactors (sequencing batch reactor and two-phase partitioning) were compared for different reaction environments (i.e., single anaerobic and sequential anaerobic-aerobic) and conditions (different pH, organic loading rates and use of polymer). In accordance with the results of each scenario, it was found that the three technical parameters leading to a change in the environmental profiles were the removal efficiency of the dyes, the type of dye eliminated, and the pollutant influent concentration. The limitation of increasing organic loading rates related to the biomass inhibition could be overcame through the use of a novel two-phased partitioning bioreactor. The use of a polymer at this type of system may help restore the technical performance (84.5 %), reducing the toxic effects of effluents and consequently decreasing the environmental impact. In terms of environmental impact, this is resulting into a reduction of the toxic effects of textile effluents in surface and marine waters compared to the homologous anaerobic-aerobic treatment in a sequencing batch reactor. However, the benefits achieved for the nature comes with an economic burden related to the consumption of the polymer. It is expected that the cost of investment of the treatment with the two-phase partitioning bioreactor rises 0.6-8.3 %, depending on market prices, compared to the other analyzed sequential anaerobic-aerobic technologies. On the other side, energy and chemical consumption did not prove to be limiting factors for economic feasibility.

Offsetting the environmental impacts of single or multi-product biorefineries from wheat straw.

Moving toward a bioeconomy system is fundamental to climate change mitigation, nevertheless, the biotechnological routes should guarantee an environmental sustainability. Isobutene, a precursor in several industrial applications, is one of those chemicals that the environmental effects of its bio-based production have been scarcely explored. This study aims to assess the environmental performance of two biorefinery systems: the first one focuses only on the production of isobutene (I) and the second one on the co-production with lignin (I + L), both from the valorisation of wheat straw. The Life Cycle Assessment methodology is used to determine the environmental impacts considering mid-point and end-point categories. Biorefineries report 0.65 and 1.32 kg CO2-eq per kg of biomass processed for I and I + L system, respectively. The most affected endpoint damage category corresponds to Human Health, regardless of the scenarios. Moreover, the pre-treatment stage constitutes the main hotspot of both systems considering midpoint and endpoint perspectives.

Techno-economic risk assessment, life cycle analysis and life cycle costing for poly(butylene succinate) and poly(lactic acid) production using renewable resources.

The sustainable production of poly(lactic acid) (PLA) or poly(butylene succinate) (PBS) from corn glucose syrup, corn stover and sugar beet pulp (SBP) have been assessed via process design, preliminary techno-economic evaluation, life cycle assessment and life cycle costing (LCC). Cost-competitive PLA and PBS production can be achieved in a SBP-based biorefinery, including separation of crude pectin-rich extract as co-product, leading to minimum selling prices of $1.14/kgPLA and $1.37/kgPBS. Acidification Potential, Eutrophication Potential and Human Toxicity Potential are lower when SBP is used. The LCC of PLA ($1.42/kgPLA) and PBS ($1.72/kgPBS) production from SBP are lower than biaxial oriented polypropylene (BOPP, $1.66/kg) and general purpose polystyrene (GPPS, $2.04/kg) at pectin-rich extract market prices of $3/kg and $4/kg, respectively. Techno-economic risk assessment via Monte-Carlo simulations showed that PLA and PBS could be produced from SBP at the market prices of BOPP ($1.4/kg) and GPPS ($1.72/kg) with 100% probability to achieve a positive Net Present Value at pectin-rich extract market prices of $3/kg and $4/kg, respectively. This study demonstrated that SBP-based biorefinery development ensures sustainable production of PLA and PBS as compared to fossil-derived counterparts and single product bioprocesses using glucose syrup and corn stover.

Cradle-to-gate Life Cycle Assessment of bio-adhesives for the wood panel industry. A comparison with petrochemical alternatives.

The wood panel industry requires the introduction of more environmental-friendly adhesives due to the strict current regulations on formaldehyde-based emissions. The purpose of this study was to environmentally analyse the production of four different bio-adhesives as alternatives to the most conventional fossil resins used in the production of wood panels. The bio-adhesives proposed for analysis derived from different available renewable biopolymers such as protein (soy) and lignin (Kraft and Organosolv), as well as tannin. The production systems were evaluated from a cradle-to-gate perspective using the Life Cycle Assessment methodology, with the aim of identifying critical parameters and comparing them with fossil substitutes. Inventory data of bio-adhesives were modelled at large scale from lab scale experiments and completed with literature reports. Our results showed that the soy-based and tannin based bio-adhesive had an overall better profile than fossil resins, identifying the production of polyacrylamide for the former, and the production of condensed tannin and glyoxal for the latter, as the main environmental hotspots. In contrast, further research is required on the use of lignins, specifically because of the electricity requirements in the lignin glyoxalation stage (a process required for the functionalization of lignin). Sensitivity analyses were conduced on these key parameters suggesting that there is room for improvement.This study provides useful information for researchers and policy-makers on where to focus their activities with the aim of making the future of bio-adhesives more technically and environmentally favourable.