Model-size reduction techniques for large-scale biomass production and supply networks

This paper is concerned with developing several model-size reduction techniques for the analysis of large-scale renewable production and supply networks. They are (i) Reducing the connectivity in a biomass supply chain network, (ii) Eliminating unnecessary variables and constraints, (iii) Merging the collection centres. The proposed model-size reduction techniques brought computational time improvements of several magnitudes compared, with the high performance linear system solution techniques and still with a little loss in accuracy. When the methods are combined the time reductions are more significant. A proposed procedure for combining the methods can be implemented for any supply chain model with a large number of components.     

Life cycle assessment of oil palm empty fruit bunch delignification using natural malic acid-based low-transition-temperature mixtures: a gate-to-gate case study

In future biorefineries, the development of cheap and environmentally friendly solvents for biomass pretreatment is highly desirable. In this sense, low-transition-temperature mixtures (LTTMs) have high potential to serve as green solvents for replacing conventional pretreatment technologies. In this study, a life cycle assessment of LTTMs pretreatment was conducted to determine the environmental impacts caused by biomass delignification. A gate-to-gate analysis which started with harvested oil palm empty fruit bunch and ended with lignin was selected. The environmental impacts such as acidification potential, global warming potential, eutrophication potential, photochemical ozone creation potential, human toxicity potential and volatile organic compounds emission were evaluated. The comparable environmental balances of commercial l-malic acid and cactus malic acid-based LTTMs pretreatment processes verified the suitability of the process with natural malic acid as the source of proton donor. This study concludes that biomass delignification using natural cactus malic acid-based LTTMs had promising features such as high delignification efficiency and environmentally friendly compared to commercial l-malic acid-based LTTMs. Based on environmental point of view, the overall process of biomass delignification using sucrose-based LTTMs had lower CO₂ emissions compared to the monosodium glutamate- and choline chloride-based LTTMs. These findings are important for verifying the greenness and sustainability of LTTMs to be applied at industrial scale.     

Effect of Various Gelling Cations on the Physical Properties of “Wet” Alginate Films

In this study, the physical properties of “wet” alginate films gelled with various divalent cations (Ba²⁺, Ca²⁺, Mg²⁺, Sr²⁺, and Zn²⁺) were explored. Additionally, the effect of adding NaCl to the alginate film‐forming solution prior to gelling was evaluated. Aside from Mg²⁺, all of the divalent cations were able to produce workable “wet” alginate films. Films gelled with BaCl₂ (without added NaCl) had the highest (P < 0.05) tensile strength and Young's modulus while films gelled with CaCl₂ (alone) had the highest puncture strength. The Zn‐alginate and Sr‐alginate films had the highest elongation at break values. Adding NaCl to the alginate film‐forming solution increased the viscosity of the solution. Films with added NaCl were less transparent and had lower tensile strength, elongation, and puncture strength than films formed without NaCl in the film‐forming solution. ATR‐FTIR results showed a slight shift in the asymmetric COO^? vibrational peak of the alginate when the “wet” alginate films were gelled with Zn²⁺.