Manufacturing of bioethylene via dehydration of bioethanol is an alternative to the fossil-based ethylene production and decreases the environmental consequences for this chemical commodity. A few industrial plants that utilize 1st generation bioethanol for the bioethylene production already exist, although not functioning without subsidiaries. However, there is still no process producing ethylene from 2nd generation bioethanol. This study is divided into two parts. Different ethanol and ethylene production methods, the process specifications and current technologies are briefly discussed in the first part. In the second part, a techno-economic analysis of a bioethylene plant was performed using Aspen plus and Aspen Process Economic Analyzer, where different qualities of ethanol were considered. The results show that impurities in the ethanol feed have no significant effect on the quality of the produced polymer-grade bioethylene. The capacity of the ethylene storage tank significantly affects the capital costs of the process.

No abstract

While citrus waste is abundantly generated, the disposal methods used today remain unsatisfactory: they can be deleterious for ruminants, can cause soil salinity, or are not economically feasible; yet citrus waste consists of various valuable polymers. This paper introduces a novel environmentally safe approach that utilizes citrus waste polymers as a biobased and biodegradable film, for example, for food packaging. Orange waste has been investigated for biofilm production, using the gelling ability of pectin and the strength of cellulosic fibres. A casting method was used to form a film from the previously washed, dried, and milled orange waste. Two film-drying methods, a laboratory oven and an incubator shaker, were compared. FE-SEM images confirmed a smoother film morphology when the incubator shaker was used for drying. The tensile strength of the films was 31.67 ± 4.21 and 34.76 ± 2.64 MPa, respectively, for the oven-dried and incubator-dried films, which is within the range of different commodity plastics. Additionally, biodegradability of the films was confirmed under anaerobic conditions. Films showed an opaque appearance with yellowish colour.

No abstract

A new method was developed to determine glucosamine (GlcN) and N-acetyl glucosamine (GlcNAc) in materials containing chitin and chitosan, such as fungal cell walls. It is based on two steps of hydrolysis with (i) concentrated sulfuric acid at low temperature and (ii) dilute sulfuric acid at high temperature, followed by one-step degradation with nitrous acid. In this process, chitin and chitosan are converted into anhydromannose and acetic acid. Anhydromannose represents the sum of GlcN and GlcNAc, whereas acetic acid is a marker for GlcNAc only. The method showed recovery of 90.1% of chitin and 85.7-92.4% of chitosan from commercial preparations. Furthermore, alkali insoluble material (AIM) from biomass of three strains of zygomycetes, Rhizopus oryzae, Mucor indicus, and Rhizomucor pusillus, was analyzed by this method. The glucosamine contents of AIM from R. oryzae and M. indicus were almost constant (41.7 +/- 2.2% and 42.0 +/- 1.7%, respectively), while in R. pusillus, it decreased from 40.0 to 30.0% during cultivation from 1 to 6 days. The GlcNAc content of AIM from R. oryzae and R. pusillus increased from 24.9 to 31.0% and from 36.3 to 50.8%, respectively, in 6 days, while it remained almost constant during the cultivation of M. indicus (23.5 +/- 0.8%).

No abstract

Extensive quantities of apple pomace are generated annually but its disposal is still challenging. This study addresses this issue by introducing a new, environmentally-friendly approach for the production of sustainable biomaterials from apple pomace, containing 55.47% free sugars and a water insoluble fraction, containing 29.42 ± 0.44% hemicelluloses, 38.99 ± 0.42% cellulose, and 22.94 ± 0.12% lignin. Solution casting and compression molding were applied to form bio-based films and 3D objects (i.e., fiberboards), respectively. Using glycerol as plasticizer resulted in highly compact films with high tensile strength and low elongation (16.49 ± 2.54 MPa and 10.78 ± 3.19%, respectively). In contrast, naturally occurring sugars in the apple pomace showed stronger plasticizing effect in the films and resulted in a fluffier and connected structure with significantly higher elongation (37.39 ± 10.38% and 55.41 ± 5.38%, respectively). Benefiting from the self-binding capacity of polysaccharides, fiberboards were prepared by compression molding at 100 °C using glycerol or naturally occurring sugars, such as plasticizer. The obtained fiberboards exhibited tensile strength of 3.02–5.79 MPa and elongation of 0.93%–1.56%. Possible applications for apple pomace biomaterials are edible/disposable tableware or food packaging.

A new method was developed in this work for extraction of chitosan from the zygomycetes cell wall. It is based on the temperature-dependent solubility of chitosan in dilute sulfuric acid. Chitin is soluble in neither cold nor hot dilute sulfuric acid. Similarly chitosan is not soluble at room temperature but is dissolved in 1% H 2SO 4 at 121 degrees C within 20 min. The new method was developed to measure the chitosan content of the biomass and cell wall. The procedures were investigated by measuring phosphate, protein, ash, glucuronic acid, and degree of acetylation. The cell wall derivatives of fungus Rhizomucor pusillus were then examined by this new method. The results indicated 8% of the biomass as chitosan. After treatment with NaOH, the alkali-insoluble material (AIM) contained 45.3% chitosan. Treatment of AIM with acetic acid resulted in 16.5% acetic-acid-soluble material (AcSM) and 79.0% alkali- and acid-insoluble material (AAIM). AcSM is usually cited as pure chitosan, but the new method shows major impurities by, for example, phosphate. Furthermore, AAIM is usually considered to be the chitosan-free fraction, whereas the new method shows more than 76% of the chitosan present in AIM is found in AAIM. It might indicate the inability of acetic acid to separate chitosan from the cell wall.