Valorization of algal waste via pyrolysis in a fixed-bed reactor: production and characterization of bio-oil and bio-char

The aim of the present work is to develop processes for the production of bio-oil andbio-char from algae waste using the pyrolysis at controlled conditions. The pyrolysiswas carried out at different temperatures 400-600 °C and different heating rates 5-50°C/min. The algal waste, bio-oil and bio-char were successfully characterized usingElemental analysis, Chemical composition, TGA, FTIR, 1H-NMR, GC-MS and SEM.At a temperature of 500 °C and a heating rate of 10 °C/min, the maximum yield of biooiland bio-char was found to be 24.10 and 44.01wt%, respectively, which was found tobe strongly influenced by the temperature variation, and weakly affected by the heatingrate variation. Results show that the bio-oil cannot be used as bio-fuel, but can be usedas a source of value-added chemicals. On the other hand, the bio-char is a promisingcandidate for solid fuel applications and for the production of carbon materials

Effect of Cellulose Nanocrystals on the Coating of Chitosan Nanocomposite Film Using Plasma Mediated Deposition of Amorphous Hydrogenated Carbon a C H Layers

The substitution of petroleum-based polymers with naturally derived biopolymers may be a good alternative for the conservation of natural fossil resources and the alleviation of pollution and waste disposal problems. However, in order to be used in a wide range of applications, some biopolymers’ properties should be enhanced. In this study, biocompatible, non-toxic, and biodegradable chitosan (CS) film and CS reinforced with 10 wt% of cellulose nanocrystals (CN–CS) were coated with amorphous hydrogenated carbon layers (a–C:H) of different thickness. To investigate the effect of the nano-reinforcement on the a–C:H layer applied, mild radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) was used to coat the CS and its CN–CS bio-nanocomposite film. Both the surface characteristics and the chemical composition were analyzed. The surface morphology and wettability were examined by ex-situ atomic force microscopy (AFM) and contact angle measurements (CA), respectively. Hereby, the relationship between sp2/sp3 ratios on a macroscopic scale was also evaluated. For the investigation of the chemical composition, the surface sensitive synchrotron X-ray radiation techniques near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) as well as diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) were used

New highly hydrated cellulose microfibrils with a tendril helical morphology extracted from agro-waste material: application to removal of dyes from waste water

Cocoa bean shells (CBS) are a by-product of the cocoa bean processing industry. They represent 12–20 wt% of dry cocoa beans, after having been separated from these by a roasting process. CBS often end up as a waste product which contains around 34 wt% of cellulose. The transformation of this waste into valuable and marketable products would help to improve waste disposal. Indeed, the large annual production of this waste makes it a sustainable and renewable bio-source for the production of chemicals and fibers for advanced applications. In this work, new cellulose microfibrils (CMFs) with a tendril helical morphology and highly hydrated gel-like behavior were successfully extracted from CBS waste using a controlled chemical extraction process. During this study, several physico-chemical characterizations were carried out in order to identify the properties of each of the products at different stages of treatment. Microscopic observations show that the extracted CMFs have a tendril helical shape like climbing plant tendrils. Due to this special morphology, the extracted CMFs show a highly hydrated state forming a gel network without additional modifications. The as-extracted CMFs were used as adsorbent material for the removal of methylene blue from concentrated aqueous solution, as an application to wastewater treatment for the removal of basic dyes. Swelling properties, adsorption kinetics and isotherms were carried out in batch experiments. The results indicated that the CMFs have a high swelling capacity (190%). The pseudo second order model can be effectively used to evaluate the adsorption kinetics and the adsorption isotherms can also be described well by the Langmuir isotherm model with a maximum adsorption capacity of 381.68 mg g−1. Thus, the as-extracted CMFs with unique characteristics have the potential to be used as efficient adsorbent material for the removal of different cationic dyes from industrial wastewater