Gel-Type and Macroporous Cross-Linked Copolymers Functionalized with Acid Groups for the Hydrolysis of Wheat Straw Pretreated with an Ionic Liquid

Exploring a facile preparation method for Co-Ni/MoS2-derived nanohybrid from wheat straw extract and its physicochemical properties

This study presents a novel approach for the fabrication of a Co,Ni/MoS2-derived nanohybrid material using wheat straw extract. The facile synthesis method involves a sol-gel process, followed by calcination, showcasing the potential of agricultural waste as a sustainable reducing and chelating reagent. The as-prepared nanohybrid has been characterized using different techniques to analyse its physicochemical properties. X-ray diffraction analysis confirmed the successful synthesis of the nanohybrid material, identifying the presence of NiMoO4, CoSO4 and Mo17O47 as its components. Fourier-transform infrared spectroscopy differentiated the functional groups present in the wheat straw biomass and those in the nanohybrid material, highlighting the formation of metal-oxide and sulphide bonds. Scanning electron microscopy revealed a heterogeneous morphology with agglomerated structures and a grain size of around 70 nm in the nanohybrid. Energy-dispersive X-ray spectroscopy analysis shows the composition of elements with weight percentages of (Mo) 9.17%, (S) 6.21%, (Co) 12.48%, (Ni) 12.18% and (O) 50.46% contributing to its composition. Electrochemical analysis performed through cyclic voltammetry showcased the exceptional performance of the nanohybrid material as compared with MoS2, suggesting its possible applications for designing biosensors and related technologies. Thus, the research study presented herein underscores the efficient utilization of natural resources for the development of functional nanomaterials with promising applications in various fields. This study paves a way for manufacturing innovation along with advancement of novel synthesis method for sustainable nanomaterial for future technological developments.

Lignin from Brewers' Spent Grain: Structural and Thermal Evaluations

Lignocellulose is a renewable ubiquitous material that comprises cellulose, hemicellulose, and lignin. Lignin has been isolated from different lignocellulosic biomass via chemical treatments, but there has been little or no investigation carried out on the processing of lignin from brewers' spent grain (BSG) to the best of authors' knowledge. This material makes up 85% of the brewery industry's byproducts. Its high moisture content hastens its deterioration, which has posed a huge challenge to its preservation and transportation; this eventually causes environmental pollution. One of the methods of solving this environmental menace is the extraction of lignin as a precursor for carbon fiber production from this waste. This study considers the viability of sourcing lignin from BSG with the use of acid solutions at 100 °C. Structural and thermal analyses were carried out on extracted samples, and the results were compared with other biomass-soured lignin to assess the proficiency of this isolation technique. Wet BSG sourced from Nigeria Breweries (NB), Lagos, was washed and sun-dried for 7 days. Tetraoxosulphate (VI) (H₂SO₄), hydrochloric (HCl), and acetic acid, each of 10 M, were individually reacted with dried BSG at 100 °C for 3 h and designated as H2, HC, and AC lignin. The residue (lignin) was washed and dried for analysis. Wavenumber shift values from Fourier transform infrared spectroscopy (FTIR) show that intra- and intermolecular OH interactions in H2 lignin are the strongest and possess the highest magnitude of hydrogen-bond enthalpy (5.73 kCal/mol). The thermogravimetric analysis (TGA) results show that a higher lignin yield can be achieved when it is isolated from BSG, as 82.9, 79.3, and 70.2% were realized for H2, HC, and AC lignin. The highest size of ordered domains (0.0299 nm) displayed by H2 lignin from X-ray diffraction (XRD) informs that it has the greatest potential of forming nanofibers via electrospinning. The enthalpy of reaction values of 133.3, 126.6, and 114.1 J/g recorded for H2, HC, and AC lignin, respectively, from differential scanning calorimetry (DSC) results affirm that H2 lignin is the most thermally stable with the highest glass transition temperature (T_g = 107 °C).

Morphological growth pattern of Phanerochaete chrysosporium cultivated on different Miscanthus x giganteus biomass fractions

BACKGROUND

Solid-state fermentation is a fungal culture technique used to produce compounds and products of industrial interest. The growth behaviour of filamentous fungi on solid media is challenging to study due to the intermixity of the substrate and the growing organism. Several strategies are available to measure indirectly the fungal biomass during the fermentation such as following the biochemical production of mycelium-specific components or microscopic observation. The microscopic observation of the development of the mycelium, on lignocellulosic substrate, has not been reported. In this study, we set up an experimental protocol based on microscopy and image processing through which we investigated the growth pattern of Phanerochaete chrysosporium on different Miscanthus x giganteus biomass fractions.

RESULTS

Object coalescence, the occupied surface area, and radial expansion of the colony were measured in time. The substrate was sterilized by autoclaving, which could be considered a type of pre-treatment. The fastest growth rate was measured on the unfractionated biomass, followed by the soluble fraction of the biomass, then the residual solid fractions. The growth rate on the different fractions of the substrate was additive, suggesting that both the solid and soluble fractions were used by the fungus. Based on the FTIR analysis, there were differences in composition between the solid and soluble fractions of the substrate, but the main components for growth were always present. We propose using this novel method for measuring the very initial fungal growth by following the variation of the number of objects over time. Once growth is established, the growth can be followed by measurement of the occupied surface by the mycelium.

CONCLUSION

Our data showed that the growth was affected from the very beginning by the nature of the substrate. The most extensive colonization of the surface was observed with the unfractionated substrate containing both soluble and solid components. The methodology was practical and may be applied to investigate the growth of other fungi, including the influence of environmental parameters on the fungal growth.

Enhancement of Biological Pretreatment on Rice Straw by an Ionic Liquid or Surfactant

Fungal delignification can be a feasible process to pretreat biomass for bioethanol production if its performance is improved in terms of efficiency through a few modifications. The aim of this study was to enhance the biodelignification pretreatment of rice straw using laccase in the presence of ionic liquid (1-Allyl-3-methylimidazolium chloride, [AMIM]Cl) or surfactant (TritonX-100). Addition of 750 mg/L [AMIM]Cl and 500 mg/L TritonX-100 increases the lignin removal to 18.49% and 31.79%, which is higher than that of laccase only (11.97%). The enzymatic saccharification process was carried out based on different strategies. The highest cellulose conversion, 40.96%, 38.24%, and 37.91%, was obtained after 72 h of enzymatic saccharification when the substrate was washed with distilled water after pretreatment of rice straw with laccase + TritonX-100, laccase + [AMIM]Cl, and laccase only, respectively. In addition, the morphology and structure changes of pretreated and untreated rice straw were studied. Both surface area and cellulose crystallinity are substantially altered after laccase + [AMIM]Cl and laccase + TritonX-100 pretreatment. Enhanced saccharification efficiency of rice straw was achieved by laccase pretreatment with ionic liquid or surfactant in a single system.

Ionic liquid based pretreatment of lignocellulosic biomass for enhanced bioconversion

Lignocellulosic biomass is the most plentiful renewable biomolecule and an alternative bioresource for the production of biofuels and biochemicals in biorefineries. But biomass recalcitrance is a bottleneck in their usage, thus necessitating their pretreatment for hydrolysis. Most pretreatment technologies, result in toxic by-products or have lower yield. Ionic liquids (ILs) have successfully advanced as 'greener and recyclable' alternatives to volatile organic solvents for lignocellulosic biomass dissolution. This review covers recent developments made in usage of IL-based techniques with focus on biomass breakdown mechanism, process parameter design, impact of cation and anion groups, and the advantageous impact of ILs on the subsequent processing of the fractionated biomass. Progress and barriers for large-scale commercial usage of ILs in emerging biorefineries were critically evaluated using the principles of economies of scale and green chemistry in an environmentally sustainable way.

Catalytic Biomass to Renewable Biofuels and Biomaterials

As the only renewable carbon source, biomass can be converted into biofuels, chemicals, and biomaterials, such as ethanol, butanol, glucose, furfural, biochar, and bio-oils, and is considered as a substitute for fossil oil [...]