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The cell wall compositional (lignin and polysaccharides) variation of two sweet sorghum varieties, Della (D) and its variant REDforGREEN(RG), was evaluated at internodes (IN) and nodes (N) using high-performance liquid chromatography (HPLC), pyrolysis–gas chromatography-mass spectrometry (Py-GCMS), X-ray diffraction (XRD), and two-dimensional (2D) 1H–13C nuclear magnetic resonance (NMR). The stalks were grown in 2018 (D1 and RG1) and 2019 (D2 and RG2) seasons. In RG1, Klason lignin reductions by 16–44 and 2–26% were detected in IN and N, respectively. The analyses also revealed that lignin from the sorghum stalks was enriched in guaiacyl units and the syringyl/guaiacyl ratio was increased in RG1 and RG2, respectively, by 96% and more than 2-fold at IN and 61 and 23% at N. The glucan content was reduced by 23–27% for RG1 and by 17–22% for RG2 at internodes. Structural variations due to changes in both cellulose- and hemicellulose-based sugars were detected. The nonacylated and γ-acylated β–O–4 linkages were the main interunit linkages detected in lignin. These results indicate compositional variation of stalks due to the RG variation, and the growing season could influence their mechanical and lodging behavior.

The effect of ethylene diamine tetraacetic acid (EDTA) modification on the physico-chemical properties and catalytic performance of silica nanosprings (NS) supported cobalt (Co) catalyst was investigated in the conversion of syngas (H2+ CO) to hydrocarbons by Fischer-Tropsch synthesis (FTS). The unmodified Co/NS and modified Co/NS-EDTA catalysts were synthesized via an impregnation method. The prepared Co/NS and Co/NS-EDTA catalysts were characterized before the FTS reaction by BET surface area, X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), differential thermal analysis (DTA) and thermogravimetric analysis (TGA) in order to find correlations between physico-chemical properties of catalysts and catalytic performance. FTS was carried out in a quartz fixed-bed microreactor (H2/CO of 2:1, 230°C and atmospheric pressure) and the products trapped and analyzed by GC-TCD and GC-MS to determine CO conversion and reaction selectivity. The experimental results indicated that the modified Co/NS-EDTA catalyst displayed a more-dispersed phase of Co3O4nanoparticles (10.9%) and the Co3O4average crystallite size was about 12.4 nm. The EDTA modified catalyst showed relatively higher CO conversion (70.3%) and selectivity toward C6–18(JP-8, Jet A and diesel) than the Co/NS catalyst (C6–14) (JP-4).

About 5% of all corrugated cardboard is coated with wax to enhance performance under humid conditions. Waxed cardboard is unrecyclable. The authors have previously shown that the wax can be effectively recovered using pyrolysis. The main compounds found in wax oil obtained from pyrolysis of waxed cardboard were alkanes, alkenes, and dienes (C9to C36). In this work, recovered wax and wax oil samples were thermally and catalytically pyrolyzed on a custom-made small tubular batch reactor, and the resultant liquid products were analyzed (GCMS, FTIR, and ESI-MS) against gasoline to evaluate their performance as a transport fuel. The products of thermal pyrolysis of the samples are mainly composed of dienes and short-chain olefins, oxygenated compounds, and minor amounts of aromatic compounds. Their functional groups resembled those found in paraffin. The analyses revealed that the liquid products of catalytic pyrolysis had chemical and functional group profiles similar to gasoline (e.g., methylbenzenes). The addition of zeolite Y as the catalyst facilitated the conversion of long-chain hydrocarbons to short-chain alkanes and aromatics. The monomer-to-oligomer ratio of the liquid products also increased significantly after catalytic pyrolysis.