Insight into effects of torrefaction on biomass: Chemical composition, pyrolysis behavior and products distribution.

This study investigated the effects of bacterial inoculants and enzyme-based silage cocktails on the dynamics of fermentation, microbiome, and nutritional value of silages produced from low-quality biomasses of reed, rice, and corn straw. A 90-day ensiling trial was performed using five distinct combinations of six basal bacterial species (Lactobacillus plantarum, Lactobacillus buchneri, Pediococcus pentosaceus, Aspergillus niger, Bacillus subtilis, and Candida utilis) and three basal enzymes (xylanase, β-mannanase, and glucanase). Each type of biomass was ensiled with six different treatments, including the Control treatment without an ensiling agent, the basal silage cocktail treatment (Mesa), and Mesa with a double dose of A. niger (MesaA), B. subtilis (MesaB), C. utilis (MesaC) and glucanase (MesaG). The “Mesa” contained (per kg silage), 1.0 × 106 CFU of L. plantarum, 1.4 × 107 CFU L. buchneri, 3.0 × 105 CFU P. pentosaceus, 8.0 × 108 CFU A. niger, 1.6 × 106 CFU B. subtilis and 1.0 × 109 CFU C. utilis, three enzymes (5.0 × 104 U xylanase, 2.5 × 103 U β-mannanase, and 1.0 × 104 U glucanase), and 20 mL molasses. Addition of the silage cocktails significantly improved the fermentation and nutritional quality of the reed, corn, and rice straw silages. Notably, the silage cocktails increased (P < 0.01) the contents of crude protein (CP), ether extract (EE), gross energy (GE), lactic acid (LA), ratio of LA to total acids and ensiling comprehensive evaluation scores, and decreased (P < 0.01) the contents of neutral detergent fiber (NDF), acid detergent fiber (ADF) and pH of reed, corn, and rice straw silages. Regarding the silage microbiome, silage cocktails decreased the relative abundance of Enterobacter and Rahnella1, and increased the relative abundance of Leuconostoc. A. niger, and B. subtilis had a strong positive correlation with CP, EE, GE and Lactobacillus, and a negative correlation with pH, Rhizobium, and Rahnella1 in reed, corn and rice straw silages. In comparison, C. utilis had a strong positive correlation with EE, and a negative correlation with pH, Rhizobium, Stenotrophomonas, and Rahnella1. Glucanase was positively correlated with LA, EE and GE, and negatively correlated with pH and Rahnella1. Silage quality characteristics and microbiome did not differ (P > 0.05) due to the composition of silage cocktails. Based on the comprehensive membership function analysis, the silage comprehensive evaluation scores were highest for double doses of B. subtilis and glucanase for reed, corn, and rice straw. This study revealed that silage cocktails upgraded straw silage fermentation and nutritional quality, and provided a practical solution for the optimal utilization of low-quality straw biomass.Graphical

For getting information about the distribution of chemical composition, several model polymers were prepared under different polymerization conditions and were measured by critical adsorption point-liquid chromatography (CAP-LC). In the copolymer system of 8- and 9- (4-oxatricyclo[5.2.1.0 2,6 ]decane-3-one) acrylate (OTDA) and 2-ethyl-2-adamantyl methacrylate (EAdMA), the peak shapes of the CAP-LC chromatogram varied according to the polymerization condition although they indicated same molecular weight and averaged chemical composition. The difference of the CAP-LC elution curves was related to the chemical composition di stribution of copolymers for CA P-LC measurement combined with proton nuclear magnetic resonance ( 1 H-NMR). The terpolymers consisted of D -hydroxy- J-butyrolactone methacrylate (GBLMA), 2-methyl-2-adamantyl methacrylate (MAdMA) and 1-hydroxy-3-adaman tyl methacrylate (HAdMA) were prepared under various polymerization conditions . In the terpolymer system that had same molecular weight and average chemical composition, the solubility parameter (G) and the dissolution rate were measured. The G value and the dissolution rate curve were different among these terpolymers. It was suggested that the G value and the chemical composition distribution of these terpolymers have a significant influence on the lithographic performance. Keywords: ArF photoresist copolymer, chemical composition distribution, solubility parameter, critical adsorption point-liquid chromatography, CAP-LC

Chemical composition distribution of bacterial copolyesters

Ethylene/1-olefin copolymers have held industrial significance for a considerable period. A series of copolymers with identical molar mass and varying 1-hexene levels were synthesized using supported metallocene catalyst. Various analytical techniques were used to characterize the copolymers, focusing on the effect of increasing 1-hexene content on their chemical properties, specifically chemical composition distribution (CCD). Initially, the investigations carried out by differential scanning calorimetry (DSC) revealed broad and asymmetric thermograms with the presence of a distinct shoulder in samples with higher 1-hexene content. Furthermore, HT-GPC with IR5 detector revealed uniform chemical composition (1-hexene concentration) along the molar mass axis. Examination of the chemical composition distribution (CCD) was conducted using two variants of high-temperature liquid adsorption chromatography (HT-LAC), namely solvent gradient interaction chromatography (SGIC) and thermal gradient interaction chromatography (TGIC). Initial testing by employing solvents common to HT-LAC showed that the elution behavior did not correspond with the distinct thermal properties DSC. In the next step, new desorption-promoting solvents were identified using a recent approach that integrates structure retention relationships (SRR), a measure of solvent–stationary phase interactions, with Hansen solubility parameters (HSP), assessing polymer–solvent interactions. The broad and asymmetric CCD in samples with higher SCB, characterized by a main peak and a shoulder, was confirmed by SGIC using newly identified desorption-promoting solvents identified via the SRR–HSP method. This CCD profile was also corroborated by TGIC using a binary solvent mixture as the mobile phase.

Determination of the chemical composition distribution of copolymers of styrene and butadiene by gradient polymer elution chromatography

Chemical composition distribution of styrene-ethyl methacrylate copolymers studied by means of t.l.c./f.i.d.: effect of high conversion in various polymerization processes

Temporal and Spatial Distribution, Utilization Status, and Carbon Emission Reduction Potential of Straw Resources in China

Enhancing fuel characteristics and combustion performance of cellulose-rich straws through CO2-assisted torrefaction

The influence of the reactor type on distribution of chemical composition of STY AN/MA terpolymers obtained by free-radical polymerization is shown. When a batch reactor was used we have obtained polymers with broad chemical composition distribution. However, if a semi-batch reactor with appropriate addition protocol was used it can be possible to synthesize terpolymers with homogeneous chemical composition.

The synthesis and characterization of polyolefins continues to be one of the most important areas for academic and industrial polymer research. One consequence of the development of new "tailor-made" polyolefins is the need for new and improved analytical techniques for the analysis of polyolefins with respect to molar mass and chemical composition distribution. The present article briefly reviews different new and relevant techniques for polyolefin analysis. Crystallization analysis fractionation is a powerful new technique for the analysis of short-chain branching in linear low-density polyethylene (LLDPE) and the analysis of polyolefin blends and copolymers regarding chemical composition. For the fast analysis of the chemical composition distribution, a new high-temperature gradient high-performance liquid chromatography (HPLC) system has been developed. The efficiency of this system for the separation of various olefin copolymers is demonstrated. The correlation between molar mass and chemical composition can be accessed by on-line coupling of high-temperature size exclusion chromatography (HT-SEC) and 1H NMR spectroscopy. It is shown that the on-line NMR analysis of chromatographic fractions yields information on microstructure and tacticity in addition to molar mass and copolymer composition.

Configurational characteristics of ethylene-vinyl chloride copolymers

The chemical composition distribution (CCD) of 1-butene comonomer in linear low-density polyethylene (LLDPE) has been studied by means of thermal analysis. After an appropriate thermal treatment of the polymers using thermal fractionated crystallization, the melting endotherms were subdivided into zones with fixed temperature ranges. The distribution of the endotherms in the different zones permitted the calculation of a composition index that gave a quantitative estimate of the CCD based on a calibration curve. Three LLDPEs and their fractions, having a significantly different CCD, have been tested using this method. A comparison with another thermal method is also discussed.

In recent years, biochar has emerged as a versatile product. Producing biochar from agricultural residue is an environmentally friendly alternative to in‐situ burning, reducing the requirement for chemical fertilizers. This study presents a comprehensive assessment of the environmental impact of biochar production. Four feedstocks are compared – rice straw, palm shell, corn stover, and mixed crop residue. The cradle‐to‐gate system boundary comprises all stages of biochar production – feedstock acquisition, transport and pre‐treatment, and biochar production. Results show that the main hotspots are emissions and electricity consumption during production. The palm shell had the highest impact on human health (4.889 kg PM2.5 eq) and ecosystem quality due to high terrestrial and aquatic acidification potential (159.600 kg SO2 eq). Mixed crop residue had the greatest global warming potential (281.884 kg CO2 eq) and resource consumption. Corn stover and rice straw had moderate impacts, with corn stover contributing significantly to ecotoxicity (2.2E+04 kg TEG water) and rice straw impacting respiratory inorganics (3.545 kg PM2.5 eq), and causes severe depletion of resources, consuming 4339.672 MJ of non‐renewable energy. These findings emphasize the importance of selecting low‐impact feedstocks for biochar production. While corn stover has high impacts in midpoint categories like carcinogens, non‐carcinogens, ionizing radiation, aquatic and terrestrial toxicity, and eutrophication, it has the lowest GWP. Rice straw has the lowest impact on human health and resources. Finally, uncertainty analysis using Monte Carlo Simulation shows that the coefficient of variation for impact categories is within ±10%, indicating that the results are reliable.

Comparative study on the pyrolysis behaviors of rice straw under different washing pretreatments of water, acid solution, and aqueous phase bio-oil by using TG-FTIR and Py-GC/MS

Pyrolysis behavior and product distribution of exinite submacerals