Investigation of the Cofiring Process of Raw or Torrefied Bamboo and Masson Pine by Using a Cone Calorimeter

Cofiring characteristics of raw or torrefied bamboo and masson pine blends with different blend ratios were investigated by cone calorimetry, and its ash performance from cofiring was also determined by a YX-HRD testing instrument, X-ray fluorescence, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Results showed that bamboo and masson pine had the different physicochemical properties. Torrefaction improved fuel performances, resulting in a more stable cofiring process. It also decreased the heat release rate, total heat release, and total suspended particulates of fuels, especially CO2 and CO release. Masson pine ash mainly included CaO, SiO2, Fe2O3, K2O, and Al2O3. Bamboo ash was mainly composed of K2O, SiO2, MgO, and SO3. There were different melting temperatures and trends between different samples. The synergistic reaction of ash components was found during the cofiring process. The surface morphology of blend ash changed with the variation of bamboo or masson pine content

Nitrogen Self-Doped Activated Carbons Derived from Bamboo Shoots as Adsorbent for Methylene Blue Adsorption

Bamboo shoots, a promising renewable biomass, mainly consist of carbohydrates and other nitrogen-related compounds, such as proteins, amino acids and nucleotides. In this work, nitrogen self-doped activated carbons derived from bamboo shoots were prepared via a simultaneous carbonization and activation process. The adsorption properties of the prepared samples were evaluated by removing methylene blue from waste water. The factors that affect the adsorption process were examined, including initial concentration, contact time and pH of methylene blue solution. The resulting that BSNC-800-4 performed better in methylene blue removal from waste water, due to its high specific surface area (2270.9 m2 g−1), proper pore size (2.19 nm) and relatively high nitrogen content (1.06%). Its equilibrium data were well fitted to Langmuir isotherm model with a maximum monolayer adsorption capacity of 458 mg g−1 and a removal efficiency of 91.7% at methylene blue concentration of 500 mg L−1. The pseudo-second-order kinetic model could be used to accurately estimate the carbon material’s (BSNC-800-4) adsorption process. The adsorption mechanism between methylene blue solution and BSNC-800-4 was controlled by film diffusion. This study provides an alternative way to develop nitrogen self-doped activated carbons to better meet the needs of the adsorption applications

Conversion and Utilization of Forest Logging Residues for Value Added Bioproducts in the Eastern United Sates

Four major studies were conducted in this dissertation to investigate the quality, availability, pretreatment, conversion, and utilization of forest logging residues in the eastern United States. The introduction and conclusion sections are found in the first and last chapters. The quality of various-year-naturally-decomposed softwood and hardwood forest logging residues from three subregions of the eastern United States was investigated in the second chapter. In the third chapter, the combustion and energy properties of hydrothermal, inert, and oxidative torrefied red maple were investigated. Finally, in the fourth and fifth chapters, KMnO4 surface-modified logging residue hydrochars were used to investigate the adsorption properties of single and mixed heavy metal solutions. Specifically, the results of second chapter indicated that an increasing natural decomposition time leads to a decrease in density for both hardwood and softwood samples. The higher heating value (HHV) of hardwood ranges from 18.69 to 20.68 MJ/Kg, which is comparatively lower than that of softwood (ranging from 19.13 to 21.16 MJ/Kg). The change of HHV in hardwood trends opposite to that of softwood. The results of the ultimate analysis indicated that softwood exhibits a higher carbon content (47.98%-51.98%) than hardwood (46.06%-49.48%). In addition, hardwood has a higher volatile matter (76%-80.85%) and lower fixed carbon (16.97%-21.68%) content compared with softwood (71.10%-79.45% and 19.03%-23.69%, respectively). There was an observed increase in the absolute lignin content of softwood as the exposure time increased, whereas the trend for holocellulose was opposite. Additionally, the proportion of lignin in hardwood and holocellulose in softwood decreased as the duration of decomposition time increased. The rate of decomposition in the southeast region was observed to be faster than that in the central Appalachian region. If 50% of logging residues produced in 2023 were used, three distinct categories of biofuel, biochar, and wood pellet could be produced by 0.385-0.605 million tons, 1.21-1.76 million tons, and 5.06-5.39 million tons, respectively. The results of third chapter showed that the physiochemical properties of hydrothermally treated (HT) samples changed dramatically compared to samples processed using inert (NT) and oxidative (OT) treatments. The HT method yielded 39.60±0.96% solid product, which is significantly lower than the OT (83.06±0.55%) and NT (91.42±0.89%) treatments. However, it has a higher fixed carbon content (44.40%) than both OT (24.74%) and NT (19.24%). With different heating rates, the weight loss of untorrefied (UT) stage 1 ranges from 70.3 to 72.1%, whereas HT decreases from 41.9 to 38.0%. For UT, OT, and NT, weight loss ranges from 59.9 to 74% at stage 1 and 22.0-37.9% at stage 2. The ranges for HT, on the other hand, are 37.7-41.9% and 53.0-57.9% for stage 1 and stage 2, respectively. Stage 1\u27s sample Ea distribution follow HT\u3eOT\u3eUT≈NT, while the average combustion Ea of stage 2 sample distribution follow HT\u3eOT\u3eUT\u3eNT. KAS calculates the highest value for stage 1 as 247.56 KJ/mol for HT and the lowest as 140.61 KJ/mol for UT. The findings in fourth chapter indicate that the output of unmodified hydrochar (250-P), hydrochar produced through a direct process (250-1), and hydrochar produced through an indirect process (250-2) were 37.14±0.24%, 36.57±0.96%, and 29.01±0.79%, respectively. Sample 250-2 displays the highest carbon content (66.88%) among all specimens. The FTIR and XRD expressed that the surface-modified hydrochar undergoes significant alterations in chemical properties. In addition, it was observed that 250-P exhibited amorphous morphology, while 250-1 displayed uniformity in the size and shape of its colloidal carbonaceous spheres, and 250-2 exhibited surface-damaged carbon spheres. The adsorption capacity of 250-2 for Cd (II), Cu (II), and Pb (II) is higher than 250-1 and 250-P. The maximum adsorption capacities of 250-P, 250-1, and 250-2 for Pb (II) were 179.13mg/g, 158.34mg/g, and 182.98mg/g, respectively, when the adsorbent concentration was 1000mg/L. The Langmuir model is a more effective representation of adsorption for all samples in comparison to the Freundlich model. The adsorption efficiency of 250-2 surface-modified hydrochar surpasses that of 250-1 and 250-P. In the fifth chapter, the results expressed that the yields for pristine (275-0), 0.5 (275-0.5), 1.0 (275-1.0), and 2.0g/L (275-2.0) KMnO4-modified hydrochar were 34.75±1.87%, 29.41±0.12%, 27.30±1.08%, and 25.68±0.64%, respectively. 275-1.0 had the highest intensity absorbance for FTIR, while the XRD results showed a slight difference. Furthermore, 275-0.5 and 275-1.0 had irregular-shaped particles with rough surfaces, indicating a higher surface area and porosity, whereas 275-0 and 275-2.0 had fewer particles and mesopores. The main functional groups on the surface of hydrochar were quinone-type carbonyl groups C=O and phenolic and ether groups C-O/C-O-C. For all heavy metal ions, 275-1.0 had the highest adsorption capacity at each time interval, followed by 275-0.5 and 275-0

Lignin-Based Porous Biomaterials for Medical and Pharmaceutical Applications

Over the past decade, lignin-based porous biomaterials have been found to have strong potential applications in the areas of drug delivery, tissue engineering, wound dressing, pharmaceutical excipients, biosensors, and medical devices. Lignin-based porous biomaterials have the addition of lignin obtained from lignocellulosic biomass. Lignin as an aromatic compound is likely to modify the materials’ mechanical properties, thermal properties, antioxidant, antibacterial property, biodegradability, and biocompatibility. The size, shape, and distribution of pores can determine the materials’ porous structure, porosity, surface areas, permeability, porosity, water solubility, and adsorption ability. These features could be suitable for medical applications, especially controlled drug delivery systems, wound dressing, and tissue engineering. In this review, we provide an overview of the current status and future potential of lignin-based porous materials for medical and pharmaceutical uses, focusing on material types, key properties, approaches and techniques of modification and fabrication, and promising medical applications

Self-Assembly of Small Organic Molecules into Luminophores for Cancer Theranostic Applications

Self-assembled biomaterials have been widely explored for real-time fluorescence imaging, imaging-guided surgery, and targeted therapy for tumors, etc. In particular, small molecule-based self-assembly has been established as a reliable strategy for cancer theranostics due to the merits of small-sized molecules, multiple functions, and ease of synthesis and modification. In this review, we first briefly introduce the supramolecular chemistry of small organic molecules in cancer theranostics. Then, we summarize and discuss advanced small molecule-based self-assembly for cancer theranostics based on three types, including peptides, amphiphilic molecules, and aggregation-induced emission luminogens. Finally, we conclude with a perspective on future developments of small molecule-based self-assembled biomaterials integrating diagnosis and therapy for biomedical applications. These applications highlight the opportunities arising from the rational design of small organic molecules with self-assembly properties for precision medicine

INVESTIGATING GASEOUS CARBON, NITROGEN, AND SULFUR COMPOUNDS OF BAMBOO, WOOD, AND COAL DURING PYROLYSIS PROCESS

Bamboo, wood, and coal were pyrolyzed by a thermogravimetric analyzer coupled with Fourier transform infrared spectrometry to investigate gaseous carbon, nitrogen, and sulfur compounds from fuels. It was found that the main gas compounds of fuels included carbon dioxide, carbon monoxide, methane, sulfur dioxide, hydrogen sulfide, ammonia gas, and hydrogen cyanide. Compared with masson pine, bamboo had a higher gas release and more mass loss due to its lower pyrolysis temperatures when temperature was lower than 350°C. Coal had the lowest gas release and the least mass loss due to the higher pyrolysis temperature during the whole pyrolysis process. The char-C, N, and S contents of all fuels increased with increase in pyrolysis temperature. The results from this research will be helpful to utilize the wastes of masson pine and bamboo for energy products. 

INVESTIGATING SYNERGISTIC INTERACTION OF BAMBOO AND TORREFIED BAMBOO WITH COAL DURING COCOMBUSTION

To investigate if there is synergistic interaction between bamboo with coal, or between torrefied bamboo with coal during cocombustion, bamboo and torrefied bamboo separately were respectively uniformly mixed with coal and the weight percentage of bamboo or torrefied bamboo in the mixture were 10%, 20%, 30%, and 40%. The combustion behaviors of blends were characterized using thermogravimentric analyzer at heating rates of 10°C/min, 20°C/min, 30°C/min, and 40°C/min. Results showed that the combustion process of bamboo and coal combustion was separated during cocombustion, and the higher temperature zone corresponding to coal combustion had a higher activation energy. Cocombustion of torrefied bamboo and coal had a combustion zone. Combustion characteristics gradually increased with increase in heating rates and decrease in mixing ratios. Theoretical combustion characteristics obviously shifted to higher temperatures, indicating synergistic interactions between bamboo/torrefied bamboo and coal. Cocombustion of torrefied bamboo and coal was more feasible with a stabler combustion process. The results might be helpful to promote bamboo resources as a blend fuel for co-firing application with coal

INVESTIGATING CHEMICAL PROPERTIES AND COMBUSTION CHARACTERISTICS OF TORREFIED MASSON PINE

To investigate chemical properties and combustion characteristics, masson pine was torrefied using GSL 1600X tube furnance in the argon atmosphere. The properties of torrefied masson pine were respectively determined through thermogravimetry (TGA), fourier transform infrared spectrometer (FTIR) and X-ray diffraction (XRD). Results showed that thermal decomposition of hemicelluloses, cellulose and lignin occurred during torrefaction process. Crystalline region of cellulose was destroyed when temperature was up to 250℃. The effect of torrefaction temperature was more significant than that of residence time. Torrefaction improved combustion characteristics of masson pine. The optimum process was 300℃ of torrefaction temperature and 2.0h of residence time. Combustion process of torrefied masson pine included drying, oxidative pyrolysis and char combustion. Torrefied masson pine had a lower H/C and O/C ratios, peak temperature of oxidative pyrolysis and char combustion and burnout temperature. It had a higher energy density, ignition temperature and activation energy. This data will be significant to understand the torrefied masson pine for energy product to directly combustion