Thermodegradation of naturally decomposed forest logging residues: Characteristics, kinetics, and thermodynamics.

Combustion and pyrolysis characteristics, kinetics, and thermodynamics of naturally decomposed softwood and hardwood forest logging residues (FLR) were investigated using thermogravimetric analysis. Results showed that calorific values of fresh red pine, two-year decomposed, four-years decomposed, fresh red maple, two-year decomposed, and four-years decomposed were 19.78, 19.40, 20.19, 20.35, 19.27, and 19.62 MJ/kg, respectively. Hemicellulose pyrolysis peak only occurred in the hardwood thermodegradation process. Softwood had a higher pyrolysis yield of solid products (16.08-19.30%) than hardwood (11.19-14.67%). The average pyrolysis activation energy (Ea) of hardwood residue increased with the year after harvest, whereas softwood samples decreased. The average combustion Ea of hardwood samples increased first, then decreased, while that of softwood samples decreased continuously. Enthalpy (ΔH), entropy (ΔS), and Gibbs free energy (ΔG) were also investigated. This research will aid in understanding the thermal decomposition properties of naturally decomposed FLR from various years after harvest.

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.

Investigating the co-firing characteristics of bamboo wastes and coal through cone calorimetry and thermogravimetric analysis coupled with Fourier transform infrared spectroscopy.

To evaluate the combustion characteristics of raw or torrefied bamboo wastes and coal blends, the co-firing process determined by cone and pollutant emission was investigated by thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. The results showed that torrefaction improved the fuel properties of bamboo wastes. Torrefied bamboo had a lower volatile fuel ratio, H/C and O/C ratios, pollutant emission and a higher heating value. They further affected the co-firing process of raw or torrefied bamboo and coal. All blends had a lower ignition temperature and a more stable flame than coal. Torrefied bamboo and coal blends had a lower percentage of quality loss, a higher heat release rate (HRR), total heat release (THR) and total smoke release (TSR). With an increase in the proportion of torrefied bamboo in the blends, the HRR, THR, TSR and percentage of quality loss increased. The main pollutant emissions included CO2, CO, SO2 and NOx. All blends of torrefied bamboo and coal had a lower pollutant emission. The optimum blend suggested was 20% torrefied bamboo/80% coal.

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.

Investigating pyrolysis characteristics of moso bamboo through TG-FTIR and Py-GC/MS.

This study was carried out to investigate pyrolysis characteristics of moso bamboo (Phyllostachys pubescens), including outer layer (OB), middle layer (MB) and inner layer (IB) and bamboo leaves (BL), through TG-FTIR and Py-GC/MS. The results showed that 70% of weight loss occurred at rapid pyrolysis stage with temperature of 200-400 °C. With increase in heating rate, pyrolysis process shifted toward higher temperature. IB, OB, MB and BL had a different activation energy at different conversion rates. BL had a higher activation energy than IB, OB and MB. The volatiles of bamboo was complicated with 2-30 of C atoms. IB, OB and MB mainly released benzofuran, hydroxyacetaldehyde and 2-Pentanone. BL released furan, acetic acid and phenol. The main pyrolysis products included H2O, CH4, CO2, CO, carboxylic acids, NO, NO2. Pyrolysis products of IB was the most and that of BL was the lowest. MB had the lowest pyrolysis temperature.

Economic analysis of a hypothetical bamboo-biochar plant in Zhejiang province, China.

Significant quantities of bamboo waste are generated in Zhejiang province, China. Many small businesses in this area convert this waste to biochar for use as a cooking fuel (in residential barbecues). This case study was conducted to evaluate the potential economic benefits of building and operating an industrial-sized plant in this province, yielding 500 tonnes per year. The researchers developed a conceptual design for a hypothetical biochar plant and then calculated net present value (NPV), investment payback period (PBP), internal rate of return (IRR), and sensitivity analysis. Results show that the static investment PBP would be 2.58 years, the IRR would be 38.8%, and the NPV would be US$ 486,700. The IRR would be higher than the forestry industry benchmark (11%), indicating that a production line of bamboo-biochar with the stated yield not only could generate higher profits, but also could achieve a better return on investment. Thus, this study indicates that there are good market prospects for the bamboo-biochar industry in this region. The influence of sales prices on the IRR was more than that of operational costs, indicating that a large-scale plant should be designed to produce a high-quality bamboo-biochar. Supply chain issues such as transportation distances between locations where bamboo wastes are generated and the biochar plant should be considered in advance when siting new bamboo-biochar plants. The results from this research provide guidance to those considering development of bamboo-biochar plants in other parts of China.

Investigating co-combustion characteristics of bamboo and wood.

To investigate co-combustion characteristics of bamboo and wood, moso bamboo and masson pine were torrefied and mixed with different blend ratios. The combustion process was examined by thermogravimetric analyzer (TGA). The results showed the combustion process of samples included volatile emission and oxidation combustion as well as char combustion. The main mass loss of biomass blends occurred at volatile emission and oxidation combustion stage, while that of torrefied biomass occurred at char combustion stage. With the increase of bamboo content, characteristic temperatures decreased. Compared with untreated biomass, torrefied biomass had a higher initial and burnout temperature. With the increase of heating rates, combustion process of samples shifted to higher temperatures. Compared with non-isothermal models, activation energy obtained from isothermal model was lower. The result is helpful to promote development of co-combustion of bamboo and masson pine wastes.

Investigating pyrolysis and combustion characteristics of torrefied bamboo, torrefied wood and their blends.

Bamboo and masson pine was torrefied with 300°C of temperature for 2.0h of residence time using GSL 1600X tube furnace in the argon atmosphere. Torrefied bamboo and masson pine particles were uniform mixed with different weight ratios. Pyrolysis and combustion characteristics were investigated through thermogravimetry (TGA). The results showed that pyrolysis and combustion process of all samples included three steps even though their characteristics were different. Torrefied biomass had a higher pyrolysis and combustion temperature, due to moisture and volatile removal and thermal decomposition of hemicelluloses, cellulose and lignin during torrefaction process. Torrefaction also increased high heating value, ash content and C/H and C/O ratio of biomass. The synergy of torrefied bamboo and torrefied mason pine was not found during pyrolysis and combustion process of blends. The results from this research will be very important and helpful to develop and utilize the wastes of masson pine and bamboo for energy products.