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.

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.

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.

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.