Biomass Sawdust Research Articles

Characteristics and catalytic properties of Ni/CaAlOx catalyst for hydrogen-enriched syngas production from pyrolysis-steam reforming of biomass sawdust

The production of hydrogen-enriched syngas from the thermo-chemical conversion of biomass was studied using Ni/CaAlOx catalysts prepared by co-precipitation method. The effect of Ca addition with different molar ratios of Ca:Al (1:3, 1:2, 1:1, 2:1, 3:1) on the properties and catalytic behavior in relation to syngas production and the coke formation on the surface of the catalysts were investigated. Catalysts were characterized by BET, XRD, TPR, SEM, and TEM. The SEM and TEM results showed that rod-shaped nano-particles were highly dispersed on the surface of the catalyst. The particle size of NiO was slightly affected with the increase of Ca content in the catalyst. It appeared that the selectivity of CO was increased and the selectivity of CO2 was reduced with the increase of Ca addition to the catalyst. For example, CO2 concentration was reduced from 20 to 12vol.%, when the molar ratio of Ca/Al was increased from 1:3 to 3:1 for the Ni/CaAlOx catalyst; it is suggested that the water gas shift reaction was inhibited and CO2 reforming reactions were promoted in the presence of the catalyst with higher Ca content. The CO/H2 molar ratio could be manipulated by changing the Ca content in the catalyst, while the H2 concentration remained almost constant (around 45vol.%). Thus, using the Ni/CaAlOx catalyst developed in this work could provide a promising route to control the syngas composition, which is an important factor for syngas applications.

Thermodynamic analysis of a novel multigeneration energy system based on heat recovery from a biomass CHP cycle

A multigeneration energy system with one fuel intake (sawdust biomass fuel) and five useful outputs is proposed and energy and exergy analyses are carried out to assess its performance. Instead of using a simple heat exchanger to satisfy district heating needs, applying a deaerator is found to result in 10% more hot water mass flow rate for the same conditions. The energy and exergy efficiencies of the multigeneration system are found to be around 60% and 25%, respectively, while the corresponding energy and exergy efficiencies of a biomass system with only electricity generation are 11% and 13%, respectively. When investigating the effect of adding various product outputs to biomass power generation, steam generation and then domestic hot water production are found to have the greatest enhancing effects on the system efficiencies. Heat recovery from exhaust gases for district heating and wood drying is found to enhance the energy efficiency more than the exergy efficiency. Also, due to the size of the heat recovery system, which is smaller than the biomass CHP cycle, district heating and drying cannot increase the energy and exergy efficiencies of the primary system like steam generation. A parametric study shows that the biomass fuel input rate affects significantly the district heating heat load and the electricity generation rate, in a linear manner. However, increasing the biomass input rate has no effect on the CHP system energy and exergy efficiencies, while increasing the exergy efficiency of the entire system and decreasing its corresponding energy efficiency slightly. Of the several heat recovery options from exhaust gases, electricity generation and wood drying result in the highest exergy efficiency while district heating and drying lead to highest energy efficiency.

Biomass Briquette Characterization for Downdraft Gasification

The present study involves the preparation and characterization of the biomass briquettes made from saw dust and rice husk. Five samples with different compositions were prepared using the old news papers as the binder for both the biomass. Ultimate analysis, proximate analysis, heating value and handling characteristic of all the samples were determined. It was observed that the compositions of the biomass sawdust (BMS)-15 and biomass rice husk (BMR)-15 are suitable for the downdraft gasifier.

Activated carbon produced from paulownia sawdust for high-performance CO2 sorbents

In this paper, activated carbons (ACs) with high specific surface areas were successfully synthesized by simple one-step carbonization-activation from paulownia sawdust biomass, and the effects of the synthetic conditions on their CO2 capture capacity were investigated as well. The results show that, when the mass ratio between activator and biomass is 4, the activation temperature is 700 °C and the activation time is 1 h, as-made AC provides the most micropores for CO2 adsorption. As a consequence, the maximum CO2 uptake of 8.0 mmol/g is obtained at 0 °C and 1 bar.

Adsorption and bio-sorption of nickel ions and reuse for 2-chlorophenol catalytic ozonation oxidation degradation from water

This work explored the preparation of an effective and low-cost catalyst and investigated its catalytic capacity for 2-chlorophenol ozonation oxidation degradation in wastewater by using an ozone oxidation batch reactor. The catalyst was directly prepared by the reuse of fly ash and sawdust after saturated adsorption of nickel ions from wastewater, which was proposed as an efficient and economic approach. The obtained catalyst was characterized by TGA, BET, FTIR, XRD, and SEM, the results showed that fly ash as the basic framework has high specific surface area and the addition of sawdust as the porogen agent could improve the pore structure of the catalyst. The adsorption of nickel ions by fly ash and sawdust from aqueous solution was also investigated in this study. The results obtained from the experiments indicated that adsorption of nickel ions by fly ash and biomass sawdust could be well described by Langmuir isotherm model and pseudo second order kinetic model. The catalytic performance of catalyst was studied in terms of the effect of time, liquid–solid ratio and pH on 2-chlorophenol ozonation degradation. It was found that the catalyst could effectively improve the ozonation reaction rate at pH=7 with a 2:1 liquid–solid ratio. The kinetic study demonstrated that the reaction followed the first order model, and the rate constant increased 267% (0.03–0.1min−1) of 2-chlorophenol ozonation degradation with 5mmol/L concentration at pH=7.0 compared with ozonation alone.

Syngas Production from Biomass Gasification Using Copper Slag Catalysts

Catalytic gasification of sawdust biomass was carried out using a specially designed flow-type double beds micro reactor in a two step process: temperature programmed non-catalytic air gasification of biomass was performed in the first bed at 800°C followed by catalytic decomposition gasification of volatile matters (including tars) in the second bed at five different temperatures. The general observation is that the conversion of sawdust biomass increases as the temperature was raised from 750 to 950°C over non-catalyst, raw copper slag or calcined copper slag. High temperature enhances secondary cracking and reforming of tars and heavy hydrocarbons. At the temperature of 950°C, the energy yield (Ey) was 13.2 MJ gas/kg biomass; The energy conversion efficiency (Eff) was 81.05%; The H2 production was 0.0296 kg/kg biomass; The CO production was 0.6685 kg/kg biomass. Furthermore, improvement in conversion of biomass is observed when copper slag is added in secondary reactor as catalysts. The use of copper slag as catalysts significantly contributes to tar conversion in lighter hydrocarbons.

Characterization of modified sawdust, kinetic and equilibrium study about methylene blue adsorption in batch mode

Methylene blue (MB) biosorption by citric acid modified pine sawdust (Pinus tabulaeformis) was studied from aqueous solutions. Batch experiments were conducted to determine the biosorption properties of the biomass. The Langmuir isotherm equation could fit the equilibrium data. The maximal equilibrium quantity of MB from Langmuir model was 111.46 mg g �1 at 293 K. The Elovich model adequately described the kinetic data in comparison to the pseu- do-first-order model and pseudo-second-order model; the process involving rate-controlling step is very complex in- volving both boundary layer and intra-particle diffusion processes. The effective diffusion parameter Di and Df values were estimated at different initial concentration, and the average values were determined to be 5.76×10 �8 and 2.12× 10 �7 cm 2 s �1 . Thermodynamic parameters showed that the adsorption of methylene blue onto pine sawdust biomass was feasible, spontaneous and endothermic under studied conditions. The physical and chemical properties of the bio- sorbent were determined by SEM, TG-DSC, XRD, and the point of zero charge (pHpzc) and the nature of biomass-dye interactions were evaluated by FTIR analysis, which showed the participation of COOH, OH and NH2 groups in the biosorption process. Biosorbents could be regenerated using 0.01 mol L �1 HCl solution at least three cycles, with up to 90% recovery. Thus, the biomass used in this work proved to be effective for the treatment of MB bearing aqueous solutions.

Converting Biomass and Waste Plastic to Solid Fuel Briquettes

This work examines the production of briquettes for household use from biomass in combination with plastic materials from different sources. Additionally, the combustion characteristics of the briquettes in a common open fireplace were studied. It is clear that the geometry of the briquettes has no influence on the smoke emissions. When the briquettes have a small amount of polyethylene terephthalate (PET), the behavior in the combustion is steadier because of the increase of oxygen supply. The smoke levels are between the 3rd and 4th grades of the smoke number scale. Measuring the carbon monoxide emission, it was observed that the burning of the plastic in the mixture with biomass increases the carbon monoxide emissions from 10% to 30% as compared to carbon monoxide emission from sawdust biomass emissions which was used as a reference.

Selectively Improving the Bio-Oil Quality by Catalytic Fast Pyrolysis of Heavy-Metal-Polluted Biomass: Take Copper (Cu) as an Example

Heavy-metal-polluted biomass derived from phytoremediation or biosorption is widespread and difficult to be disposed of. In this work, simultaneous conversion of the waste woody biomass into bio-oil and recovery of Cu in a fast pyrolysis reactor were investigated. The results show that Cu can effectively catalyze the thermo-decomposition of biomass. Both the yield and high heating value (HHV) of the Cu-polluted fir sawdust biomass (Cu-FSD) derived bio-oil are significantly improved compared with those of the fir sawdust (FSD) derived bio-oil. The results of UV-vis and (1)H NMR spectra of bio-oil indicate pyrolytic lignin is further decomposed into small-molecular aromatic compounds by the catalysis of Cu, which is in agreement with the GC-MS results that the fractions of C7-C10 compounds in the bio-oil significantly increase. Inductively coupled plasma-atomic emission spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy analyses of the migration and transformation of Cu in the fast pyrolysis process show that more than 91% of the total Cu in the Cu-FSD is enriched in the char in the form of zerovalent Cu with a face-centered cubic crystalline phase. This study gives insight into catalytic fast pyrolysis of heavy metals, and demonstrates the technical feasibility of an eco-friendly process for disposal of heavy-metal-polluted biomass.

Dynamic Study on Vacuum Pyrolysis Reaction of Chinese Fir Sawdust Biomass

This thesis does thermal gravimetric analysis（TGA）studies on Chinese fir sawdust biomass by integrated thermal analyzer under vacuum conditions. Through the analysis on lostmass curve at different heating rate of 10, 15, 20 and 30°C/min, we found the process of Chinese fir sawdust vacuum pyrolysis can be mainly divided into three stages: evaporation of free water and combined water desorption, rapid lostmass of pyrolysis and slow decomposition of residues. The lostmass major temperature range is between 250 ~ 450°C, the peak temperature is between 365 ~ 400°C. When the pyrolysis temperature is 500°C, vacuum pyrolysis reaction of Chinese fir sawdust has basically completed. As the heating rate rises, the lostmass curve is moving to the right, the peak temperature is shifting to higher temperature, and the temperature range of thermal decomposition reaction widens significantly. According to experimental datas, we tried to obtain the vacuum pyrolysis dynamic parameters of Chinese fir sawdust, and the results are that the apparent activation energy of vacuum pyrolysis reaction of Chinese fir sawdust biomass is 128.34kJ/mol, with the pre-exponential factor being 6.42×109 and reaction order being 1.08, similar to first order reaction.

Thermal study of decomposition of selected biomass samples

Abstract Fears of climate change and increasing concern over the global warming have prompted a search for new, cleaner methods for electricity power generation. Technologies based on utilising biomass are attracting much attention because biomass is considered to be CO2 neutral. Co-firing of biomass fuels with coal, for example, is presently being considered as a mean for reducing the global CO2 emissions. Biomass is also applied in thermal conversion processes to produce fuels with higher calorific values and adsorbents. In any case, thermal decomposition is essential stage where volatiles and tars are evolved followed by consequent heats of reactions. In this work sawdust biomass samples were selected in order to study their thermal conversion behaviour. Heats of decomposition for each sample were measured during continuous heating at a prescribed heating rate under inert atmospheric conditions. The decomposition generally commenced in all samples at 150C and was completed at 460C in a series of endo ...