• Energy Research

Catalytic fast pyrolysis of biomass offers an opportunity for upgrading of pyrolysis bio-oils using mono- and bimetallic-supported catalysts, which have been demonstrated to improve the bio-oil qua...

Blast Furnace Slag (BFS) is a by-product of the iron ore processing industry with potential to be used in different industrial applications. In this research, BFS was used to examine its ability for dye removal from wastewater. The efficiency of two types of BFS samples for removal of cationic methylene blue (MB) and acidic methyl orange (MO) dyes was investigated and results found that the optimal conditions for treatment of wastewater were 80 g/L of adsorbent dose and 1 h of treatment time for both dyes. BFS was found to be more effective for removal of the acidic MO dye than the cationic MB dye. Under shorter residence times, the results showed reverse trends with BFS samples removing higher concentrations of MB than MO. The BFS chemistry had additional impacts on the efficiency of dye removal. Higher basicity of BFS had lower dye removal ability for adsorption of acidic dye when applied at smaller concentrations, while for cationic dye when applied at higher concentrations. The results showed that BFS has potential role for pre-treatment of industrial wastewater contaminated with dyes and may contribute to reduced use of more expensive adsorbents, such as activated carbons.

Abstract Increasing global energy demand and concerns of carbon emissions have driven the utilisation of renewable sources such as biomass. Biomass pyrolysis in the presence of catalyst, i.e., biomass catalytic pyrolysis (CP), is one of the most efficient routes for generating renewable hydrocarbon fuels or commodity chemicals. Most previous review papers on biomass CP focused on the summary of catalyst classification, properties and performance based on product yields and oil quality. Information on biomass CP process especially effects of different reaction atmospheres has not been reviewed or discussed in sufficient detail. This paper aims to provide a review and insights of the essential process factors and system structure of the lignocellulosic biomass CP with emphasis on process performance indexes such as bio-oil’s effective hydrogen to carbon ratio, deoxygenation degree, carbon efficiency and energy efficiency. The paper sections are organised in order of biomass CP catalysts, biomasss CP assessment, modification of essential process factors (e.g., biomass pre-treatment, co-feeding with other materials, atmosphere and temperature) and variations in the system structure (e.g., heat source alternatives, staged catalysis and process integration). Variations in process factors and system structure can possibly tailor the products and improve the economic attraction. A number of questions about biomass CP are still unclear. The current status, challenges and future research directions of biomass CP are also discussed in the paper. The comprehensive review and insights of the biomass CP process in this work will provide reference for the research and industrialisation of biomass CP for renewable fuel production.

The products of a commercial one-stage anaerobic digestion and a laboratory-scale pyrolysis of raw food waste (RFW) and digestated food waste (DFW) were characterized to evaluate the treatment effect, product yield, and physicochemical properties. The pyrolysis of the RFW and DFW resulted in generation of 7.4 and 5.3 wt % of gas and 60.3 and 52.2 wt % of bio-oil, while biochar yields decreased with an increase in the pyrolysis temperature. Differential thermogravimetric tests of RFW and DFW show 20% in both solid residues produced at a temperature of 550 °C, indicating a relatively low impact of the digestion process on the RFW. The mineral matter content was found to be lower for RFW compared to DFW. The variation in the content of fixed carbon and volatile matter reflected the effect of anaerobic degradation of the food waste. The bio-oils showed a low concentration of phenols, esters, and derivatives of hydrocarbons for DFW compared to RFW. The specific heat capacities were determined for RFW and DFW, ...

Abstract Pyrolysis is one of the significant technologies that can utilize lignocellulose biomass to produce different bioenergy fuels, such as bio-oil, pyrolytic gases and bio-char. The application of pyrolysis has been extensively studied to produce bio-oil, which is foreseen as the potential transportation fuel in the near future. However, the presence of oxygenated compounds, such as phenols and alcohols in bio-oil makes it highly acidic and unstable for a suitable transportation fuel. These oxygenated compounds can be converted to refinable hydrocarbons by using different catalysts. Therefore, this study aimed to prepare a catalyst that is Cu10%-zeolite and investigated its deoxygenation activity for bio-oil produced from pyrolysis of pine wood sawdust. The catalyst was prepared by a wet-impregnation method. Subsequently, the catalyst was characterized by X-ray diffraction and transmission electron microscopy. Furthermore, the catalyst was applied for in-situ (catalyst: biomass=5) and ex-situ catalytic pyrolysis (catalyst: biomass=3) and the results were compared with those from sole zeolite support. The pyrolysis process was carried out at a heating rate of 100 °C/min to a final temperature of 700 °C and the composition of bio-oil was examined by gas chromatography-mass spectroscopy. The results revealed that Cu-zeolite showed significant deoxygenation activity for bio-oil as compared to zeolite or without any catalyst. Evidently, Cu-zeolite after in-situ pyrolysis produced bio-oil with 20.9% aromatic hydrocarbons and 7.5% aliphatic hydrocarbons, which were approximately 80% and several times higher than with only zeolite, respectively. Meanwhile the concentration of alcohols was reduced from 47.5% to 5%. On the other hand, bio-oil produced from ex-situ catalytic pyrolysis was enriched with 41.6% aromatic hydrocarbons while only 1% alcohols were present in bio-oil. This promising deoxygenation activity can be ascribed to Cu-zeolite’s catalytic activity that converted phenol and alcohols to refinable hydrocarbons via various reactions, such as dehydration, decarboxylation and decarbonylation.

Application of solar energy for biomass pyrolysis is a promising technology for converting biomass to energy, fuels, and other chemical substances with neutral CO2 emissions. In comparison to the conventional pyrolysis process, the biomass conversion efficiency can be greatly improved if the pyrolysis heat is supplied from a concentrated solar system, which can be achieved at reasonably moderate solar radiations. This paper discusses fast pyrolysis of chicken litter at different temperatures (560, 760, 860, and 900 °C) supplied from a solar dish of maximum flux density of 69 087 W/m2 under 1000 W/m2 of net (all wave) solar radiation. Yields of the different product fractions (gas, liquid bio-oil, and solid biochar) were assessed using different techniques. The gas yield increased with the temperature from 45.3 wt % at 560 °C to its maximum value of 58.6 wt % at 860 °C. Gas chromatograph results showed CO2, CO, and CH4 as the dominant gases, with contents of 30.2, 22.4, and 2.4 wt %, respectively. When the...

The metal(loid)-enriched Avicennia marina biomass obtained from phytoremediation was impregnated with two ferric salts (FeCl3 and Fe(NO3)3) prior to pyrolysis at 300-700 °C, aiming to study the influence on pyrolytic product properties and heavy metal(loid) deportment. Results showed that the impregnated ferric salts increased the fixed carbon content of biochars, hydrocarbon fractions in bio-oils, and the evolution of CO and H2 in gases. Cd in biomass could be effectively removed from the biomass by FeCl3 impregnation. During pyrolysis, the ferric salts enhanced the elemental recovery of As, Cr, Ni and Pb in the biochars and decreased their distribution in gases. Notably, the ferric salt pre-treatment inhibited the mobility and bio-availability of most elements in the biochars. This study indicated that ferric salt impregnation catalysed the pyrolysis process of metal(loid) contaminated biomass, enabled the operation temperature at 500-700 °C with minimal environmental risks, providing a safe and value-added way to the phytoremediation-pyrolysis scheme.

NiCu/γ-Al2O3 catalysts with different Cu loadings were prepared using an ultrasonic-assisted impregnation method. The effect of the Cu content in the catalyst on the mass loss behavior of coffee grounds and the evolution of gaseous products during pyrolysis were investigated. The effect of two different heating rates of 10 and 60 °C/min on the catalytic pyrolysis was also studied. The mass loss and evolution of the main pyrolytic volatiles were analyzed with a thermogravimetric (TG) analyzer connected to a Fourier transform infrared (FTIR) spectrometer. The bio-oils collected from non-catalytic and catalytic pyrolyses of coffee grounds were subjected to gas chromatography–mass spectrometry (GC–MS) analysis. Gram–Schmidt curves obtained by TG–FTIR indicated that the addition of NiCu/γ-Al2O3 catalysts and the increase in the Cu content in the catalysts increased the concentrations of CO2 and CO in the produced gas evolved during coffee grounds pyrolysis. In comparison to the slow heating rate of 10 °C/min, ...

AbstractVegetation has successfully been used for cleaning up metal(loid) polluted water bodies and lands through extracting and accumulating of contaminants in their aboveground biomass (phytoextraction). As this remediation technique is approaching extensive demonstration scale application and potential commercialisation, research efforts have been investigating new ways to achieve valorization of its by‐products, the heavy‐metal‐enriched biomass (HMEB). Biomass pyrolysis as an energy conversion technique represents a key step to numerous valorization options of HMEB. During the pyrolysis of HMEB, understanding the thermal decomposition pathways, and the migration and transformation of metal(loid)s are critical for the production of clean, safe and value‐added end‐products. This work performs a state‐of‐the‐art review of the studies conducted on phytoextraction and biomass pyrolysis of HMEB with emphasis on the properties of pyrolysis products as well as the behavior of heavy metal(loid)s during pyrolysis in relation to HMEB feedstock properties and the variables of the process.