Catalytic Combustion of Biodiesel Wastewater on Red Mud Catalyst.

The resource utilization of red mud (RM) has attracted widespread attention for achieving the waste-to-waste treatment goal. In this work, the RM catalysts were synthesized at different calcination temperatures by a simple method. The calcination temperature had a great effect on catalyst activity in the catalytic combustion of biodiesel wastewater.

Efficient Treatment of Oily Sludge via Fast Microwave-Assisted Pyrolysis, Followed by Thermal Plasma Vitrification.

Oily sludge, as a critical hazardous waste, requires appropriate treatment for resource recovery and harmfulness reduction. Here, fast microwave-assisted pyrolysis (MAP) of oily sludge was conducted for oil removal and fuel production. The results indicated the priority of the fast MAP compared with the MAP under premixing mode, with the oil content in solid residues after pyrolysis reaching below 0.

Pyrolysis of Methyl Ricinoleate: Distribution and Characteristics of Fast and Slow Pyrolysis Products.

A stable temperature site and the speed of heating the feedstocks play a key role in pyrolysis processes. In this study, the product distribution arising from pyrolysis of methyl ricinoleate (MR) at 550 °C with low and high heating rates was first studied by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results show that fast pyrolysis of MR favored the production of undecylenic acid methyl ester (UAME) and heptanal (HEP).

Sulfonated Sargassum horneri carbon as solid acid catalyst to produce biodiesel via esterification.

A solid acid catalyst prepared by sulfonated Sargassum horneri carbon was utilized for the esterification reaction of oleic acid and methanol. The formed amorphous carbon layers during carbonization and the access of sulfonic acid groups during sulfonation can catalyze the esterification reaction for biodiesel preparation efficiently. The catalyst was characterized by various methods to investigate its physical and chemical properties.

Biosorption of hexavalent chromium from aqueous solution by polyethyleneimine-modified ultrasonic-assisted acid hydrochar from Sargassum horneri.

In this study, an efficient route to synthesizing polyethyleneimine-modified ultrasonic-assisted acid hydrochar (PEI-USAH) is developed and reported. Ultrasonic irradiation technique was used as surface modification method to shorten the crosslinking reaction for hydrochar and polyethyleneimine (PEI). The PEI-USAH showed an excellent adsorption capacity for Cr(VI) from aqueous solution.

Degradation of methylene blue by dielectric barrier discharge plasma coupled with activated carbon supported on polyurethane foam.

The degradation of methylene blue (MB) using a novel dielectric barrier discharge plasma reactor coupled with activated carbon supported polyurethane foam (AC/PUF) was investigated in this paper. The plasma reactor combining a glass bead-packed bed and a microporous plate was developed. The AC/PUF provided sufficient contact area between carbon media and pollutants and hence revealed a good MB removal capacity.

Room-temperature production of bio-based aldehydes from vegetable oil-derived epoxide HWO@Al-MCM-41 as recyclable catalyst.

The oxidative cleavage of vegetable oils and their derivatives to produce bio-based aldehydes is a potentially useful process, although the aldehyde products are readily oxidized to carboxylic acids and thus seldom obtained in high yields. The present study developed a room-temperature method for the synthesis of bio-aldehydes the oxidative cleavage of vegetable oil-derived epoxides, using HWO as the catalyst, HO as the oxidant, and -BuOH as the solvent. Reactions were carried out at temperatures ranging from 25 to 35 °C for 3.

Two-step fast microwave-assisted pyrolysis of biomass for bio-oil production using microwave absorbent and HZSM-5 catalyst.

A novel technology of two-step fast microwave-assisted pyrolysis (fMAP) of corn stover for bio-oil production was investigated in the presence of microwave absorbent (SiC) and HZSM-5 catalyst. Effects of fMAP temperature and catalyst-to-biomass ratio on bio-oil yield and chemical components were examined. The results showed that this technology, employing microwave, microwave absorbent and HZSM-5 catalyst, was effective and promising for biomass fast pyrolysis.

Utilization of municipal solid and liquid wastes for bioenergy and bioproducts production.

Municipal wastes, be it solid or liquid, are rising due to the global population growth and rapid urbanization and industrialization. Conventional management practice involving recycling, combustion, and treatment/disposal is deemed unsustainable. Solutions must be sought to not only increase the capacity but also improve the sustainability of waste management.

Fast microwave-assisted catalytic co-pyrolysis of corn stover and scum for bio-oil production with CaO and HZSM-5 as the catalyst.

This study investigated fast microwave-assisted catalytic co-pyrolysis of corn stover and scum for bio-oil production with CaO and HZSM-5 as the catalyst. Effects of reaction temperature, CaO/HZSM-5 ratio, and corn stover/scum ratio on co-pyrolysis product fractional yields and selectivity were investigated. Results showed that co-pyrolysis temperature was selected as 550°C, which provides the maximum bio-oil and aromatic yields.

Glycerin esterification of scum derived free fatty acids for biodiesel production.

Scum is an oily waste stream of the wastewater treatment process that can be used to produce biodiesel. Combining acid hydrolysis and solvent extraction, a free fatty acid and acyl-glycerol rich product was produced. Free fatty acids (FFAs) present were converted to acyl-glycols via a high temperature (238°C) glycerin esterification process known as glycerolysis.

Catalytic fast co-pyrolysis of biomass and food waste to produce aromatics: Analytical Py-GC/MS study.

In this study, catalytic fast co-pyrolysis (co-CFP) of corn stalk and food waste (FW) was carried out to produce aromatics using quantitative pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and ZSM-5 zeolite in the hydrogen form was employed as the catalyst. Co-CFP temperature and a parameter called hydrogen to carbon effective ratio (H/C(eff) ratio) were examined for their effects on the relative content of aromatics. Experimental results showed that co-CFP temperature of 600 °C was optimal for the formation of aromatics and other organic pyrolysis products.

Process development for scum to biodiesel conversion.

A novel process was developed for converting scum, a waste material from wastewater treatment facilities, to biodiesel. Scum is an oily waste that was skimmed from the surface of primary and secondary settling tanks in wastewater treatment plants. Currently scum is treated either by anaerobic digestion or landfilling which raised several environmental issues.

Fast microwave-assisted catalytic pyrolysis of sewage sludge for bio-oil production.

In this study, fast microwave-assisted catalytic pyrolysis of sewage sludge was investigated for bio-oil production, with HZSM-5 as the catalyst. Pyrolysis temperature and catalyst to feed ratio were examined for their effects on bio-oil yield and composition. Experimental results showed that microwave is an effective heating method for sewage sludge pyrolysis.

Fast microwave-assisted pyrolysis of microalgae using microwave absorbent and HZSM-5 catalyst.

Fast microwave-assisted pyrolysis (fMAP) in the presence of a microwave absorbent (SiC) and catalyst (HZSM-5) was tested on a Chlorella sp. strain and on a Nannochloropsis strain. The liquid products were characterized, and the effects of temperature and catalyst:biomass ratio were analyzed.

Fast microwave assisted pyrolysis of biomass using microwave absorbent.

A novel concept of fast microwave assisted pyrolysis (fMAP) in the presence of microwave absorbents was presented and examined. Wood sawdust and corn stover were pyrolyzed by means of microwave heating and silicon carbide (SiC) as microwave absorbent. The bio-oil was characterized, and the effects of temperature, feedstock loading, particle sizes, and vacuum degree were analyzed.

Fast microwave-assisted catalytic gasification of biomass for syngas production and tar removal.

In the present study, a microwave-assisted biomass gasification system was developed for syngas production. Three catalysts including Fe, Co and Ni with Al2O3 support were examined and compared for their effects on syngas production and tar removal. Experimental results showed that microwave is an effective heating method for biomass gasification.

Fine root branch orders contribute differentially to uptake, allocation, and return of potentially toxic metals.

Growing evidence has revealed high heterogeneity of fine root networks in both structure and function, with different root orders corporately maintaining trees' physiological activities. However, little information is available on how fine root heterogeneity of trees responds to environmental stresses. We examined concentrations of seven potentially toxic metals (Cr, Ni, Cu, Zn, As, Cd, and Pb) within fine root networks and their correlations with root morphological and macro-elemental traits in six Chinese subtropical trees.

Syngas production by two-stage method of biomass catalytic pyrolysis and gasification.

A two-stage technology integrated with biomass catalytic pyrolysis and gasification processes was utilized to produce syngas (H(2)+CO). In the presence of different nickel based catalysts, effects of pyrolysis temperature and gasification temperature on gas production were investigated. Experimental results showed that more syngas and char of high quality could be obtained at a temperature of 750°C in the stage of pyrolysis, and in the stage of gasification, pyrolysis char (produced at 750°C) reacted with steam and the maximum yield of syngas was obtained at 850°C.