A study of fast pyrolysis of plant biomass assisted by the conversion of volatile products using Fe(Co, Ni)/ZSM-5 catalysts

Feedstock particle size and pyrolysis temperature regulate effects of biochar on soil nitrous oxide and carbon dioxide emissions

Fast pyrolysis of bagasse catalyzed by mixed alkaline-earth metal oxides for the selective production of 4-vinylphenol

Research in Thermochemical Biomass Conversion

Gasification is a promising technology for the conversion of mixed solid waste like refuse-derived fuel (RDF) and municipal solid waste (MSW) into a valuable gas consisting of H2, CO, CH4 and CO2. This work aims to identify the basic challenges of a single-stage batch gasification system related to tar and wax content in the producer gas. RDF was first gasified in a simple semi-batch laboratory-scale gasification reactor. A significant yield of tars and waxes was received in the produced gas. Waxes were analyzed using gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectrometry. These analyses indicated the presence of polyethylene and polypropylene chains. The maximum content of H2 and CO was measured 500 sec after the start of the process. In a second series of experiments, a secondary catalytic stage with an Ni-doped clay catalyst was installed. In the two-stage catalytic process, no waxes were captured in isopropanol and the total tar content decreased by approximately 90 %. A single one-stage semi-batch gasification system is not suitable for RDF gasification; a large fraction of tar and waxes can be generated which can cause fouling in downstream processes. A secondary catalytic stage can significantly reduce the tar content in gas.

In situ catalytic pyrolysis of Jatropha wastes using ZSM-5 from hydrothermal alkaline fusion of fly ash

Influence of fast pyrolysis temperature on biochar labile fraction and short-term carbon loss in a loamy soil

Products distribution of catalytic co-pyrolysis of greenhouse vegetable wastes and coal

Fast biomass pyrolysis is an effective method for bio-oil production and can be performed in fluidised beds, augers, and drop-tube reactors. In this study, the fast pyrolysis of agricultural biomass (oat and corn straw) in a drop-tube reactor was investigated by applying multiparameter analysis involving numerical calculations. The main motivation for this analysis was to determine the operating parameters for fast pyrolysis under which the highest bio-oil production was achieved. In this study, the following operating parameters were involved: pyrolysis temperature (500 – 700 °C), volume flow rate of the carrier gas (3 – 5 l/min), mass flow rate of the feedstock (10 – 30 g/h), and diameter of the particle (250 – 750 µm). The analysis was performed using numerical methods with the Euler-Lagrange multiphase theory in a 2D axisymmetric model. According to the numerical results, selection of a particle size of 500 µm, pyrolysis temperature of 500 °C, and nitrogen flow rate of 3 l/min allows obtaining 51.16% and 52.09% of bio-oil for oat straw and corn straw pyrolysis, respectively. The biomass mass load did not influence the final product yield. The numerical results were successfully confirmed by experimental investigations where experiments supplied 53.2% and 51.3% of bio-oil to oat straw and corn straw, respectively.

Developing an effective cleaner process technology for maize-cob biomass wastes is of utmost importance. This work involved the comparison of products yield (bio-oil, biogas, and biochar) from the fast, slow, and flash pyrolysis of maize-cob biomass wastes using a fixed-bed reactor; evaluation of the individual and combined influences of pyrolysis temperature, biomass particle size, and residence time on the yield of product, and the determination of the optimum pyrolysis conditions/products yield of fast pyrolyzed maize-cob. The fast pyrolysis was performed according to the Box-Behnken Design of Experiment with three variables and three levels of the response surface methodology. The bio-oil fuel properties were determined utilizing ASTM methods and chemically characterized using CHNS elemental analyzer, GC/MS, and FTIR. The performance of the three pyrolysis techniques in terms of their product yield is in the following order: Flash pyrolysis > Fast pyrolysis > Slow pyrolysis (for bio-oil); Slow pyrolysis > Fast pyrolysis > Flash pyrolysis (for biochar and biogas). An optimum bio-oil yield of 43.13% with a high heating value (HHV) of 30.59 MJ/kg, biochar yield of 37.18% with HHV of 20.41 MJ/kg, and biogas yield of 26.05% (HHV = 13.19 MJ/kg) was respectively obtained at an optimum temperature of 567.72, 463.71, and 593.17 °C; biomass particle size of 0.51, 3.83, and 2.58 mm; and residence time of 10.01, 15.28, and 18.92 min. The determined physicochemical characterized properties of the maize-cob-derived-bio-oil revealed that the bio-oil can potentially be valued as a biofuel and as a more promising feedstock for value-added chemical production.

A review of operating parameters affecting bio-oil yield in microwave pyrolysis of lignocellulosic biomass

Fast pyrolysis of macadamia nutshell in an auger reactor: Process optimization using response surface methodology (RSM) and oil characterization

The gases produced by fast pyrolysis method can be used as an alternative to fossil fuels. In order to use gaseous products of flash pyrolysis of carbon-containing biomass wastes effectively there is required its purification from resins. One of the promising ways of such purification is thermocatalytic conversion of tars with the production of volatile hydrocarbons. In current work thermocatalytic treatment of tar-containing gases obtained via biomass waste flash pyrolysis was studied. It was found that the use of zeolite catalysts on the base of iron subgroup metals leads to the decrease of tars content in the gaseous product of biomass fast pyrolysis as well as to the increase in ?1-?4 hydrocarbons, hydrogen and carbon monoxide (II) concentration.

Pyroligneous acid also called wood vinegar is an aqueous liquid produced from pyrolysis of lignocellulose waste and biomass. In general, the pyrolysis types are classified base on heating rate mainly either fast or slow pyrolysis. The characteristic and properties of wood vinegar are primarily influenced by the type of carbonaceous feedstocks as well as the production techniques. Wood vinegar is a complex mixture of polar and non-polar chemicals with various molecular weights and compositions. Its major constituent is water (80–90%). Some physical properties; such as pH, specific gravity, dissolved tar content are, respectively, within the range of 2–4, 1.005–1.016 g/mL, 0.23–0.89% wt, and color, odor and transparency have been reported. In addition, the degree of oBrix was ranged between 1.7 and 6.6. Besides water, the chemical compositions of wood vinegars consisted of acetic acid with the largest component (30.45–70.60 mg.mL−1). A high number of phenol derivatives have been found and those in higher concentrations were 4-propyl-2-methoxyphenol (5–11 mg.mL−1) followed by 2-methylphenol (2–4 mg.mL−1). Wood vinegar has been regarded as a natural product, which claimed to be capable in several fields of application. In agriculture, wood vinegar has been used in vegetable cropping in order to combat disease, pest control, improve growth and fruit quality, seed germination accelerator as well as herbicide. In pharmaceutical and medical applications, it is used for the preparation of detoxification pad while in veterinary and animal production, incorporation of the wood vinegar in feed could promote acidity in large intestine to inhibit growth of enteropathogenic microbes. In food processing, wood vinegar has a characteristic smoke flavor, and also exhibits microbial growth inhibition. In addition, several investigators reported that bio-oil and wood vinegar obtained from fast pyrolysis and carbonization showed a high potential on organic wood preservative. In summary, the wood vinegar prepared from the tropical wood and/or biomass waste is widely beneficial. The chapter attempts to provide essential knowledge relevant to physicochemical characteristics of wood vinegar and its applications.

Comparison of bio-chars formation derived from fast and slow pyrolysis of walnut shell

Selective production of 4-ethyl guaiacol from catalytic fast pyrolysis of softwood biomass using Pd/SBA-15 catalyst