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This work investigates the feasibility of extracting biofuels from general wastes, with significant non-recyclable and inorganic components, through the novel thermo-catalytic reforming (TCR®) technology. Two forms of general waste (Up-Sieve Material and Grey Compost) supplied by Risorse Ambiente Palermo (RAP) are studied. Each feedstock is shredded, pelletised and characterised. Analyses of the feedstock materials show the Up-Sieve Material has a higher heating value (HHV) of 17.6 MJ kg−1 with an ash content of 19.60% (by weight), while the Grey Compost has a HHV of 11.5 MJ kg−1 and an ash content of 40.16%. The results of the TCR® experiments on both feedstock materials show they can be thermochemically converted into energy carriers in significant quantities. The characterisation results of the oil and char from the Up-Sieve Material show they have HHVs of 38.2 MJ kg−1 and 13.6 MJ kg−1 respectively, while the oil and char from the Grey compost have HHVs of 37.0 MJ kg−1 and 5.7 MJ kg−1 respectively. In addition, the biogases produced from both feedstock materials are rich in hydrogen (up to 30% by volume each). Hence, apart from the chars and the reaction product water, the products can be further processed into biofuels due to their fuel-grade properties. Therefore, the successful extraction of biofuels from general waste is an important step in renewable energy harnessing, waste management and environmental protection. • Thermo-catalytic reforming involves intermediate pyrolysis and catalytic reforming • General waste converted to biofuels using this technology • Two types of general waste studied: up-sieve material and grey compost • Both produce biochars with high ash contents and biooils with high heating values • Both produce biogases with high hydrogen fractions, compared to gasification and pyrolysis [ABSTRACT FROM AUTHOR]

The effect of three operating parameters (peak temperature, pressure, and pyrolysis atmosphere) during the slow pyrolysis of three biomass sources (corn stover, vine shoots, and two-phase olive mill waste) was extensively analyzed. A 2-level full factorial design of experiments was adopted to assess the effect of the above-mentioned factors on the potential stability of biochar as well as the yields of the main pyrolysis products. To evaluate the effect of the biomass feedstock, the design was divided into three blocks (one per biomass feedstock). Results from the statistical analyses indicated that the properties of biochar related to its potential stability were mainly affected by the peak temperature and, to a lesser extent, the biomass feedstock. A significant increase in the yield of produced gas was observed when pressure was raised. This increase in the total gas yield was in part due to a higher release of CO, CH 4 , and H 2 . Using a pyrolysis atmosphere of CO 2 (instead of N 2 ) did not result in any remarkable change in neither the distribution of the pyrolysis products nor the potential stability of biochar. However, when CO 2 was used as carrier gas, a significant increase in the yield of CO, at the expense of produced CO 2 , was observed. The findings reported herein suggest that processing biomass through pressurized slow pyrolysis under CO 2 atmosphere is interesting to simultaneously obtain two valuable products: a biochar with an appropriate carbon sequestration potential, and a produced gas with an appropriate composition for energy recovery purposes. [ABSTRACT FROM AUTHOR]

New analytical tools that enable analytical laboratories to quantitatively and qualitatively analyze alternative and renewable solid biofuels are needed. Fourier transform infrared (FTIR) spectroscopy was applied in combination with a two-step multivariate modelling procedure. In the first instance, a C&RT (classification and regression trees) model was developed and validated for use in distinguishing different biomass origins and possible sources of contamination. Once the solid fuels were correctly identified, the model was used to predict the concentrations of individual components using partial least squares regression (PLSR) models. The first C&RT model differentiated between the different classes of biofuel origins. Using the absorption intensity in the wavenumber range of 1800–400 cm −1 , the prediction had a recovery of between 92% and 99%. The second C&RT model differentiated between the possible sources of contamination, which could be predicted with a recovery between 76% and 91% based on the FTIR results. Accuracy profiles based on the analysis results of validation samples were then calculated to prove the reliability of the developed regression models. The developed spectroscopic methods rapidly and adequately determined (qualitative analysis) the origin of the biofuels and indicated the possible source of contamination. The effects of two spectral data pre-processing methods (PQN & SNV) were also compared based on the accuracy of the developed models. [ABSTRACT FROM AUTHOR]

Two different pathways for utilizing Miscanthus giganteus biochar were evaluated, namely, for the production of sustainable solid biofuels and as a precursor of high surface area activated carbons. Biochars were produced through a simple thermochemical conversion method via pyrolysis at 400, 500, 600, and 800 °C. The obtained biochars and raw biomass were characterized in detailed by proximate and ultimate analyses. The thermal behaviour and structural and strength properties were evaluated. The chemical composition (cellulose, hemicellulose, and lignin content) of raw Miscanthus giganteus was investigated. The biochars afforded a sufficient higher heating value (HHV) of up to 32 MJ kg−1. Activated carbon was obtained via chemical activation with KOH at 800 °C. The effect of the pyrolysis temperature on the surface properties of the activated carbons was investigated over a wide temperature range. The resulting activated carbons were characterised by N 2 adsorption–desorption at −196 °C and by determining the pH of aqueous extracts. As a potential application, the obtained activated carbon series was used for the adsorptive removal of isoproturon from aqueous media. The adsorption capacity was as high as 384 mg g−1 and depended on the pore size distribution of the activated carbons. The conducted study follows the current trend of search for novel energy sources and water purification. [Display omitted] • Miscanthus giganteus biochar was produced by pyrolysis at 400–800 °C. • Pyrolysis temperature affected properties of biochar and activated carbon. • The higher heating value of biochar pyrolysed at 600 °C was 32.8 MJ kg−1. • Biochar was used as precursor of activated carbon with high specific surface area. • Activated carbon efficiently adsorbed isoproturon from aqueous solution. [ABSTRACT FROM AUTHOR]

Abstract: Pyrolysis of rice straw to create biochar for soil amendment appears to be a promising method to address concerns with regard to improving soil fertility, increasing Carbon storage and decreasing Green House Gas emissions. However, the ability of rice straw-derived biochar to affect these factors might vary depending on its characteristics. It is therefore essential to investigate the properties before large-scale application of rice straw-derived biochar. In this study, rice straw-derived biochars produced at different temperatures (300, 400, 500, 600 & 700 °C) and residence time (1, 2, 3 & 5 h) were characterized using a suite of analytical techniques. Results showed that pyrolysis temperature had a greater influence than residence time on the chemical composition and structure of rice straw-derived biochar produced at low heating rate. The rice straw-derived biochars especially produced at 400 °C had high alkalinity and cation exchange capacity, and high levels of available phosphorus and extractable cations. These properties indicate potential application of rice straw-derived biochar as a fertilizer and soil amendment. Fourier transform infrared spectra showed that higher pyrolysis temperatures promote condensation reactions. Rice straw-derived biochars contained turbostratic crystallites at 400 °C, and displayed a high level of aromatization at 500 °C. Increasing charring temperature will increase the aromaticity of biochar, and might include its recalcitrance. [Copyright &y& Elsevier]

Abstract: Pyrolytic cook stoves in smallholder farms may require different biomass supply than traditional bioenergy approaches. Therefore, we carried out an on-farm assessment of the energy consumption for food preparation, the biomass availability relevant to conventional and pyrolytic cook stoves, and the potential biochar generation in rural households of western Kenya. Biomass availability for pyrolysis varied widely from 0.7 to 12.4 Mg ha−1 y−1 with an average of 4.3 Mg ha−1 y−1, across all 50 studied farms. Farms with high soil fertility that were recently converted to agriculture from forest had the highest variability (CV = 83%), which was a result of the wide range of farm sizes and feedstock types in the farms. Biomass variability was two times lower for farms with low than high soil fertility (CV = 37%). The reduction in variability is a direct consequence of the soil quality, coupled with farm size and feedstock type. The total wood energy available in the farms (5.3 GJ capita−1 y−1) was not sufficient to meet the current cooking energy needs using conventional combustion stoves, but may be sufficient for improved combustion stoves depending on their energy efficiency. However, the biomass that is usable in pyrolytic cook stoves including crop residues, shrub and tree litter can provide 17.2 GJ capita−1 y−1 of energy for cooking, which is well above the current average cooking energy consumption of 10.5 GJ capita−1 y−1. The introduction of a first-generation pyrolytic cook stove reduced wood energy consumption by 27% while producing an average of 0.46 Mg ha−1 y−1 of biochar. [Copyright &y& Elsevier]

Abstract: This paper examines some of the economic tradeoffs in the joint production of biochar and bio-oil from cellulosic biomass. The pyrolysis process can be performed at different final temperatures, and with different heating rates. While most carbonization technologies operating at low heating rates (large biomass particles) result in higher yields of charcoal, fast pyrolysis (which processes small biomass particles) is the preferred technology to produce bio-oils. Varying operational and design parameters can change the relative quantity and quality of biochar and bio-oil produced for a given feedstock. These changes in quantity and quality of both products affect the potential revenue from their production and sale. We estimate quadratic production functions for biochar and bio-oil. The results are then used to calculate a product transformation curve that characterizes the yields of bio-oil and biochar that can be produced for a given amount of feedstock, movement along the curve corresponds to changes in temperatures, and it can be used to infer optimal pyrolysis temperature settings for a given ratio of biochar and bio-oil prices. [Copyright &y& Elsevier]

The depletion of fossil fuels as well as the greenhouse gas emissions from fossil fuel use have led to growing interest in biofuel production from biomass. A new technology, thermo-catalytic reforming (TCR), is one of the contributing interests. TCR technology integrates intermediate pyrolysis with a post-reforming stage to convert biomass into a high-quality bio-oil, biochar, and syngas. In this study, experiments were carried out using three Alberta-based biomass feedstocks – hardwood pellets, softwood pellets, and chips – in a 2 kg h−1 laboratory-scale TCR plant. The results show that the composition of the biomass has little effect on product yield and quality. The TCR gases had a higher heating value of 12.5–12.8 MJ kg−1 and a hydrogen content of 13–15 vol %. The produced TCR bio-oil had low water content (~5 wt %) and a heating value of 32–34 MJ kg−1. The high quality of the bio-oil is reflected in the low O/C ratio of 0.15 and TAN of 6–15 mg KOH g−1. The TCR biochar from all three feedstocks had a high heating value and a high carbon content, as well as low O/C and H/C ratios. A parametric study was conducted for the softwood pellets to observe the effect of reformer temperature (500–700 °C) and reactor temperature (400–550 °C). It was observed that at a reformer temperature of 700 °C, the gas yield increases at the expense of a reduction in bio-oil and biochar. The optimum reactor temperature for the TCR of softwood pellets was found to be 500 °C, in terms of both bio-oil quality and yield. • Thermo-catalytic reforming (TCR) technology incorporates intermediate pyrolysis with high temperature reforming. • The TCR bio-oil had low TAN (6–15 mg KOH/g), and high HHV (32–34 MJ kg−1). • The TCR gases had a hydrogen content of 13–15 vol % and HHV of 12–14 MJ kg−1. • Higher reforming temperature led to increase in gases at the expense of bio-oil. [ABSTRACT FROM AUTHOR]

In the current scenario of climate change, the search for alternative energy sources is very important to reduce the use of fossil fuels. Undesired biomass (weed) from agricultural fields can be used to produce biofuels through nano catalysts enhanced gasification and process. Lignocellulosic part of weedy plants represents a potential alternative feedstock for economic production of bioethanol. Large numbers of weedy plant species are growing all over the world. However, high energy requirements and poor-quality biofuel products are the major constraints for utilization of this technology. Nanomaterials could be used as a catalyst to enhance the energy use efficiency and product quality. So, present study was conducted to produce bio-gas, bio-diesel and bio-char from mixed weed biomass of weeds like Carthamous oxyacantha, Asphodelus tenuifolius and Chenopodium album through gasification process using nano-materials as catalysts. Nickel and cobalt nano-particles were used as nano-catalysts to expedite the bio-chemical reactions for the generation of these products at lower temperatures i.e. (400 C°) in a muffle furnace. Further, these products were characterized using GC-MS analysis. It was observed that biodiesel contained 65.47% esters, which indicates its better quality than the normally produced biodiesel having 15–20% esters contents. Similarly, GC-MS analysis of biogas produced from mixed weed biomass showed 3.76% Methane, 8.32% Propane, 50.16% Ethene, 3.12% Propyne and 34.64% Methanol. The present results clearly exhibited the improved product quality and better energy use efficiency in gasification of weed biomass for bioenergy production. Image 1 • Strategic recycling of weed biomass into useful biofuels and biochar using nano-catalysts. • Nano-catalysts can accomplish gasification of weed biomass at lower temperatures. • Biodiesel of weed biomass is of better quality and environment friendly. • The biochar produced from weed biomass can be used as soil amendment. • Biogas produced from weed biomass is a good source of hydrocarbon fuel gases. [ABSTRACT FROM AUTHOR]