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Plastic film mulching (FM) became a general practice to enhance crop productivity and its net primary production (NPP), but it can increase greenhouse gas (GHG) emissions. The proper addition of organic amendments might effectively decrease the impact of FM on global warming. To evaluate the feasibility of biomass addition on decreasing this negative influence, cover crop biomass as a green manure was incorporated with different recycling levels (0-100% of aboveground biomass) under FM and no-mulching. The net global warming potential (GWP) which integrated with soil C stock change and GHG (N2O and CH4) fluxes with CO2-equivalent was evaluated during maize cultivation. Under the same biomass incorporation, FM significantly enhanced the grain productivity and NPP of maize by 22-61 and 18-58% over no-mulching, respectively. In contrast, FM also highly increased the respired C loss, which was 11-95% higher than NPP increase, over no-mulching. Irrespective with biomass recycling ratio and mulching system, negative NECB which indicates the decrease of soil C stock was observed, mainly due to big harvest removal. FM decreased more soil C stock by 57-158% over no-mulching, but its C stock was clearly increased with increasing biomass addition. FM significantly increased total N2O and CH4 fluxes by 4-61 and 140-600% over no-mulching, respectively. Soil C stock changes mainly decided net GWP scale, but N2O and CH4 fluxes negligibly influenced. As a result, FM highly increased net GWP over no-mulching, while this net GWP was clearly decreased with increasing biomass application. However, cover cropping, and its biomass recycling was not enough to compensate the negative impact of FM on global warming. Therefore, more biomass incorporation might be essential to compensate this negative effect of FM.

In this study, pyrolysis of residual biomass from the agro-alimentary industry of Argentina was investigated. The studied biomasses were rice husk, peanut shell and wheat straw. The effect of pyrolysis temperature over solid (bio-char), liquid (bio-oil) and gas (bio-gas) fractions weight yields were evaluated for each biomass, in the range of 350-650 °C. The maximum yield of bio-oil was obtained at 550 °C for rice husk (45 wt%) and wheat straw (58 wt%), and at 500 °C for peanut shells (51 wt%). At those temperatures, the data recorded the smallest spread around the mean. Different characterization techniques of raw biomass were reported, namely, thermal behavior; proximate and ultimate analysis; content of Ca, Al, K, Si and Fe; and hemicellulose, cellulose and lignin composition. Bio-oils characterization included water content and chemical compounds identification. Furthermore, bio-char HHV and BET surface area were measured. Rice husk bio-oil showed 21% selectivity towards furans of which 75% corresponded to furfural and 5-HMF. Peanut shell bio-char presented the highest Higher Heating Value (7250 kcal/kg) and BET surface area (215 m2/g). In addition, co-pyrolysis reactions and the synergistic effects over obtained products completed this study. Co-pyrolysis bio-oils yields varied between 41 and 46 wt%, for all the mixtures. Bio-oil water content decreased up to 15% for rice husk mixed with peanut shell or wheat straw. Moreover, 5-HMF was detected in all bio-oils, and furfural selectivity was higher than 5% in the three mixtures investigated.

Bioenergy is considered a sustainable substitute to fossil-fuel resources and the development of a prudent combination of renewable and innovative conversion technologies are essential for the valorization and effective conversion of biowaste to value-added commodities. Here, a negative pressure-induced carbonization process was proposed for the valorization of lignin-enriched biowaste precursor to bio-oil and environmental materials (biochar) at various temperatures. The high heating values (HHV) of the as-prepared biochars from the lignin enriched precursor under negative pressure (low-medium vacuum) were within 25.9-31.5 MJ/kg, which matched satisfactorily to the commercial charcoal. Whereas, the bio-oils produced from the lignin enriched precursor under vacuum conditions was a blend of complex aromatic and straight-chain hydro-carbons, including aldehyde, ketone, phenol, and furans, exhibiting ability as potential heating-oil with HHV within 21.2-28.2 MJ/kg. Moreover, the biochars produced under vacuum environments at higher temperature showed greater stability (22.5-35.9%) than those produced under N2 atmosphere.

The potential of deoiled Azolla pinnata biomass (DAB) as electrode and substrate was evaluated for microbial fuel cell (MFC) operation. The anode electrode was fabricated using biochar obtained by subjecting DAB to pyrolysis at 600 °C, while the reducing sugars after hydrolysis of DAB by acid pretreatment was used as substrate. The post pyrolyzed biochar (P-DAB) was characterized for structural and elemental functionalities using SEM, XRD and Raman spectroscopy, whereas the reducing sugar obtained from hydrolyzed DAB (H-DAB) was analyzed for its composition. Experimental results indicated that at a given 3 g COD/L resulted in a voltage of 382 mV with 65.6% of COD reduction in closed circuit (CC) mode of operation. Cyclic voltammetric analysis depicted maximum oxidative and reductive peak currents of 3.42 mA and -4.0 mA. Noticeable peaks were also identified in CC (-0.2 V to +0.2 V and -0.19 V to -0.3 V) and OC (+0.2 V to +0.4 V and -0.1 V to -0.3 V) corresponding to complex IV cytochrome c couples (cytochrome Cox (Cyt Cox)/cytochrome Crd (Cyt Crd)), signifying the participation of electron carriers during electron transfer. The microbiome diversity showed dominance of Proteobacteria, a phylum known for exo-electrogenic bacterial species. The DAB-derived products account to environmental sustainability and support circular bioeconomy in a biorefinery mode.

The increasing demand for lignocellulosic biomass for the production of biofuels provides value to vegetative plant tissue and leads to a paradigm shift for optimizing plant architecture in bioenergy crops. Plant height (PHT) is among the most important biomass yield components and is the focus of this review, with emphasis on the energy grasses maize (Zea mays) and sorghum (Sorghum bicolor). We discuss the scientific advances in the identification of PHT quantitative trait loci (QTLs) and the understanding of pathways and genes controlling PHT, especially gibberellins and brassinosteroids. We consider pleiotropic effects of QTLs or genes affecting PHT on other agronomically important traits and, finally, we discuss strategies for applying this knowledge to the improvement of dual-purpose or dedicated bioenergy crops.

A giant sensitive plant (Mimosa pigra L.) or Mimosa is a fast growing woody weed that poses a major environmental problem in agricultural and wet land areas. It may have potential to be used as a renewable energy source. In this work, thermal behaviour of dried Mimosa was investigated under inert atmosphere in a thermogravimetric analyzer at the heating rates of 10, 30, and 50 degrees C/min from room temperature to 1000 degrees C. Pyrolysis kinetic parameters in terms of apparent activation energy and pre-exponential factor were determined. Two stages of major mass loss occurred during the thermal decomposition process, corresponding to degradation of cellulose and hemicellulose between 200-375 degrees C and decomposition of lignin around 375-700 degrees C. The weed mainly devolatilized around 200-400 degrees C, with total volatile yield of about 60%. The char in final residue was about 20%. Mass loss and mass loss rates were strongly affected by heating rate. It was found that an increase in heating rate resulted in a shift of thermograms to higher temperatures. As the heating rates increased, average devolatilization rates were observed to increase while the activation energy decreased.

Abstract Sugarcane is a major crop cultivated globally and the residue left over after the crop harvest and extraction of juice is a good biomass source that can be used for the production of several useful chemicals. The sugarcane bagasse is an excellent substrate for the production of various biochemicals and enzymes through fermentation. Now major interest is focused on the utilization of these residue for biofuel production. The sugarcane crop residue is rich in cellulose and hemicellulose, hence it can be used for the production of bioethanol and other liquid transportation fuels. The present review gives a detailed account of the availability of sugarcane residue and various commercially important products that can be produced from this residue. It also provides recent developments in R&D on the bioconversion of sugarcane crop residue for value added products.

Volatile organic compounds (VOCs) can lead to environmental pollution and threaten human health due to their toxic and carcinogenic nature. The emission of VOCs increases dramatically with the accelerated industrialization and economic growth. Adsorption is identified as one of the most promising recovery technologies owing to its cost-effectiveness, flexible operation, and low energy consumption. In particular, adsorption-based technologies have a high potential to recycle both adsorbents and adsorbates, typically to capture valuable aromatic VOCs from industrial exhaust. Porous materials such as carbon-based materials, zeolite-based materials, and organic polymers and their composites have been extensively developed for VOCs adsorption focusing in adsorption capacity, hydrophobic property, thermal stability and regenerability. Among them, porous carbons as VOCs adsorbents have attracted increasingly attention, because they can be regulated by tuning the pore structure for VOCs accessibility during the adsorption process. Moreover, porous carbons can adsorb target VOCs by controlling the pore structure and surface functional groups. Significantly, the pore size distribution of porous carbons mostly controls the VOCs sorption process. Micropores provide the main adsorption sites, while mesopores enhance the diffusion of VOCs. In this review, the adsorption mechanism of VOCs onto porous carbons was generally concluded. Porous carbons can be designed as a specific structure for adsorption of aromatic VOCs by controlling the pore structure, hydrophobic sites, π-electronic structure, and surface functional groups. Since there are limited review literatures on porous carbons derived from renewable resources for VOCs adsorption, this paper will provide an overview on the synthesis of porous carbons from biomass and other organic wastes for VOCs adsorption or integrated oxidation processes (e.g., photocatalysis, non-thermal plasma catalysis, chemical catalysis) under ambient conditions with the objective of guiding ...