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1.
Front Physiol ; 12: 768522, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34925064

RESUMO

Slow pyrolysis is a process for the thermochemical conversion of biomasses into bio-oils that may contain a rich chemical composition with biotechnological potential. Bio-oil produced from crambe fruits was investigated as to their acaricidal effect. Slow pyrolysis of crambe fruits was performed in a batch reactor at 400°C and chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). The bio-oil collected was used in bioassays with larvae and engorged females of the cattle tick Rhipicephalus microplus. Biological assays were performed using the larval packet test (LPT) and adult immersion test. The GC-MS of crambe fruit bio-oil revealed mainly hydrocarbons such as alkanes and alkenes, phenols, and aldehydes. The bio-oil in the LPT exhibited an LC90 of 14.4%. In addition, crambe bio-oil caused female mortality of 91.1% at a concentration of 15% and a high egg-laying inhibition. After ovary dissection of treated females, a significant reduction in gonadosomatic index was observed, indicating that bio-oil interfered in tick oogenesis. Considering these results, it may be concluded that slow pyrolysis of crambe fruit affords a sustainable and eco-friendly product for the control of cattle tick R. microplus.

2.
Rev. colomb. quím. (Bogotá) ; 49(2): 23-29, mayo-ago. 2020. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1115659

RESUMO

Abstract The agricultural economic policy of Cuba pretends to triplicate the crops of coffee and cocoa by 2021, a measure which will bring about both an increase in biomass waste and the need to find a proper method for its disposal. Slow pyrolysis process can transform lignocellulosic waste into added value products as biochar, bio-oil and gas. The present research evaluated the yield and the theoretical potential energy of co-products (bio-char, bio-oil, and gas) from coffee and cocoa seed husks using the pyrolysis process as a source of friendly and renewable energy. Results indicated that coffee husks are more suitable for the production of gas with a yield of 40.4%, while cocoa seed husks are better suited for the production of bio-oil, with a yield of 37.4%. For 2021 the theoretical energy potential estimated is 8291 MWh, equivalent to 716000 kg for the coffee husks, and 1384 MWh equivalent to 121000 kg for the cocoa seed husks. The bio-char characterization indicated high contents of carbon, calcium, potassium, nitrogen, and oxygen, which makes it a suitable candidate for being used as a soil amendment. The conversion of coffee and cocoa seed husks into added value products through slow pyrolysis process will help clean the environment, decrease the greenhouse effect, and will aid farmers in the rural populations by providing them with an additional source of income.


Resumen La política económica agrícola de Cuba pretende triplicar los cultivos de café y cacao para el año 2021, lo cual implica un aumento de residuos de biomasa y la necesidad de encontrar un uso adecuado para su eliminación. El proceso de pirólisis lenta permite convertir los residuos lignocelulósicos en productos de valor agregado como bio-carbón, bio-combustible y gas. En este trabajo se evaluó el rendimiento y el potencial energético teórico de estos co-productos como fuente de energía renovable. Las cascaras de café son más adecuadas para la producción de gas con un rendimiento del 40,4%, mientras que las de semilla de cacao para bio-combustible, con un rendimiento del 37,4%. Para el 2021, el potencial energético teórico estimado es de 8291 MWh, equivalente a 716000 kg para las cascaras de café; y de 1384 MWh equivalente a 121000 kg para las semillas de cacao. La caracterización del bio-carbón indicó altos contenidos de carbono, calcio, potasio, nitrógeno y oxígeno, lo que los convierte en un candidato adecuado para su uso como fertilizante del suelo. La conversión de estas biomasas en productos de valor agregado a través del proceso de pirólisis lenta contribuirá a mantener un ambiente limpio, reducir el efecto invernadero y ayudará a generar un ingreso adicional a los agricultores de las poblaciones rurales.


Resumo A política económica agrícola de Cuba visa triplicar as safras de café e cacau até 2021, o que significa um aumento nos resíduos de biomassa e a necessidade de encontrar usos adequados para sua eliminação. O processo de pirólise lenta permite converter lixo lignocelulósico em produtos de alto valor agregado, como bio-carvão, biocombustível e gás. No presente trabalho, avaliou-se o desempenho e o potencial energético teórico de co-produtos (bio-carvão, biocombustível e gás) do processo de pirólise lenta de casca de café e de cascas de sementes de cacau como fonte de energia renovável. As cascas de café são mais adequadas para a produção de gás com rendimento de 40,4%, enquanto que as cascas de sementes de cacau para biocombustível, com rendimento de 37,4%. Até 2021, o potencial energético teórico calculado é de 8291 MWh equivalente a 716000 kg para cascas de café e 1384 MWh equivalente a 121000 kg para cascas de sementes de cacau. A caracterização de bio-carvão indicou altos teores de carbono, cálcio, potássio, nitrogénio e compostos oxigenados, o que os torna candidatos ideais para uso como fertilizantes do solo. A conversão da casca do café e a casca das sementes de cacau em produtos de maior valor agregado, através do processo de pirólise lenta, ajudará a manter o um ambiente limpo, reduzirá o efeito estufa e contribuirá com renda adicional para os agricultores das populações rurais.

3.
Waste Manag ; 103: 177-186, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887690

RESUMO

Many specialized technologies are available to convert waste biomass into secondary products that have a higher value and are more convenient to process than the original feedstock. This study evaluated the potential of waste pequi seeds to produce high-quality charcoal for subsequent gasification into low-tar producer gas for heat engine applications. We focused on the characterization of pequi seeds, the derived charcoal, and the collected bio-oil from slow pyrolysis conversion of the feedstock. Thermodynamic equilibrium calculations were conducted to assess gasification performance of the parent biomass and its charcoal. We also investigated the thermal degradation kinetics of pequi seeds through non-isothermal thermogravimetric analysis. Finally, a two-step energy-extraction analysis was performed for the carbonization of the parent biomass and further utilization of its charcoal in an integrated gasification gas-engine cycle. Slow pyrolysis of pequi seeds (2 °C min-1, 430 °C) produced up to 40% of high-grade charcoal with 60% fixed carbon, 43% of bio-oil, and 16% of light gases. The overall energy extraction efficiency was estimated as 61%, based on the higher heating value of wet pequi seeds. The investigation confirmed that waste pequi seeds could be considered a promising renewable energy source for combined heat and power generation for the Brazilian agro-food industry.


Assuntos
Carvão Vegetal , Temperatura Alta , Biomassa , Brasil , Gases
4.
Environ Sci Pollut Res Int ; 26(32): 33294-33303, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31520379

RESUMO

This study evaluates the filtration potential of the biomass obtained from Andropogon grass (Andropogon gayanus Kunth cv. Planaltina) that was converted to biochar by pyrolysis. The biochar is used in filtration systems for the post-treatment of paint industry effluents. The biomass is characterized by elemental analysis (CHSN-O), determination of specific compounds (cellulose/hemicellulose/lignin), FTIR, and SEM. The produced biochar is characterized by SEM, TGA, and surface area analysis. The efficiency of the filters is evaluated by the following parameters: color, turbidity, removal of total solids (suspended and sedimentable), chemical oxygen demand (COD), and metals (Al, Cu, Zn, Co, Cd, and Cr(VI)). Over 99% removal of aluminum, cadmium, and hexavalent chromium is achieved. Moreover, almost 100% of COD and solids are removed, whereas turbidity and color are reduced by over 90%.


Assuntos
Carvão Vegetal/química , Pintura , Eliminação de Resíduos Líquidos/métodos , Adsorção , Andropogon , Biomassa , Cádmio/análise , Cromo , Filtração , Lignina , Poaceae
5.
J Appl Microbiol ; 124(1): 85-96, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29095556

RESUMO

AIMS: This work aimed to evaluate the antibacterial and antifungal activities of two types of pyroligneous acid (PA) obtained from slow pyrolysis of wood of Mimosa tenuiflora and of a hybrid of Eucalyptus urophylla × Eucalyptus grandis. METHODS AND RESULTS: Wood wedges were carbonized on a heating rate of 1·25°C min-1 until 450°C. Pyrolysis smoke was trapped and condensed to yield liquid products. Crude pyrolysis liquids were bidistilled under 5 mmHg vacuum yielding purified PA. Multi-antibiotic-resistant strains of Escherichia coli, Pseudomonas aeruginosa (ATCC 27853) and Staphylococcus aureus (ATCC 25923) had their sensitivity to PA evaluated using agar diffusion test. Two yeasts were evaluated as well, Candida albicans (ATCC 10231) and Cryptococcus neoformans. GC-MS analysis of both PAs was carried out to obtain their chemical composition. Regression analysis was performed, and models were adjusted, with diameter of inhibition halos and PA concentration (100, 50 and 20%) as parameters. Identity of regression models and equality of parameters in polynomial orthogonal equations were verified. Inhibition halos were observed in the range 15-25 mm of diameter. CONCLUSIONS: All micro-organisms were inhibited by both types of PA even in the lowest concentration of 20%. SIGNIFICANCE AND IMPACT OF THE STUDY: The feasibility of the usage of PAs produced with wood species planted in large scale in Brazil was evident and the real potential as a basis to produce natural antibacterial and antifungal agents, with real possibility to be used in veterinary and zootechnical applications.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Eucalyptus/química , Mimosa/química , Terpenos/farmacologia , Antibacterianos/isolamento & purificação , Antifúngicos/isolamento & purificação , Brasil , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Terpenos/isolamento & purificação , Madeira/química , Leveduras/efeitos dos fármacos
6.
Environ Sci Pollut Res Int ; 23(3): 2684-92, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26438367

RESUMO

Sorption and desorption of heavy metals (Cd, Cu, Pb, and Zn) was evaluated in biochars derived from sugarcane bagasse (SB), eucalyptus forest residues (CE), castor meal (CM), green coconut pericarp (PC), and water hyacinth (WH) as candidate materials for the treatment of contaminated waters and soils. Solid-liquid distribution coefficients depended strongly on the initial metal concentration, with K d,max values mostly within the range 10(3)-10(4) L kg(-1). For all biochars, up to 95 % removal of all the target metals from water was achieved. The WH biochar showed the highest K d,max values for all the metals, especially Cd and Zn, followed by CE (for Cd and Pb) and PC (for Cd, Pb, and Zn). Sorption data were fitted satisfactorily with Freundlich and linear models (in the latter case, for the low concentration range). The sorption appeared to be controlled by cationic exchange, together with specific surface complexation at low metal concentrations. The low desorption yields, generally less than 5 %, confirmed that the sorption process was largely irreversible and that the biochars could potentially be used in decontamination applications.


Assuntos
Carvão Vegetal , Metais Pesados/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Saccharum , Solo , Purificação da Água , Zinco/isolamento & purificação
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