Pyrolysis of spent coffee grounds using a screw-conveyor reactor

Kelkar, Shantanu; Saffron, Christopher M.; Chai, Li; Bovee, Jonathan; Stuecken, Tom; Garedew, Mahlet; Li, Zhenglong; Kriegel, Robert M.

doi:10.1016/j.fuproc.2015.04.006

Cited by 93 publications

(47 citation statements)

References 42 publications

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“…Cellulose, with higher decomposition temperatures, is decomposed in the second peak formed at this stage, with a temperature of approximately 400 °C, representing 19% of mass loss. The lignin structure, which decomposes over a wide temperature range (280-550 °C), showed no evident mass loss, indicating a possible contribution to the decomposition peaks of the other two structures (hemicellulose and cellulose) and also for the final solids mass, as already observed by Kelkar et al 21 The third stage, which occurred at temperatures above 600 °C and at a very low rate of mass loss, represents the formation of the carbonaceous solid. As the objective of this work is the higher yield of the liquid product, pyrolysis can be suggested to be carried out at temperatures lower than 600 °C, confirming the results of other studies.…”

Section: Characterization Of the Solid Residue From The Soxhlet Extrasupporting

confidence: 69%

“…As the objective of this work is the higher yield of the liquid product, pyrolysis can be suggested to be carried out at temperatures lower than 600 °C, confirming the results of other studies. 2,11,21 In addition, the high content of volatile and semi-volatile compounds indicates that the biomass is a potential source of organic compounds generated through a thermochemical process, such as pyrolysis. Figure 3 shows the FTIR analyses of the biomass, the solid residue from the Soxhlet extraction and the biochar after the pyrolysis.…”

Section: Characterization Of the Solid Residue From The Soxhlet Extramentioning

confidence: 99%

“…17 Therefore, bio-oil has great potential for application as a source of raw material for chemicals as well as in the fuel industry. 18 Some authors have performed the pyrolysis of coffee grounds and reported a bio-oil with a high content of fatty acids (around 10% in weight), [19][20][21][22][23][24] due to the thermal degradation of glycerides presented in the vegetable oil. Aiming its energetic application, Vardon et al 23 performed pyrolysis of the biomass after the process of extracting the vegetable oil and noticed a considerable decrease in the content of fatty acids.…”

Section: Introductionmentioning

confidence: 99%

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Production and Characterization of the Bio-Oil Obtained by the Fast Pyrolysis of Spent Coffee Grounds of the Soluble Coffee Industry

Krause

Moitinho

Ferreira

et al. 2019

J. Braz. Chem. Soc.

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Agro-industrial wastes are abundant and low-cost sources of energy and chemicals. Biomass account for 14% of the world's energy production. Industrial residues of production of soluble coffee (spent coffee grounds -SCG) have great potential due to its large-scale production and can be transformed by pyrolysis, in liquid, solid and gaseous products with applications from energy to chemicals. This work has the objective of producing bio-oil from the pyrolysis of industrial SCG, characterize it by chromatography and indicate its possible applications. As SGC contains a large amount of glycerides, they were extracted from SGC before the pyrolysis, aiming to obtain a better bio-oil from the residue. The yield in vegetable oil was 5.2% and its analyses showed that 50% are saturated acids (mainly palmitic 27.6%) and other 50% are unsaturated ones (mainly linoleic acid 35.3%). This composition qualifies this oil for biodiesel purposes. The residue (SGC after extraction) was submitted to pyrolysis, yielding 30% in liquid products, being 6% bio-oil. The bio-oil was analyzed by gas chromatography being identified free fatty acids, hydrocarbons, phenols and N-compounds. The heteroatomic compounds limit the use as biofuel but can be interesting for the pharmaceutical, agrochemical and fine chemicals industries.

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Section: Characterization Of the Solid Residue From The Soxhlet Extrasupporting

confidence: 69%

Section: Characterization Of the Solid Residue From The Soxhlet Extramentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Production and Characterization of the Bio-Oil Obtained by the Fast Pyrolysis of Spent Coffee Grounds of the Soluble Coffee Industry

Krause

Moitinho

Ferreira

et al. 2019

J. Braz. Chem. Soc.

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“…The WCG oil higher heating value (HHV) was measured to be 38.85 MJ/kg, exceeding the HHV of other biodiesel feedstocks such as waste cooking oil [43], cottonseed oil [44] and rice bran oil [45]. The higher calorific value might be due to the high carbon to oxygen ratios [46].…”

Section: Properties Of Recovered Lipidmentioning

confidence: 92%

Resource Recovery from Waste Coffee Grounds Using Ultrasonic-Assisted Technology for Bioenergy Production

et al. 2020

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Biodiesel is a proven alternative fuel that can serve as a substitute for petroleum diesel due to its renewability, non-toxicity, sulphur-free nature and superior lubricity. Waste-based non-edible oils are studied as potential biodiesel feedstocks owing to the focus on the valorisation of waste products. Instead of being treated as municipal waste, waste coffee grounds (WCG) can be utilised for oil extraction, thereby recovering an energy source in the form of biodiesel. This study evaluates oil extraction from WCG using ultrasonic and Soxhlet techniques, followed by biodiesel conversion using an ultrasonic-assisted transesterification process. It was found that n-hexane was the most effective solvent for the oil extraction process and ultrasonic-assisted technology offers a 13.5% higher yield compared to the conventional Soxhlet extraction process. Solid-to-solvent ratio and extraction time of the oil extraction process from the dried waste coffee grounds (DWCG) after the brewing process was optimised using the response surface methodology (RSM). The results showed that predicted yield of 17.75 wt. % of coffee oil can be obtained using 1:30 w/v of the mass ratio of DWCG-ton-hexane and 34 min of extraction time when 32% amplitude was used. The model was verified by the experiment where 17.23 wt. % yield of coffee oil was achieved when the extraction process was carried out under optimal conditions. The infrared absorption spectrum analysis of WCG oil determined suitable functional groups for biodiesel conversion which was further treated using an ultrasonic-assisted transesterification process to successfully convert to biodiesel.Coffee is the world's second-largest traded liquid commodity, after oil, with approximately 8 million tons of coffee produced each year [13]. A large amount of heat energy is used to convert green coffee beans into brown roasted beans in the brewing process, generating large amounts of volatile organic compounds (VOCs) [14]. The enormous demand for this beverage also produces a large quantity of residual waste after brewing. Every 1 ton of coffee beans produces 650 kg of coffee residue after brewing, known as WCG [15]. The global coffee industry produced an estimate of 9.34 million tons of waste in 2017, which was either incinerated, dumped in landfills or composted [16]. Every year Australia produces an estimated 75,000 tonnes of used ground coffee waste, and 93% of cafes send their WCGs to landfill. The annual domestic coffee consumption in Australia has reached almost 1.9 million 60 kg bags. On average, Australians consumed around 1.92 kilograms of coffee per person in 2017 [17]. The grounds that are used to make coffee are used only once and then immediately discarded. With rising rates of consumption, waste residues from the coffee industry (by-products from harvesting, processing, roasting and brewing stages of coffee production and processing) represent a challenge to worldwide directives aiming to reduce landfill volume. The inherent toxicity of several constituents within coffee...

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“…Observações semelhantes, com elevados rendimentos de biochar em temperaturas mais baixas foram encontradas por outros pesquisadores para vários tipos de biomassa, incluindo borra residual do café, haste de algodão, sorgo, madeira, semente de crambe e palha da cana-de-açúcar [11,12,73,100,301,302]. Bedmutha et al(2011)De acordo comKelkar et al (2015) pequenos tempos de residência ajudam a reter ácidos e ésteres graxos contidos no bio-óleo, enquanto tempos de residência prolongados resultam na degradação de produtos primários da pirólise, formando moléculas menores, como carbonilas e hidrocarbonetos alifáticos [300]. …”

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Valorização de resíduos agroindustriais de café e algodão para pordução de bio-óleo e biochar

Primaz¹

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VALÈNCIA, JULHO DE 2018 DEDICATÓRIAAos meus amados pais Armelindo Primaz e Ieda Janete Primaz pelo amor incondicional, paciência, compreensão e apoio durante toda esta jornada, que mesmo de longe nunca deixaram de se fazer presentes.Ao meu marido Raoni Spyker Monteiro pelo amor, carinho, companheirismo e infinitos conselhos, que foram essenciais e me ajudaram sempre a seguir em frente nos momentos mais difíceis.i DECLARAÇÃO DE AUTORIA E ORIENTAÇÃOA presente tese de doutorado foi realizada pela autora, exceto pelas colaborações às quais foram devidamente citadas nos agradecimentos e no corpo do texto. Este trabalho é totalmente original e não foi apresentado previamente para obtenção de nenhum tipo de grau.

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Pyrolysis of spent coffee grounds using a screw-conveyor reactor

Cited by 93 publications

References 42 publications

Production and Characterization of the Bio-Oil Obtained by the Fast Pyrolysis of Spent Coffee Grounds of the Soluble Coffee Industry

Production and Characterization of the Bio-Oil Obtained by the Fast Pyrolysis of Spent Coffee Grounds of the Soluble Coffee Industry

Resource Recovery from Waste Coffee Grounds Using Ultrasonic-Assisted Technology for Bioenergy Production

Valorização de resíduos agroindustriais de café e algodão para pordução de bio-óleo e biochar

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