Spent coffee grounds as heat source for coffee roasting plants: Experimental validation and case study

Allesina, Giulio; Pedrazzi, Simone; Allegretti, Francesco; Tartarini, Paolo

doi:10.1016/j.applthermaleng.2017.07.202

Cited by 40 publications

(28 citation statements)

References 23 publications

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“…An alternative way to make profits from these pelletized by-products consists in selling them as fuel for biomass boilers and stoves. A similar approach was already presented by the authors using spent coffee grounds [1] and digestate from anaerobic biomass power plants [12]. In this paper, different combustion tests were performed using an Ecofaber hot air generator of 29 kWth nominal thermal power.…”

Section: Introductionmentioning

confidence: 95%

“…Food processing industries consume large quantity of energy in their processes, thus causing massive CO2 emissions while increasing the final cost of the goods [1]. Energy efficiency and renewable energy production constitute fundamental strategies to pursue a sustainable development [2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, among the different renewable energy resources, bio-energies are the most suitable to be integrated under a circular economy plan. This approach allows companies to produce considerable earnings while producing value with their by-products [1,[7][8]. The industrial wheat milling sector in Italy represents a significant share of the agro-industrial market.…”

Section: Introductionmentioning

confidence: 99%

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By-products of wheat milling process as fuel for biomass boilers and stoves

Pedrazzi¹,

Allesina²,

Tartarini³

2018

TI-IJES

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This work aims at experimentally testing wheat milling by-products (bran, fine bran and middlings) as fuel into a biomass fired hot air generator, with the final purpose of demonstrating the advantages of selling these goods to the energy market. The by-products were pelletized and the thermal efficiency of the generator was assessed for each type of pellets including 'EN A1 plus' wood pellets for comparison. Results show a small decrease of performance of the generator using the by-products pellets with respect to wood pellets. In addition, combustion instability given by the clinkering phenomenon was recognized using middlings pellets. ESEM technology was applied to bran pellets ashes in order to evaluate ashes composition and discuss possible application as soil fertilizer. Finally, an economic comparison between by-products sale as fuel and as animal feed demonstrated that it is more convenient to sell these biomasses as fuel considering the actual market situation.

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Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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By-products of wheat milling process as fuel for biomass boilers and stoves

Pedrazzi¹,

Allesina²,

Tartarini³

2018

TI-IJES

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“…Within the solid biofuel production, the high content of lignin in SCG indicates its advantage within the densification process because lignin is a natural binder. Such an advantage was investigated in research focused on the production of pellets from SCG mixed with wood sawdust [14,23,24].…”

Section: Yearmentioning

confidence: 99%

Valorization of Bio-Briquette Fuel by Using Spent Coffee Ground as an External Additive

et al. 2019

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The present study investigates the quality changes of wood bio-briquette fuel after the addition of spent coffee ground (SCG) into the initial feedstock materials (sawdust, shavings) in different mass ratios (1:1, 1:3). Analysis of SCGs fuel parameter proved great potential for energy generation by a process of direct combustion. Namely, level of calorific value (GCV = 21.58 MJ·kg −1 ), of ash content (Ac = 1.49%) and elementary composition (C = 55.49%, H = 7.07%, N = 2.38%, O = 33.41%) supports such statement. A comparison with results of initial feedstock materials exhibited better results of SCG in case of its calorific value and elementary composition. Bulk density ρ (kg·m −3 ) and mechanical durability DU (%) of bio-briquette samples from initial feedstock materials were following for sawdust: ρ = 1026.39 kg·m −3 , DU = 98.44% and shavings: ρ = 1036.53 kg·m −3 , DU = 96.70%. The level of such mechanical quality indicators changed after the addition of SCG. Specifically, SCG+sawdust mixtures achieved ρ = 1077.49 kg·m −3 and DU = 90.09%, while SCG + shavings mixtures achieved ρ = 899.44 kg·m −3 and DU = 46.50%. The addition of SCG increased wood bio-briquettes energy potential but decreased its mechanical quality. Consequently, the addition of SCG in wood bio-briquette has advantages, but its mass ratio plays an important key role.Energies 2020, 13, 54 2 of 15 economics, politics, and the trade of many developing countries. The coffee production industry, i.e., plant cultivation, cherries harvest, bean processing, product packaging, sale marketing, and final product transportation, offers job opportunities for millions of people [5].Brazil belongs to the top countries in coffee production, as well as Vietnam, Indonesia, and Colombia. Together those countries generate more than 50% of the world's coffee production. Specific statistical data provided by the Food and Agriculture Organization of the United Nations (FAO) and by the International Coffee Organization (ICO) related to the coffee industry in the last years are expressed in Table 1.

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“…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.…”

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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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Spent coffee grounds as heat source for coffee roasting plants: Experimental validation and case study

Cited by 40 publications

References 23 publications

By-products of wheat milling process as fuel for biomass boilers and stoves

By-products of wheat milling process as fuel for biomass boilers and stoves

Valorization of Bio-Briquette Fuel by Using Spent Coffee Ground as an External Additive

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

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