Global Reaction Model to Describe the Kinetics of Catalytic Pyrolysis of Coffee Grounds Waste

Abstract

In view of the constant search for new sources of renewable energy, the particulate agro-industrial waste reuse emerges as an advantageous alternative. However, despite the advantages of using the biomass as an energy source, there is still strong resistance as the large-scale replacement of petroleum products due to the lack of scientifically proven efficient conversion technologies. In this context, the pyrolysis is presented as one of the most widely used thermal decomposition processes. The knowledge of aspects of chemical kinetics, thermodynamics these will, heat and mass transfer, are so important, since influence the quality of the product. This paper presents a kinetic study of slow pyrolysis of coffee grounds waste from dynamic thermogravimetric experiments (TG), using different powder catalysts. The primary thermal decomposition was described by the one-step reaction model, which considers a single global reaction. The kinetic parameters were estimated using nonlinear regression and the differential evolution method. The coffee ground waste was dried at 105°C for 24 hours. The sample in nature was analyzed at different heating rates, being 10, 15, 20, 30 and 50 K/min. In the catalytic pyrolysis, about 5% (w/w) of catalyst were added to the sample, at a heating rate of 30 K/min. The results show that the one-step model does not accurately represent the data of weight loss (TG) and its derivative (DTG), but can do an estimative of the activation energy reaction, and can show the differences caused by the catalysts. Although no one can say anything about the products formed with the addition of the catalyst, it would be necessary to micro-pyrolysis analysis, we can say the influence of the catalyst in the samples, based on the data obtained in thermogravimetric tests.

Effect of Temperature and MgCl2 Concentration on the Catalytic Pyrolysis of Malt Waste Using Response Surface Methodology

“…The catalytic and non-catalytic kinetics of MW pyrolysis was investigated by thermogravimetry, also used to calculate the thermodynamic parameters of pyrolysis. A Reparametrized Global Reaction (RGR) Model [16] was employed for the first time to represent the kinetic behavior of MgCl 2 -catalyzed pyrolysis of MW. The kinetic parameters were estimated using the Differential Evolution (DE) algorithm [32,[48][49][50] and then analyzed.…”

“…[3,4] This process is normally carried out in the total or partial absence of oxygen, at a temperature range of 400-600 °C. [5] Many industrial wastes, such as plastic waste, [6,7] spent tire, [8] tetra pak residue, [9] cellulose, [10,11] lignin, [12] sugarcane bagasse, [13][14][15] coffee residues, [16,17] corncob, [18] fruit residue, [19] oilseed shells, [20] microalgae, [21,22] seeds [23,24] and pine wood, [25] among others, have been evaluated as sources for the pyrolysis process.…”

Thermokinetic study of macadamia carpel pyrolysis using thermogravimetric analysis

“…[4] Lignocellulosic residues from industry, forestry, and agriculture are widely available and can be used as feedstock for pyrolysis. [3] The literature presents pyrolysis studies for a wide variety of biomasses and residues, such as sugarcane bagasse, [5] coconut fibre, [6] rice husk, [7] corn stalks, [8] sorghum, [9] malt waste, [10] spent coffee grounds, [11] nut shells, [12] macadamia shells, [13] and cartoon packages. [14] The majority of these residues is usually underutilized or discarded; therefore, pyrolysis could be a good alternative for their destination.…”

Reaction chemistry and kinetics of corn stalk pyrolysis without and with Ga/HZSM-5

“…Batista et al. [20] used thermogravimetric (TG) analysis to study the catalytic pyrolysis kinetics of coffee grounds waste. They found that there were some differences in the experimental curves between pyrolysis of biomass and biomass mixed with zeolites and, therefore, a single global reaction model could not accurately reproduce the experimental data.…”