The Utilization of Plum Stones for Pellet Production and Investigation of Post-Combustion Flue Gas Emissions

Abstract

Agri-food waste is generated at various food cycle stages and is considered to be a valuable feedstock in energy systems and chemical syntheses. This research identifies the potential and suitability of a representative agri-food waste sample (i.e., plum stones) as a solid fuel. Ground plum stones containing 10, 15, and 20 wt.% of rye bran were subjected to pelletization. The pelletizer was operated at 170, 220, and 270 rpm, and its power demand for the mixture containing 20 wt.% of rye bran was 1.81, 1.89, and 2.21 kW, respectively. Such pellets had the highest quality in terms of their density (814.6 kg·m−3), kinetic durability (87.8%), lower heating value (20.04 MJ·kg−1), and elemental composition (C: 54.1 wt.%; H: 6.4 wt.%; N: 0.73 wt.%; S: 0.103 wt.%; Cl: 0.002 wt.%; O: 38.2 wt.%). Whole plum stones and pellets were subjected to combustion in a 25 kW retort grate boiler in order to determine the changes in the concentrations of NO, SO2, CO, CO2, HCl, and O2 in the post-combustion flue gas. Collected results indicate that plum stone–rye bran pellets can serve as effective substitutes for wood pellets in prosumer installations, meeting the Ecodesign Directive requirements for CO and NO.

Control method of mechanical smoke emission in high-rise building corridor

“…It can be seen from the analysis of fig. 2 that, under the same experimental environment, the control precision of the method in this paper, the method in [5] and the method in [6] is constantly changing with the change of the number of experiments. When the number of iterations is 20, the control accuracy of the method in this paper is about 93%, that of the method in [5] is about 63%, and that of the method in [6] is about 80%.…”

“…2 that, under the same experimental environment, the control precision of the method in this paper, the method in [5] and the method in [6] is constantly changing with the change of the number of experiments. When the number of iterations is 20, the control accuracy of the method in this paper is about 93%, that of the method in [5] is about 63%, and that of the method in [6] is about 80%. When the number of iterations is 50, the control accuracy of the method in this paper is about 98%, that of the method in [5] is about 82%, and that of the method in [6] is about 81%.…”

“…where j is the smoke emission, ithe total number of floors in a high-rise building, Cthe estimated emissions of mechanical flue gas from historic high-rise building corridors, U ss (k)the time domain of mechanical smoke emission control for corridors of historic high-rise buildings [6], Tthe current scale of mechanical smoke emission in high-rise building corridors, and Vthe current evaluation function of mechanical smoke emission in high-rise building corridors.…”

“…In order to verify the advantages of this method, the experiment adopts the method of comparison, the method in this paper, the method of [5], and the method of [6], compare the three methods in corridor in the sample building mechanical time consuming of flue gas emission control precision and control for experimental index, in order to ensure the accuracy of the experiment, the experimental data are repeated analysis and processing, with the highest precision to ensure the effectiveness of the experiment.…”

Pelletization of Post-Harvest Tobacco Waste and Investigation of Flue Gas Emissions from Pellet Combustion

“…The contents of carbon, hydrogen, nitrogen [44] and sulfur (dry basis (d.b.) %) [45] were determined by IR (infrared radiation) detection through high-temperature combustion; nitrogen (d.b.%) was analyzed by a catarometric method, which was also described in [46]. The chlorine content (d.b.%) was examined using the Mohr method [47], with the use of Eschka's mixture.…”