This study considers the possibility of utilizing agri-byproducts as energy sources via pelletization and torrefaction. Pellets were placed in a capsule and torrefied in an electrical furnace. Subsequently, they were cooled for 30 min, and their mass loss was measured. To investigate the resulting changes in fuel characteristics, ultimate and proximate analyses were performed, and calorific values were measured. To estimate the water absorption of the pellets, hygroscopicity evaluations were conducted. Based on the experimental results, the energy yield, lower heating value, and exergy were calculated to determine the optimum conditions for torrefaction. The calculation was performed by utilizing the useful exergy and standards applied to biomass power plants. We determined that torrefaction for agro-pellets should be conducted under low-to-intermediate temperatures (210–250 °C) within a period of 50 min. Under these conditions, 7–55% mass reductions were observed, the higher heating value increased from 4110 to 6880 kcal kg−1, and the lower heating value changed from 3780 to 6520 kcal kg−1 owing to reduced hygroscopicity. So, Agro-byproducts can contribute to the practical application by improving the heating value through torrefaction as an alternative to wood pellets.
When glycosaminoglycan (GAG)-degrading enzymes were measured in normal human stool suspensions, all 5 tested different stools degraded titrable heparin and acharan sulfate. GAG-degrading bacteria were screened from the isolates of human stools. Among them, HJ-15 had the most potent activities of heparinases (GAGs-degrading enzymes). However, HJ-15 produced the enzyme even if in the media without heparin. Acharan sulfate lyase was induced by acharan sulfate and heparin. Heparinase production was also induced by these GAGs. These enzymes, acharan sulfate lyase and heparinase, were produced in exponential and stationary phase of HJ-15 growth, respectively. Optimal pHs of the acharan sulfate lyase and heparinase activities were 7.2 and 7.5, respectively. The biochemical properties of HJ-15 was similar to those of B. stercoris. However, difference from B. stercoris was utilization of raffinose. This HJ-15 also degraded chondroitin sulfates A and C.
The continued use of fossil fuels is contributing to severe environmental pollution and the establishment of an abnormal climate; consequently, alternative renewable energy sources are being actively investigated worldwide. Further, following global trends, numerous countermeasures aimed at improving carbon neutrality, promoting sustainable agriculture, and reducing fossil fuel dependence are being implemented in the Republic of Korea. Therefore, this study was conducted to investigate the application of renewable energies for greenhouse heating in the Republic of Korea. Three hybrid systems, numbered 1–3, were constructed using a pellet boiler, hydrothermal heat pump, and solar heat collection system, respectively. Thereafter, the heating performance, combined heat efficiency, energy consumption per temperature lifting, and energy cost per temperature lifting of the systems were compared. The combined thermal efficiency results showed no significant differences. However, in terms of energy consumption and cost, hybrid system 1 demonstrated 25.7 and 24.1% savings, respectively, compared with the other systems. Moreover, based on economic analysis via the net present value and life cycle cost analysis methods, the system reduced costs by 29.2 and 27.7%, respectively, compared with conventional fossil fuel boilers. Thus, hybrid system 1 was identified as the most economical system.
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