• Proceedings of the Korea Forestry Energy Research Society Conference
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• 2011.02a
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• pp.27-30
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• 2011

• Proceedings of the Korea Forestry Energy Research Society Conference
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• 2011.02a
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• pp.31-33
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• 2011

• Proceedings of the Korea Forestry Energy Research Society Conference
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• 2011.02a
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• pp.84-87
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• 2011

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.224-230
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• 2015

This study was conducted to investigate the effects of several variables on the durability of wood pellets fabricated with torrefied larch (LAR) and tulip tree (TUT) chips. Microscopic observation by scanning electron microscope-energy dispersive X-ray spectrometer was also performed to identify the surface of the wood pellets visually. In addition, torrefied-LAR and TUT pellets were fabricated with the addition of moisture, lignin, starch and protein as binders, and durabilities of the pellets were analyzed statistically. Durabilities of torrefied-LAR and TUT pellets were lower than one of non-torrefied-LAR and TUT pellets. Durabilities of both pellets fabricated with the wood chips, which were torrefied with $230^{\circ}C$ and 30 min, were the highest among all torrefaction conditions used in this study. From the microscopic observations, lignin was distributed broadly on the surface of non-torrefied wood pellets, whereas congregated partially on the surface of torrefied wood pellets. Durability of LAR pellets increased with the addition of moisture, but that of TUT pellets was reduced. Addition of binders contributed to increase the durability of LAR and TUT pellets. As a binder, lignin and protein were more effective than starch for improving the durability. In conclusion, mild torrefaction treatment, such as $230^{\circ}C$ and 30 min, might be an optimal condition to minimize the durability reduction of the LAR and TUT pellets. In addition, when torrefied woody materials with high and low specific gravities are used as a raw material for the production of durable wood pellets, it might be required to adjust moisture content and torrefaction conditions of woody materials, respectively.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.5
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• pp.436-447
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• 2019

The circulating fluidized bed boiler has an advantage that can burn a variety of fuels from low-grade fuel to coal. In this study, for the design of a circulating fluidized bed boiler using wood pellets, a circulating fluidized bed combustion test device using no external heater was manufactured and used. According to the increase of co-combustion rate with wood pellet, combustion fraction and heat flux by combustor height were measured and pollutant emission characteristics were analyzed. In terms of combustibility, the effect on primary and secondary air ratio were also studied. In addition, as a result of analysis of the effect of corrosive nanoparticles on the combustion of coal with wood pellets, it was confirmed that coal is mostly composed of Ca and S, whereas wood pellets are mostly composed of K, Cl, and Na.

• Proceedings of the Korea Forestry Energy Research Society Conference
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• 2011.02a
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• pp.57-60
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• 2011

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.71-73
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• 2008

Different biosolid fuel (wood pellet) properties between trunk and root of pine (Pinus densiflora) biomass were investigated. Trunk has more organic solvent extracts and Klason lignin content which has higher heating values than root biomass component. In root biomass, polysaccharides content was higher than trunk biomass. Based on Higher Heating Value (HHD) analysis and ash content, trunk biomass showed better solid fuel characteristics than root biomass. But pine root biomass had lower HHD than trunk biomass, its HHD values were higher than other hardwood or annual plant lignocellulosic biomass.

• Journal of Energy Engineering
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• v.19 no.4
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• pp.251-257
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• 2010

Korea have a plan to enforce the Renewable Portfolio Standard(RPS) in 2012 for climate change action and effective use of energy but because of lack of renewable energy resources and limits of technology development, it will be hard to fullfill a target for RPS obligation in domestic power generation sector and woodchip biomass cofiring with coal combustion is the one of the alternative methods of the goal. Woodchip biomass cofiring with coal combustion is easy to approach technical design and has competitiveness of $CO_2$ & renewble energy certificate benefit and also has much lower generation cost than any other renewable energy resources. Because of that reason, woodchip biomass cofiring with coal combustion should be needed to fullfill the goal for RPS obligation in domestic power generation sector with midlong-term direction.

• Korean Journal of Organic Agriculture
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• v.21 no.3
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• pp.335-350
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• 2013

With the efforts to development of renewable energy technologies, and increasing awareness to environmental issues, the usage of wood pallets has been increasing every year since the introduction of wood pallet technology to the domestic market. until 2009, majority usage of pellet boiler was in the residential houses. In an effort to increase the distribution of wood pellet boiler to cultivation facilities with high usage of fuels, The Ministry of Agriculture and Forestry has launched a distribution project of wood pellet boiler for fuel usage as a part of the agricultural and fishery energy efficiency projects. Although only small number of farms with a heat-culturing facility have replaced from conventional boiler to pellet boiler. Although part of reason for low usage of pallet boiler is lack of understanding and information of it, the main reasons are high initial cost and uncertainty of its cost efficiency. Also, most people from agricultural industry don't realize it's significance in terms of environmental benefit due to lack of understanding in 'resource circulation' and 'adopting to climate change'. In this study, first, we did a cost-efficiency analysis of the farm which uses a diesel boiler to grow cucumber, tomato, paprika. Then we replaced the diesel boiler to a pallet boiler and measured its cost-efficiency again. By comparing the cost-efficiency of the diesel boiler with the pellet boiler, we analyzed the economic viability of pellet boiler. Then we analyzed viability of pallet boiler usage in terms of 'resource circulation' and 'adopting to climate change'. As a result of our analysis, we have found out that under the current system of government support, the energy usage varies depends of the types crops grown and the higher the energy use, the more cost efficient it is to use the pallet boiler. Also, it is economically viable to use the pallet boiler in terms of 'resource circulation' and 'adopting to climate change'.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.103.1-103.1
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• 2010

Recently domestic wood pellet boilers are installed in rural and forestry houses. The fuel price per lower heating value of wood pellet is about 20 % lower than that of heating oil on July 2010. In spite of lower price of wood pellet, a few user of wood pellet boiler complain expensive fuel cost. One of this reason is inaccurate or improper air-fuel ratio setting of wood pellet boiler. O2 concentration of flue gas of domestic wood pellet boiler is about 9.7 % and there are few domestic wood pellet boiler which can control air-fuel ratio automatically. We tested a domestic wood pellet boiler in changing boiler thermal output and air-fuel ratio. The nominal boiler thermal output is 25 kW (21 500 kcal/h). We measured thermal efficiency and flue gas concentrations such as CO and NOx at each boiler thermal load with various air-fuel ratio. The results show that if air flow rate is the same as full load and part load, thermal efficiency of part load of 40 % drops about 7.7 %p compared to boiler full load case.