Initial Ignition Time and Calorific Value Enhancement of Briquette with Added Pine Resin

Gustan PARI,Lisna EFIYANTI,Saptadi DARMAWAN,Nur Adi SAPUTRA,Djeni HENDRA,Joseph ADAM,Alfred INKRIWANG,Rachman EFFENDI 한국목재공학회 2023 목재공학 Vol.51 No.3

The increasing demand for clean energy requires considerable effort to find alternative energy sources, such as briquettes. This research aims to develop a charcoal briquette with added pine resin (API) that has excellent combustion speed and distinctive aroma. Briquettes are composed of charcoal, pine resin (concentration: 0%–30%), and starch (up to 7%). They are produced in several stages, including coconut shell pyrolysis in conventional combustion, to obtain charcoal for the briquette precursor. Briquette compaction is conducted by mixing and densifying the charcoal, pine resin, and starch using a hydraulic press for 3 min. The hydraulic press has a total surface area and diameter of 57.7 cm2 and 3.5 cm, respectively. The briquettes are dried at different temperatures, reaching 70℃ for 24 h. The study results show that the briquettes have a thickness and diameter of up to 2 and 3.5 cm, respectively; moisture of 2.18%–2.62%; ash of 11.61%–13.98%; volatile matter of 27.15%– 51.74%; and fixed carbon content of 40.24%–59.46%. The compressive strength of the briquettes is 186–540 kg/cm2. Their calorific value is 5,338–6,120 kcal/kg, combusting at a high speed of 0.15–0.40 s. The methoxy naphthalene, phenol, benzopyrrole, and lauryl alcohol; ocimene, valencene, and cembrene are found in the API. The API briquette has several chemical compounds, such as musk ambrette, ocimene, sabinene, limonene, 1-(p-cumenyl) adamantane, butane, and propanal, which improve aroma, drug application, and fuel production. Accordingly, API briquettes have considerable potential as an alternative energy source and a health improvement product.

침엽수단판의 수지함침처리에 의한 압밀화 특성

서진석 한국가구학회 2003 한국가구학회지 Vol.14 No.2

This study was carried out to investigate characteristics of plywood overlaid with softwood veneers densified by resin impregnation and compression. The resin impregnability of Korean pine veneer under atmospheric pressure soaking was greater than that of larch, and impregnability of melamine resin was slightly greater than phenolic resin. It was suggested that resin impregnation ratio was affected by density and thickness of veneer. The largest melamine resin impregnation ratio of 50.7% was obtained with 1.26mm thick Korean pine veneer, and the lowest phenolic resin impregnation ratio of 11.7% with 3.41mm thick larch veneer. Therefore, it was suggested that the vacuum-pres sure-soak treatment is required at thick larch veneer. In densifying resin-impregnated veneers, densification ratio from 13.4 to 31.2% was obtained by high pressure from 15.6 to $20.8kgf/cm^2$. Impregnation of melamine resin also showed relatively greater at densification than that of phenolic resin. So it showed the degree of densification of about 20% or greater. It was seemed that adhesive bonding strength of plywood(base panel) which was directly pressed and overlaid with resin-impregnated veneer was affected by resin tackiness after resin impregnation followed by semi-drying. In laboratory scale, melamine resin impregnation was more favorable for the development of adhesive bonding strength owing to moisture control.

SOME FIXED POINTS FOR EXPANSIVE MAPPINGS AND FAMILIES OF MAPPINGS

Liu, Z.,Feng, C.,Kang, S.M.,Kim, Y.S. The Youngnam Mathematical Society Korea 2002 East Asian mathematical journal Vol.18 No.1

In this paper we obtain some fixed points theorems of expansive mappings and several necessary and sufficient conditions for the existence of common fixed points of families of self-mappings in metric spaces. Our results generalize and improve the main results of Fisher [1]-[5], Furi-Vignoli [6], $Is\'{e}ki$ [7], Jungck [8], [9], Kashara-Rhoades [10], Liu [13], [14] and Sharma and Strivastava [16].

포플러로부터 고밀화연료의 제조

한규성,최돈하 한국산림바이오에너지학회 2002 산림바이오에너지 Vol.21 No.3

최근 들어, 북미와 유럽에서는 바이오매스로부터 제조한 고밀화연료가 재생가능하며 청정한 바이오에너지로서 널리 사용되고 있다. 고밀화연료를 얻기 위한 현사시(Populus tomentiglandulosa)와 수원포플러(Populus davidiana) 톱밥의 압밀화에 대하여 연구하였다. 이들 수종의 연료적 가치를 평가하기 위하여 열량 및 원소분석을 하였다. 고밀화를 위해 전분접착제를 첨가한 열압공정을 채택하였으며, 압밀화는 120-l60℃에서 50kgf/㎠ 압력으로 소정시간(정확한 시간?) 시행하였다. 고밀화연료의 특성은 비중, 압축강도 및 미세분 발생량으로 평가하였다. 유접착제 공정에서는 160℃에서 7.5분 이상의 열압에 의해 미세분 발생량이 5% 미만인 고밀화연료를 얻을 수 있었다. 한편, 열압조건과 톱밥의 함수율을 조절함으로써, 무접착제 조건에서도 미세분 발생량이 5% 미만의 고밀화연료를 얻을 수 있음이 밝혀졌다. Recently, densified fuels from biomass are widely used North America and Europe as a regenerable and clean bioenergy. Compaction of sawdust of poplars(Populus tomentiglandulosa and Populus davidiana) with starch glue for densified fuel were studied. Calorific and elemental analysis were carried out to assess these species as fuel. Hot-press process was used and compaction was performed under temperatures from 120 to $160^{\circ}C$ and at pressure of 50kgf/$cm^2$ for prescribed time. Densified fuels were evaluated by its specific gravities, compressive strengths and fines. In the case of with-glue system, when the press temperature is $160^{\circ}C$ and press time is above 7.5 minutes, densified fuels with fines less than 5% can be produced. On the contrary, in the case of without-glue system, densified fuels with fines less than 5% can be produced by controlling the press conditions and the moisture content of sawdust.

Thermal durability of ytterbium silicate environmental barrier coating prepared by suspension plasma spray

Park Soo Min,남산,오윤석 한국세라믹학회 2021 한국세라믹학회지 Vol.58 No.2

Owing to their superior high-temperature stability, SiC-based ceramic matrix composites are widely used in turbine engine components for launch vehicles and other applications in the aerospace industry. However, because of the deterioration that occurs in these materials in high-temperature wet operating environments, researchers have developed environmental barrier coating technologies to protect the substrate. In this study, a top coat was prepared using Yb 2 SiO 5 and Yb 2 Si 2 O 7 as the third-generation coating of a rare-earth silicate with high thermal, chemical, and mechanical stability in high-temperature environments above 1400 °C. A new bond coat was prepared, incorporating Si, whose thermal expansion coeffi cient is similar to that of the SiC substrate, and Hf, which is expected to signifi cantly contribute to high-temperature stability. The coating was prepared by suspension plasma spraying rather than atmospheric plasma spraying to realize a fi ne coating particle structure; to densify the coating layers, secondary densifi cation coatings were created using ytterbium (III) nitrate pentahydrate (Yb(NO 3 ) 3 ∙5H 2 O) and tetraethyl orthosilicate (C 8 H 20 O 4 Si). The prepared specimens were measured in terms of weight change and weight change ratio with respect to temperature under high-temperature fl ames (1400 ᕑ and 1700 ᕑ). After the secondary densifi cation coating, the microstructure of the specimen was observed to be denser and the surface layer of the coating exhibited crystallinity. For the tested samples, a decrease in weight was observed. The largest weight loss was observed under the 1700 ᕑ fl ame.

An approach of using ideal grading curve and coating paste thickness to evaluate the performances of concrete-(1) Theory and formulation

H.Y. Wang,C.L. Hwang,S.T. Yeh 사단법인 한국계산역학회 2012 Computers and Concrete, An International Journal Vol.10 No.1

The performance of a concrete is significantly influenced by its mixture proportion and the coating thickness on aggregate surface. The concrete in this study is designed by estimating the blending ratio of aggregate using a densified mixture design algorithm (DMDA) based on an ideal grading curve and estimating the paste volume as the sum of the amount of paste needed to provide an assigned coating paste thickness. So as to obtain appropriate concrete amount, and thus can accurately estimate the property of concrete. Deduction of this mix design formula is simple and easy understanding, and meanwhile to obtain result is fast. This estimation model of mix design is expected to reward to industry and effectively upgrade concrete quality.

Densified biocoal from woodchips: Is it better to do torrefaction before or after densification?

Ghiasi, B.,Kumar, L.,Furubayashi, T.,Lim, C.J.,Bi, X.,Kim, C.S.,Sokhansanj, S. Applied Science Publishers 2014 APPLIED ENERGY Vol.134 No.-

Torrefied biomass represents a high quality renewable energy commodity that can be used to substitute fossil fuels such as coal. However, densification processes such as pelletisation is necessary to improve the tradability of ''low-dense'' torrefied biomass. In this work, two process pathways were assessed for energy and mass balance in making torrefied pellets from softwood chips and qualities of the resulting torrefied pellets were compared. Pathway I involve drying the wood chips, torrefaction, grinding followed by densification. In pathway II, wood chips were dried, ground, densified and finally torrefied. The results showed that it was difficult to bind the torrefied biomass particles and a binding agent was necessary to enable their effective pelletisation with reasonable energy consumption. In contrary, pelletization of raw materials was possible without using binding agents and when the ''raw wood pellets'' were torrefied, the pellets surprisingly stayed intact and had several promising properties such as higher energy/carbon value, reduced moisture content and higher stability in water. In addition, the pathway II was more efficient in terms of overall energy and material balance.

Characterization of Li1.5Al0.5Ge1.5(PO4)3 solid electrolyte with an added sintering aid

Hyun-Joon Lee,Liyu-Liu,Won-Jong Jeong,Seoung-Ki Lee,Bong Ki Ryu 대한금속·재료학회 2023 ELECTRONIC MATERIALS LETTERS Vol.19 No.1

In compliance with the current trends, lithium secondary batteries are gaining attention as next-generation eco-friendlyenergy sources. However, the conventional liquid electrolytes are limited by their propensity to cause explosions and fi res. Several studies have been conducted on solid electrolytes owing to their stability and enlargement advantages. However,the mass production of solid electrolytes through the processing of crystallized glass is challenging because of the highcost, processing diffi culty, and extensive equipment requirements. The potential alternative strategy of using a molding andsintering manufacturing method is limited by performance degradation due to the presence of pores in the sintered body. To improve the performance of the Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 solid electrolyte sintered body, Bi 2 O 3 was applied as a sinteringaid, which improved its physical and electrochemical characteristics. The addition amount of the sintering aid was varied todetermine the optimal sintering conditions. A characteristic evaluation was conducted using the as-determined conditions,and reliability was ensured by evaluating long-term chemical durability.

Evaluation of high nutrient diets on litter performance of heat-stressed lactating sows

Choi, Yohan,Hosseindoust, Abdolreza,Shim, YoungHo,Kim, Minju,Kumar, Alip,Oh, Seungmin,Kim, YoungHwa,Chae, Byung-Jo Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.11

Objective: The present study investigated the litter performance of multiparous sows fed 3% and 6% densified diets at farrowing to weaning during summer with mean maximum room temperature of $30.5^{\circ}C$. Methods: A total of 60 crossbred multiparous sows were allotted to one of three treatments based on body weight according to a completely randomized design. Three different nutrient levels based on NRC were applied as standard diet (ST; metabolizable energy, 3,300 kcal/kg), high nutrient level 1 (HE1; ST+3% higher energy and 16.59% protein) and high nutrient level 2 (HE2; ST+6% higher energy and 17.04% protein). Results: There was no variation in the body weight change. However, backfat thickness change tended to reduce in HE1 in comparison to ST treatment. Dietary treatments had no effects on feed intake, daily energy intake and weaning-to-estrus interval in lactating sows. Litter size, litter weight at weaning and average daily gain of piglets were significantly greater in sows in HE1 compared with ST, however, no difference was observed between HE2 and ST. Increasing the nutrient levels had no effects on the blood urea nitrogen, glucose, triglyceride, and creatinine at post-farrowing and weaning time. The concentration of follicle stimulating hormone, cortisol and insulin were not affected by dietary treatments either in post-farrowing or weaning time. The concentration of blood luteinizing hormone of sows in ST treatment was numerically less than sows in HE2 treatment at weaning. Milk and colostrum compositions such as protein, fat and lactose were not affected by the treatments. Conclusion: An energy level of 3,400 kcal/kg (14.23 MJ/kg) with 166 g/kg crude protein is suggested as the optimal level of dietary nutrients for heat stressed lactating sows with significant beneficial effects on litter size.

Pyrolysis of Lignin Obtained from Cinnamyl Alcohol Dehydrogenase (CAD) Downregulated Arabidopsis Thaliana

( Kwang Ho Kim ),( Jae-Young Kim ),( Chang Soo Kim ),( Joon Weon Choi ) 한국목재공학회 2019 목재공학 Vol.47 No.4

Despite its potential as a renewable source for fuels and chemicals, lignin valorization still faces technical challenges in many aspects. Overcoming such challenges associated with the chemical recalcitrance of lignin can provide many opportunities to innovate existing and emerging biorefineries. In this work, we leveraged a biomass genetic engineering technology to produce phenolic aldehyde-rich lignin structure via downregulation of cinnamyl alcohol dehydrogenase (CAD). The structurally altered lignin obtained from the Arabidopsis thaliana CAD mutant was pyrolyzed to understand the effect of structural alteration on thermal behavior of lignin. The pyrolysis was conducted at 400 and 500 °C using an analytical pyrolyzer connected with GC/MS and the products were systematically analyzed. The results indicate that aldehyde-rich lignin undergoes fragmentation reaction during pyrolysis forming a considerable amount of C6 units. Also, it was speculated that highly reactive phenolic aldehydes facilitate secondary repolymerization reaction as described by the lower yield of overall phenolic compounds compared to wild type (WT) lignin. Quantum mechanical calculation clearly shows the higher electrophilicity of transgenic lignin than that of WT, which could promote both fragmentation and recondensation reactions. This work provides mechanistic insights toward biomass genetic engineering and its application to the pyrolysis allowing to establish sustainable biorefinery in the future.