Earticle

White rot fungus Cerrena unicolor IUM 5400 produced ethanol from diverse sugars, including glucose, mannose, galactose, and cellobiose at 0.38, 0.28, 0.08, and 0.27 g of ethanol per g of sugar consumed, respectively. The fungus produced relatively high amounts of ethanol from xylose (0.28 g of ethanol per g of sugar consumed); however, the ethanol conversion rate of arabinose was relatively low (at 0.08 g of ethanol per g sugar consumed). When cultured in a basal medium containing 20 g/L rice straw or corn stalks, C. unicolor IUM 5400 produced 0.18 g and 0.18 g of ethanol per g of rice straw and corn stalks, respectively. The results suggest that C. unicolor IUM 5400 is a white rot fungus that can effectively hydrolyze cellulose or hemicellulose to sugars and simultaneously convert them to ethanol.

The possibility of employing biomass of Salix viminalis cv. Q683 as a resource of bio-energy was evaluated. The chemical analysis of S. viminalis cv. Q683 leaf biomass showed components such as, extractives (2.57%), lignin (39.06%), hemicellulose (21.61%), and cellulose (37.83%), whereas, its stem was composed of extractives (1.67%), lignin (23.54%), hemicellulose (33.64%), and cellulose (42.03%). The biomass of S. viminalis cv. Q683 was saccharified using two enzymes celluclast and viscozyme. The saccharification of S. viminalis cv. Q683 biomass was influenced by enzymes and their strengths. The optimal enzyme combination was found to be celluclast (59 FPU/g substrate) and viscozyme (24 FBG/g substrate). On saccharification the glucose from leaf and stem biomass was 7.5g/L and 11.7g/L, respectively after 72 hr of enzyme treatment. The biomass and enzyme-treated biomass served as the feedstock for ethanol production by fermentation. The ethanol production from stem and leaf biomass was 5.8 g/L and 2.2 g/L respectively, while the fermentation of the enzymatic hydrolysates yielded 5 g/L to 8 g/L bioethanol in 72 hours.

증류수 또는 염산 촉매 수열처리에 의한 단독 가수분해, 또는 수열처리 - 효소에 의한 순차적 가수분해 공정에 의해 갈조류 일종인 다시마와 미역을 가수분해하여 생성되는 환원당과 글루코오스 함량을 조사하였다. 또, 가수분해 산물을 대상으로알루미늄 실리케이트에 고정된 효모를 이용하여 바이오에탄올 생산성에 대하여 검토하였다. 그 결과, 다시마와 미역에서 증류수 수열처리로부터 생성되는 환원당 농도는 각각 66.7과 80.7 mg/g-dry biomass이었으나, 염산 수열처리 한 경우는 각각112.1과 140.0 mg/g-dry biomass로, 1.7배 증가한 결과를 보였다. 또 증류수나 염산 촉매 수열처리 경우, 생성되는 글루코오스 양은 아주 미미하였다. 증류수나 염산 촉매 수열처리 후 효소가수를 실시한 순차적 가수분해의 경우 생성되는 환원당 농도는 증가하였다. 그 결과, 다시마는 증류수 수열처리 - 효소 가수분해한 경우 112.9 mg/g-dry biomass, 염산 수열처리 - 효소가수분해한 경우 142.8 mg/g-dry biomass이었으며, 미역은 증류수 수열처리 - 효소 가수분해한 경우 117.1 mg/g-dry biomass, 염산 수열처리 - 효소 가수분해한 경우 161.7 mg/g-dry biomass이었다. 그러나 비록 염산 촉매 수열처리 결과에서 환원당 농도는 높았다 하더라도, 바이오에탄올로의 전화율은 낮았다.

Bioethanol was produced from the Laminaria japonica and the Undaria pinnatifida hydrolysates by sequential hydrothermal (with distilled water or hydrochloric acid) and enzymatic hydrolysis (Celluclast® 1.5 L) using immobilized Saccharomyces coreanus into/on aluminum silicate. The concentration of the reducing sugar in the hydrothermal treatment with distilled water from the L. japonica and the U. pinnatifida were 66.7 and 80.7 mg/g-dry biomass, respectively, while the result with hydrochloric acid were 112.1 and 140.0 mg/g-dry biomass, increasing as much as 1.7 factors, respectively. Glucose in the reducing sugar was very low, for distilled water or hydrochloric acid. The hydrolysis rate of reducing sugar was improved by the sequential enzymatic hydrolysis after hydrothermal treatment with distilled water or hydrochloric acid, reducing sugar were 112.9 and 142.8 mg/g-dry biomass for L. japonica, and 117.1 and 161.7 mg/g-dry biomass for U. pinnatifida. Above all, glucose was produced to 49.8-59.4 mg/g-dry biomass for both algae. Although the acid hydrolysates with hydrochloric acid were shown a remarkable increased hydrolysis yield of sugar for both algae, it was not linked to higher ethanol production.

This study intends to use the possibility of an eco-friendly alternative fuel to be applied to ships as a sample manufacturing method for ship MGO and bioethanol mixed fuel oil as basic evidence. The components of the manufactured mixed fuel oil were analyzed using the ISO-8217 standard testing method. As a result of analysis showed that in the lower calorific value decreased to 43030J/g at BE0 fuel and 37010J/g at BE30 fuel. The high calorific value decreased to 46.065MJ/kg at BE0 fuel and 39.460MJ/kg at BE30 fuel. The density decreased to 840.8kg/m3 at BE0 fuel and 837.0kg/m3 at BE30 fuel. In the case of flash point it was 67.5℃ when BE0, and decreased to less than 40.0℃ when BE10 to BE30. Finally the Kinematic Viscosity was 3.011mm2/s at BE0 and decreased to 2.502mm2/s at BE30.

This study intends to analyze physical and chemical changes using Thermo-Gravimetric Analysis (TGA) of MGO-bioethanol mixed fuel oil. We will analyze the thermal stability and state changes of MGO-Bioethanol mixed fuel oil and conduct and utilize various basic experiments on its applicability as ship fuel oil in the future and eco-friendly alternative fuels. The physical and chemical conditions set through this experiment were set through non-isothermal heating at about 20°C to 933°C, and the heating rate was 100°C/min, the measurement time was 10 minutes, and the amount of samples in each mixed fuel oil was about 18mg-24mg. In the range of pyrolysis temperatures from 235.241°C to 253.320°C, the weight of BE0 was 30.992%, BE10 was 36.199.%, BE20 was 35.879%, and BE30 was 35.725%, indicating that the pyrolysis temperature and weight tended to increase as the bioethanol content increased.

Diesel engine has the advantages of strong power, low fuel consumption and good durability, so it has been widely used in transportation, automobile, ship and other fields. However, the nitrogen oxides(NOx) and particulate matter(PM) emitted by diesel engines have become one of the main causes of air pollution. Especially during idling, the engine temperature is low, and there are more residual exhaust gases in the combustion chamber, resulting in the formation of more harmful emissions. In this study, performance of a single cylinder, four-stroke, direct injection (DI) diesel engine fueled with diesel–biodiesel mixtures has been experimentally investigated. The findings show that a remarkable improvement in PM–NOx trade-off can be achieved by burning diesel-bioethanol blend fuels.

Diesel engine has the advantages of strong power, low fuel consumption and good durability, so it has been widely used in transportation, automobile, ship and other fields. However, the nitrogen oxides(NOx) and particulate matter(PM) emitted by diesel engines have become one of the main causes of air pollution. Especially during idling, the engine temperature is low, and there are more residual exhaust gases in the combustion chamber, resulting in the formation of more harmful emissions. In this study, performance of a single cylinder, four-stroke, direct injection (DI) diesel engine fueled with diesel–biodiesel mixtures has been experimentally investigated.

The high costs for ethanol production with lignocellulosic biomass as a second generation energy materials currently deter commercialization of lignocellulosic biomass, especially wood biomass which is considered as the most recalcitrant material for enzymatic hydrolysis mainly due to the high lignified structure and the nature of the lignin component. Therefore, overcoming recalcitrance of lignocellulosic biomass for converting carbohydrates into sugar that can subsequently be converted into biobased fuels and biobased products is the primary technical and economic challenge for bioconversion process. This study was mainly reviewed on the research trend of the enhancement of enzymatic hydrolysis for lignocellulosic biomass after pretreatment in bioethanol production process.

Recently, various efforts for the extended utilization of woody biomass has been attempted due to the fact that global warming, energy and environmental problems are urgent ones to be solved. Development of new energy sources at our national security level is desperately needed as we depend on almost all of energies supplied from other countries, let alone the economic crisis caused by oil price hike. Woody biomass can be converted to energy by means of thermochemical, biological, or direct combustion processes. Many processes are available for producing bioenergy, such as bioethanol, wood pellet, wood chip, combined heat, and power system. Political support and R&D investment should be provided that can boost the utilization of the wood biomass, the eco-environment, and recyclable and alternative energy resources for national power security. In addition, a long-term strategy that can utilize unused and low efficient woody biomass resources, and systematically collect and manage them in a national level should be set up. Even though the possibility in total exchange of fossil oil with woody biomass is quite low, technology developments of woody biomass for the solution to global warming and environmental problem through its commercialization are expected to grow steadily.

최근 우리나라 서·남해안에 대량 유입되고 있는 괭생이모자반은 갈조류로서 바이오연료 생산용 바이오매스로서의 잠 재성이 높다. 이에 본 연구에서는 괭생이모자반을 대상으로 가수분해 공정에 미치는 염분의 영향을 검토하였다. 미세척 시료의 회분을 분석한 결과, 회분의 약 7 3%가 염분으로 나타났으며, 3회 반복 세척으로 총 염분의 96.0%가 제거되었다. 가수분해 방법에 따른 환원당의 생산량은, 수열처리에 의해 미세척시료 및 세척시료에서 각각 27.95 및 35.25 mg/gbiomass( 가수분해 효율 4.1–4.4%), 효소처리에 의해 3 7 .72 및 61.71 mg/g-biomass(가수분해 효율 5.9–7.2%), 수열–효소 순차 처리에 의해 100.49 및 138.91 mg/g-biomass(가수분해 효율 15.7–16.1%)로, 미세척시료와 비교하여 세척시료에서 1.26–1.64배 높은 환원당을 얻을 수 있었다. 특히 시료 중 염분은 생물학적 가수분해 공정에 뚜렷한 영향을 미쳤다.

Recently, Sargassum horneri, which has been introduced in large quantities to the west and south coasts of Korea, belongs to brown macroalgae and has high potential as a biomass for biofuel production. Therefore, in this study, the effect of salinity on the hydrolysis process was examined for the S. horneri. As a result of analyzing the ash of the unwashed sample, about 73% of the ash was found to be salts. And 96.0% of the total salt was removed by 3 repeated washing. The production of reducing sugars according to the hydrolysis method was 27.95 and 35.25 mg/g-biomass (4.1– 4.4% of hydrolysis efficiency), respectively in unwashed and washed samples by hydrothermal treatment, 37.72 and 61.71 mg/g-biomass (5.9–7.2% of hydrolysis efficiency) by enzyme treatment, and 100.49 and 138.91 mg/g-biomass (15.7– 16.1% of hydrolysis efficiency) by hydrothermal–enzyme sequential treatment, consequently, compared to the unwashed sample, it was possible to obtain 1.26–1.64 times higher reducing sugar in the washed sample. Especially, salinity in the sample has a significant effect on the bio-hydrolysis process.

This study was initiated to evaluate ethanol production by a Korean isolate of white rot fungus Irpex consors. It was found that the fungus could produce ethanol by converting glucose, mannose, xylose, and cellobiose under semi-aerobic condition with yields of 0.23, 0.19, 0.21, and 0.17 g ethanol per g sugars, respectively. Furthermore, the strain produced ethanol by simultaneous saccharification and fermentation of rice straw treated with steam pressured boiling water, 3% NaOH, and 3% H2SO4 with maximum yields of 0.12, 0.15, and 0.19 g ethanol per g rice straw, respectively. These results suggested that I. consors could produce ethanol from the components of cellulose and hemicellulose including glucose, mannose, xylose, cellobiose as well as rice straw treated with steam pressured boiling water, dilute sodium hydroxide, and dilute sulfuric acid. This is the first report that I. consors mycelia produce ethanol from various sugars and lignocellulosic substance including rice straw.

최근 우리나라의 제주와 남해 해안에 중국에서 발생한 괭생이모자반이 해류를 따라 대량 유입되고 있다. 대량 유입된 괭생이모자반은 해상에서 인간에게 피해를 입힐 뿐만 아니라, 해안에 밀려와 쌓여 악취를 풍기는 원인이 되고 있다. 이에 본 연구에서는 수거한 괭생이모자반을 바이오에탄올 생산용 바이오매스로써의 활용 가능성을 검토하였다. 그 결과, 괭생 이모자반과 다른 갈조류로부터의 바이오에탄올 생산성을 비교했을 때, 괭생이모자반으로부터 비슷한 양의 환원당이 추 출되었으나, 바이오에탄올 생산성은 낮게 평가되었다.

Recently, lots of Sargassum horneri were flowed in Jeju and south coast of South Korea from China by oceanic currents. The massive influx of S. horneri do not only damage human beings at sea, but also pile up on the coasts, consequently emitting an offensive odor by decay. In this study, as a result, the use as a biomass for bioethanol production of the collected S. horneri was examined. When comparing the bioethanol productivity of the S. horneri and other brown algae, a similar amount of reducing sugar was extracted from the S. horneri, while bioethanol was lower.

This study reviewed on the research trend of sources and utilization of the byproducts(Lignin) from bioethanol production process with lignocellulosic biomass such as wood, agri-processing by-products(corn fiber, sugarcane bagasse etc.) and energy crops(switch grass, poplar, Miscanthus etc.). During biochemical conversion process, only Cellulose and hemicellulosic fractions are converted into fermentable sugar, but lignin which represents the third largest fraction of lignocellulosic biomass is not convertible into fermentable sugars. It is therefore extremely important to recover and convert biomass-derived Lignin into high-value products to maintain economic competitiveness of cellulosic ethanol processes. It was introduced that lignin types and characteristics were different from various isolation methods and biomass sources. Also utilization and potentiality for market of those were discussed.

Seaweed is a third-generation biomass that can be used in bioenergy production and has many advantages. The seaweed grows quickly, is lignin-free and is not used as a food crop. The red seaweed, Euchema sponosum, is cultivated in Indonesia. The first step, seaweed slurry was pretreated by thermal acid hydrolysis and enzyme treatment. Optimal pretreatment condition was determined with 11% (w/v) solid content of seaweed and 150 mM sulfuric acid at 121℃ for 40 min. And enzyme saccharification was carried out Celluclast 1.5L and Viscozyme L at pH 4.5, 40℃. However, E. spinosum produced Five-HMF of 6 g/L after thermal acid hydrolysis. To removed 5-HMF, in addition of active charcoal was carried out in the range of 3-6% at room temperature for 2 hour. 5-HMF was reduced from 6 g/L to 1 g/L on 6% active charcoal. The ethanol fermentation was carried out using SHF with Kluyveromyces marxianus KCTC 7150. The ethanol fermentation from 5-HMF removed E. sponosum hydrolysate produced 18 g/L using K. marxianus for 48 h. On the other hand, ethanol fermentation was prolonged when 5-HMF existed.

5.6 Million ton/year of rice straw is produced in Korea. If this amount of rice straw is used for lignocellulosic biothanol production, it can replace more than 10% of the whole transport gasoline use in Korea. In this study, the ethanol conversion rate was evaluated by simultaneous saccharification and fermentation (SSF) for the development of bioethanol production techniques from dilute-acid pretreated rice straw biomass. From analysis of NREL standard quantification method of cellulosic biomass, Rice straw consisted of 40~42% of cellulose, 23~25% of hemicellulose, 20~22% of lignin and 10-12% of ash, and 2% of etc. The sample was pretreated with 1% H2SO4 solution at 160℃ for 5 minutes using cylinder type reactors. Pretreated sample contained of 39% of glucan. Alcohol fermentation was performed according to NREL standard protocols of SSF. For the enzymatic reaction, cellulase complex and β-glucosidase were added as 30FPU/g and 30CBU/g respectively. Before the fermentation seed culture was carried out with Saccharomyces cerevisiae KACC30008 at 30℃ for 24 hours. Culture media consisted of 5% of glucose, 1% of yeast extract and 2% of peptone. SSF fermentation was carried out for 72 hours and ethanol yields of α-cellulase, dilute-acid pretreated rice straw and hot water pretreated rice straw were 92.3%, 81.2% and 25.7%, respectively. In conclusion, it was confirmed that one ton of rice straw produced 214L of ethanol. which was 73.3% of theoretical yield.

Lignocellulosic materials are regarded as an alternative energy source for bioethanol production to reduce our reliance on fossil fuels. Pretreatment is important for improving the enzymatic digestibility and fermentation yield. In this study, barley straw was pretreated by using NaOH, to produce bioethanol. And by using RSM(Response urface Methodology), the optimum conditions of pretreatment was investigated. The independent variables for pretreatment were selected as pretreatment temperature, pretreatment time and NaOH concentration. The determined optimum condition is pretreatment temperature ; 129.02°C, pretreatment time ; 3.23h, NaOH concentration ; 12.58% (w/w, NaOH/Biomass). The results are as follow : Delignification ; 71.50%, Glucose concentration ; 31.61g/L, Ethanol concentration : 15.36g/L. This results may provide useful information with regard to the development of more economic and efficient bioethanol production.

Eichhornia crassipes is macrophyte that originated in Amazon in South America. Eichhornia crassipes is utilized for purification of water or as a feedstock of producing useful materials and feed of animals. Eichhornia crassipes is one of the potential biomass for production of bioethanol, because of it grows fast and it is not edible [1]. For the production of bioethanol, most effective pretreatment method of water hyacinth is alkaline/oxidative pretreatment (A/O pretreatment) using NaOH/H2O2 solution [2]. In this study, to increase the production of bioethanol we optimized A/O pretreatment condition and hydrolysis condition. For hydrolysis of biomass, different commercial enzymes were used. A/O pretreatment was treated in different NaOH/H2O2 concentration and reaction temperature. Enzymatic hydrolysis was performed under different enzyme concentrations and enzyme ratios. After ethanol fermentation using Saccharomyces cerevisiae KCTC 7928, the concentration of glucose and ethanol was analyzed by HPLC with RI.

As biorefineries replace oil refineries, society and the environment will benefit from a switch from hydrocarbon feedstocks to renewable carbohydrates as a source of energy, materials and chemicals. Lignocellulosic biomass-based ethanol technologies are rapidly evolving and bottlenecks are being identified that need to be overcome to achieve widespread commercialization. The study, in this sense, was carried out ammonia percolation (AP) pretreatment using cassava stem as lignocellulosic biomass, performed enzymatic saccharification and fermented into ethanol by Saccharomyces cerevisiae. As results of the pretreatment, the delignification ratio appeared very efficiently of 45% or more (120°C, 120min) and cellulose which can be converted to ethanol was excellently conserved. Also, the result of the saccharification, glucose is obtained 27.4 g/L by enzymatic digestibility. And ethanol concentration reached to 12.4 g/L in 24 h. This study showed not only total process for bioethanol production from agricultural biomass but also efficient pretreatment of lignocellulosic material.