Supply Portfolio of Bioethanol in the Republic of Korea

배정환 한국경제학회 2014 The Korean Economic Review Vol.30 No.1

Despite the co-benefits of bioethanol, such as energy security, environmentalimprovement, CO2 emission reduction and development of associated industry, bioethanolblendedgasoline without subsidy is more expensive than pure gasoline in Korea. Therenewable fuel standard (RFS) can contribute to the development of a bioethanol market. However, without controlling the portions of domestic bioethanol, it is highly plausible thata new bioethanol market will be filled with imported bioethanol. If the entire supply ofbioethanol is imported, Korea can no longer expect those co-benefits. This study aims atsimulating the desirable ratios of domestic versus imported bioethanol as well as domesticversus imported feedstock for producing bioethanol in Korea by combining the marginalsocial benefit (MSB) with the marginal social cost (MSC) for bioethanol supply. MSB isderived from a choice experiment and the MSC is derived from the differences in thebioethanol production costs and the petroleum price. The simulation results show thatconsiderable portions of bioethanol should be produced domestically under the conditionthat MSB is equivalent to MSC in bioethanol production. Thus, the upcoming RFS policyshould allow for some quota on behalf of domestic bioethanol with domestic feedstock ormore credit should be given to the petroleum companies that use domestic bioethanol withdomestic feedstock.

Supply Portfolio of Bioethanol in the Republic of Korea

( Jeong Hwan Bae ) 한국경제학회 2014 The Korean Economic Review Vol.30 No.1

Despite the co-benefits of bioethanol, such as energy security, environmentalimprovement, CO2 emission reduction and development of associated industry, bioethanolblendedgasoline without subsidy is more expensive than pure gasoline in Korea. Therenewable fuel standard (RFS) can contribute to the development of a bioethanol market. However, without controlling the portions of domestic bioethanol, it is highly plausible thata new bioethanol market will be filled with imported bioethanol. If the entire supply ofbioethanol is imported, Korea can no longer expect those co-benefits. This study aims atsimulating the desirable ratios of domestic versus imported bioethanol as well as domesticversus imported feedstock for producing bioethanol in Korea by combining the marginalsocial benefit (MSB) with the marginal social cost (MSC) for bioethanol supply. MSB isderived from a choice experiment and the MSC is derived from the differences in thebioethanol production costs and the petroleum price. The simulation results show thatconsiderable portions of bioethanol should be produced domestically under the conditionthat MSB is equivalent to MSC in bioethanol production. Thus, the upcoming RFS policyshould allow for some quota on behalf of domestic bioethanol with domestic feedstock ormore credit should be given to the petroleum companies that use domestic bioethanol withdomestic feedstock.

국내 바이오에탄올에 대한 비선형적 선호에 관한 연구

배정환 ( Jeong Hwan Bae ) 한국환경경제학회·한국자원경제학회(구 한국환경경제학회) 2014 자원·환경경제연구 Vol.23 No.3

최근 우리나라에서도 바이오에탄올 혼합을 의무화하는 제도 도입을 준비하고 있다. 바이오에탄올은 기후변화에 대응하기위한 수단일 뿐만 아니라 에너지 안보 측면에서 휘발유에 대한 유력한 대체연료이다. 그러나 일반 휘발유보다 판매가격이 더 높은 바이오에탄올 혼합 휘발유를 유통시키기 위해서는 정부 지원이 선행되어야 한다. 따라서 바이오에탄올 소비로 인한 편익이 비용보다 높다면 정부 지원의 정당성이 확보될 수 있을 것이다. 본 연구는 전국의 휘발유 자동차 운전자를 대상으로 바이오에탄올 선호도를 조사하였다. 패널로짓모형을 이용하여 3~10% 바이오에탄올 혼합 휘발유에 대한 속성을 분석한 결과 국산원료를 이용한 에탄올 지불용의액이 리터당 52원으로 나타났다. 한편 바이오에탄올 혼합률이 증가할수록 역 U자형의 비선형 선호도를 갖는 것으로 추정되었고, 전환점에서 바이오에탄올 혼합률은 6.5%로 나타났다. 또한 소득수준과 바이오에탄올 선호간에도 역 U자형의 관계가 나타났고, 전환점 소득 구간이 250~299만 원인 것으로 나타났다. 한편 정치적으로 보수 성향일수록 바이오에탄올혼합유를 선호하고, 바이오에탄올에 대한 사전 지식이 있거나 환경보전에 대한 중요성이 높을수록 바이오에탄올혼합유 이용에 비판적인 것으로 나타났다. 다만 본 연구는 휘발유에 바이오에탄올의 혼유를 의무화하는 정책에 대한 소비자의 지불용의액을 실증분석하고자 하였지만, 우리나라에서 법제화된 RFS 제도에 직접적으로 부합하게 설문이 설계되지 않았고, 바이오에탄올의 원료조달, 제조, 의무혼합비율, 가격인상액 간에 직교관계를 가정했다는 한계가 존재한다. 또한 모형 추정결과가 확정적이지 않다는 점에서, 위 결과를 우리나라에서 법제화된 RFS 제도에 그대로 적용하는 데는 주의를 요한다. Recently, there has been a debate as to whether bioethanol should replace some portion of gasoline for fuels in South Korea, as energy security as well as climate change issues are rising as a significant national agenda. However, a considerable amount of subsidy will be required to compensate for the higher price of bioethanol-blended gasoline. In this context, government subsidy will obtain justification only when the positive social gains from consuming bioethanol for fuels can exceed the negative social costs. Through a nation-wide choice experimental survey, we examine if South Koreans have a positive value as well as non-linear preferences on substituting bioethanol for gasoline. The results reveal that the willingness to pay for purely domestic bioethanol-blended gasoline within 10% is about 52 KRW; Koreans have concave preferences on the blending ratio of bioethanol to gasoline. The turning point of the blending ratio of bioethanol was 6.5%. Also, we found inverse U-shaped curve between income and bioethanol choice probability and the turning point of the income was calculated as 250~299million KRW. Politically conservative propensity advocates uses of bioethanol blended gasoline, but awareness on bioethanol or more weights on environmental conservation have significantly negative effects on the choice of bioethanol. However, the design of the survey questionnaire is incompatible with the RFS of Korea and assumes orthogonality among the following four interrelated attributes: (i) domestic or offshore procurement of feedstocks in the case of domestic production, (ii) domestic production or import of bioethanol, (iii) the blending ratios, and (iv) the retail price increases. In addition, the results of model estimation and of model selection test are not definite. Hence, the results in this study should not be directly applied to the design of the specifics of the Korean RFS. Hence, the results in this study require cautions in applying to the design of the Korean RFS policy.

미세조류를 이용한 바이오 에탄올 생산 연구에 관한 고찰

박종관(Jongkwan Park),문한솔(Hansol Mun),박민주(Min-Ju Park),장희원(Heewon Jang),정대운(Dae-Woon Jeong) 대한환경공학회 2020 대한환경공학회지 Vol.42 No.3

목적 : 바이오 에탄올은 식물체로부터 유래하고, 추가적인 시설 투자없이 기존의 에너지 인프라를 이용할 수 있다는 점에서 중요한 에너지원으로 알려져 있다. 또한 연소시에도 저농도의 오염물질을 매출하는 친환경 에너지 자원이다. 특히, 미세조류는 빠르게 성장하고 바이오에너지로 변환할 때 상대적으로 쉬운 전처리를 할 수 있다는 점에서 효과적인 바이오 에탄올을 위한 생물자원으로 보고되었다. 본 총설에서는 미세조류를 이용한 바이오 에탄올 생산에 대한 일반적인 내용과 다양한 생산 방식, 그리고 바이오 에탄올에 대한 경제적 전망에 대한 정보를 제공하는 것을 목적으로 한다. 방법 : 최근에 게제된 논문을 수집하고 분석하였으며, 연구 내용은 현재 바이오 에탄올과 미세조류 연구에 관한 소개, 바이오 에탄올 생산에 관한 일반적인 정보, 바이오 에탄올 생산 공정, 경제적 실효성, 마지막으로 한계점 및 앞으로의 전망의 순서로 구성되어 있다. 결과 및 토의 : 높은 수율의 바이오 에탄올을 얻기 위해서 적절한 미세조류의 선택과 배양 방법이 중요하다. 그리고 바이오 에탄올 생산을 위한 미세조류의 물리적, 화학적, 생물학적 전처리 방법과 다양한 생산 공정에 대한 장단점을 소개하였다. 결론 : 미세조류는 빠른 성장 주기, 높은 탄수화물 함량, 상대적으로 손쉬운 전처리 방법으로 인해 바이오 에탄올 생산을 위한 에너지원으로 기대가 된다. 그러나 경제성 향상을 위해 조류의 배양방법, 전처리 기술, 높은 수율의 바이오 에탄올을 생산하기 위한 적절한 발효 단계 등에 대한 추가적인 연구가 필요하다. Objectives : Bioethanol is known as an important energy source that comes from plants, uses existing energy infrastructure without additional investment, and emits a low concentration of pollutants during combustion as eco-friendly renewable energy. Microalgae is reported as an effective material for producing bioethanol because of rapid biomass growth and relatively easy pretreatment steps. The objectives of this study are 1) to introduce general information of bioethanol production, 2) to show various processes for bioethanol production from microalgae, and 3) to provide an economic perspective of bioethanol. Methods : Recent published peer-reviewed papers were collected and analyzed. The contents follow the order: 1) introduction, 2) general information about microalgae for bioethanol production, 3) bioethanol producing processes, 4) economic feasibility, and 5) conclusion. Results and Discussion : The selection of the microalgae species and growing method are important to obtain high yield bioethanol. Physical, chemical, biological pretreatment was introduced. Also, comparison of the bioethanol producing processes was provided. Conclusions : Bioethanol production from microalgae is a promising energy source because microalgae have lots of advantages as effective biomass such as rapid growth, high polysaccharide contents, and easy preparing step for bioethanol production. However, it has some limitations that need to overcome. Algae growing method, pretreatment technology, and fermentation steps still require advanced technology, which can improve economic feasibility.

Membrane separation processes for dehydration of bioethanol from fermentation broths: Recent developments, challenges, and prospects

Khalid, Azqa,Aslam, Muhammad,Qyyum, Muhammad Abdul,Faisal, Abrar,Khan, Asim Laeeq,Ahmed, Faisal,Lee, Moonyong,Kim, Jeonghwan,Jang, Nulee,Chang, In Seop,Bazmi, Aqeel Ahmed,Yasin, Muhammad Elsevier 2019 RENEWABLE & SUSTAINABLE ENERGY REVIEWS Vol.105 No.-

<P><B>Abstract</B></P> <P>Bioethanol has garnered a great interest as a potential energy source, mainly due to its sustainable and green nature. Generally, bioethanol is produced through the microbial conversion of biomass and biomass derived syngas. However, the dehydration and purification steps for achieving fuel-grade ethanol from the microbial production process consume tremendous amounts of energy. This high energy consumption limits the feasibility of microbial ethanol production on the commercial scale. In this context, selection of an optimal technology for product separation is essential for successful commercialization of microbially produced bioethanol. This article presents the recent developments in dehydration and purification technologies for bioethanol production using distillation and membrane based separation. Distillation and pervaporation are analyzed on the basis of the overall energy requirement, consumption, and economics. Pervaporation-assisted distillation approaches are also examined from the perspective of process systems engineering, including factors affecting the system performance. Furthermore, the role of simulation in technological development along with available mathematical models is discussed, and commercial status of pervaporation based separation is presented. Finally, the current status of the existing technology, challenges, and future research directions are identified from the perspective of achieving process sustainability on the industrial scale. Economic comparison between distillation and different hybrid schemes revealed that integrating distillation with membrane based separation techniques reduce the bioethanol production cost. Moreover, hybrid schemes that combine distillation with pervaporation, and steam stripping with vapor permeation are proved to be the best combinations for the cheapest bioethanol production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Recent developments in dehydration of bioethanol are presented. </LI> <LI> Conventional and membrane-based technologies are compared. </LI> <LI> Integrating pervaporation with distillation reduce the bioethanol production cost. </LI> <LI> The most economical hybrid schemes for bioethanol separation is identified. </LI> <LI> Operational optimization and thermodynamic evaluation of hybrid processes are required. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Impact of biodiesel in bioethanol blended diesel on the engine performance and emissions characteristics in compression ignition engine

Park, S.H.,Cha, J.,Lee, C.S. Applied Science Publishers 2012 APPLIED ENERGY Vol.99 No.-

In engine combustion studies of bioethanol blended diesel fuels, biodiesel is a very important blending fuel for preventing phase separation between diesel and bioethanol. The purpose of this study is to investigate the impact of biodiesel in bioethanol blended diesel fuel on ignition delay, premixed combustion phasing, engine performance and exhaust emissions characteristics. In this work, the fuel properties of diesel-bioethanol blends were measured and engine tests were conducted using a single cylinder diesel engine. Based on the experimental results, we found that increasing the biodiesel blending ratio recovered the reduced fuel density and cetane number of bioethanol blended diesel fuel, while the kinematic viscosity and surface tension both increased. In addition, the lower heating value (LHV) slightly decreased when biodiesel fuel was added. By increasing the blending ratio of biodiesel fuel, the ignition delay and the premixed combustion phasing advanced, and the IMEP decreased. However, the premixed combustion duration in all tested blended fuels showed almost similar values, regardless of the biodiesel contents. Biodiesel blending decreased the EI-HC emission in wide engine operating regions. In addition, for the premixed combustion phasing and ignition delay, the increase of biodiesel fuel influenced the decrease of EI-HC emission. In the case of EI-CO and EI-soot emissions at advanced injection timings (around 30<SUP>o</SUP> BTDC), when the combustion occurred in the squish area of the combustion chamber, the biodiesel blending impact was clear. The increase of biodiesel fuel reduced EI-CO and EI-soot emissions. In addition, the increase of biodiesel fuel slightly reduced the EI-NO<SUB>x</SUB> emission.

Determination of Water Content in Bioethanol Using the 1H NMR Chemical Shift Change

윤정빈,윤수연,김병주,안상두,최기환 대한화학회 2019 Bulletin of the Korean Chemical Society Vol.40 No.4

Chemical shift change in 1H NMR spectroscopy was used to determine water content in bioethanol. As water content in ethanol is increased, the proton peaks shifted to down-field due to the change in the microstructure of the water-ethanol mixture. The linear correlation between water content and chemical shift change enables the evaluation of water content in bioethanol. Because the same relationship between chemical shift change and the water content is obtained for both ethanol and bioethanol, water content in bioethanol can be determined using the calibration curve obtained with anhydrous ethanol. The developed method was validated by comparison to the results of Karl Fischer titration and was applied to commercially available bioethanols.

Comparison of red microalgae (<i>Porphyridium cruentum</i>) culture conditions for bioethanol production

Kim, Ho Myeong,Oh, Chi Hoon,Bae, Hyeun-Jong Elsevier Applied Science 2017 Bioresource technology Vol.233 No.-

<P><B>Abstract</B></P> <P>Microalgae biomass are useful resources in biofuel production. The objective of this study was to evaluate bioethanol production in response to <I>Porphyridium cruemtum</I> culture conditions. Enzymatic hydrolysis of seawater <I>P. cruemtum</I> (SPC) and freshwater <I>P. cruemtum</I> (FPC, 1% substrate loading, w/v) resulted in glucose conversion yields of 89.8 and 85.3%, respectively, without any pretreatment. However, FPC hydrolysate was more efficiently converted to ethanol about 7.1% than SPC hydrolysate. The comparison of separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) showed that SSF processing is a superior method for bioethanol production from both SPC and FPC. Though SSF processing (5% substrate loading, w/v) in a 500-mL twin-neck round bottom flask, we achieved ethanol conversion yields of 65.4 and 70.3% from SPC and FPC, respectively, after 9h. These findings indicate that <I>P. cruemtum</I> can grow in freshwater conditions and is an efficient candidate for bioethanol production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Porphyridium cruemtum</I> (PC) can grow in seawater and freshwater conditions. </LI> <LI> Freshwater <I>P. cruemtum</I> (FPC) biomass can efficiently produce the bioethanol. </LI> <LI> SSF process was superior to SHF process for bioethanol production from PC. </LI> </UL> </P>

Long-term production of bioethanol in repeated-batch fermentation of microalgal biomass using immobilized Saccharomyces cerevisiae

El-Dalatony, M.M.,Kurade, M.B.,Abou-Shanab, R.A.I.,Kim, H.,Salama, E.S.,Jeon, B.H. Elsevier Applied Science 2016 Bioresource Technology Vol.219 No.-

Separate hydrolysis fermentation (SHF) and simultaneous saccharification fermentation (SSF) processes were studied for bioethanol production from microalgal biomass. SSF was selected as an efficient process to enhance the bioethanol yield through repeated-batches using immobilized yeast cells. Combined sonication and enzymatic hydrolysis of Chlamydomonas mexicana generated 10.5 and 8.48g/L of ethanol in SSF and SHF, respectively. Yeast utilized maximum portion of total reducing sugar (TRS) reaching a consumption efficiency of 91-98%. A bioethanol yield of 0.5g/g (88.2% of theoretical yield) and volumetric productivity of 0.22g/L/h was obtained after 48h of SSF. Immobilized yeast cells enabled repetitive production of ethanol for 7 cycles displaying a fermentation efficiency up to 79% for five consecutive cycles. The maximum ethanol production was 9.7g/L in 2nd-4th cycles. A total energy recovery of 85.81% was achieved from microalgal biomass in the form of bioethanol. Repeated-batch SSF demonstrated the possibility of cost-effective bioethanol production.

Ethylene from renewable ethanol: Process optimization and economic feasibility assessment

Martina Frosi,Antonio Tripodi,Francesco Conte,Gianguido Ramis,Nader Mahinpey,Ilenia Rossetti 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

At present, ethylene is the most widely produced organic compound in the chemical industry. The maincommercial way to obtain ethylene is by steam cracking of a wide range of hydrocarbon feedstocks, butbiomass-derived ethanol can be catalytically dehydrated as a sustainable alternative route in order toexploit new renewable sources. The aim of this work is to design an optimal bioethanol-tobioethyleneplant, with a capacity of 445,652 ton/year, and to assess its economic feasibility. This designfeatures an improved production capacity and intensified energy management. The main novelty of this study is the use of diluted bioethanol solutions, bypassing the energy intensiveand expensive dehydration step. Moreover, while the first industrial bioethanol-to-bioethylene processuses NaOH to purify the outcoming flow from CO2, this plant uses diluted Methyldiethanolamine(MDEA), regenerated in situ. With this plant, the double of the capacity of the Braskem’s plant, nowthe largest one, can be reached in an environmentally more sustainable manner. A pinch analysis was performed, in order to minimize the energy consumption of the process by optimizingthe heat recovery systems. The economic analysis of the process consists of the evaluation of thetotal cost of the plant (TOC) including the sum of the CAPital EXpenditures (CAPEX) and the OPeratingones (OPEX), together with some sensitive profitability indexes (net yearly profit, net present value,net rate of return and cash flow analysis). The designed process presents an economically competitivesolution compared to the current bioethylene production units. Assuming a premium price of between 0.293 $/kg for diluted bioethanol, the proposed plant is competitivewith the lowest production cost for bioethylene (Brazil and India), while a sensitivity analysis ondiluted bioethanol price evidenced that this option remains competitive still in Europe with a bioethanolcost 0.65 $/kg.