Engine technology and research trends of advanced biofuel as alternative fuel for transportation vehicles

Chia sẻ: Nguyễn Thảo | Ngày: | Loại File: PDF | Số trang:9

Thêm vào BST

Báo xấu

24
lượt xem 1
download

Download Vui lòng tải xuống để xem tài liệu đầy đủ

The reckless use of fossil fuels causes a lot of problems such as depletion of fossil fuels, rising oil prices, air pollution, and fine dust. 27% of the world's major energy sources are used for transportation, and most of the transportation fuels are used as fossil fuels.

Chủ đề:

Bình luận(0) Đăng nhập để gửi bình luận!

Lưu

Nội dung Text: Engine technology and research trends of advanced biofuel as alternative fuel for transportation vehicles

International Journal of Mechanical Engineering and Technology (IJMET) Volume 10, Issue 03, March 2019, pp. 576-584. Article ID: IJMET_10_03_059 Available online at http://www.iaeme.com/ijmet/issues.asp?JType=IJMET&VType=10&IType=3 ISSN Print: 0976-6340 and ISSN Online: 0976-6359 © IAEME Publication Scopus Indexed ENGINE TECHNOLOGY AND RESEARCH TRENDS OF ADVANCED BIOFUEL AS ALTERNATIVE FUEL FOR TRANSPORTATION VEHICLES Byungmo Yang and Haengmuk Cho Division of Mechanical and Automotive Engineering, Kongju National University, Chungnam, Cheonan, Republic of Korea. *Corresponding author ABSTRACT The reckless use of fossil fuels causes a lot of problems such as depletion of fossil fuels, rising oil prices, air pollution, and fine dust. 27% of the world's major energy sources are used for transportation, and most of the transportation fuels are used as fossil fuels. Biofuels, which are attracting attention as a clean alternative energy source, are most actively applied to transportation fuels because of their environment- friendly characteristics, but they have problems in fuel production cost and engine technology development. In order to solve these problems, research trends in domestic and overseas researches and engine dedicated to biofuels are described. In addition, the development of technologies that can reduce fuel production costs and the establishment and operation of policies for more stable fuel supply are required more flexibly to cope with sudden environmental changes. Key words: Advanced biofuel, Engine technology, Emission characteristic, Engine performance Cite this Article Sutrisno, Setyawan Bekti Wibowo, Sigit Iswahyudi and Tri Agung Rohmat, Vortex Dynamic Investigation of Wing Slotted Gap of Saab Jas Gripen C- Like Fighter, International Journal of Mechanical Engineering and Technology, 10(3), 2019, pp. 576-584. http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=10&IType=3 1. INTRODUCTION Thoughtless use of fossil fuel is causing numerous problems such as depletion of fossil fuel, oil price rise and air pollution. In particular, 27 % of major energy source is globally used for transportation and fossil fuel is mostly used as transportation fuel [1,2]. The exhaust gas emitted from fossil fuel is the key pollutant of green-house gas that causes global warming, and the exhaust gas resulting from combustion of such fossil fuel generates substances harmful to human health. For NOx and PM which are major exhaust gases, the emission http://www.iaeme.com/IJMET/index.asp 576 editor@iaeme.com
On-Street Parking Problems in Cbd Area & Remediel Measures-A Case Study of Godhra City standard has been strengthened in phases from EURO 1 (enforced in 1993) to EURO 6 (enforces in 2014). EURO 6 is the highest level exhaust gas control among the EURO controls enforced previously, and the controls on NOx and PM have been strengthened to 80 % and 60 % of the immediately preceding EURO 5 control respectively. New policies that support diffusion of environment-friendly alternative fuels have been announced by many countries in the world to overcome the limit of fossil fuel while solving problems of global warming and environmental pollution. Biofuel that receives attention as a clean alternative energy source is most actively used as a transportation fuel due to its environment-friendly characteristic. Biofuel can replace fossil fuel without causing a major change in the existing supply base and can also substantially reduce emission of environmental pollutants. Moreover, the high oil price continuing recently makes the countries that want to bail out of dependence on the petroleum from the Middle East enforce a policy of expanding supply of and support for biofuel. Also, as the concentration of ultrafine dust in Korea caused by automobile exhaust gas is at a very serious level, the Government has enforced the Polluting Vehicle Operation Control System on old diesel vehicles pursuant to „Emergency Measures to Reduce Fine Dust‟, and it is scheduled to be gradually expanded to other areas. According to the „First Annual Report on Global Air announced by „HEI (Health Effect Institute)‟, a US private environmental health organization, the mean annual ultrafine dust concentration in Korea on which population weight is reflected has increased from 26 (1 microgram per of air) in 1990 to 29 in 2015(Fig. 1). Following the promotion of the policies at home and abroad that make use of new renewable energy mandatory, use of bioenergy of which the percentage is the highest next to waste energy (67.7 % in 2012) among the total new renewable energy supply is planned to gradually increase. In this study, we intend to introduce the trends of studies carried out at home and abroad to solve such issues and the technologies related to the engines that exclusively use biofuel. Figure 1 Average annual population – weighted PM2.5 concentrations in 2015 2. ADVANCED BIOFUEL R&D TREAND 2.1. Utilization of nonedible raw materials From a raw material point of view, as all the existing biofuels use grain as the raw material, all the biofuels made from nonedible bio-mass fall under the next generation biofuels. Representative examples of such nonedible biomass include lignocellulose and marine algae. The process of manufacturing biofuels from nonedible raw materials can be divided into http://www.iaeme.com/IJMET/index.asp 577 editor@iaeme.com
Naitik Gandhi and Jayesh Juremalani biological technology and thermo-chemical technology. As shown in Fig. 2, when sugar is extracted from biomass, it can be converted into a fuel by microbes. Bio-oil or synthetic gas can be manufactured by pyrolyzing lignocellulosic materials in an oxygen poor condition, and such an intermediate can be also converted into a biofuel through the conversion process using a chemical catalyst. Figure 2 Synthetic method of biodiesel from triglyceride. 2.2. Utilization of marine algae as raw materials As the perception that not only the limited land but also the sea have to be utilized to cope with the demand for bioenergy which will rapidly increase in the future proliferates, studies attempting to mass produce marine biomass to utilize it for production of biofuel are also actively carried out. Differently from lignocellulose which is an actually existing biomass resource, in the case of marine bio-mass, uncertainty about resource acquisition is found to be an obstacle. In the case of microalgae being particularly reviewed as promising species among marine biomass, though there are autotrophic culture for which the energy source is sunlight and heterotrophic culture for which the energy source is organic carbon, as stable supply of organic carbon may be difficult in the case of a mass production process, studies on development of autotrophic culture technology have been more invigorated. However, as the utilization efficiency of sunlight which is the main energy source rapidly drops when the volume of the reactor increases, no mass production technology has yet developed. Besides, in the case of microalgae, as much energy is consumed for harvest of biomass with the existing technology because the cell density of the culture medium is very low showing a value not higher than 2g/l, the technologies of harvesting and enriching microalgae more efficiently are required to be developed. As not only a light source, CO2 and water but also different nutritive salts such as nitrogen, phosphorous, etc. are required for growth of microalgae, such nutritive salts should be added to the culture medium when culturing microalgae. As the nutritive salts added at this time have a direct effect on the production unit price of bio-diesel, the unit price of culturing microalgae can be lowered if low-priced nutritive salts are added. For such a reason, studies on reducing the unit price of culturing microalgae by using wastewater containing nutritive salts are actively carried out. If wastewater is utilized as a nutrition source, the effects of reducing the unit price of culturing microalgae and of removing pollutants can be expected. But, as the chemical composition of the wastewater changes every day, there is a difficulty in using it as a microalgae culture medium. As biodiesel raw materials in diverse forms show differences in their chemical compositions, etc., to actually utilize them as a fuel, the composition and characteristics of each raw material are required to be studied. The first problem of the next generation biofuel is stable supply of raw material. Though the production of the biofuel for transportation has steeply increased since 2005 when climatic change became a serious issue in earnest, the increasing trend of biofuel production stopped after 2010 as the price of the grain used as the raw material jumped. However, as mentioned http://www.iaeme.com/IJMET/index.asp 578 editor@iaeme.com
On-Street Parking Problems in Cbd Area & Remediel Measures-A Case Study of Godhra City earlier, because supply of biofuel 9 times that currently supplied is required to solve the climatic change problem, a raw material supply plan for this is required to be established. Second, as the fuel properties of bio-ethanol and bio-diesel which are currently used as biofuels for transportation are not good, the maximum mixing rate is 10 % and 7 % respectively. But, as the biofuel mixing rate should be in-creased to minimum 27 % to realize 450 scenario, new biofuels with superior fuel properties are required to be developed. Third, though the objective of supplying biofuel is reduction of CO2 in the transportation sector, as the CO2 reduction effect of the biofuel currently supplied is found to be not high in LCA (Life Cycle Analysis), supply of biofuel with a higher CO2 reduction effect is important. EU and USA are planning to strength the minimum CO2 reduction rate of biofuel supplied after 2014 and 2018 to 35 % and 50 % respectively to increase the CO2 reduction effect of biofuel supply. 2.3. Improvement of biofuel properties Mixed use of bioethanol and bio-diesel which are the biofuels currently supplied is permitted only at a very limited concentration due to the difference in the material properties from those of the petroleum-based fuel. Bioethanol and biodiesel are permitted to be mixed at the concentration of maximum 10 % and 7 % respectively. For high content mixing of biofuel, improvement of bio-fuel properties is important. The key in such improvement of material properties is deoxydation, removal of oxygen contained in biofuel. The processes reviewed for deoxydation include hydrogenation carried out with hydrogen added and decarboxylation carried out without adding hydrogen. Though the hydro deoxygenation has an advantage that yield can be increased, it has a problem that hydrogen should be supplied from outside and, though the decarboxylation does not require an outside hydrogen supply source, it has a problem that the yield of biofuel decreases due to loss of carbon. Accordingly, if no large quantity hydrogen supply source is available, the deoxydation technology by decarboxylation is required to be applied. As to biofuel with improved material properties, only Hydro treating Bio-Diesel (HBD) has been commercialized [1]. Bioethanol not only has a higher oxygen content than that of gasoline but also its material properties are very different as it is a low molecular weight compound. Accordingly, the interest in butanol of which the molecular weight is bigger is picking up. Though the material properties of bio-butanol is superior not only because its oxygen content is lower than that of ethanol but also because its molecular weight is bigger, as it is highly toxic to microbes, the maximum concentration that can be manufactured through a fermentation process is very low showing a value of about 2 %, which is about 1/6 that of ethanol [5]. Accordingly, as the enriched energy cost of bio-butanol is so high that there are difficulties in commercializing it. To solve such a problem, along with development of the strain with reinforced resistance to butanol, a study on development of a low energy consumption type butanol refinement technology is being carried out. Recently, studies on conversion of biomass to long chain hydrocarbon utilizing a chemical catalyst or biological catalyst is being carried out to develop biofuel of which the properties are closer to those of the petroleum-based fuel. 2.4. Carbon Dioxide Reduction Efficiency Besides the problem that the biofuels currently supplied is made from grain, many controversies are raised on its CO2 reduction effect. In the case of ethanol produced from corn of which the quantity actually supplied is the biggest, it is reported through an LCA that it actually aggravates the global warming problem as it generates 3 % more CO2 than gasoline does if the process fuel is utilized as coal [6]. If the by-products generated in corn plantations are utilized as an energy source, it is shown that the CO2 reduction rate can be increased by about 50 % at the maximum. Also, if the raw material is replaced with lignocellulose not http://www.iaeme.com/IJMET/index.asp 579 editor@iaeme.com
Naitik Gandhi and Jayesh Juremalani corn, the CO2 reduction rate of ethanol is reported to increase by maximum about 86 %. Such a study result shows that the rate of CO2 reduction resulting from use of biofuel differs greatly depending not only on the raw material used but also the process technology applied. 3. ADVANCED BIOFUEL ISSUE Thoughtless use of fossil fuel causes numerous problems such as depletion of fossil fuel, oil price increase, etc., and new policies have been announced by many countries in the world that support diffusion of environment-friendly alternative fuels to overcome the limit of fossil fuels while solving the problems of global warming and environmental pollution. Therefore, bio-diesel which receives attention as a clean alternative energy source is most actively used as a fuel for translation. Bio-diesel can replace fossil fuel without causing a major change in the existing supply base and can also substantially reduce emission of environmental pollutants. Moreover, the high oil price continuing recently makes the countries that want to bail out of dependence on the petroleum from the Middle East enforce a policy of expanding supply of and support for biofuel. Though the next generation bio-fuel is desirable in that it utilizes nonedible raw material, it has a problem that the production unit price is still high. Accordingly, development of technologies for improvement in the economic efficiency of the next generation bio-fuel is actively in progress. The core of such improvement in economic efficiency is simplification of process and enhancement of bio-fuel yield through application of a highly efficient catalyst. For this reason, as biotechnology advances recently, development of a customized microbial catalyst that has diverse fermentation functions is intensively studied in particular. As shown in Fig. 6, though production of catalyst and C5, C6 fermentation were carried out by a different strain respectively in the case of lignocellulosic ethanol manufacturing process in the past, studies are carried out recently to lower the ethanol manufacturing cost by simplifying the manufacturing process of lignocellulosic ethanol through development of a customized strain that contains each and every gene related to fermentation [3]. Genomics Proteomics Bio-Informatics Custom biocatalyst - C5, C6 degradative enzyme production Biomass - C5 alcohol fermentation function Bioalcohol - C6 alcohol fermentation function - Production of lignin-degrading enzyme Figure 3 Biocatalyst for the consolidate bioprocess Recently, a study result has been announced on development of a strain that converts biomass directly into the bio-gasoline having the same material properties as the petroleum- based hydrocarbon. To avoid the difficulty in sugar extraction process which is the biggest obstacle in the production process of a lignocellulosic bio-fuel, a fusion process which gasifies a lignocellulosic material through thermal decomposition and then converts the synthetic gas so generated into a fuel using microbes is also under development. Though the said technology has an advantage that pre-treatment which is the most serious problem in production of a lignocellulosic fuel through a bioprocess can be avoided, there is a problem that, as the water solubility of the synthetic gas is low, its contact efficiency with microbes as http://www.iaeme.com/IJMET/index.asp 580 editor@iaeme.com
On-Street Parking Problems in Cbd Area & Remediel Measures-A Case Study of Godhra City a substrate is low. Accordingly, to improve the reaction speed and the yield, a process is required to be developed that can enable the synthetic gas substrate to more efficiently contact the microbial catalyst. Chemical Biocatalyst catalyst Gasification / Fermentation Biomass Bioalcohol Refining / Refining Figure 4 Hybrid process for biofuels 3. BIOFUEL ENGIEN 3.1. SI engine The representative biofuel used for SI engine is ethanol and ethanol is used as mixed fuels of various forms rather than being used as pure ethanol. Up to 10 % ethanol is already used for the gasoline supplied in the market, and technology is being developed in the form of a leaded fuel car that can use up to E85 (mixture of 85 % ethanol and 15 % gasoline in volume ratio) in the form of a full-scale alternative fuel. Ethanol mixed fuels emit less volatile materials and carbon mon-oxide than gasoline does and emission of harmful materials such as benzene can be reduced considerably. On the other hand, it is known that emission of a toxic pollutant such as acetaldehyde increases. The US government positively recommend use of leaded fuel cars and recycled fuels by granting tax benefits to the users of leaded fuel cars. The representative US auto manufacturers are producing leaded fuel passenger cars of diverse models. 3.2. CI engine As to the bio-diesel technology and status, biodiesel that is receiving attention as an environment-friendly fuel to replace diesel can be also manufactured from oil-based biomass including oil. Though bio-diesel fuel has sufficient calorie to be used as a vehicle fuel, it is difficult to be directly applied to a vehicle diesel engine as the viscosity is high because it is a high polymer. Accordingly, the viscosity should be lowered to the level similar to that of diesel by depolymerizing the oil through a chemical reaction. When a catalyst is put into the fat (animal/ vegetable fat) to react it with alcohol, it is decomposed into 3 molecules of alkyl ester and glycerin, which can be applied to diesel engines (after removing glycerin) as it has material properties similar to those of diesel. Figure 4 Injection characteristics of multistage fuel http://www.iaeme.com/IJMET/index.asp 581 editor@iaeme.com
Naitik Gandhi and Jayesh Juremalani Bio-diesel brings about less engine abrasion as its lubricating property is better than that of petroleum diesel and emits less environmental pollutant than diesel does as more complete combustion takes place during engine combustion than with diesel due to the oxygen contained in bio-diesel because biodiesel is an oxygenated fuel which contains about 10 % oxygen differently from diesel. But, as the material properties of bio-diesel are a little different from those of diesel, if the content of bio-diesel is high, it may cause a problem to the existing diesel vehicle, and auto manufacturers are currently providing warranty repair for failures of the vehicles which use diesel fuel mixed with bio-diesel only when the percent-age is 5 % or less. Accordingly, in line with the promotion of the policy, positive R&D of diesel engines which exclusively use bio fuel is required. Also, following the reinforcement of the control on automobile exhaust gas, it is a high time to promote reduction of harmful exhaust gas emitted by car, as a result of which positive study on application of bio-fuel to automobile is required to be carried out. According to Diesel Technology Forum, domestic sales of diesel cars in the USA achieved outstanding growth of 37 % increase in 2011 when compared with that of 2010. Professional market forecasting organizations are predicting that diesel car sales which is about 3 % of the total US market at present will grow to the extent it reaches 6.0 ~ 6.5 % by 2015 and 7.4 % in 2017. Though German auto manufacturers are expected to enjoy a dominant position also in 2012 by introducing up to 16 motels in the US diesel passenger car market, the three biggest US manufacturers are also expected to introduce diesel types of full-size trucks and super duty pickup trucks. The American Society for Testing and Materials has defined the standard for pure bio- diesel (B100) and approves mixing of up to 20 % volume of bio-diesel (ASTM D7467) with petroleum extracted diesel fuel. Though not all the engine manufacturers have adopted the Bio-diesel Regulation ASTM D-6751 as the fuel condition specified in the user manual, all the diesel engine manufacturers are expected to include this regulation in their manuals in the near future. Figure 5 Injector diesel injection and combustion characteristic Though the companies that manufacture engines/vehicles that can use pure bio-diesel (B100) include Case IH, Deutz AG, Fairbanks Morse and New Holland, 77 % or more of the US engine/vehicle manufacturers currently produce equipment that can use B20 or lower percentage bio-diesel. While most of US engine manufacturers are developing engines that can use B20 bio-diesel, the bio-diesel mixing ratios of the fuels that can be used for the products of the engine manufactures in the countries other than the USA are much lower and products are developed to allow even B5 bio-diesel to be used. Including the 2011 model, the new Chevrolet diesel car of GM has been approved to use B20 bio-diesel. The diesel engine used for the F-series super duty truck of Ford is also produced to be able to use B20 biodiesel. The Ram Pickup Truck of Chrysler is also approved to use B20 bio-diesel. Also in the medium and high speed diesel engine field, the http://www.iaeme.com/IJMET/index.asp 582 editor@iaeme.com
On-Street Parking Problems in Cbd Area & Remediel Measures-A Case Study of Godhra City representative engine and vehicle manufacturers are developing diesel engines that can use bio-diesel. In addition to the C series engines of Caterpillar, the diverse engines of Cummins are also approved to use B20 bio-diesel. Though the existing diesel engine technology is applied as the base technology of bio-diesel engine technology, the technologies that are substantially affected by fuel change (example: injector, post-treatment device, engine control and operation mode, and part materials) are the fields that require more aggressive research and development to improve fuel efficiency and reduce the emission. Among the technological trend of engines that use recycled fuel to which we have to pay attention, there is the field of alternative fuel for military use. For example, the GGF (Green Great Fleet) program of the Navy Department is being carried out with the goal of increasing supply of alternative fuel to 50 % of the total fuel consumption by 2020 and, as recycled fuel accounts for a consider-able percentage of the alternative fuel, many studies for development and improvement of engines are carried out, for such a reason, in the academic, industrial and governmental research institutes. 5. CONCLUSION The renewability of bio-fuel eventually provides sufficient basis and possibility for it to become the basic fuel for power producing equipment replacing fossil fuels. But we can say that much effort is still required to be made in the aspects of policy and technology until we have flexibility toward natural factors such as drought, flood and scorching heat in short-term fuel supply problems. The price of corn is rapidly rising as a result of the rapid decrease in the corn production to the lowest level since 1995 due to the high temperature and scorching heat which have occurred almost all over the USA in the second and third quarters of 2012. When we take into account that about 27 % (2012 World of Corn Report) of the corn production is used for production of ethanol for fuel, the fuel production cost is expected to rapidly rise to meet the quantity of ethanol production defined by law. Moreover, the trend of crude oil price that shows more fluctuation than the technical factor does causes many risks to continuous use of alternative fuels and establishment of development/production plans for electric power machinery. Development of technologies that can lower the fuel manufacturing cost as well as establishment and application of various policies for stable supply of fuels are increasingly required so that even sudden environmental changes can be coped with. ACKNOWLEDGMENT This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT, Ministry of Science and ICT) (No. NRF- 2019R1A2C1010557). REFERENCES [1] IEA, World Energy Outlook, 2010. [2] IEA, Renewable Energy – Medium term market report, 2014 [3] Zyl, W.H. Lynd, L.R., Haan, R., McBride, J.E., “Consolidated bioprocessing for bioethanol production using Saccharomyces cerevisiae”, Adv. Biocehm. Eng., Vol. 108, pp.205-235, 2007. [4] Huber, G.W., O‟Connor, P., Corma, A., “Processing biomass in conventional oil refineries: Production of high quality diesel by hydrotreating vegetable oils in heavy vacuum oil mixtures”, Appl. Catal. A: General, Vol. 329, pp. 120-129, 2007. http://www.iaeme.com/IJMET/index.asp 583 editor@iaeme.com
Naitik Gandhi and Jayesh Juremalani [5] Lin, X., Wu, J., Jin, X., Fan, J., Li, R., Wen, Q., Qian, W., Liu, D., Chen, X., Chen, Y., Xie, J., Bai. J., Ying, H., “Selective separation of biobutanol from acetonebutanol-ethanol fermentation broth by means of sorption methodology based on a novel macroporous resin”, Biotechnol Prog., Vol. 28, pp. 962-972, 2012. [6] Wang, M., Wu, M., Huo, H., “Life-cycle energy and greenhouse gas emission impacts of different corn ethanol plant types”, Environ. Res. Lett., Vol. 2, pp.024001, 2007. [7] C.D. Rakopoulos, K.A. Antonopoulos, D.C. Rakopoulos, D.T. Hountalas and E.G. Giakoumis, “Comparative performance and emissions study of a direct injection Diesel engine using blends of Diesel fuel with vegetable oils or bio-diesels of various origins”, En- ergy Conversion and Management, vol. 47, pp. 3272-3287, 2006. [8] Z Utlu, M S Kocak. “The effect of biodiesel fuel obtained from waste frying oil on direct injection diesel engine performance and exhaust emissions”. Renewable energy, 2008. http://www.iaeme.com/IJMET/index.asp 584 editor@iaeme.com