BIOETHANOL Research Papers - Academia.edu (original) (raw)

The use of lignocellulosic biomass for the production of bio-based products is a worldwide tendency. The present study examines steam explosion pretreatment and subsequent enzymatic hydrolysis of different fast-growing tree species... more

The use of lignocellulosic biomass for the production of bio-based products is a worldwide tendency. The present study examines steam explosion pretreatment and subsequent enzymatic hydrolysis of different fast-growing tree species (poplar, willow, black locust, paulownia and ailanthus) to obtain sugars that can be substrate in various fermentation processes. Experimental results showed that the pretreatment of species with low wood density can be carried out under milder conditions compared to those with higher density. It was established that the efficiency of hydrolysis by a commercial cellulase complex also depends on the wood density, and the highest yield of glucose is reached from paulownia. The topochemical kinetic mechanism of cellulase hydrolysis of fast-growing tree species was established, and it was found that the activation energy and the pre-exponential factor increase with wood density decrease. The determinant for the process rate is the pre-exponential factor.

Performance and emissions characteristics from port injection SINJAI engine 650 cc operating on bioethanol-gasoline blended fuels of 0%, 5%, 10%, 15% and 20% were investigated on water brake dynamometers with power capacity 120 hp. The... more

Performance and emissions characteristics from port injection SINJAI engine 650 cc operating on bioethanol-gasoline blended fuels of 0%, 5%, 10%, 15% and 20% were investigated on water brake dynamometers with power capacity 120 hp. The properties of bioethanol were measured based on American Society for Testing Materials (ASTM) standards. Fuel consumption was measured by the time fuel consumption per 25 cc of fuel in a measuring glass whereas combustion air consumption was measured using an air flow meter. The emission parameters, exhaust gas temperature and air fuel ratio were measured using STARGAS exhaust gas analyzer. The increase of bioethanol content will increases the engine performance and reduces pollutan emission. The highest engine performance produced by E15 blended fuel with increased torsi, mean effective pressure and power output of 10,27 %, thermal efficiency 1,8% but specific fuel consumption increased approximatelly 12,42%. This condition occurs at engine speed 300...

The use of macroalgae (seaweed) as a potential source of biofuels has attracted considerable worldwide interest. Since brown algae, especially the giant kelp, grow very rapidly and contain considerable amounts of polysaccharides, coupled... more

The use of macroalgae (seaweed) as a potential source of biofuels has attracted considerable worldwide interest. Since brown algae, especially the giant kelp, grow very rapidly and contain considerable amounts of polysaccharides, coupled with low lignin content, they represent attractive candidates for bioconversion to ethanol through yeast fermentation processes. In the current study, powdered dried seaweeds (Ascophylum nodosum and Laminaria digitata) were pre-treated with dilute sulphuric acid and hydrolysed with commercially available enzymes to liberate fermentable sugars. Higher sugar concentrations were obtained from L. digitata compared with A. nodosum with glucose and rhamnose being the predominant sugars, respectively, liberated from these seaweeds. Fermentation of the resultant seaweed sugars was performed using two non-conventional yeast strains: Scheffersomyces (Pichia) stipitis and Kluyveromyces marxianus based on their abilities to utilise a wide range of sugars. Altho...

The Response Surface Methodology (RSM) is used here to analyse a large set of experimental data regarding the mechanical and environmental performances of an internal combustion engine (ICE) used to power a farm tractor. The aim is... more

The Response Surface Methodology (RSM) is used here to analyse a large set of experimental data regarding the mechanical and environmental performances of an internal combustion engine (ICE) used to power a farm tractor. The aim is twofold: (i) to demonstrate the effectiveness of RSM in quantitatively assessing the effects of biofuels on a complex system like an ICE; (ii) to supply the users with easy-to-use models to predict the effect of biofuel blends on performance and emissions of tractor engines and find an optimal blend according to given user-defined parameters. The methodology showed good prediction abilities: the calculated average errors for the first models were lower than 0.38 and 1.40% on 6 test cases, with a higher accuracy in the assessment of the ICE mechanical performance. As a result, two effective and user-friendly models for torque and NOx emissions were developed; they were subsequently used to single out some fuel blends having interesting effects in terms of ...

An industrial-scale molasses-based bioethanol production system was modeled and studied by conducting exergy, exergoeconomic, and exergoenvironmental analyses. The entire process was represented by a control volume, and its exergoeconomic... more

An industrial-scale molasses-based bioethanol production system was modeled and studied by conducting exergy, exergoeconomic, and exergoenvironmental analyses. The entire process was represented by a control volume, and its exergoeconomic and exergoenvironmental parameters were determined using the specific exergy costing (SPECO) approach. These exergy-based analyses were carried out to measure the overall exergy dissi-pation, cost, and environmental impact of the bioethanol production process based on actual operational ther-modynamic, economic, and environmental data. Natural gas showed the highest contribution to the total input exergy (61.1%) and total environmental impact rate (56.6%) of the process, while the highest contribution to its total cost rate (75.7%) was from molasses. The exergetic efficiency determined for the process was 35.9%, while the exergy dissipation accounted for 60.8% of its total input exergy. The unit exergoeconomic costs of the fuel and product were determined to be 6.2 and 20.9 USD/GJ, while the unit exergoenvironmental impacts of the fuel and product were 15.5 and 31.5 mPts/GJ, respectively. The exergoeconomic factor of the process was found to be 29.4%, while the exergoenvironmental factor was 0.74%. Overall, natural gas consumption was the most significant exergetic hotspot of the process, and hence more exergetically-sustainable alternatives should be considered to improve the process. Low-cost waste feedstocks need to be utilized to improve the economic viability of the process.

Switchgrass is currently being developed as a sustainable bio-energy crop due to its broad adaptability, high mass yield and low agricultural input. Its current conversion to biofuels is detrimentally impacted by its native recalcitrance... more

Switchgrass is currently being developed as a sustainable bio-energy crop due to its broad adaptability, high mass yield and low agricultural input. Its current conversion to biofuels is detrimentally impacted
by its native recalcitrance which is typically addressed using chemical and/or biological pretreatments. In this study, extractives free switchgrass was pretreated with steam, dilute H2SO4 and lime at 160 C for 1 h. The degradation and impact of pretreatment was estimated semi-quantitatively by 13Ce1H HSQC (heteronuclear single quantum coherence) NMR analysis of ball milled untreated and pretreated
switchgrass samples in perdeuterated pyridinium chlorideeDMSO-d6 solvent system. As a result of steam pretreatment the resulting switchgrass was depleted of xylan and a slight degradation of lignin
were observed. This was confirmed by the relative decrease of cross peak intensity for b-aryl ether, phenylcoumaran, resinol and dibenzodioxocin units. Significant structural changes observed due to the
lime pretreatment of switchgrass was deacetylation/dissolution of hemicellulose and the extent of delignification was less however, a preferential removal p-hydroxy of benzoyl ester, ferulate and coumarate type linkages were notified from the HSQC studies. Finally the most significant degradation resulted in acid pretreatment involving w90% loss of hemicellulose and a substantial degradation of various lignin sub-units. These results are further supported by the composition analysis of the respective switchgrass samples.

The biofuel industry is rapidly growing with a promising role in producing renewable energy and tackling climate change. Nanotechnology has tremendous potential to achieve cost-effective and process-efficient biofuel industry. Various... more

The biofuel industry is rapidly growing with a promising role in producing renewable energy and tackling climate change. Nanotechnology has tremendous potential to achieve cost-effective and process-efficient biofuel industry. Various nanomaterials have been developed with unique properties for enhanced biofuel production/utilization. The way forward is to develop nanotechnology-based biofuel systems at industrial scale.

–This study shows waste potato starch as potential feedstock for microbial single vessel SSF process for ethanol production using amylolytic fungi Aspergillus niger MTCC 281 and Saccharomyces cerevisiae MTCC 170. The modified single... more

–This study shows waste potato starch as potential feedstock for microbial single vessel SSF process for ethanol production using amylolytic fungi Aspergillus niger MTCC 281 and Saccharomyces cerevisiae MTCC 170. The modified single vessel process of combining two separate processes in one vessel was successful in producing maximum ethanol yield of about 15.85% (v/v) from 100 g/L dry waste potato powder using 12% (v/v) of Aspergillus niger and 12% (v/v) of Saccharomyces cerevisiae at 30 O C in shaker incubator, at 150 rpm for five days. The SSF process is economical, greener, safer, and sustainable as it is based on use of renewable and biological resources for production of bioethanol. This economical process could be a new biotechnological innovation as it can be efficiently implemented in industrial bioethanol production.

Fuel ethanol is an important renewable and sustainable fuel, produced in China by fermentation of mostly corn, wheat and cassava feedstock. Fermentation produces an ethanol-lean broth (10 to 12 vol%). Ethanol is recovered by distillation,... more

Fuel ethanol is an important renewable and sustainable fuel, produced in China by fermentation of mostly corn, wheat and cassava feedstock. Fermentation produces an ethanol-lean broth (10 to 12 vol%). Ethanol is recovered by distillation, followed by a molecular sieve drying beyond the azeo-tropic point. The distillation and molecular sieve operations consume most of the total energy used, with the steam consumption currently being ~1.8 kg/kg ethanol, including 0.5 kg/kg ethanol in the final molecular sieve stage during regeneration. The objectives of the paper are fourfold: 1) firstly to study the distillation process of a large-scale cassava-based fuel ethanol production (200,000 tons per year), by field measurements and by using an Aspen Plus V8.2 simulation, with and without energy integration of condensers and reboilers, resulting in a distillation steam consumption of ~1.3 kg/kg ethanol; 2) secondly, to examine the effects of using Very High Gravity (VHG) fer-mentation of cassava meal mash. By using VHG fermentation, the ethanol concentration in the fermenter broth is significantly increased, to about 19 vol% (15.4 wt%). The steam consumption is then reduced to ~0.94 kg/kg, representing a considerable saving in comparison with the current operation. Applying VHG fermentation needs minor additional investment, rapidly recovered through the energy savings and the smaller size of equipment; 3) thirdly, to assess the application of a hybrid operation, where pervaporation will be used to selectively and continuously remove ethanol from the fermenter broth, thus slightly increasing the fermentation yield by reducing the risk of ethanol inhibition, whilst producing an ehtanol-rich permeate (about 30 wt%); and finally 4) to demonstrate that the production cost of cassava-based ethanol can substantially be reduced by applying the proposed improvements.

Bioethanol successfully finds its role in the development of renewable energy sources to supplement the world's increasing demand in energy supply. In this study, elephant foot yam (Amorphophalluspeoniifolius), a starch-based crop,... more

Bioethanol successfully finds its role in the development of renewable energy sources to supplement the world's increasing demand in energy supply. In this study, elephant foot yam (Amorphophalluspeoniifolius), a starch-based crop, abundantly grown in tropical countries like Philippines, was used for the evaluation of the effect of substrate concentration and yeast loading (Saccharomyces cerevisiae) in Simultaneous Saccharification and Fermentation (SSF). In SSF, the optimum condition was observed at10% w/v substrate concentration in 20 mL yeast loadingwith an ethanol yield of 12.02 ± 0.21 %. As substrate concentration decreases and yeast loading increases, percent ethanol yield increases. Best mathematical model was generated to describe the relationship of the substrate concentration and yeast loading to ethanol yield. The generated quadratic model, í µí±Œ 2.47 = 80.63 − 84.46 í µí°´+µí°´+ 126.73 í µí°µ − 17.49í µí°´í µí°µ + 65.59í µí°´2µí°´2 + 91.02í µí°µ 2 ,can explain 99.96 % (R 2) of the variability in the yield. The statistical significance of the model was evaluated by F-test for analysis of variance (p<0.05). The results showed that the production of ethanol was more strongly affected by the variation of yeast loading. Using the best substrate concentration and yeast loading, ethanol yield was determined in SSF coupled with Acid Hydrolysis (SSF-AH) having an ethanol yield of 19.1952%. The results revealed that subjecting first the substrate to acid hydrolysis could increase the ethanol yield for it increased the reducing sugar of the substrate.

Lignocellulosic-bioethanol-fuel (LBF) technology faces challenges due to cost/energy intensive nature of lignocellu-losic biomass (LB) pretreatment and saccharification. Ionic liquid (IL) based pretreatment of LB has recently emerged as... more

Lignocellulosic-bioethanol-fuel (LBF) technology faces challenges due to cost/energy intensive nature of lignocellu-losic biomass (LB) pretreatment and saccharification. Ionic liquid (IL) based pretreatment of LB has recently emerged as an environmentally friendly approach. However, for sacchar-ification of IL pretreated LB, IL stable enzymes must be used else the latter may be inhibited. Furthermore, availability of IL stable enzymes may help designing novel consolidated process by in situ coupling of IL mediated pretreatment of LB and enzymatic saccharification processes in a single vessel, that is, one pot consolidated bioprocess (OPCB). OPCB may potentially offer new avenues for technoeconomic feasibility of LBF. In this study, an OPCB was developed and optimized for the first time for bioethanol production from pine needle biomass (PNB) using in situ IL pretreatment and enzymatic saccharification in a single pot. Various process parameters, namely, biomass loading, reaction time, and cellulase/xyla-nase enzyme dose were optimized, and sugar yield of 1.88 g per five gram of PNB was obtained. The sugar hydrolysate obtained was subjected to ethanol fermentation using dual yeast culture, that is, Saccharomyces cerevisiae and Pichia stipitis. The maximum ethanol yield of 0.148 g/g PNB was obtained after 72 h of fermentation representing an efficiency of 41.39%. The study shows that consolidated processing of PNB may be an efficient, sustainable, and feasible approach for valorization of PNB for industrial production of second generation ethanol-biofuel. V C 2017 American Institute of Chemical Engineers Environ Prog, 00: 000–000, 2017

This review focuses on current approaches to metabolic engineering of ethanologenic yeast species for the production of bioethanol from complex lignocellulose biomass sources. The experimental strategies for the degradation of the... more

This review focuses on current approaches to metabolic engineering of ethanologenic yeast species for the production of bioethanol from complex lignocellulose biomass sources. The experimental strategies for the degradation of the cellulose and xylose-components of lignocellulose are reviewed. Limitations to the current approaches are discussed and novel solutions proposed.

The alternatives to the oil based fuels for transportation are considered and analysed. These are the synthetic fuels, made from coal, the liquid petroleum gases of propane and butane, compressed natural gas and methanol. The problems... more

The alternatives to the oil based fuels for transportation are considered and analysed. These are the synthetic fuels, made from coal, the liquid petroleum gases of propane and butane, compressed natural gas and methanol. The problems associated with the use of electric vehicles are discussed; the main problem being that of range.The possible use of hydrogen as a fuel is

Serat biji ketapang merupakan salah satu sumber alam yang cukup melimpah terutama di daerah Purwokerto. Dalam setiap biji ketapang mengandung sekitar 11% serat yang menyelimuti biji Serat ketapang ini melalui proses fermentasi menggunakan... more

Serat biji ketapang merupakan salah satu sumber alam yang cukup melimpah terutama di daerah Purwokerto. Dalam setiap biji ketapang mengandung sekitar 11% serat yang menyelimuti biji Serat ketapang ini melalui proses fermentasi menggunakan khamir S. cereviseae dapat dihasilkan bioetanol yang dapat dimanfaatkan di sektor indstri terutama industri kecil menengah yang berada di Purwokerto. Pemanfaatan bioetanol dari serat biji ketapang dapat membantu indutri kecil-menengah tersebut dalam upaya untuk mempertahankan kelangsungan aktivitas produksinya di tengah perdagangan bebas pada tahun 2015 mendatang.

En este trabajo se determinó la dependencia de la parte real de la permitividad relativa de mezclas de bioetanol y nafta con la composición y temperatura en un rango entre 25°C y 50°C, a frecuencias de 10 kHz y 100 kHz. Los resultados son... more

En este trabajo se determinó la dependencia de la parte real de la permitividad relativa de mezclas de bioetanol y nafta con la composición y temperatura en un rango entre 25°C y 50°C, a frecuencias de 10 kHz y 100 kHz.
Los resultados son de interés para la aplicación de propiedades eléctricas en la caracterización de mezclas nafta-bioetanol durante la producción, transporte y almacenamiento.
En todas las muestras medidas, la parte real de la permitividad relativa disminuye con la temperatura con un muy buen ajuste a una función lineal. Los parámetros de ajuste se encuentran dentro de un rango estrecho para todas las muestras.
A medida que se incrementa el contenido de bioetanol en las muestras, a temperatura constante, la parte real de la permitividad relativa aumenta. Se tiene un ajuste satisfactorio de la permitividad en función de la composición mediante un polinomio de cuarto orden.

This study determined if Banana- Mango Peelings bioethanol is an eco-friendly fuel compared to diesel in terms of its fire duration. It also determined what the fuel’s percent ethanol is. The null hypothesis stated that Banana- Mango... more

This study determined if Banana- Mango Peelings bioethanol is an eco-friendly fuel compared to diesel in terms of its fire duration. It also determined what the fuel’s percent ethanol is. The null hypothesis stated that Banana- Mango Peelings bioethanol would not be of good quality in terms of fire duration. The alternative hypothesis stated that Banana- Mango Peelings bioethanol would be of good combusting quality and be better than other fuels in terms of fire duration.
The study would find out the difference between Banana- Mango Peelings bioethanol and diesel in terms of fire duration and percentage ethanol only. The concentration of Banana- Mango Peelings bioethanol was tested at the National Institute of Molecular Biology and Biotechnology by ethanol- gas chromatography.
The t- test was used since banana- mango peelings bioethanol fuel would only be compared to diesel. The results would be considered statistically significant at 95% confidence to determine significant differences between the two fuels. The critical value used for the experiment was 4.303 where the degree of freedom is 2.
The value of t yielded -0.08. The value is lower than the critical value used therefore signifies a difference between the fire duration of the Banana- Mango Peeling bioethanol and the diesel. Also it was found out that banana- mango peelings bioethanol has a percentage ethanol of 2.23±0.09.
This study can be improved by using thorough distillation; makeshift apparatuses can also be used. Also, it is recommended to have longer fermentation. Varying the fermentation weeks can also show different results that would lead to more useful data that show better analysation.

THIS ABOUT ALL BIOETHANOL

Bioethanol production from lignocellulosic biomass (LCB) has been demonstrated as alternative to conventional fuel, as it is considered to be renewable and clean energy. The major problem of bioethanol is the availability of biomass... more

Bioethanol production from lignocellulosic biomass (LCB) has been demonstrated as alternative to conventional fuel, as it is considered to be renewable and clean energy. The major problem of bioethanol is the availability of biomass materials for its production. This review paper aims to provide an overview of the recent developments and potential regarding production techniques, ethanol yields, and properties, as well as the effects of bioethanol fuel as replacement for fossil fuel. The literature indicates that the best results have been obtained with cellulase and β-glucanase cocktail which significantly increases bioethanol production compared to fermented acid pretreatment. The classification of pretreatment, hydrolysis, and fermentation have significant effects on physico-chemical properties of bioethanol fuel, which also influence the internal combustion engines. Difference in operating conditions and physico-chemical properties of bioethanol fuels, may change the combustion behaviors and sometimes makes it difficult to analyze the fundamentals of how it affects emissions.

A B S T R A C T Fuel security, economics and climate change issues are creating a requirement for alternative renewable fuels. Bioethanol produced by algal biomass is becoming increasingly popular all over the world due to the... more

A B S T R A C T Fuel security, economics and climate change issues are creating a requirement for alternative renewable fuels. Bioethanol produced by algal biomass is becoming increasingly popular all over the world due to the sustainability of feed stock and environmentally friendly nature. This review paper describes the bioethanol production technology from algae using various cultivation, harvesting, extraction and commercialization techniques and its environmental perspectives. The economic sustainability of algae-derived bioethanol biofuel depends on the cost of production that could be minimized by producing valuable secondary by-products, which is the aim of current algal biofuel research. Future technologies with sufficient potential for maximum extraction capacity and minimal downstream processing using low cost feedstock will address the cost-effectiveness of renewable bioethanol biofuel.

Biochemical conversion of lingo cellulosic biomass to ethanol provides a sustainable energy production system. Ragi straw is a fast growing domestic feedstock for Bio-ethanol production. In the present study ragi straw (Eleusine coracana... more

Biochemical conversion of lingo cellulosic biomass to ethanol provides a sustainable energy production system.
Ragi straw is a fast growing domestic feedstock for Bio-ethanol production. In the present study ragi straw
(Eleusine coracana L) was supplemented with different nitrogen Source prior to enzymatic hydrolysis by
Bacillus pumilus isolated from marine sources process to produce fermentable sugars using different
concentrations of the nitrogen source in the range of 0.5%, 1.0%, 1.5 % and 2.0%.The presence of nitrogen
sources had an impact on the growth of the organism and supported enzymatic hydrolysis to degrade complex
sugars to simple sugars, which could be further used for Bio-ethanol production. Ammonium nitrate proved to be
the best nitrogen source at 0.5% concentration to support enzymatic hydrolysis of ragi straw which could be
utilized for ethanol production as ragi straw is abundantly available.

This paper aims to examine the potential of waste biorefineries in developing countries as a solution to current waste disposal problems and as facilities to produce fuels, power, heat, and value-added products. The waste in developing... more

This paper aims to examine the potential of waste biorefineries in developing countries as a solution to current waste disposal problems and as facilities to produce fuels, power, heat, and value-added products. The waste in developing countries represents a significant source of biomass, recycled materials, chemicals, energy, and revenue if wisely managed and used as a potential feedstock in various biorefinery technologies such as fermentation, anaerobic digestion (AD), pyrolysis, incineration, and gasification. However, the selection or integration of biorefinery technologies in any developing country should be based on its waste characterization. Waste biorefineries if developed in developing countries could provide energy generation, land savings, new businesses and consequent job creation, savings of landfills costs, GHG emissions reduction, and savings of natural resources of land, soil, and groundwater. The challenges in route to successful implementation of biorefinery concept in the developing countries are also presented using life cycle assessment (LCA) studies.

Bioethanol adalah ethanol yang bahan utamanya dari tumbuhan dan umumnya menggunakan proses farmentasi. Ethanol atau ethyl alkohol C2H5OH berupa cairan bening tak berwarna, terurai secara biologis (biodegradable), toksisitas rendah dan... more

Bioethanol adalah ethanol yang bahan utamanya dari tumbuhan dan umumnya menggunakan proses farmentasi. Ethanol atau ethyl alkohol C2H5OH berupa cairan bening tak berwarna, terurai secara biologis (biodegradable), toksisitas rendah dan tidak menimbulkan polusi udara yg besar bila bocor. Ethanol yg terbakar menghasilkan karbondioksida (CO2) dan air. Ethanol adalah bahan bakar beroktan tinggi dan dapat menggantikan timbal sebagai peningkat nilai oktan dalam bensin. Dengan mencampur ethanol dengan bensin, akan mengoksigenasi campuran bahan bakar sehingga dapat terbakar lebih sempurna dan mengurangi emisi gas buang (seperti karbon monoksida/ CO).

It is obvious that Iran agricultural industry, unlike Brazil and USA, cannot afford to provide conventional biomass, i.e. sugary or starchy biomass for bioethanol production, mainly due to climatic and geographic conditions. With some... more

It is obvious that Iran agricultural industry, unlike Brazil and USA, cannot afford to provide conventional biomass, i.e. sugary or starchy biomass for bioethanol production, mainly due to climatic and geographic conditions. With some exception of date (fruit), first-generation ethanol production triggers food vs. fuel debates in Iran and put nation to hunger. Agricultural products including apple, barley, carrot, corn, grape, orange, potato, rice, sugar beet, sugarcane, and wheat are consumed domestically, exported, or even lost because of poor harvesting and processing conditions such as transportation or packaging. These products may alone generate 21.56 million ton per annum green wastes upon processing in the food industry. Every year about 5.4 billion liters of bioethanol can be produced by establishing second-generation ethanol plants next to the food processing sectors. Seventy-seven-percent of this amount of bioethanol can easily support 5% ethanol (E5) policy to phase out the consumption of 4.2 billion liters methyl tert-butyl ether (MTBE) for raising the octane number of gasoline in the country. If more comprehensive policy is adopted, larger quantities of lignocellulosic feedstocks can be gathered from agro as well as forestry practices. Second-generation bioethanol technology can help Iran to tackle air pollution in its big cities and to address the adverse effects of MTBE on its populations and ecosystem. The other advantages are improvement of fuel security, mitigation of climate change, and development of economy. The motivation can be created through passing a framework policy to cut fossil fuel subsidies , to mandate bioethanol blends in gasoline, and to impose carbon taxes. Development of coherent socially and environmentally relevant strategies and facilitation of investment in bioethanol industry are also necessary.

The increasing demand for biofuels has encouraged the researchers and policy makers worldwide to find sustainable biofuel production systems in accordance with the regional conditions and needs. The sustainability of a biofuel production... more

The increasing demand for biofuels has encouraged the researchers and policy makers worldwide to find sustainable biofuel production systems in accordance with the regional conditions and needs. The sustainability of a biofuel production system includes energy and greenhouse gas (GHG) saving along with environmental and social acceptability. Life cycle assessment (LCA) is an internationally recognized tool for determining the sustainability of biofuels. LCA includes goal and scope, life cycle inventory, life cycle impact assessment, and interpretation as major steps. LCA results vary significantly, if there are any variations in performing these steps. For instance, biofuel producing feedstocks have different environmental values that lead to different GHG emission savings and energy balances. Similarly, land-use and land-use changes may overestimate biofuel sustainability. This study aims to examine various biofuel production systems for their GHG savings and energy balances, relative to conventional fossil fuels with an ambition to address the challenges and to offer future directions for LCA based biofuel studies. Environmental and social acceptability of biofuel production is the key factor in developing biofuel support policies. Higher GHG emission saving and energy balance of biofuel can be achieved, if biomass yield is high, and ecologically sustainable biomass or non-food biomass is converted into biofuel and used efficiently.

An extensive background overview on the use of agricultural residues (wastes) for production of paper, board, binderless board, energy, different types of fuels by pyrolysis (solid, liquid and gaseous fuel), many petrochemicals... more

An extensive background overview on the use of agricultural residues (wastes) for production of paper, board, binderless board, energy, different types of fuels by pyrolysis (solid, liquid and gaseous fuel), many petrochemicals substitutes, charcoal (activated carbon), dissolving pulps and rayon. It includes both scientific and industrial data, case studies, current status, sustainability of paper and sugar industries, green nanotechnology, and future prospects.
Keywords: Agricultural Residues (Wastes); Paper and Board manufacture; Sustainability of Paper and Sugar Industries; Green Nanotechnology; Future Prospects

A study of CO2 emissions and energy density of biofuels US and EU regulations are encouraging the development of new technologies for the production of biofuels. There are two principal purposes: reduction of CO2 emissions and reduction... more

Ketersediaan tandan kosong kelapa sawit (TKKS) di Indonesia yang berlimpah menyediakan stok lignoselulosa yang tinggi, yang artinya dapat dikonversi menjadi etanol dengan kapasitas yang besar. Pengolahan TKKS menjadi etanol terdiri dari... more

Ketersediaan tandan kosong kelapa sawit (TKKS) di Indonesia yang berlimpah menyediakan stok lignoselulosa yang tinggi, yang artinya dapat dikonversi menjadi etanol dengan kapasitas yang besar. Pengolahan TKKS menjadi etanol terdiri dari empat tahap penting yaitu pretreatment (delignifikasi), sakarifikasi (hidrolisis), fermentasi, dan destilasi. TKKS terlebih dahulu melalui proses delignifikasi untuk mendegradasi lignin yang mengganggu tahapan selanjutnya. Delignifikasi dilakukan dengan menggunakan fungi spesifik Penicillium simplicissimum dengan suplemen sumber C (glukosa, pati, dan gliserol dengan kadar 5, 1, dan 0,1 g) dan N (pepton, amonium nitrat, dan L-asparagin dengan kadar 3; 0,5; dan 0,1 g); serta inducer 4.5 μmol ABTS dan 4.5 μmol xylidin pada suhu 30˚C selama 25 hari. Proses dilanjutkan dengan sakarifikasi dan fermentasi simultan/SSF (dengan pembanding SHF) menggunakan enzim selulase (dengan pembanding NaOH) dan Zymomonas mobilis yang telah diimobilisasi Ca-Alginat (dengan pembanding PVA) pada suhu 30˚C. Hasil sakarifikasi-fermentasi kemudian didestilasi dan diukur kadar etanol yang dihasilkan. Kadar etanol tertinggi diperoleh dari suplemen 5 g glukosa 0,5 g amonium nitrat dan penambahan ABTS pada pretreatment; enzim selulase dan Z. mobilis yang diimobilisasi Ca-Alginat dengan metode SSF. Rendemen etanol SSF(6,05%) signifikan lebih tinggi daripada SHF(4,74%) dan waktu rendemen tertinggi diperoleh dari SSF. Penelitian ini diharapkan mampu menjawab permasalahan keberlangsungan ketersediaan energi baik bagi pemerintah, produsen bioetanol, bahkan masyarakat, serta untuk terus mendukung penggunaan energi baru terbarukan serta ramah lingkungan.

The global fossil fuel crisis and emission problems lead to investigations on alternative fuels. In this quest, a successful finding is the partial substitution of diesel with ethanol/bioethanol rather than completely replacing it. These... more

The global fossil fuel crisis and emission problems lead to investigations on alternative fuels. In this quest, a successful finding is the partial substitution of diesel with ethanol/bioethanol rather than completely replacing it. These blends of diesel and ethanol/bioethanol can be used in the existing CI engines without any major modifications and the most significant result of using this blend is the lower emission with almost the same performance as of diesel fuel alone. Two major drawbacks of using this blend are low miscibility of ethanol/bioethanol in diesel and low temperature instability of produced blend. However, biodiesel can be successfully added to prevent the phase separation of diesel–ethanol/bioethanol blend. Thus, this blend becomes stable even at lower temperatures and more amount of ethanol/bioethanol can be added to them. It is found that a maximum of 25% biodiesel and 5% of ethanol/bioethanol can be added to the diesel fuel effectively. Adding ethanol/bioethanol to diesel fuel alters the properties of the blend, which does not meet some of the standards. Biodiesel addition to this blend helps in regaining the fuel properties to the standard values and thus the blend can be efficiently used in the existing diesel engines. From the review, it can be said that, the use of diesel–biodiesel–ethanol/bioethanol blend can minimize the use of diesel fuel by approximately 25–30%.