Competitive liquid biofuels from biomass

The cost of biodiesels varies depending on the feedstock, geographic area, methanol prices, and seasonal variability in crop production. Most of the biodiesel is currently made from soybean, rapeseed, and palm oils. However, there are large amounts of low-cost oils and fats (e.g., restaurant waste, beef tallow, pork lard, and yellow grease) that could be converted to biodiesel. The crop types, agricultural practices, land and labor costs, plant sizes, processing technologies and government policies in different regions considerably vary ethanol production costs and prices by region. The cost of producing bioethanol in a dry mill plant currently totals US$1.65/galon. The largest ethanol cost component is the plant feedstock. It has been showed that plant size has a major effect on cost. The plant size can reduce operating costs by 15–20%, saving another $0.02–$0.03 per liter. Thus, a large plant with production costs of $0.29 per liter may be saving $0.05–$0.06 per liter over a smaller plant. Viscosity of biofuel and biocrude varies greatly with the liquefaction conditions. The high and increasing viscosity indicates a poor flow characteristic and stability. The increase in the viscosity can be attributed to the continuing polymerization and oxidative coupling reactions in the biocrude upon storage. Although stability of biocrude is typically better than that of bio-oil, the viscosity of biocrude is much higher. The bio-oil produced by flash pyrolysis is a highly oxygenated mixture of carbonyls, carboxyls, phenolics and water. It is acidic and potentially corrosive. Bio-oil can also be potentially upgraded by hydrodeoxygenation. The liquid, termed biocrude, contains 60% carbon, 10–20 wt.% oxygen and 30–36 MJ/kg heating value as opposed to <1 wt.% and 42–46 MJ/kg for petroleum.     

Production of liquid biofuels from renewable resources

This article is an up-to-date review of the literature available on the subject of liquid biofuels. In search of a suitable fuel alternative to fast depleting fossil fuel and oil reserves and in serious consideration of the environmental issues associated with the extensive use of fuels based on petrochemicals, research work is in progress worldwide. Researchers have been re-directing their interests in biomass based fuels, which currently seem to be the only logical alternative for sustainable development in the context of economical and environmental considerations. Renewable bioresources are available globally in the form of residual agricultural biomass and wastes, which can be transformed into liquid biofuels. However, the process of conversion, or chemical transformation, could be very expensive and not worth-while to use for an economical large-scale commercial supply of biofuels. Hence, there is still need for much research to be done for an effective, economical and efficient conversion process. Therefore, this article is written as a broad overview of the subject, and includes information based on the research conducted globally by scientists according to their local socio-cultural and economic situations.     

The technical potential of first-generation biofuels obtained from energy crops in Spain

Biofuels have been recently the subject of a sustained interest due to the ambitious goals set out in developed, and some developing, countries as they transition to more sustainable and self-sufficient energy models. Thus, EU Directive 2003/30 established certain minimimun shares of biofuels in the transport sector for the member states, viz 2% by 2005 and 5.75% by 2010. More recently, the EU Directive 2009/28/EC imposes a target share of 10% renewables in the transport sector by 2020. Different roadmaps can be envisaged based on the varying contributions from first and second-generation biofuels; the controversial role of biomass imports for biofuel production adds some additional uncertainties. Against this backdrop, this work presents a comprehensive view of the technical potential for first-generation biofuels (biodiesel and bioethanol) from energy crops in Spain, and their prospects in the short and mid terms. The methodology has been implemented in a Geographical Information System. The calculated technical potentials for biodiesel range between 730 and 1830 ktoe year⁻¹ for land occupations of 10% and 25% of the arable land, respectively. The corresponding bioethanol potentials for the same levels of land occupation are 1228 and 3070 ktoe year⁻¹. The calculated potentials indicate that the Spanish agricultural system would be severely strained if the 2020 target, 4755 ktoe year⁻¹, is to be met with locally-grown biofuel crops. The study further estimates the resulting first-generation biofuel costs, and concludes that incentives are needed for the price to be competitive with that of oil-based fuels, even in a scenario of high oil prices.     

A critical review of biochemical conversion,sustainability and life cycle assessment of algal biofuels

The increasing global demand of biofuels for energy security and reduction in climate change effects generate the opportunity to explore new biomass sources. Algae is a very promising source of biomass in this context as it sequester a significant quantity of carbon from atmosphere and industrial gases and is also very efficient in utilizing the nutrients from industrial effluents and municipal wastewater. Therefore cultivation of algal biomass provide dual benefit, it provides biomass for the production of biofuels and also save our environment from air and water pollution. The life cycle assessment (LCA) of algal biofuels suggests them to be environmentally better than the fossil fuels but economically it is not yet so attractive.     

Development and implementation of an optimisation model for biofuels supply chain

Biofuels supply chain comprises a wide set of activities involving a rather complex set of parameters. Cultivation of the raw materials is closely related to the agricultural sector whereas the production of the final product presumes the operation of a conversion plant. The distribution network aims at delivering the final product close to the consumption. The extent of the involvement of each one of the previously mentioned sectors is the result of strategic and operational planning of the whole supply chain and, in the general case, determines the efficiency of the biofuels sector. Taking also into account the very rapidly changing opinions related to the environmental behaviour of the whole biofuels supply chain, it becomes very clear that the parameters in the sector are continuously changing. Therefore, the consideration of an integrated supply chain appropriately modelled is believed to be very critical and could result in the optimal solution per case, economically and/or environmentally speaking. In this paper the development of a mathematical model for the optimal design and operation of Biofuels Supply Chain is proposed as an integrated approach that can take into account both technical and economic parameters affecting the performance of the whole value chain. Model implementation would facilitate and support the decision taking in various planning and operational issues such as infrastructure investments, the quantities of raw materials to be cultivated, the quantities of biofuels to be produced in the domestic market or imported, identifying the best available solution for the optimal design and operation of the biofuels supply chain.     

The substitutive effect of biofuels on fossil fuels in the lower and higher crude oil price periods

Various biofuels, including bioethanol and biodiesel are technologically being considered replacements for fossil fuels, such as the conventional gasoline and diesel. This paper aims to measure whether economic substitutability can be generated during periods of higher and/or lower prices of crude oil. The empirical results of the bivariate EGARCH model prove that this substitutive effect was occurred during the higher crude oil price period due to the significant price spillover effects from crude oil futures to corn and soybean futures, indicating that the increase in food prices can be attributed to more consumption of biofuels. We suggest more extensive research in the search for fuel alternatives from inedible feedstock such as pongamia, jojoba, jatropha, especially the 2nd generation biofuel technologies such as algae-based biofuels.     

Application of exhaust gas fuel reforming in diesel and homogeneous charge compression ignition (HCCI) engines fuelled with biofuels

This paper documents the application of exhaust gas fuel reforming of two alternative fuels, biodiesel and bioethanol, in internal combustion engines. The exhaust gas fuel reforming process is a method of on-board production of hydrogen-rich gas by catalytic reaction of fuel and engine exhaust gas. The benefits of exhaust gas fuel reforming have been demonstrated by adding simulated reformed gas to a diesel engine fuelled by a mixture of 50% ultra low sulphur diesel (ULSD) and 50% rapeseed methyl ester (RME) as well as to a homogeneous charge compression ignition (HCCI) engine fuelled by bioethanol. In the case of the biodiesel fuelled engine, a reduction of NO_x emissions was achieved without considerable smoke increase. In the case of the bioethanol fuelled HCCI engine, the engine tolerance to exhaust gas recirculation (EGR) was extended and hence the typically high pressure rise rates of HCCI engines, associated with intense combustion noise, were reduced.     

Co-generation of biofuels for transportation and heat for district heating systems—an assessment of the national possibilities in the EU

Biomass gasification with subsequent synthesis to liquid or gaseous biofuels generates heat possible to use in district heating (DH) systems. The purpose here is to estimate the heat sink capacity of DH systems in the individual EU nations and assess the possibilities for biomass-gasification-based co-generation of synthetic biofuels for transportation and heat (CBH) for DH systems in the EU countries. The possibilities are assessed (i) assuming different levels of competiveness relative to other heat supply options of CBH corresponding to the EU target for renewable energy for transportation for 2020 and (ii) assuming that the potential expansion of the DH systems by 2020 is met with CBH. In general, the size of the DH heat sinks represented by the existing national aggregated DH systems can accommodate CBH at a scale that is significant compared to the 2020 renewable transportation target. The possibilities for CBH also depend on its cost-competitiveness compared to, e.g., fossil-fuel-based CHP. The possible expansion of the DH systems by 2020 represents an important opportunity for CBH and is also influenced by the potential increase in the use of other heat supply options, such as, industrial waste heat, waste incineration, and CHP.     

The rationality of biofuels

In an editorial of a recent issue of a known academic journal, Prof. Hartmut Michel affirmed that “…the production of biofuels constitutes an extremely inefficient land use… We should not grow plants for biofuel production.”, after comparing the area occupied with plants for bioenergy production with the one required for photovoltaic cells to supply the same amount of energy for transportation. This assertion is not correct for all situations and this comparison deserves a more careful analysis, evaluating the actual and prospective technological scenarios and other relevant aspects, such as capacity requirements, energy consumed during the life cycle of energy systems and the associated impacts. In this communication this comparison is revaluated, presenting a different perspective, more favorable for the bioenergy routes.     

Development status and life cycle inventory analysis of biofuels in Taiwan

This research conducted the life cycle inventory analyses of biofuels in Taiwan. The biofuels considered include bioethanol production from sugarcane as well as biodiesel production from soybean and rapeseed. Energy inputs and pollutant emission (including carbon dioxide) are the input/output items analyzed. Results obtained from the inventory analyses can be summarized as follows. Bioethanol production from per hectare sugarcane cropland is 5160 L (liters), meanwhile, 476 and 1012 L biodiesel can be produced from 1 ha of soybean and rapeseed, respectively. The energy input to produce a liter ethanol, a liter biodiesel produced from soybean and rapeseed are 1256, 9602 and 5191 kcal, respectively. Those energy inputs are still less than the energy content of ethanol or biodiesel. It can be concluded that there is a positive energy benefit in producing biofuels based on a comparison with the previous work. In addition, through their life cycle, 1478.4 kg CO₂ emission is generated from one hectare of soybean land and 2954.1 kg is generated from rapeseed land. Life cycle carbon dioxide emissions released from burning ethanol is 0.08 kg/LOE in contrast to 2.6 kg/LOE released from burning fossil gasoline.     

Greenhouse gas balances of transportation biofuels,electricity and heat generation in Finland—Dealing with the uncertainties

One way to reduce greenhouse gas emissions from the transportation sector is to replace fossil fuels by biofuels. However, production of biofuels also generates greenhouse gas emissions. Energy and greenhouse gas balances of transportation biofuels suitable for large-scale production in Finland have been assessed in this paper. In addition, the use of raw materials in electricity and/or heat production has been considered. The overall auxiliary energy input per energy content of fuel in biofuel production was 3–5-fold compared to that of fossil fuels. The results indicated that greenhouse gas emissions from the production and use of barley-based ethanol or biodiesel from turnip rape are very probably higher compared to fossil fuels. Second generation biofuels produced using forestry residues or reed canary grass as raw materials seem to be more favourable in reducing greenhouse gas emissions. However, the use of raw materials in electricity and/or heat production is even more favourable. Significant uncertainties are involved in the results mainly due to the uncertainty of N₂O emissions from fertilisation and emissions from the production of the electricity consumed or replaced.     

Renewable energy from agro-residues in China: Solid biofuels and biomass briquetting technology

China has the abundant agro-residue resources, producing more than 630 million tons of agro-residues in 2006, and amounting to about 20% of total energy consumption in rural areas. Efficient utilization of enormous agro-residues resource is crucial for providing bioenergy, releasing risk of environmental pollution, and increasing farmers’ income. The paper presented the feasibility of densified solid biofuels technology for utilizing agro-residues in China. The output and distribution of agro-residues in recent 10 years, the R&D of briquetting technology, and the market of densified solid biofuels from agro-residues in China have been analyzed. The result indicated that the abundant agro-residue resources can provide the economical and sustainable raw material for densified solid biofuels development in China. The R&D of briquetting technology at present can strongly support the large scale production of densified solid biofuels. With continued improvement and cost reduction of briquetting technology, along with the support of nation energy policy on biomass energy, the market of densified solid biofuels from agro-residues in China will be more fully deployed. Based on the above mentioned key factors, development of densified solid biofuels from agro-residues in China will be promising and feasible.     

Biofuel implementation in East Europe: Current status and future prospects

There is a continuously increasing interest concerning the biofuel implementation in Europe, mainly because of environmental protection and energy supply security reasons. In this context, the European Union (EU) strongly encourages the use of biofuels through a number of Directives. To that effect, EU members follow the Directives implementing various political, fiscal and technical measures and incentives. In the light of the potential created by the recently joined Eastern European countries, an increasing interest is shown in the whole biofuel supply chain within the EU. In parallel, the status of the Eastern European countries domestic market, as far as biofuels are concerned, is an interesting issue, since most of these countries present a significant potential, however still lagging in biofuel implementation. In the above context, the objective of the present work is to give a concise and up-to-date picture of the present status of biofuel implementation in East Europe. The work also aims at identifying the prospects of these countries as far as biofuels are concerned and their role in the EU framework as potential suppliers of a wider market.     

Current status and future forecasting of biofuels technology development

Over the last few decades, the significant increase in energy demand followed by increasing fossil fuels depletion convinced countries authority to choose renewable energy to satisfy demand. Therefore, global enthusiasm in renewable energy such as bioenergy technology is increased. Is biofuels technology ready to address the global demand for energy? Investigating in technology development can answer. In this paper, the current statuses of biofuel technologies are determined. Regarding patent codes, seven technologies are identified, which are CHP turbines for biofeed, gas turbine for biofeed, biodiesel, grain bioethanol, bio‐pyrolysis, torrefaction of biomass, and cellulosic bioethanol. The results of patent investigating show that the biodiesel technology is in the mature status and its technology trend is going to go downward. The others six technologies are in the growth stage. Analysis of 57 619 patents in biofuel technologies for technology forecasting has been done by technology life cycle. The torrefication of biomass technology has started its growth stages and will become mature in 2061. In this research, the S‐curves of all biofuel groups are plotted and maturity phases are forecasted.     

An overview of biomass energy utilization in Vojvodina

The Autonomous Province of Vojvodina is an autonomous province in Serbia. It is located in the northern part of the country, in the Pannonia plain. Vojvodina is an energy-deficient province. Energy plays a pivotal role in socio-economic development by raising the standard of living. Biomass has been used by mankind as an energy source for thousands of years. Traditional fuels like firewood, dung and crop residues currently contribute a major share in meeting the everyday energy requirements of rural and low-income urban households in Vojvodina. Contribution of the renewable energy sources in the total consumption of energy in Vojvidina is less than 1%, i.e. it amounts to 280 KWh/year. Production of biodiesel in the year 2008 was 0.07 million tons, what is for 133% higher with respect to the production in the year 2007 (0.03 million tons). In Vojvodina, as the raw materials for bioethanol production are seen primarily sugar beet, corn, wheat surpluses, potato surpluses and waste potato, as well as the raw materials intended for these purposes grown on the uncultivated soils, such as hybrid broomcorn, Jerusalem artichoke and triticale. With introduction of new technologies for cultivation and collecting of biomass production of the electrical energy could be raised to 6.4 GWh/m² year, what, with retention of the contemporary consumption, would represent the significant 9% of the total consumption in the province. According to programme of realisation of energy strategy of Vojvodina/Serbia in the field of the renewable energy sources for to period till the year 2010 and its completion, till the year 2015, in Vojvodina could be created conditions for the employment of about 24,000 workers, i.e. 4000 employed for maintenance of the newly constructed plants, 17,000 employed on designing and manufacturing of plants and 3000 employed in auxiliary activities.     

Can the environmental benefits of biomass support agriculture?—The case of cereals for electricity and bioethanol production in Northern Spain

Recent policy documents, such as the EC Communication on an Energy Policy for Europe (January 2007) make emphasis on the opportunities that energy applications can offer certain agricultural commodities, especially in the framework of a progressive dismantling of the Common Agricultural Policy. This paper analyses whether this can be true for wheat and barley farmers, using the real example of a straw-based power plant in Northern Spain and a theoretical factory for bioethanol production fed with cereal grain. The outcomes of such an exercise, in which their relative environmental benefits vis-à-vis fossil fuel alternatives are worked out with the aid of a simplified life-cycle approach, show that the characteristics of the electricity and biomass markets, the baseline scenario and the fuel prices are crucial for the future of the sector.     

Emission factors and thermal efficiencies of cooking biofuels from five countries

The aim of the study was to compare the environmental and thermal performance of cooking biofuels from five countries. The standard water boiling test was used to determine thermal parameters. The fuels were burnt in a metal stove in a test chamber in accordance with standard protocol. Low-flow air samplers were used for particulate matter measurements, both TSP and RSP. Later, benzo(a)pyrene was determined using the high performance liquid chromatography (HPLC) technique after extraction from particulate samples in benzene. CO was measured using an electronic datalogger and HCHO using a passive sampler. The ventilation conditions during the experiments were manipulated by using different combinations of doors, windows and fans to ensure minimum stratification of pollutants in the chamber. The indirect method of deriving emission factors was used. Levels of most of the pollutants measured was found to be higher than that reported by previous studies, especially that of benzo(a)pyrene. The thermal efficiency was found to be in the range 10-15%. The emission per task of RSP was 0.27-0.77 g and that of B(a)P in RSP was 1.87-4.17 mg.     

Capturing latecomer advantages in the adoption of biofuels: The case of Argentina

Although Argentina came late to the biofuels revolution, a series of measures taken recently at federal and provincial government level have created new opportunities. New federal laws on biofuels promotion have sparked an investment boom. The main activity has been in the biodiesel sector—partly because diesel is the dominant fuel sector in Argentina, and partly because the country had already engineered a soy revolution over the past 15 years, becoming the world's largest exporter of soy oil and soy meal. Biodiesel allows this revolution to be extended—from soy as foodstuff to soy as fuelstock. The biodiesel revolution now underway promises to extend Argentina's latecomer advantages by combining greater scale and lower costs with introduced technical innovations such as genetically modified crops and no-till farming. In this way, Argentina can be seen to be demonstrating the superiority of biofuel production in countries of the South over the conditions obtaining in countries of the North—including superior resources availability, superior energetics and lower costs. Whereas Brazil has demonstrated its superiority in sugarcane-based ethanol, Argentina is about to demonstrate its superiority in soy-based biodiesel.     

Biomass upgrading by torrefaction for the production of biofuels: A review

An overview of the research on biomass upgrading by torrefaction for the production of biofuels is presented. Torrefaction is a thermal conversion method of biomass in the low temperature range of 200–300 °C. Biomass is pre-treated to produce a high quality solid biofuel that can be used for combustion and gasification. In this review the characteristics of torrefaction are described and a short history of torrefaction is given. Torrefaction is based on the removal of oxygen from biomass which aims to produce a fuel with increased energy density by decomposing the reactive hemicellulose fraction. Different reaction conditions (temperature, inert gas, reaction time) and biomass resources lead to various solid, liquid and gaseous products. A short overview of the different mass and energy balances is presented. Finally, the technology options and the most promising torrefaction applications and their economic potential are described.     

Role of energy policy in renewable energy accomplishment: The case of second-generation bioethanol

Renewable energy has been in the limelight ever since the price of crude petroleum oil increases to the unprecedented height of US$96 per barrel recently. This is due to the diminishing oil reserves in the world and political instabilities in some oil-exporting countries. The advantages of renewable energy compared to fossil fuels are enormous in terms of environment and availability. Biofuels like bioethanol and biodiesel are currently being produced from agricultural products such as sugarcane and rapeseed oil, respectively. Collectively, these biofuels from food sources are known as first-generation biofuels. Although first-generation biofuels have the potential to replace fossil fuels as the main source of energy supply, its production is surrounded by certain issues like tropical forests’ destruction. Instead, second-generation bioethanol, which utilizes non-edible sources such as lignocellulose biomass to produce ethanol, has been shown to be more suitable as the source of renewable energy. However, there are challenges and obstacles such as cost, technology and environmental issues that need to be overcome. Hence, the introduction of energy policy is crucial in promoting and implementing second-generation bioethanol effectively and subsequently become a major source of renewable energy.