Potential of bioethanol production from agricultural wastes in Iran

The production of bioethanol from agricultural residues such as wheat, barley, sugar cane, corn and rice in Iran is investigated in this paper. In Iran, agricultural residues are not commonly used for energy application. This paper aims to cover several perspectives on the size of the bioethanol feedstock resource in Iran. Crop residues and sugar cane bagasse are included in feedstock for production of bioethanol. There are approximately 17.86 MT of wasted crops in Iran that can potentially produce 4.91 GL of bioethanol per year. Wheat, sugar cane bagasse, rice, barely and corn are the most favourable bioethanol production source in Iran. Agricultural waste materials can be used for production of bioethanol fuel. Bioethanol can be considered as the optimum alternative fuel for gasoline. Bioethanol is an environmentally friendly fuel and has the potential to provide comparable engine performance results.     

Algae as a sustainable energy source for biofuel production in Iran: A case study

Algae can be converted directly into energy, such as biodiesel, bioethanol and biomethanol and therefore can be a source of renewable energy. There is a growing interest for biodiesel production from algae because of its higher yield non-edible oil production and its fast growth that does not compete for land with food production. About 50% of algae weight is oil that this lipid oil can be used to make biodiesel. Algae is capable of yielding 30 times more oil per acre than the crops currently used in biodiesel production. Processes for biodiesel production from algae-oil are similar to food and non-food crops derived biodiesel processes. Because of disadvantages of fossil fuels, renewable energy sources are getting importance for sustainable energy development and environmental protection. Among the renewable sources, Iran has high biofuel energy potential. The Iranian government is considerable attention to the utilization of renewable energy, especially biofuels. Iran has enough land in order to algae cultivation that does not compete with food production. A salt lake (Lake Orumieh) in Iran's West Azarbaijan province, Maharlu salt lake in Iran's Fars province, Qom salt lake in Iran's Qom province have given rise to a new species of algae for biofuel. Algae are frequent in the shallow-marine lime stones in Zagros Mountains in north of Fars province. Greenish blooms of algae can be seen in the Persian Gulf and Caspian Sea, south and north of Iran respectively. This study presents a brief introduction to the resource, status and prospect of algae as a sustainable energy source for biodiesel production in Iran. The main advantages of using algae for biodiesel production in Iran are described.     

Bioethanol production from Asphodelus aestivus

The increase on the price of fossil fuels and the need to protect the environment from greenhouse gases urge the investigation of the possibility of using biofuels to replace them. Cyprus is faced with severe water shortage and unavailability of agricultural land that limit the cultivation of energy crops that supply the feedstock for biofuel production. A possibility would be to use Asphodelus aestivus L. that is encountered in Cyprus and other Mediterranean countries, growing wild in pastures. Its tubers contain starch that was measured to be 10.1%. The bioethanol is produced by fermentation of the mash produced by crashing the tubers of the plant. The first stage of the process was cooking the mash at a temperature of 95 °C, combined by liquefaction and saccharification of the starch using enzymes, like alpha-amylase and glucoamylase. The process was followed by fermentation of the mash for three days and finally distillation of bioethanol. The alcohol yield per kilogram tubers was 49.52 ml/kg, compared to the theoretical value of 83.72 ml/kg, mainly due to the incomplete fermentation of the sugars. The plant seems to be a potential energy plant for bioethanol production in arid regions cultivated on degraded land.     

Palm-based biofuel refinery (PBR) to substitute petroleum refinery: An energy and emergy assessment

As the most active palm industry cluster in the world, Malaysia produces enormous amount of biomass from the industry. This work studies the possibility of creating a renewable and sustainable source of energy by fully utilizing an area of land to provide liquid biofuel for the country. Palm-based biofuel refinery (PBR) proposed in this study has the ultimate goal to displace petroleum fuels and fulfill domestic energy demand. It fully utilizes indigenous palm biomass to fulfill 35.5% of energy demand in the country by using land area of only 8% of current palm cultivation. The operation concept of PBR is similar to petroleum refinery in which a single source feedstock (crude petroleum) can be processed to multiple products. In PBR, products from an oil palm plantation will be converted to various biofuel end products. Renewable biofuel such as biodiesel and bioethanol can be produced from crude palm oil and lignocellulosic residues. Energy and emergy assessment were made in this work to evaluate the sustainability and efficiency of PBR. Biofuel produced from PBR has a high energy equivalent of 31.56 MJ/kg as 1 ha of land can produce 182,142 MJ annually. Although there are still obstacles to be overcome, it is important for Malaysia to develop its own energy supply from indigenous resources as an initiative not only for security but also lower carbon emission.     

Review of China’s bioethanol development and a case study of fuel supply, demand and distribution of bioethanol expansion by national application of E10

The increasing dependence on imported oil and tremendous greenhouse gases (GHG) emission is making the diversification of primary fuel such as petroleum a critical vital energy and environmental issue in China. China is promoting bioethanol by mandatory use in nine provinces and the expansion is on agenda. This paper first reviews China’s bioethanol development. Next, suitable feedstock crops for expanded ethanol production are discussed. Particularly, bioethanol expansion by national application of E10 is investigated from perspectives of potential in bioethanol supply, projected ethanol demand, and the possible cost-effective bioethanol distribution system. It is calculated that by making use of un-used land for feedstock planting and introduction of improved feedstock varieties, potential bioethanol production capacity in China will be up to 25.33 million tons per year. Ethanol demand for national application of E10 is projected to be around 7 million tons per year. A linear optimization model is used to consider the economic costs of distributing bioethanol in China. The optimization result suggests that development of bioethanol industry may focus on Henan, Jilin, Anhui, Jiangxi and Sichuan basin. It also estimates 53.79 RMB per ton of bioethanol for downstream rail or truck transportation remain a relatively small fraction of total fuel cost. Thanks to the well developed railway network in China, more bioethanol can be distributed at a relatively modest premium distribution costs and with low environmental influences.     

Life cycle analysis for bioethanol production from sugar beet crops in Greece

The main aim of this study is to evaluate whether the potential transformation of the existing sugar plants of Northern Greece to modern bioethanol plants, using the existing cultivations of sugar beet, would be an environmentally sustainable decision. Using Life Cycle Inventory and Impact Assessment, all processes for bioethanol production from sugar beets were analyzed, quantitative data were collected and the environmental loads of the final product (bioethanol) and of each process were estimated. The final results of the environmental impact assessment are encouraging since bioethanol production gives better results than sugar production for the use of the same quantity of sugar beets. If the old sugar plants were transformed into modern bioethanol plants, the total reduction of the environmental load would be, at least, 32.6% and a reduction of more than 2 tons of CO₂e/sugar beet of ha cultivation could be reached. Moreover bioethanol production was compared to conventional fuel (gasoline), as well as to other types of biofuels (biodiesel from Greek cultivations).     

Optimization and analysis of a bioethanol agro-industrial system from sweet sorghum

The use of non-food crops for bioethanol production represents an important trend for renewable energy in China. In this paper, a bioethanol agro-industrial system with distributed fermentation plants from sweet sorghum is presented. The system consists of the following processes: sweet sorghum cultivation, crude ethanol production, ethanol refining and by-product utilization. The plant capacities of crude ethanol and pure ethanol, in different fractions of useful land, are optimized. Assuming a minimum cost of investment, transport, operation and so on, the optimum capacity of the pure ethanol factory is 50,000 tonnes/year. Moreover, this bioethanol system, which requires ca. 13,300 ha (hectares) of non-cultivated land to supply the raw materials, can provide 26,000 jobs for rural workers. The income from the sale of the crops is approximately 71 million RMB Yuan and the ethanol production income is approximately 94 million RMB Yuan. The potential savings in CO₂ emissions are ca. 423,000 tonnes/year and clear economic, social and environmental benefits can be realized.     

Optimization of bioenergy yield from cultivated land in Denmark

A cost minimization model for supply of starch, oil, sugar, grassy and woody biomass for bioenergy in Denmark was developed using linear programming. The model includes biomass supply from annual crops on arable land, short rotation forestry (willow) and plantation forestry. Crop area distributions were simulated using cost data for year 2005. Five scenarios with different constraints, e.g. on food and feed supply and on nitrogen balance were considered focusing on: a) constraints as the year 2005, b) landscape aesthetics and biodiversity c) groundwater protection, d) maintaining current food and feed production, or e) on site carbon sequestration. In addition, two oil price levels were considered. The crop area distributions differed between scenarios and were affected by changing fossil oil prices up to index 300 (using 55$ per barrel in 2005 as index = 100). The bioenergy supply (district heating, electric power, biogas, RME or bioethanol) varied between 56 PJ in the “2005” scenario at oil index 100 and 158 PJ at oil index 300 in the groundwater scenario. Our simple model demonstrates the effect of prioritizing multiple uses of land resources for food, feed or bioenergy, while maintaining a low nitrogen load to the environment. In conclusion, even after drastic landuse changes the bioenergy supply as final energy will not exceed 184 PJ annually (including 26 PJ processed biowaste sources) by far lower than the annual domestic total energy consumption ranging between 800 and 850 PJ yr^?1.     

Distribution and potential of bioenergy resources from agricultural activities in Mexico

Biomass is the most abundant and versatile form of renewable energy in the world. The bioenergy production from crop residues is compatible with both food and energy production. Currently, several technologies are available for transforming crop residues into utilizable energy such as direct combustion and fermentation. Mexico is the third largest country in LAC in terms of the cropland area and would become a central focus of attention for the production of biofuels. In this paper we examined the type, location and quantities of various crop residues in Mexico to evaluate their potential for conversion into bioenergy through combustion and fermentation. It was estimated that 75.73 million tons of dry matter was generated from 20 crops in Mexico. From this biomass, 60.13 million tons corresponds to primary crop residues mainly from corn straw, sorghum straw, tops/leaves of sugarcane and wheat straw. The generation of secondary crop residues accounted for 15.60 million tons to which sugarcane bagasse, corncobs, maguey bagasse and coffee pulp were the main contributors. The distribution of this biomass showed that several Mexican municipalities had very high by-product potentials where each municipality could have an installed capacity of 78 MW (via direct combustion) or 0.3 million m³ of bioethanol per year (via anaerobic fermentation). The identification of these municipalities where the biomass potential is high is important since it constitutes the first step towards evaluating the current biomass availability and accurately estimating the bioenergy production capacity from crop residues.     

The potential for hydrogen-enriched biogas production from crops: Scenarios in the UK

There is increasing international interest in developing low carbon technologies to provide hydrogen renewably. Hydrogen can be produced through dark anaerobic fermentation using carbohydrate-rich substrates, and methane can be produced in a methanogenic second stage. The suitability of a range of crops for hydrogen and methane production in the UK is examined, using selection criteria including yield, harvest window and composition of the crops. The annual potential for hydrogen and methane production is calculated using the selected crops, taking into account the energy required to grow and harvest the biomass and run the process. The fermentable energy crops fodder beet, forage maize, sugar beet and rye grass were identified as the most suitable substrates for this farm-scale process. A conservative estimate of the amount of agricultural land in the UK excluding permanent grassland not already used for food production or energy crops (currently unused “set-aside” land) has been made (294,960 ha). If this was used to grow a rotation of the selected crops, 9.6 TW h net energy could be produced per year. This equates to electrical power for 2.2 million homes in the UK annually and a reduction of CO₂ emissions by over 2.3 million tones per annum in the UK.     

Diesterol: An environment-friendly IC engine fuel

Diesterol is a new specific term which denotes a mixture of fossil diesel fuel (D), vegetable oil methyl ester called biodiesel (B) and plant derived ethanol (E). In the context of the present paper, this term refers specifically to the combination of diesel fuel, bioethanol produced from potato waste, dehydrated in a vapor phase using 3A Zeolite, and sunflower methyl ester produced through transesterification. The mixture of DBE, i.e. diesterol, was patented under the Iranian patent No. 39407, dated 12-3-2007. The main purpose of this research work was to reduce engine exhaust NO_x, CO, HC and smoke emissions due to application of biofuel and the increase of fuel oxygen content. It was needed to prepare suitable low cost and renewable additives. The diesterol properties such as pour point, viscosity, flash point, copper strip corrosion, ash content, sulfur content and cetane number were determined experimentally. The optimum ratio of bioethanol and biodiesel was found to be 40/60 considering fuel oxygen content, fuel price and mixture properties. Bioethanol was added to enhance the oxygenated component in the fuel, while the sunflower methyl ester was added to maintain the fuel stability at low temperatures. The parameters considered for investigation are the engine power, torque, specific fuel consumption and exhaust emissions for various mixture proportions. The experimental results showed that bioethanol plays an important role in determining the flash point of the blends. By adding 3% bioethanol to diesel and sunflower methyl ester, the flash point was reduced by 16 °C. The viscosity of the blend was also reduced by increasing the amount of bioethanol. The sulfur content of bioethanol and sunflower methyl ester is very low compared to diesel fuel. The sulfur content of diesel is 500 ppm whereas that of bioethanol and sunflower methyl ester is 0 and 15 ppm, respectively. This lower sulfur content is another factor enhancing the use of fuel blends in diesel engines. The bioethanol and sunflower methyl ester combination has sulfur content less than 20 ppm. The maximum power and torque using diesel fuel were 17.75 kW and 64.2 Nm at 3600 and 2400 rpm, respectively. Adding oxygenated compounds to the new blend seems to slightly reduce the engine power and torque and increased the average sfc for various speeds. The experimental measurement and observation of smoke concentration, NO_x, CO and HC concentration indicated that both of these pollutants reduced by increasing the biofuel composition of diesterol throughout the engine operating range.     

Production possibility frontier analysis of biodiesel from waste cooking oil

This paper presents an assessment of the productive efficiency of an advanced biodiesel plant in Japan using Data Envelopment Analysis (DEA). The empirical analysis uses monthly input data (waste cooking oil, methanol, potassium hydroxide, power consumption, and the truck diesel fuel used for the procurement of waste cooking oil) and output data (biodiesel) of a biodiesel fuel plant for August 2008–July 2010. The results of this study show that the production activity with the lowest cost on the biodiesel production possibility frontier occurred in March 2010 (production activity used 1.41 kL of waste cooking oil, 0.18 kL of MeOH, 16.33 kg of KOH, and 5.45 kW h of power), and the unit production cost in that month was 18,517 yen/kL. Comparing this efficient production cost to the mean unit production cost on the production possibility frontier at 19,712 yen/kL, revealed that the cost of producing 1 kL of biodiesel could be reduced by as much as 1195 yen. We also find that the efficiency improvement will contribute to decreasing the cost ratio (cost per sale) of the biodiesel production by approximately 1% during the study period (24 months) between August 2008 and July 2010.     

The reuse of waste cooking oil and spent bleaching earth to produce biodiesel

Currently, semi-refined and refined vegetable oils are used as a feedstock in biodiesel production. However, criteria such as competition with conventional fossil fuel, economic reasons, shortage supply of food and its social impact on the global scale have somewhat slowed the development of the biodiesel industry. Spent bleaching earth is currently under-utilized by deposition in landfills with no attempt to recover the oil. In this study the waste oil adsorbed on spent bleaching earth, refined soybean oil, and waste cooking oil were evaluated as potential sources of biodiesel production in Iran. Different characteristics of the oil samples, such as fatty acid composition, peroxide, iodine, acid values, etc., were evaluated. A two-step esterification reaction using methanol was conducted to produce biofuel. Subsequently, physicochemical properties of produced biodiesel were analyzed. The oil content in spent bleaching earth was 19.3%, which was lowered to 3.7% using hexane as the solvent. Gas chromatography showed that palmitic, oleic, and linoleic acids were predominantly fatty acids, respectively, and the highest content of saturated acids belonged to waste cooking oil (24%). The acidity of 8.3% was obtained for the oil recovered from spent bleaching earth followed by waste cooking oil (3.6%) and refined soybean oil (0.1%). Totally, the specifications of all biodiesel produced were in the range defined by ASTM D6751 and EN 14214 standards. Since about 2000–3000 tones of spent bleaching earth residual oil is annually dumped and the amount of waste cooking oil produced yearly is 500,000 tones, there is a great potential for Iran to produce biodiesel from waste oils.     

Potential contribution of bioethanol fuel to the transport sector of Vojvodina

The Autonomous Province of Vojvodina is an Autonomous Province in Serbia and it is an energy-deficient country. The indigenous reserves of oil and gas are limited and the country is heavily dependent on the import of oil. The oil import bill is a serious strain on the country's economy and has been deteriorating the balance of payments situation. The country has become increasingly more dependent on fossil fuels and its energy security hangs on the fragile supply of imported oil that is subject to disruptions and price volatility. The transport sector has a 26% share in the total commercial energy consumption in Vojvodina. About 0.62 million tons of gasoline were consumed by this sector in 2008. Gasoline consumption in the transport sector is also a major source of environmental degradation especially in urban areas. Consequently, Vojvodina needs to develop indigenous, environment-friendly energy resources, such as bioethanol, to meet its transport sector's energy needs. Vojvodina produces about 3 million tons of sugar beet every year. There is a vast potential for bioethanol production from molasses of sugar beet in the country. Bioethanol can be used in transport sector after blending with gasoline, in order to minimize gasoline consumption and associated economical and environmental impacts. This paper presents the assessment of the potential contribution of bioethanol in the transport sector of Vojvodina. It is concluded that 20% of annual gasoline consumption in transport sector could be met from ethanol by the year 2026.     

Key prospects and major development of hydrogen and bioethanol production

Cheap Production of bioethanol from renewable lignocellulosic waste has the imperative potential to economically cut burgeoning world dependency on fossils while reducing net emission of carbon dioxide (CO₂), a principal greenhouse gas (GHGs). This paper highlights key benefits and status of bioethanol production technologies, aiming mainly on recent developments and its key potentials in Pakistan. Most sector of Pakistan economy heavily rely on the energy and power that is being produced using traditional approaches like from oil and hydel. However, the sedimentation in dams cut-down the energy generation and overwhelmed severe energy crisis that are witnessed since last decade. Thus, Pakistan must go to avail alternative sources of energy like hydro, biomass and solar so that energy security can be ensured to recover the tremendous loss of economy. Renewable biomass is abundantly available in Pakistan which can be used to produce bioethanol and electricity. Currently, 22 distilleries are producing the ethanol from sugar cane bagasse and out of these only 8 distillation units are producing motor fuel grade ethanol. The current bioethanol production of country is about 403,500 tons/year along with 2423 tons of biodegradable waste available in major cities. In addition, Pakistan produces 6.57, 0.5, 0.66, and 2.66 million tons of sugarcane, corn, rice, and wheat straw per annum, respectively. This biomass can produce 1.6 million liters of bioethanol which can produce approximately 38% of Pakistan's electricity annually. Despite having large potential, Pakistan is still producing a few volumes of ethanol from sugarcane bagasse. The production of bioethanol can be boosted using (I) pretreatment of agricultural biomass by alkali (II) enzymatic and bacteria-based hydrolysis of the biomass (III) post-hydrolysis using pressurized steam above 100 °C (IV) Fermentation of the biomass@ 7–10 h and (V) and (VI) distillation of bioethanol. This study recommends (1) increase R&D capacities mainly in the west and central regions of Pakistan, (2) initiate mega-projects to promote integrated bio-ethanol production at agriculture farms by providing 1/3 subsides, (3) purchase of bioethanol directly from the major agricultural farms, (4) produce bioethanol related manpower from the key research institutes as specified in this study.     

Worldwide commercial development of bioenergy with a focus on energy crop-based projects

Bioenergy consumption is greatest in countries with heavy subsidies or tax incentives, such as China, Brazil, and Sweden. Conversion of forest residues and agricultural residues to charcoal, district heat and home heating are the most common forms of bioenergy. Biomass electric generation feedstocks are predominantly forest residues (including black liquor), bagasse, and other agricultural residues. Biofuel feedstocks include sugar from sugarcane (in Brazil), starch from maize grain (in the US), and oil seeds (soy or rapeseed) for biodiesel (in the US, EU, and Brazil). Of the six large land areas of the world reviewed (China, EU, US, Brazil, Canada, Australia), total biomass energy consumptions amounts to 17.1 EJ. Short-rotation woody crops (SRWC) established in Brazil, New Zealand, and Australia over the past 25 years equal about 50,000 km². SRWC plantings in China may be in the range of 70,000–100,000 km². SRWC and other energy crops established in the US and EU amount to less than 1000 km². With some exceptions (most notably in Sweden and Brazil), the SRWC have been established for purposes other than as dedicated bioenergy feedstocks, however, portions of the crops are (or are planned to be) used for bioenergy production. New renewable energy incentives, greenhouse gas emission targets, synergism with industrial waste management projects, and oil prices exceeding 60 $ Bbl⁻¹ (in 2005) are major drivers for SRWC or energy crop based bioenergy projects.     

The feasibility and implications for conventional liquid fossil fuel of the Indonesian biofuel target in 2025

This paper identifies conventional liquid fossil fuels that can be replaced or blended with biofuel and quantifies the biofuels required to meet the Indonesian biofuel target of at least 5% of the total primary energy mix in 2025. The analysis was conducted using the Long range Energy Alternatives Planning (LEAP) system with an energy elasticity of 1 and maximum allowable biofuel blending ratios according to the current best practices. The results show that the target could be achieved with the maximum blending alternative based on constant energy demand growth of 6%. The target requires a total contribution from biofuel of about 8–27 GL in 2025 depending on blending ratios. In energy terms, these are equivalent to 232–782 PJ or about 40–135 million barrels crude oil, which constitute roughly around 3.3–11.0% of the estimated liquid fossil fuel oil annual consumption in that year. The results imply that it may have detrimental environmental impact, as it requires 5.2 million ha of palm oil and sugar cane plantations. On the positive side, achieving the target offers potential new employment opportunities of about 3.4 million jobs, particularly in the agricultural sector relevant to liquid biofuel production.     

Future prospects of delignification pretreatments for the lignocellulosic materials to produce second generation bioethanol

Production of bioethanol is winning support from masses because it is a workable choice to solve the problems associated with the fluctuating prices of crude petroleum oil, climatic change, and reducing non‐renewable fuel reserves. First‐generation biofuels are produced directly from food crops. The biofuel (bioethanol, biodiesel) is ultimately derived from the starch, sugar, animal fats, and vegetable oil that these crops provide. It is important to note that the structure of the biofuel itself does not change between generations, but rather the source from which the fuel is derived changes. Corn, wheat, and sugar cane are the most commonly used first‐generation bioethanol feed stocks. Lignocellulosic materials are used as a feed stock for the production of second‐generation bioethanol. The major production steps are (1) delignification, (2) depolymerisation, and (3) fermentation. Agricultural residues are waste materials produced through the processing of agricultural crops. The main reason to use of these agricultural residues to produce bioethanol is to convert waste to value added products. The main challenges are the low yield of the cellulosic hydrolysis process due to the presence of lignin and hemicellulose with cellulose. Pretreatments of lignocellulosic materials to remove lignin and hemicellulose are the techniques used to enhance the hydrolysis. Present review article comprehensively discusses the different pretreatment methods of delignification for ethanol production. Published literature on pretreatments from 1982 to 2018 has been studied. Perspectives, gaps in studies, and recommendations are given to fully describe implementation of eight prominent pretreatments (milling, pyrolysis, organic solvents, steam explosion, hot water treatments, ozonolysis, enzymatic delignification, and genetic modification) for future research. The energy and environmental features of lignocellulosic materials are elaborated to show a sustainable aspect of second‐generation biofuel. It was felt necessary to discuss the concept of bio refinery to make biofuel production financially more attractive as well because the future prospects of second‐generation biofuel are promising.     

Biofuel production potentials in Europe: Sustainable use of cultivated land and pastures. Part I: Land productivity potentials

IIASA's agro-ecological zones modelling framework has been extended for biofuel productivity assessments distinguishing five main groups of feedstocks covering a wide range of agronomic conditions and energy production pathways, namely: woody lignocellulosic plants, herbaceous lignocellulosic plants, oil crops, starch crops and sugar crops. A uniform Pan-European land resources database was compiled at the spatial resolution of 1 km². Suitability and productivity assessments were carried out by matching climate characteristics with plant requirements, calculating annual biomass increments or yields including consideration of soil and terrain characteristics of each grid-cell.Potential biomass productivity and associated energy yields were calculated for each grid-cell. Spatial distributions of suitabilities of biofuel feedstocks in Europe were generated for each individual feedstock as well as for the five biofuel feedstock groups. Estimated agronomical attainable yields, both in terms of biomass (kg ha^?1) as well as biofuel energy equivalent (GJ ha^?1), were mapped and tabulated by agriculture and pasture land cover classes as derived from the CORINE land cover database. Results have been further aggregated by administrative units at NUTS 2 level.     

Outlook for advanced biofuels

To assess which biofuels have the better potential for the short-term or the longer term (2030), and what developments are necessary to improve the performance of biofuels, the production of four promising biofuels—methanol, ethanol, hydrogen, and synthetic diesel—is systematically analysed. This present paper summarises, normalises and compares earlier reported work. First, the key technologies for the production of these fuels, such as gasification, gas processing, synthesis, hydrolysis, and fermentation, and their improvement options are studied and modelled. Then, the production facility's technological and economic performance is analysed, applying variations in technology and scale. Finally, likely biofuels chains (including distribution to cars, and end-use) are compared on an equal economic basis, such as costs per kilometre driven. Production costs of these fuels range 16–22 €/GJ_HHV now, down to 9–13 €/GJ_HHV in future (2030). This performance assumes both certain technological developments as well as the availability of biomass at 3 €/GJ_HHV. The feedstock costs strongly influence the resulting biofuel costs by 2–3 €/GJ_fuel for each €/GJ_HHV feedstock difference. In biomass producing regions such as Latin America or the former USSR, the four fuels could be produced at 7–11 €/GJ_HHV compared to diesel and gasoline costs of 7 and 8 €/GJ (excluding distribution, excise and VAT; at crude oil prices of ∼35 €/bbl or 5.7 €/GJ). The uncertainties in the biofuels production costs of the four selected biofuels are 15–30%. When applied in cars, biofuels have driving costs in ICEVs of about 0.18–0.24 €/km now (fuel excise duty and VAT excluded) and may be about 0.18 in future. The cars’ contribution to these costs is much larger than the fuels’ contribution. Large-scale gasification, thorough gas cleaning, and micro-biological processes for hydrolysis and fermentation are key major fields for RD&D efforts, next to consistent market development and larger scale deployment of those technologies.