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).     

Spatial variation of environmental impacts of regional biomass chains

In this study, the spatial variation of potential environmental impacts of bioenergy crops is quantitatively assessed. The cultivation of sugar beet and Miscanthus for bioethanol production in the North of the Netherlands is used as a case study. The environmental impacts included are greenhouse gas (GHG) emissions (during lifecycle and related to direct land use change), soil quality, water quantity and quality, and biodiversity. Suitable methods are selected and adapted based on an extensive literature review. The spatial variation in environmental impacts related to the spatial heterogeneity of the physical context is assessed using Geographical Information System (GIS). The case study shows that there are large spatial variations in environmental impacts of the introduction of bioenergy crops. Land use change (LUC) to sugar beet generally causes more negative environmental impacts than LUC to Miscanthus. LUC to Miscanthus could have positive environmental impacts in some areas. The most negative environmental impacts of a shift towards sugar beet and Miscanthus occur in the western wet pasture areas. The spatially combined results of the environmental impacts illustrate that there are several trade offs between environmental impacts: there are no areas were no negative environmental impacts occur. The assessment demonstrates a framework to identify areas with potential negative environmental impacts of bioenergy crop production and areas where bioenergy crop production have little negative or even positive environmental impacts.     

What crop rotation will provide optimal first-generation ethanol production in Ireland, from technical and economic perspectives?

This paper describes a technical and economic analysis of the potential ethanol production from wheat, barley and sugar beet in Ireland for three different combinations of the crops. Scenarios are investigated which include for three crop rotations: (1) wheat, barley and sugar beet; (2) wheat, wheat and sugar beet; and (3) wheat only.Ethanol production facilities typically employ either starch or sugar feedstocks which may not be optimised if both starch and sugar feedstocks are used. Thus, the scenarios which include sugar beet require two separate facilities.The study shows that technical optimisation gives a different rotation to an economic optimisation. It was found that the starch feedstocks (wheat and barley) produce more ethanol per tonne of feedstock than the sugar feedstock (sugar beet). However, on a land area basis, sugar beet produces significantly more ethanol, and hence more energy, than either wheat or barley. In order to meet the EU Biofuels Directive, it is crucial to maximise the energy return per unit of land. Thus, optimisation on the basis of minimisation of land take gives a rotation of wheat, wheat and sugar beet, as this scenario produces the greatest quantity of energy per hectare, whereas optimisation on an economic basis suggests wheat alone with the lowest production cost of €0.6/l.     

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.     

Future trends of bioethanol co-production in Serbian sugar plants

Due to the reduction of the economic support for refined sugar efforts have been made to find new ways of using sugar beet outside food industry. This paper investigates the possibilities of introducing bioethanol co-production in Serbian sugar plants. Research shows current state of Serbian sugar industry and technical aspects of bioethanol co-production in sugar plants. These results represent important step toward mass production of bioethanol in Serbian factories. The main goals of introducing the concept of sugar and bioethanol coproduction would be efficient use of available resources for the production of energy, reduction of greenhouse gases emission, decreased dependence on import and creation of new jobs. Besides that, it would provide flexibility in terms of variation of produced quantities of sugar and ethanol, depending on the conditions prevailing on the market.     

Research on ethanol production and use from sugar beet in Turkey

Emissions of greenhouse gases such as CO₂, CO, CH₄ and NO_X from fossil fuel use are implicated in climate change. The use of bioethanol is one means to reduce fossil fuel use and emissions of greenhouse gases. This study investigated research to produce ethanol from sugar beet and use as fuel in Turkey. The calculated demand for bioethanol amounted to some 220,000 m³ where a 5% ethanol mix in petrol was used. Turkey has the potential to produce 30 million ton of sugar beet, which is sufficient to meet the bioethanol demand.     

Optimization of very high gravity fermentation process for ethanol production from industrial sugar beet syrup

In order to reduce production costs and environmental impact of bioethanol from sugar beet low purity syrup 2, an intensification of the industrial alcoholic fermentation carried out by Saccharomyces cerevisiae is necessary. Two fermentation processes were tested: multi-stage batch and fed-batch fermentations with different operating conditions. It was established that the fed-batch process was the most efficient to reach the highest ethanol concentration. This process allowed to minimize both growth and ethanol production inhibitions by high sugar concentrations or ethanol. Thus, a good management of the operating conditions (initial volume and feeding rate) could produce 15.2% (v/v) ethanol in 53 h without residual sucrose and with an ethanol productivity of 2.3 g L h⁻¹.     

Liquid biofuels potential and outlook in Iran

Iran’s diversity of terrain and climate enables cultivation of a variety of energy crops suitable for liquid biofuels production. In Iran, the easily and readily available biofuel feedstock today for production of bioethanol is molasses from sugar cane and sugar beet. There is also about 17.86 million tons of crops waste from which nearly 5 billion liters of bioethanol could be produced annually. This amount of bioethanol is sufficient to carry out E10 for spark ignition engine vehicles in Iran by 2026. There is also enormous potential for cultivation of energy plants such as cellulosic materials and algae. Iran has 7%of its area covered with forest products which are suitable sources for liquid biofuels such bioethanol and biodiesel. Iran also has a long tradition of fishing in Caspian Sea and Persian Gulf with about 3200 km coastline and on inland rivers. The produced fish oil and other plant oils such as palm tree, jatropha, castor plant and algae are suitable biodiesel feedstock. Out of 1.5 million tons of edible cooking oil consumed in Iran annually, about 20% of it can be considered as waste, which is suitable biodiesel feedstock.This quantity along with the other possible potential feedstock are favorable sources to carry out B10 step by step until 2026.     

Energy return on investment of Austrian sugar beet: A small-scale comparison between organic and conventional production

In near future it is essential for human society to switch its primary energy use from finite sources to renewable ones. Ethanol has been claimed to be a potential candidate to replace oil use to great extent. This study illustrates that ethanol production has the potential to rely on organic agriculture and thereby to reduce reliance on fossil fuels. Case studies were carried out by examining three farms (2 conventional, 1 organic) in Austria who are mainly producing sugar beet. We found that organic sugar beet production provided an overall energy return on investment (EROI) of 11.3 whereas the conventional farming practice showed an EROI of 14.1 and 15, respectively. Our study indicates that organic sugar beet production shows potential to substitute conventional industrial sugar beet production to provide inputs to ethanol production. By using organically produced sugar beets as inputs to the ethanol production, fossil fuels can perhaps be avoided to a large extent in the production process, thus, it may be possible to mitigate some of the environmental impacts associated with ethanol production. Larger studies are however needed to better visualise such results.     

Sustainability of bioethanol production from wheat with recycled residues as evaluated by Emergy assessment

An Emergy assessment study of 24 bioethanol production scenarios was carried out for the comparison of bioethanol production using winter wheat grains and/or straw as feedstock and conversion technologies based on starch (1st generation) and/or lignocellulose (2nd generation). An integrated biomass utilization system (IBUS) was used for combining the two kinds of feedstock. The crop was cultivated under four combinations of Danish soil conditions (sand or sandy loam) and crop managements (organic or conventional). For each of the production processes, two scenarios, with or without recycling of residues, were considered. Material and energy flows were assessed to evaluate the bioethanol yield, the production efficiency in terms of Emergy used compared to energy produced (transformity), and the environmental load (ELR) in terms of use of non-renewable resources. These three indicators varied among the four feedstock production scenarios to the same extent as among the three different industrial production scenarios and in each case the efficiency was lower and the use of non-renewables higher for the non-recycling system. The system most efficient for production of bioethanol (lowest transformity) and with the lowest environmental load (ELR) was bioethanol produced from grains cultivated in the organic sandy loam scenario; systems with the highest transformity and ELR were bioethanol production based on straw from conventional cultivation and without recycling of residues. The IBUS concept obtained the best bioethanol production efficiency for each cultivation system but its consumption of non-renewable resources was not optimal.     

Technical and economic analysis of biogas production in Ireland utilising three different crop rotations

The Biofuels Directive sets reference values for the quantity of biofuels and other renewable fuels to be placed on the transport market. Biogas from agricultural crops can be used to meet this directive. This paper investigates biogas production for three crop rotations: wheat, barley and sugar beet; wheat, wheat and sugar beet; wheat only. A technical and economic analysis for each crop rotation was carried out. It was found that wheat produces significantly more biogas than either barley or sugar beet, when examined on a weight basis. However sugar beet produces more biogas and subsequently more energy when examined on an area basis. When producing biofuels, land is the limiting factor to the quantity of energy that may be produced. Thus if optimising land then a crop rotation of wheat, wheat and sugar beet should be utilised, as this scenario produced the greatest quantity of energy. This scenario has a production cost of €0.90/m_N³, therefore, this scenario is competitive with petrol when the price of petrol is at least €1.09/l (VAT is charged at 21%). If optimising the production costs then a crop rotation of wheat only should be utilised when the cost of grain is less than €132/ton. This scenario has the least production cost at €0.83/m_N³, therefore, this scenario is competitive with petrol when the price of petrol is at least €1.00/l. But as this scenario produces the least quantity of biogas, it also produces the least quantity of energy. In comparing with other works by the authors it is shown that a biomethane system produces more energy from the same crops at a cheaper cost than an ethanol system.     

Bioethanol production from thick juice as intermediate of sugar beet processing

The aims of this study were to investigate the bioethanol production of thick juice as intermediate from sugar beet processing in batch culture by free Saccharomyces cerevisiae cells and the effect of sugar concentration on ethanol yield and CO₂ weight loss rate. Thick juice and molasses of sugar beet from a domestic sugar factory were diluted with distilled water to give a total sugar concentration of 5, 10, 15, 20 and 25% (w w^?1). Initial concentration of fermentable sugars of 20% (w w^?1) in culture medium can be taken as optimal, enabling maximal ethanol yield (68%) and maximal CO₂ evolution rate was realized, amounting to more than 90 g L^?1 h^?1. The optimal concentration of fermentable sugar from thick juice for bioethanol production by free S. cerevisiae cells was 20% (w w^?1) at 30 °C, pH 5 and agitation rate 200 rpm gave maximum ethanol concentration of 12% (v v^?1).     

How to improve the economy of bioethanol production in Serbia

Bioethanol accounts for the majority of biofuel use worldwide, either as a fuel or a gasoline enhancer. In Serbia, the industrial production of bioethanol still relies on conventional feedstocks containing starch and sugar such as corn, wheat and molasses. In order to improve the economy of bioethanol production and to avoid the competition of the feedstock utilization for food and energy, several production approaches based on crop selection, process integration and waste utilization were considered in this paper. Particular attention was put on utilization of non conventional crops such as triticale and damaged crops not appropriate for food consumption. Potential of lignocellulosic biomass for the production of second generation ethanol in Serbia was also considered as well as the utilization of stillage as a main by-product. The investigated approaches can significantly improve the economy of bioethanol production and contribute to solve serious environmental problems.     

Life cycle assessment and life cycle costing of bioethanol from sugarcane in Brazil

Brazil has always been the pioneer in the application of bioethanol as a main fuel for automobiles, hence environmental and economic analyses of the Brazilian ethanol industries are of crucial importance. This study presents a comparative life cycle assessment (LCA) on gasoline and ethanol as fuels, and with two types of blends of gasoline with bioethanol, all used in a midsize car. The focus is on a main application in Brazil, sugarcane based ethanol. The results of two cases are presented: base case—bioethanol production from sugarcane and electricity generation from bagasse; future case—bioethanol production from both sugarcane and bagasse and electricity generation from wastes. In both cases sugar is co-produced. The life cycles of fuels include gasoline production, agricultural production of sugarcane, ethanol production, sugar and electricity co-production, blending ethanol with gasoline to produce E10 (10% of ethanol) and E85 (85%), and finally the use of gasoline, E10, E85 and pure ethanol. Furthermore, a life cycle costing (LCC) was conducted to give an indication on fuel economy in both cases. The results show that in the base case less GHG is emitted; while the overall evaluation of these fuel options depends on the importance attached to different impacts. The future case is certainly more economically attractive, which has been the driving force for development in the ethanol industry in Brazil. Nevertheless, the outcomes depend very much on the assumed price for crude oil. In LCC a steady-state cost model was used and only the production cost was taken into account. In the real market the prices of fuels are very much dependent on the taxes and subsidies. Technological development can help in lowering both the environmental impact and the prices of the ethanol fuels.     

Which is the preferable transport fuel on a greenhouse gas basis; biomethane or ethanol?

Biomethane and ethanol are both biofuels which are generated from agricultural crops that can be utilised to meet the Biofuels Directive. In Ireland with the demise of the sugar industry 48,000 Ha of land is readily available for biofuel production, without unduly effecting food production. Which biofuel should dominate? This paper investigates biofuel production for three different crop rotations: wheat, barley and sugar beet; wheat, wheat and sugar beet; wheat only. A greenhouse gas balance is performed to determine under what conditions each biofuel is preferable. For both biofuels, the preferred crop on a weight basis is wheat, while on an area basis the preferred crop is sugar beet. Biomethane scenarios produce more gross energy than ethanol scenarios. Under the base assumption (7.41% biogas losses, and biomethane utilised in a converted petrol engine, such as a bi-fuel car, and thus underperforming on a km/MJ basis) ethanol generated more net greenhouse gas savings than biomethane. This was unexpected as biomethane produces twice the net energy per hectare as ethanol. If either biogas losses were reduced or biomethane was utilised in a vehicular engine optimised for biomethane (such as a bus powered solely on gaseous biofuel) then biomethane would generate significantly more net greenhouse gas savings than ethanol. It was found that if biogas losses were eliminated and the biomethane was used in a vehicle optimised for biomethane, then the net greenhouse gas savings are 2.4 times greater than those from ethanol generated from the same feedstock.     

Comparison of renewable fuels based on their land use using energy densities

In this article energy densities of selected renewable fuels are determined. Energy density is defined here as the annual energy production per hectare, taking energy inputs into account. Using 5 scenarios, consisting of 1 set focusing on technical differences and 1 set focusing on geographical variations, the range of energy densities currently obtained in Europe was determined for the following fuels: biodiesel from rapeseed; bioethanol from sugar beet; electricity from wood, wind and solar PV.The energy densities of the fuels produced from biomass were calculated by determining the energy contained in the energy carrier produced from the crop annually produced on 1 ha, from which the energy inputs for crop cultivation and conversion were subtracted. For wind and solar electricity, the energy density calculation was based on the energy production per turbine or cell and the number of turbines or cells per hectare after which the manufacturing energy was subtracted.Comparing the results shows that, for the average energy density scenarios, the ratio between the energy densities for wind, solar, and biomass is approximately 100:42:1, with wind electricity also having the highest energy output/input ratio.A case study was done in which the energy density was used to calculate the distance a vehicle can cover using the energy carrier annually produced per hectare. This was done for 3 regions, in Mid-Sweden, North-Netherlands, and South-East Spain. The results of the case show that wind electricity results in the largest distance covered, except in Spain, where solar electricity is the most favourable option.     

Sustainable production of bioethanol from renewable brown algae biomass

Brown algae have been considered as renewable biomass for bioethanol production because of high growth rate and sugar level. Saccharification of brown algae biomass is relatively easy due to the absence of lignin. Among the major sugar components of brown algae, alginate cannot be directly used because industrial microorganisms are not able to metabolize alginate. This problem has been overcome by the development of metabolically engineered microbes to efficiently utilize alginate. This review analyzes and evaluates recent research activities related to bioethanol production from brown algae. This review mainly deals with the recent development and potential of a metabolically engineered microbial cell factory and bioethanol production from brown algae biomass including alginate as the main carbohydrate. Future researches for cost-effective bioethanol production from brown algae are discussed.     

Energy crops for biofuel production: Analysis of the potential in Tuscany

The possibility of using biomass as a source of energy in reducing green-house gas emissions is a matter of great interest. In particular, biomasse from agriculture represent one of the largest and most diversified sources to be exploited and more specifically, ethanol and diesel deriving from biomass have the potential to be a sustainable means of replacing fossil fuels for transportation. Nevertheless, the cultivation of dedicated energy crops does meet with some criticism (competitiveness with food crop cultivation, water requirements, use of fertilizers, etc.) and the economical and environmental advantages of this activity depend on accurate evaluations of the total efficiency of the production system. This paper illustrates the production potential of two energy crops, sunflower (Helianthus annuus) and maize (Zea mais), cultivated with different water and fertilization supplies in the region of Tuscany, in central Italy. A 50-year climatic series of 19 weather stations scattered around Tuscany was used to run the crop model CropSyst for obtaining crop biomass predictions. The effect of climate change and variability was analyzed and the potential production of bioenergy was investigated in terms of pure vegetable oil (sunflower) and bioethanol (maize). The results demonstrated that despite a reduction in crop yields and an increase of their variability due to climate change, the cultivation of maize in the regional set-aside areas would be capable of supplying approximately 50% of the energy requirements in terms of biofuel for transportation obtained, while the cultivation of a sunflower crops would supply less than 10%.     

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.