Environmental and life cycle analysis of a biodiesel production line from sunflower in the Province of Siena (Italy)

The Directive 2009/28/EC established the overall target that 20% of energy consumption should be represented by renewable energy sources by 2020 in each European member state. Furthermore, the Directive sets a mandatory 10% minimum target for biofuels in the transport sector.Biofuels are potentially an important alternative to mineral diesel. We propose a pilot production line of biodiesel from sunflower on local scale in the Province of Siena (Tuscany) to research a possible reduction of fossil fuel consumption in the transport sector.This study might represent an opportunity to reduce petroleum dependence in the transport sector.Environmental Impact Indicators were provided by Material Flow Accounting, Embodied Energy Analysis and Emergy Accounting. Results showed that agricultural phase is the critical step in the production line.A comparative Life Cycle Assessment analysis for the biodiesel production line with mineral diesel production showed environmental advantages of the biofuel production, however requiring a higher land demand. Therefore, biodiesel may not the optimal solution on large scale but might be a good alternative to fossil fuel. This would depend upon the entire production cycle taking place in a limited area. This is necessary in order to fulfill the needs of local farms and small enterprises.     

Reduction of energy consumption in biodiesel fuel life cycle

Essential requirements for biofuel are that (a) it should be produced from renewable raw material, and (b) it should have a lower negative environmental impact than that of fossil fuels. Apart from direct assessment of the engine emissions, environmental impact is also determined by performing life cycle analysis. Life cycle energy balance depends on specific climatic conditions and the agro- and processing technologies used. Rapeseed oil methyl ester life cycle energy ratios in Lithuanian conditions have been calculated as a function of rapeseed productivity, oil pressing and transesterification technologies used.Opportunities to improve biodiesel fuel life cycle energy efficiency, by implementing new technologies in agriculture as well as in industrial processing, were reviewed. The effectiveness of new technologies was evaluated on the basis of energy balance comparison.     

A cycle simulation model for predicting the performance of a diesel engine fuelled by diesel and biodiesel blends

Among the alternative fuels, biodiesel and its blends are considered suitable and the most promising fuel for diesel engine. The properties of biodiesel are found similar to that of diesel. Many researchers have experimentally evaluated the performance characteristics of conventional diesel engines fuelled by biodiesel and its blends. However, experiments require enormous effort, money and time. Hence, a cycle simulation model incorporating a thermodynamic based single zone combustion model is developed to predict the performance of diesel engine. The effect of engine speed and compression ratio on brake power and brake thermal efficiency is analysed through the model. The fuel considered for the analysis are diesel, 20%, 40%, 60% blending of diesel and biodiesel derived from Karanja oil (Pongamia Glabra). The model predicts similar performance with diesel, 20% and 40% blending. However, with 60% blending, it reveals better performance in terms of brake power and brake thermal efficiency.     

Net energy balance of small-scale on-farm biodiesel production from canola and soybean

One necessary criterion for a biofuel to be a sustainable alternative to the petroleum fuels it displaces is a positive net energy balance. This study estimated the net energy ratio (NER), net energy balance (NEB), and net energy yield (NEY) of small-scale on-farm production of canola [Brassica napus (L.)] and soybean [Glycine max (L.)] biodiesel in the upper Midwest. Direct and embodied energy inputs based on well-defined system boundaries and contemporary data were used to estimate the energy requirement of crop production, oil extraction, and biofuel processing. The NER of canola biodiesel was 1.78 compared with 2.05 for soybean biodiesel. Canola biodiesel had a NEB of 0.66 MJ MJ⁻¹ of biofuel compared with 0.81 MJ MJ⁻¹ for soybean biodiesel. The NEY of soybean biodiesel was 10,951 MJ ha⁻¹, less than canola biodiesel which had a NEY of 11,353 MJ ha⁻¹. Use of soybean as a biodiesel feedstock was more energetically efficient than canola primarily due to reduced nitrogen fertilizer requirement. In terms of energetic productivity, canola was a more productive biodiesel feedstock than soybean due to its higher oil content. A best-case scenario based on optimal feedstock yields, reduced fertilizer input, and advanced biofuel processing equipment suggested that potential gains in energetic efficiency was greater for canola than soybean. According to our results, small-scale on-farm biodiesel production using canola and soybean can be an energetically efficient way to produce energy for on-farm use.     

Economic simulation of biodiesel production: SIMB-E tool

Recently biodiesel has been receiving increasing attention as an alternative fuel due to its environmental benefits. It is derived from renewable sources which are considered as strategic opportunities to favor environmental sustainability, to improve the population's quality of life and to promote the development of more efficient and equitable economic systems. Besides technical aspects, economics feasibility is also of great importance to access the biodiesel production viability. This paper traces the development of a software tool capable of performing economic analysis of different biodiesel plants considering the contemporary industry practices. The economic indexes considered during the analysis are the net present value (NVP), the Benefit–Costs Ratio (BCR), the Capital Return Time (CRT) and the Internal Rate of Return (IRR). Fixed capital costs, operating costs, depreciation, and auxiliary costs are also taken into account for the economic calculations.     

Microalgae for biodiesel production and other applications: A review

Sustainable production of renewable energy is being hotly debated globally since it is increasingly understood that first generation biofuels, primarily produced from food crops and mostly oil seeds are limited in their ability to achieve targets for biofuel production, climate change mitigation and economic growth. These concerns have increased the interest in developing second generation biofuels produced from non-food feedstocks such as microalgae, which potentially offer greatest opportunities in the longer term. This paper reviews the current status of microalgae use for biodiesel production, including their cultivation, harvesting, and processing. The microalgae species most used for biodiesel production are presented and their main advantages described in comparison with other available biodiesel feedstocks. The various aspects associated with the design of microalgae production units are described, giving an overview of the current state of development of algae cultivation systems (photo-bioreactors and open ponds). Other potential applications and products from microalgae are also presented such as for biological sequestration of CO₂, wastewater treatment, in human health, as food additive, and for aquaculture.     

Organic municipal solid waste (MSW) as feedstock for biodiesel production: A financial feasibility analysis

The pursuit towards an alternative solution to fossil fuel has facilitated science investigation initiatives that compare various options leading to biodiesel production. Besides conventional feedstock derived from vegetable oils, alternative sources that could be produce in large scale at competitive costs are the main scope of research in this field. This paper investigates the financial feasibility using organic solid waste as a feedstock, which results in the production of biodiesel through the conversion of volatile fatty acids into lipids (VFA). As a result, based on existing references of capital and operating costs, production and extraction yields for VFA and lipids and an internal rate of return of 15% in real terms, we concluded that biodiesel production is competitive compared to subsidized biodiesel traded in regions of Europe and the United States. These results encourage research aims to examine this technology at a larger scale. The adoption of public policies for the urban waste's disposal and collection, to reduced municipality's costs associated to the treatment, is also important for the implementation of these technologies.     

Impacts of biodiesel production on Croatian economy

The aim of this paper is to assess the direct and indirect impacts on a national economy from biodiesel (rapeseed methyl ester (RME)) production using input–output (I–O) analysis. Biodiesel development in Croatia is used as a case study. For Croatia, as for many other countries in Europe, biodiesel is a new activity not included in the existing I–O sectoral accounts. For this reason the I–O table has to be modified accordingly before being able to quantify the effect of an exogenous demand for biodiesel. Impacts in terms of output, income and employment lead to the conclusion that biodiesel production could have significant positive net impact on the Croatian economy despite the high level of subsidies for rapeseed growing.     

Life cycle assessment (LCA) and exergetic life cycle assessment (ELCA) of the production of biodiesel from used cooking oil (UCO)

The paper assesses the life cycle of biodiesel from used cooking oil (UCO). Such life cycle involves 4 stages: 1) collection, 2) pre-treatment, 3) delivery and 4) transesterification of UCO. Generally, UCO is collected from restaurants, food industries and recycling centres by authorised companies. Then, UCO is pre-treated to remove solid particles and water to increase its quality. After that, it is charged in cistern trucks and delivered to the biodiesel facility to be then transesterified with methanol to biodiesel.     

A well to pump life cycle environmental impact assessment of some hydrogen production routes

In the present study, a comparative well to pump life cycle assessment is conducted on the hydrogen production routes of water electrolysis, biomass gasification, coal gasification, steam methane reforming, hydrogen production from ethanol and methanol. The CML 2001 impact assessment methodology is employed for assessment and comparison. Comparatively higher life cycle Carbon dioxide and Sulphur oxide emissions of 27.3 kg/kg H₂ and 50.0 g/kg H₂ respectively are determined for the water electrolysis hydrogen production route via U.S. electricity mix. In addition, the life cycle global warming potential of this route (28.6 kg CO_2eq/kg H₂) is found to be comparatively higher than other routes followed by coal gasification (23.7 kg CO_2eq/kg H₂)_. However, the ethanol based hydrogen production route is estimated to have comparatively higher life cycle emissions of nitrogen dioxide (19.6 g/kg H₂) and volatile organic compounds (10.3 g/kg H₂). Moreover, this route is determined to have a comparatively higher photochemical ozone creation potential of 0.0045 kg-ethene_eq/kg H₂ as well as eutrophication potential of 0.0043 kg PO_4eq/kg H_2. The results of this study are comparatively discussed to signify the importance of life cycle assessment in comparing the environmental sustainability of hydrogen production routes.     

Life cycle assessment of biodiesel production using alkali, soluble and immobilized enzyme catalyst processes

This study deals with the Life Cycle Assessment (LCA) of three different catalytic processes for biodiesel production. In the LCA study, a “cradle to gate” approach was adopted to estimate the environmental impact of different catalytic processes such as immobilized, soluble biocatalyst and alkali catalyst. The results revealed that, biodiesel production using immobilized biocatalyst has less environmental impact compared to alkali and soluble biocatalyst. The environmental impact of the immobilized biocatalyst depends on the reusability factor.     

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.     

Energy analysis of jojoba plantation systems for the production of biodiesel

The aim of this study is to investigate the energy chain of biodiesel production from jojoba seed oil using a life cycle approach. The system boundary starts with jojoba plantation and includes extraction and conversion of seed oil into biodiesel. Energy inputs during fertilizer production and application, jojoba plantation and harvesting, oil extraction, biodiesel production, product transportation and distribution are included. Energy outputs from biodiesel and its co-products (straw, seed cake, and glycerin) are considered in the analysis. Energy efficiency is expressed in terms of the net energy gain (NEG) and the net energy ratio (NER). The results show that the NEG and NER values are calculated at 46724.1 MJ/ha (28.9 MJ/L biodiesel produced) and 2.16, respectively. Nevertheless, if manure is used as fertilizer for jojoba plant cultivation, the primary energy input will fall by 9.52% (to 22.49 MJ/L of biodiesel).     

A comparative life cycle analysis of hydrogen production via thermochemical water splitting using a Cu-Cl cycle

In this paper, a comparative environmental study is reported of the Cu-Cl water-splitting cycle with various other hydrogen production methods: the sulphur-iodine (S-I) water-splitting cycle, high temperature water electrolysis, conventional steam reforming of natural gas and hydrogen production from renewable resources. The investigation uses life cycle assessment (LCA), which is an analytical tool to identify and quantify environmentally critical phases during the life cycle of a system or a product and/or to evaluate and decrease the overall environmental impact of the system or product. The LCA results for the hydrogen production processes indicate that the thermochemical cycles have lower environmental impacts while steam reforming of natural gas has the highest.     

Thermodynamic analysis of syngas production from biodiesel via chemical looping reforming

In this study, thermodynamic analysis of the syngas production using biodiesel derived from waste cooking oil is studied based on the chemical looping reforming (CLR) process. The NiO is used as the oxygen carrier to carry out the thermodynamic analysis. Syngas with various H₂/CO ratios can be obtained by chemical looping dry reforming (CL-DR) or steam reforming (CL-SR). It is found that the syngas obtained from CL-DR is suitable for long-chain carbon fuel synthesis while syngas obtained from CL-SR is suitable for methanol synthesis. The carbon-free syngas production can be obtained when reforming temperature is higher than 700 °C for all processes. To convert the carbon resulted from biodiesel coking and operate the CLR with a lower oxygen carrier flow rate, a carbon reactor is introduced between the air and fuel reactors for removing the carbon using H₂O or CO₂ as the oxidizing agent. Because of the endothermic nature of both Boudouard and water-gas reactions, the carbon conversion in the carbon reactor increases with increased reaction temperature. High purity H₂ or CO yield can be obtained when the carbon reactor is operated with high reaction temperature and oxidizing agent flow.     

Comparison of different pretreatment methods for hydrogen production using environmental microbial consortia on residual glycerol from biodiesel

The pretreatment of environmental microbial consortia by five methods (acid, base, heat shock, dry heat and desiccation, freezing and thawing) was conducted in order to evaluate their applicability for the selection of hydrogen-producing bacteria capable of using residual glycerol from biodiesel synthesis as substrate. Results showed that substrate degradation rates of consortia pretreated with dry heat and desiccation and heat shock were higher compared with controls during the fermentation using glycerol, with degradation rates as high as 65%. The maximal hydrogen and biomass productions were obtained by dry heat and desiccation: 34.19% mol and 4340 mg/L, respectively. Dry heat and desiccation followed by heat shock are simple pretreatments methods that can be used to improve the biotechnological production of hydrogen. DNA sequencing performed to identify the bacteria strains present in the consortium showed that they belonged to the genus Klebsiella and Pantoea.     

Process simulation and analysis of a five‐step copper–chlorine thermochemical water decomposition cycle for sustainable hydrogen production

A process model of a five‐step copper–chlorine (Cu–Cl) cycle is developed and simulated with the Aspen Plus simulation code. Energy and mass balances, stream flows and properties, heat exchanger duties, and shaft work are determined. The primary reactions of the five‐step Cu–Cl cycle are assessed in terms of varying operating and design parameters. A sensitivity analysis is performed to examine the effect of parameter variations on other variables, in part to assist optimization efforts. For each cycle step, reaction heat variations with such parameters as process temperature are described quantitatively. The energy efficiency of the five‐step Cu–Cl thermochemical cycle is found to be 44% on the basis of the lower heating value of hydrogen, and a parametric study of potential efficiency improvement measures is presented. Copyright © 2014 John Wiley & Sons, Ltd.     

Pressurized ultrasonic production of biodiesel from Jatropha oil: optimization and energy analysis

The present study deals with the development of a biodiesel production reactor based on pressurized ultrasonic cavitation technique. Transesterification of Jatropha oil takes place by passing low-frequency ultrasonic irradiation in the reaction mixture flowing at pressurized conditions in the sonochemical reactor. Reaction variables such as reaction time, molar ratio, catalyst concentration, and pressure of the reaction mixture were investigated to find the optimal parameters for biodiesel production. The energy requirement decreases with increase in pressure. Very low value of Specific Energy Consumption (0.018 kWh/kg) and significantly high value of Energy Use Index (598.83) are obtained when the pressure of reaction mixture is 15 bar. Increasing the pressure thereafter, leads to nominal gains. Ultrasonic irradiation at high-pressure condition has an additional advantage of rapid reaction and lower requirement of alcohol to oil molar ratio and catalyst concentration. Fifteen bar pressure is optimal for biodiesel production.     

Opportunities and challenges for biodiesel fuel

Fossil fuel resources are decreasing daily. As a renewable energy, biodiesel has been receiving increasing attention because of the relevance it gains from the rising petroleum price and its environmental advantages. This review highlights some of the perspectives for the biodiesel industry to thrive as an alternative fuel, while discussing opportunities and challenges of biodiesel. This review is divided in three parts. First overview is given on developments of biodiesel in past and present, especially for the different feedstocks and the conversion technologies of biodiesel industry. More specifically, an overview is given on possible environmental and social impacts associated with biodiesel production, such as food security, land change and water source. Further emphasis is given on the need for government’s incentives and public awareness for the use and benefits of biodiesel, while promoting policies that will not only endorse the industry, but also promote effective land management.     

Use of bioethanol for biodiesel production

Faced with the energy crisis and environmental degradation, due to the massive use of fossil energy sources, biodiesel is an attractive alternative to diesel fuel. With a view to developing local biodiesel production, using bioethanol as a sustainable reactant for biodiesel production, rather than methanol, is leading to increasing interest, notably in emerging countries. Indeed, bioethanol, which is less toxic than methanol, is produced from local and renewable agricultural resources, being more sustainable and providing access to greater energy independence. However, some issues are limiting the process like purification problems, or the presence of water in bioethanol leading to a drop in yield. Although several studies have already been published on ethyl ester production, most of them primarily focus on homogeneous alkaline catalysis, and report various data. Therefore, this paper aims at presenting a review of previous studies on the subject.