Sustainability assessment of <Emphasis Type="Italic">Ricinus communis</Emphasis> biodiesel using LCA Approach

Biofuels are considered as eco-friendly fuels and can readily replace fossil fuels while helping to reduce greenhouse gas emissions and promoting sustainable rural development. Although Algeria is an oil producer and exporter, the development of renewable energies is a strategic goal for public authorities, which are giving new impetus to this sector to replace the fossil energy resources of which are becoming increasingly scarce. In this context, the life-cycle assessment (LCA) of a second-generation biodiesel derived from Ricinus communis feedstock is undertaken. LCA is a tool that can be used effectively in evaluating various renewable energy sources for their sustainability and can help policy makers to choose the optimal energy source for specific purpose. The life cycle of Castor bean-based biodiesel production includes the stages of cultivation, oil extraction, and biodiesel production. The impact categories studied were global warming, Energy return-on-energy investment (EROEI), human health, and ecosystem. We have used the impact 2002 + evaluation method which is implemented in the SimaPro© software package. Moreover, it is the most useful method for identifying and measuring the impact of industrial products on the environment. Results show that among all the production stages, the cultivation process of Ricinus communis and the conversion of oil to biodiesel are the largest contributors to most of environmental impact categories. Life-cycle analysis revealed that the use of castor for biodiesel production could have many advantages like an energy return-on-energy investment (EROEI) of 2.60 and a positive contribution to climate-change reduction as revealed by a positive carbon balance.     

Life cycle assessment of palm-derived biodiesel in Taiwan

In Taiwan, due to the limited capacity of waste cooking oil, palm oil has been viewed as the potential low-cost imported feedstock for producing biodiesel, in the way of obtaining oil feedstock in Malaysia and producing biodiesel in Taiwan. This study aims to evaluate the cradle-to-grave life cycle environmental performance of palm biodiesel within two different Asian countries, Malaysia and Taiwan. The phases of the life cycle such as direct land-use-change impact, plantation and milling are investigated based on the Malaysia case and those of refining, and fuel production as well as engine combustion is based on Taiwan case. The greenhouse gas (GHG) emission and energy consumption for the whole life cycle were calculated as ?28.29 kg CO₂-equiv. and +23.71 MJ/kg of palm-derived biodiesel. We also analyze the impacts of global warming potential (GWP) and the payback time for recovering the GHG emissions when producing and using biodiesel. Various scenarios include (1) clearing rainforest or peat-forest; (2) treating or discharging palm-oil-milling effluent (POME) are further developed to examine the effectiveness of improving the environmental impacts     

Life cycle assessment of dewatering routes for algae derived biodiesel processes

Biodiesel derived from algae is considered as a sustainable fuel, but proper downstream processing is necessary to minimize the environmental footprint of this process. Algae is grown in dilute liquid cultures, and achieving the low water contents required for extraction represents one of the greatest challenges for the production of algae derived biodiesel. An analysis of the life cycle emissions associated with harvesting, dewatering, extraction, reaction, and product purification stages for algae biodiesel were performed. This “base case” found 10,500 kg of total emissions per t of biodiesel with 96 % of those attributed to the spray dryer used for dewatering. Alternative cases were evaluated for various sequences of mechanical and thermal dewatering techniques. The best case, consisted of a disk-stack centrifuge, followed by the chamber filter press, and a heat integrated dryer. This resulted in 875 kg emissions/t of biodiesel, a 91 % reduction from the base case. Significant reductions in life cycle emissions were achieved for all mechanical dewatering alternatives compared to the base case, but further improvements using these existing technologies were limited. Additional improvements will require the development of new techniques for water removal or wet extractions.     

Strategy for waste management in the production and application of biosurfactant through surface response methodology

This study aims to identify the optimal biosurfactant production process via fermentation by Bacillus subtilis, using waste material as alternative substrates (glycerin, water from potatoes processing, corn steep liquor, and frying oil), thereby highlighting the absence of synthetic substrates. A fractional factorial design 2^4?1 was previously used to determine the effects of the concentrations of the four substrates, selecting three of them to be used in a central composite rotatable design (CCRD) 2³. Responses of the emulsifying index after 24 h (EI₂₄) were first evaluated for fermentation in 250-mL flasks. Thus, the concentration of waste material that is able to provide EI₂₄ up to 100 % from 9 % of glycerin and 1 % of potato peel was determined, with subsequent experimental validation at the optimized point. One-liter-bench-batch fermentation with the optimum medium (based on the CCRD) was also carried out. In order to compare, another 1-L-bench-batch fermentation was performed using residual glycerin through the biosurfactant concentrations, dry weight, oxygen dissolved, and pH profile. Evidence of high potential for biosurfactant production (with EI₂₄ 100 % to toluene, 67 % to hexane, and 62 % to soybean oil), which can be suitable for applications in oil recovery was presented.     

Preparation and characterization of hydrotalcite-like materials from flyash for transesterification

In the present study, attempts were made to synthesize Mg–Al hydrotalcite-like materials with bifunctional properties from flyash and flyash-based zeolite by coprecipitation method. The synthesized hydrotalcite and their corresponding Mg–Al mixed oxides obtained after calcination were characterized for their structural, compositional, thermal, and morphological properties. The synthesized hydrotalcite had Mg/Al ranging from 1.3 to 2.3. The activity of the synthesized catalyst was estimated in transesterification of mustard oil, and the effects of reaction time, catalyst concentration, and methanol-to-oil molar ratio on biodiesel production were also investigated. A maximum yield of 93.4 % was obtained with methanol-to-oil molar ratio of 12:1, 7 wt% catalyst concentration for 6 h of reaction at 65 °C. The average value of activation energy of biodiesel in the conversion range of 0.2 < X < 0.9 was 130.5 kJ mol^?1. This study showed the potential application of flyash and its use in modified Mg–Al hydrotalcite materials as heterogeneous catalysts in biodiesel production.     

Spent coffee grounds for biodiesel production and other applications

This work evaluates the possibility of using spent coffee grounds (SCG) for biodiesel production and other applications. An experimental study was conducted with different solvents showing that lipid content up to 6 wt% can be obtained from SCG. Results also show that besides biodiesel production, SCG can be used as fertilizer as it is rich in nitrogen, and as solid fuel with higher heating value (HHV) equivalent to some agriculture and wood residues. The extracted lipids were characterized for their properties of acid value, density at 15 °C, viscosity at 40 °C, iodine number, and HHV, which are negatively influenced by water content and solvents used in lipid extraction. Results suggest that for lipids with high free fatty acids (FFA), the best procedure for conversion to biodiesel would be a two-step process of acid esterification followed by alkaline transesterification, instead of a sole step of direct transesterification with acid catalyst. Biodiesel was characterized for its properties of iodine number, acid value, and ester content. Although these quality parameters were not within the limits of NP EN 14214:2009 standard, SCG lipids can be used for biodiesel, blended with higher-quality vegetable oils before transesterification, or the biodiesel produced from SCG can be blended with higher-quality biodiesel or even with fossil diesel, in order to meet the standard requirements.     

Process analysis and optimization of biodiesel production from soybean oil

The overall goal of this work is to design and optimize a biodiesel production process from soybean oil. To achieve this goal, several inter-connected activities were undertaken. First, an initial flowsheet for the process was synthesized. The performance of this flowsheet along with the key design and operating criteria were identified by conducting computer-aided simulation using ASPEN Plus. Various scenarios were simulated to provide sufficient understanding and insights and to select a base-case flowsheet. Next, mass and energy integration studies were performed to reduce the consumption of material and energy utilities, improve environmental impact, and enhance profitability. Capital cost estimation was carried out using the ICARUS Process Evaluator computer-aided tool linked to the results of the ASPEN Plus simulation. The operating cost of the process was estimated using the key information on process operation such as raw materials, utilities, and labor. A profitability analysis was carried out by examining the return on investment and the payback period. It was found that the cost of soybean oil is the largest contributor to the production cost. A sensitivity analysis was carried out to determine the effect of soybean oil prices on the process profitability.     

Sustainability assessment for biodiesel production via fuzzy optimisation during research and development (R&D) stage

Biodiesel is regarded as an important renewable fuel for meeting the global future energy demand and resolving the environmental problems (e.g. global warming). Despite its known advantages, it is still very critical to assess the sustainability of biodiesel production prior to greater expansion for commercialisation. Early hazard assessment when the process is still under development and design is very beneficial as process modifications to eliminate or reduce hazards can be made easier at lower costs. In this paper, inherent safety, health and environment (SHE) and economic performance (EP) analysis is conducted for biodiesel production during the earliest process lifecycle which is named as research and development (R&D) stage. Prior to the assessment, eight biodiesel production pathways via base-catalysed, acid-catalysed, enzymatic and supercritical transesterification using fresh or waste oil are classified. The inherent SHE assessments are conducted using the renowned methods of the Prototype Index of Inherent Safety (PIIS), Inherent Occupational Health Index (IOHI) and Inherent Environmental Toxicity Hazard (IETH) for inherent safety, health and environmental friendliness, respectively. The EP assessment is done using a proposed costing assessment based on operating cost and revenue. A systematic framework for assessing alternative biodiesel production pathways during the R&D stage is presented. Fuzzy optimisation approach is used to assess the pathway candidates based on multiple objectives of inherent SHE and EP. From the assessment result, it is found that biodiesel production based on enzymatic transesterification using waste oil is the most desirable pathway. Following the result of the assessments, several improvement actions for inherent SHE in biodiesel production are proposed and discussed.     

Extensive comparison of biodiesel production alternatives with life cycle,PESTLE and multi-criteria decision analyses

Biodiesel production showed an immense increase worldwide in the past decade. Since the comprehensive analyses of biodiesel production processes and their comparative evaluation are both rare and not informative enough, e.g., for scientists and decision makers, in this work different, favored biodiesel production alternatives (rapeseed, soybean and palm) are analyzed from multiple viewpoints and compared. A complex examination is carried out with Political, Economic, Social, Technological, Legal and Environmental (PESTLE) analysis, where cradle-to-grave life cycle analysis is incorporated and performed within PESTLE factors. Life cycle inventory is set up based on Ecoinvent 3.3 database, while life cycle impact assessments are achieved by IPCC 2013, IMPACT 2002+, EPS 2000 and 2015dx methods. Monte Carlo analysis is also carried out in order to make certain about the robustness of input data. The investigated factors are weighted and ranked with multi-criteria decision analysis, wherein Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) method is applied for the comparison of alternatives. Our work presents a clear methodology for the comprehensive evaluation of biodiesel production alternatives, but the guideline can be followed for the evaluation of other production alternatives. In spite that the life cycle analysis shows the palm oil as the best alternative, the results of our comprehensive analysis show that the highest overall TOPSIS score can be achieved with rapeseed-based biodiesel pathway, especially for the European region.     

Optimization and sensitivity study of biodiesel synthesis from Jojoba oil using mixed-integer programming

Jojoba oil-based biodiesel is promising alternative fuel due to its versatile properties. Renewable transportation fuels are considered as promising alternatives to conventional fuels. The physical and chemical properties of these fuels enabled them to be used in modern internal combustion engines; this makes them attractive for use as direct replacements or as additives of fossil fuels. Jojoba oil is extracted from Jojoba seeds, and it is an excellent feedstock for biodiesel after the transesterification process. The plant is highly adaptable to harsh weather including salty water, desert, and hot temperatures; thus, it can be grown in Saudi Arabia. This research work comprises a detailed optimization study of biodiesel production from Jojoba oil using mixed-integer programming. golden section search method was used for the optimization and sensitivity study was conducted for reaction time and temperature. The result shows that 54.1 minutes and 47.5 °C are the optimized reaction time and temperature to produce biodiesel which is considerably low as compared to previous studies.     

Liquid–liquid equilibrium (LLE) study for six-component transesterification system

Transesterification of oils/triglycerides (TGs) with alcohol in the presence of catalyst has been the most commonly used process to produce biodiesel. Major limiting factors of conventional biodiesel transesterification process are phase separation and product purification. Precise and correct knowledge of the phase equilibrium behaviour is crucial for future industrial biodiesel reaction, separation and purification processes. For this purpose, it is important to consider the phase equilibrium behaviour in order to thoroughly understand the entire transesterification system for biodiesel production, which consists of six components. This work is to discuss on the liquid–liquid equilibrium (LLE) data of six-component system which involves TG, palm biodiesel (FAME), methanol (MeOH), glycerine (GLY), diglyceride (DG) and monoglyceride (MG). The phase equilibrium data of this system were determined experimentally through transesterification of crude palm oil (CPO). The experimental LLE data have been transposed into a pseudo-ternary diagram as TG–DG–MG + MeOH–GLY + FAME for better visualisation and understanding of the six-component system. Results showed that the transesterification of TG to FAME has formed a two-phase system where CPO-rich phase and MeOH-rich phase co-existed during the reaction. Due to immiscibility of CPO and MeOH, as well as the miscibility of FAME and MeOH, the LLE data suggested that at specific reaction operating condition, the reacted product (FAME) could be continuously removed by separating the MeOH phase from the CPO phase. This favours the forward transesterification reaction and eventually enhances the reaction efficiency to produce an oil-free FAME.     

Influence of fatty acids content in non-edible oil for biodiesel properties

Physical and chemical properties of biodiesel are influenced by the structural features of fatty acid, such as with saturated, monounsaturated and polyunsaturated fatty acids. In this study, seven non-edible oils have been selected, which include waste cooking oil derived palm olein, Calophyllum inophyllum, jatropha oil, castor oil, rubber seed oil, kapok seed oil and karanja oil. The critical parameters, e.g. cetane number (CN), iodine value (IV) and oxidation stability (OS) of biodiesel were correlated with the degree of unsaturated (DU) fatty acid, whereas the cold filter plugging point (CFPP) was correlated with the long chain saturated factor (LCSF). To meet the minimum EU requirement of EN 14214 of the critical parameter, the DU value of the CN was ≤133.5, IV ≤123.2 and OS ≤98.9. The LCSF values satisfied the Spanish regional standard—RD 61/2006 in summer (0 °C) at ≤8.4 and winter (?10 °C) at ≤0.1 of the CFPP. Based on the composition of the saturated, monounsaturated and polyunsaturated fatty acids, a triangular chart for the biodiesel property prediction was developed. This can then be used as a reference for non-edible oils.     

Soybean oil methanolysis over scallop shell-derived CaO prepared via methanol-assisted dry nano-grinding

Calcium oxides with a specific surface area between 4.5 m² g^?1 and 62.5 m² g^?1 were obtained by calcination of scallop shells, following by methanol-assisted dry nano-grinding. Three distinct phases are formed on the surface of these catalysts during nano-grinding: calcium methoxide, calcium hydroxide, and calcium oxide. The effects of specific surface area and active surface phase composition on the catalytic activity of calcium oxide during methanolysis of soybean oil were investigated. The properties of the calcium oxide before, during, and after methanol assisted dry nano-grinding were studied by XRD, FTIR, and nitrogen gas adsorption based on the BET method. The ground calcium oxides were found to be effective in catalyzing the methanolysis of soybean oil, with the optimal catalyst producing a 72.3% ester yield after 20 mins of reaction. The improvements in rate of reaction were attributed to the rapid formation of calcium diglyceroxide during the initial stages of methanolysis. A combination high specific surface area and effective active phases on the surface of the calcium oxide catalysts is correlated with reductions in mass transfer limitations in the early steps of the reaction, indicated by the rapid formation of calcium diglyceroxide.     

Analytical and experimental study on thermal conductivity of hardened cement pastes

Thermal conductivity of hardened cement pastes (hcps) in a wide range of water–cement ratio (w/c) is quantitatively investigated using a transient plane source measurement technique. Alkyl alkoxysilane and rapeseed oil were also added to determine the effect of internal hydrophobation on thermal conductivity of solid structure of hcps. The measurements were performed after drying at 50 and 105 °C as well as water submersion. A nonlinear relation was observed between thermal conductivity and w/c which is in alignment with Powers’ model. Samples dried at 50 °C still contained some moisture which increased thermal conductivity up to 11 % compared to samples dried at 105 °C. Furthermore, hydrophobic agents reduced thermal conductivity of dried samples up to 9 % which indicates the reduction in thermal conductivity of solid structure and is in line with observations by scanning electron microscope. A three phase model which can predict thermal conductivity of plain and hydrophobed hcps at different moisture states is presented by exploiting composite models and Hashin–Shtrikman bounds.     

An optimization approach for the sustainable water management at macroscopic level accounting for the surrounding watershed

Water is one of the most important resources in the world because it is essential for the life. Recently, several strategies for the proper use of water in different sectors (industrial, agricultural and domestic) have been ported, which involve options such as recycling, reusing and regeneration. However, the overall water management in a macroscopic level has received lower attention. In the macroscopic level, numerous water uses are involved and several sources of freshwater can interact to satisfy the freshwater demands, where also recycling, reusing and regeneration strategies can be implemented. Therefore, in this paper is proposed a new optimization formulation for the proper use of water in a macroscopic level involving water recycling, reusing and regeneration as well as accounting for the impact in the surrounding watershed. A case study from the central-west part of Mexico was analyzed, and the results show that is possible to reduce the freshwater consumption by 21 % with an investment of US $686,510,000/year.     

An optimization model for a crop deficit irrigation system under uncertainty

In this study, an inexact nonlinear programming model under uncertainty is developed by incorporating a water production function into the crop irrigation system optimization framework. By introducing a time parameter, this model can address the uncertainty associated with the irrigation schedule for different crops and their planting stages. The developed model was applied to a case study of an agricultural water resources management problem to demonstrate its applicability. Through scenario analysis under different precipitation levels, the key planting stage of crops and the amount of water for the irrigation schedule that could significantly affect system benefits were identified. By using intervals to represent uncertain parameters, more reliable and practical decision alternatives were generated through the presented model in typical hydrological years (i.e. wet, normal and dry years).     

Investigation of Thermophysical Properties of Thermal Degraded Biodiesels

Biofuels are an alternative to fossil fuels and can be made from many different raw materials. The use of distinct catalyst and production processes, feedstocks, and types of alcohol results in biofuels with different physical and chemical properties. Even though these diverse options for biodiesel production are considered advantageous, they may pose a setback when quality specifications are considered, since different properties are subject to different reactions during usage, storage and handling. In this work, we present a systematic characterization of biodiesels to investigate how accelerated thermal degradation affects fuel properties. Two different types of biodiesel, commercially obtained from distinct feedstocks, were tested. The thermal degradation process was performed by maintaining the temperature of the sample at \(140 \,^{\circ }\hbox {C}\) under constant air flux for different times: 0 h, 3 h, 6 h, 9 h, 12 h, 24 h and 36 h. Properties such as density, viscosity, activation energy, volumetric thermal expansion coefficient, gross caloric value, acid value, infrared absorption, and temperature coefficient of the refractive index were used to study the thermal degradation of the biodiesel samples. The results show a significant difference in fuel properties before and after the thermal degradation process suggesting the formation of undesirable compounds. All the properties mentioned above were found to be useful to determine whether a biodiesel sample underwent thermal degradation. Moreover, viscosity and acid value were found to be the most sensitive characteristics to detect the thermal degradation process.     

Modification of FAU zeolite as an active heterogeneous catalyst for biodiesel production and theoretical considerations for kinetic modeling

In this work, a high purity FAU-type zeolite catalyst was prepared from shale rock and modified as a heterogeneous efficient catalyst for biodiesel production from sunflower oil. The characterization properties for both of the prepared catalysts were determined using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDAX), Brunauer–Emmett–Teller (BET), and Fourier-transform infrared spectroscopy (FTIR). The incipient wetness impregnation method was adopted for loading the catalyst with three base precursors: NaOH, KOH, and Ca(OH)3. Different factors affecting transesterification reaction onto modified Na-K-Ca-FAU zeolite were investigated such as; temperature (35, 45, 55, and 65 °C), catalyst concentrations (2, 3,4, 5, and 6 wt%) and the molar ratio of methanol to sunflower oil (3:1, 6:1, 9:1 and 12:1). The optimum conditions of transesterification reactions were obtained for reaction time (4 h) and agitation rate (700 rpm) in a batch reactor at 65 °C reaction temperature, 5% catalyst concentration, and a 9:1 M ratio of methanol to oil. The experimental results showed that the conversion of triglyceride in sunflower oil to fatty acid methyl ester (FIME) increased from 48.62 to 91.6% when the FAU zeolite was loaded with 15 wt% of the three bases. The properties of the produced biodiesel were evaluated within the standard performance ASTM D-6751. This study shows that the three base precursors (i.e., NaOH, KOH, and Ca(OH)3) were successfully loaded onto support FAU zeolite and functioned as excellent catalysts for biodiesel production. Theoretical considerations for kinetic modeling in the heterogeneous transesterification reaction were investigated using MATLAB programming. The experimental and theoretical considerations for kinetic modeling were fitted well.     

Certification of Three Reference Materials for α- and γ-Tocopherol in Edible Oils

Tocopherols are important vegetable oil constituents, and their reliable quantitative analysis depends largely on the existence and quality of certified reference materials (CRMs) which provides traceability of the measurement results to the SI units. Since there is a lack of suitable CRMs in case of tocopherols analysis, three matrix reference materials from corn, peanut and soybean oils were certified for the content of α and γ-tocopherols. Homogeneity and stability of the prepared reference materials were studied and certification was done by two independent chromatographic analytical methods. The measurement results were statistically treated and the certified values of α and γ-tocopherol in corn, peanut and soybean oils were assigned and their associated expanded uncertainties were estimated as: 322.04 ± 8.62, 771.48 ± 15.31, 106.23 ± 5.19, 108.94 ± 9.72, 140.66 ± 5.93, 418.00 ± 14.36 mg/kg, respectively. These values were found useful for many food testing laboratories in validation of analytical methods and analytical quality control.     

Implementation of ultra high pressure water cutting for treatment of flushed chip seals in the US

This paper discusses implementation of ultra-high pressure (UHP) water cutting as a pavement maintenance strategy based on the first large-scale application of UHP water cutting for treatment of flushed chip seals in the USA. Data are from 13 field sites located in four different climatic regions in Texas. Production rates and treatment costs are sensitive to the UHP water cutter equipment, road surface condition, environmental factors and other variables. Production rates for UHP water cutting under Texas road conditions ranged from 490 m²/h to 1560 m²/h, average 830 m²/h, for treatment of light to heavy flushing. Turn-key unit costs for UHP water cutting varied from US $1.77/m² to US $2.08/m² for an average savings of 41% as compared to the cost of typical Texas maintenance solutions for treatment of flushed chip seals. Overall, UHP water cutting shows positive results in terms of treatment effectiveness, durability and production considerations.