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Background The energy requirements are globally on a rapid escalation, as technology advances, which is also true for a developing country like Nigeria, which is dependent on fossil fuels and its derivatives. Apart from its adverse effect on its economy, it has also negative impacts on the health and the environment, in general. However, investments in renewable energy are faced by the competitive oil prices, the very high investment cost for renewable energy, and high local electricity prices. This paper appraises the attractiveness of investing in renewable energy sources over the continued use of non-edible oil for electricity generation. Methods This paper explores the application of biomass seed oil to produce a renewable fuel (biodiesel) using heterogeneous base catalyst. Meanwhile, two-step processes were employed to produce the biofuel. In the first step (esterification), the acid value of the oil was reduced to the recommended limit (FFA ≤ 1.5) using H2SO4, while in the second step (transesterification), the catalyst calcination of grounded Brette Pearl Spar Mable (BPSM) pre-soaked in methanol was used as a biobase for biodiesel production. For the optimization, minitab response surface (MRS) and artificial neural network (ANN) were employed to model and optimize the process variables responsible for the optimum production of the oil and the biodiesel. Results The result presented showed that T. peruviana seed was found to be rich in oil with an average yield of 44.00% (w/w), and the oil was highly unsaturated with a high FFA. The maximum experimental biodiesel yield obtained was 86.00% at a catalyst amount of 4 g, a reaction time of 70 min, and a methanol/oil ratio of 0.1(v/v). This result was validated in triplicate under the same conditions, which yielded 85.70% (v/v) for MRS and 85.98% (v/v) for ANN. Furthermore, the optimization results also indicated that the p values (p R2 depict that both optimization tools gave good predictions of R2 (MRS: R2 = 99.98% and ANN: R2 = 99.97%). The properties of the biodiesel, as described in other earlier reports using the same feedstock with different catalysts, indicated that the produced biodiesel had properties which agreed to those reported in the literature. Conclusions T. peruviana seed has proved to be a good biomass raw material for oil production, and its conversion to biofuel using a heterogeneous biobase catalyst showed its suitability as a renewable environmental friendly fuel. Government should invest in more sustainable sources of energy by imposing law for the use of non-edible oil or decreasing the price of electricity.

The high frequency data in intensive care unit is flashed on a screen for a few seconds and never used again. However, this data can be used by machine learning and data mining techniques to predict patient outcomes. Learning finite-state transducers (FSTs) have been widely used in problems where sequences need to be manipulated and insertions, deletions and substitutions need to be modeled. In this paper, we learned the edit distance costs of a symbolic univariate time series representation through a stochastic finite-state transducer to predict patient outcomes in intensive care units. The Nearest-Neighbor method with these learned costs was used to classify the patient status within an hour after 10 h of data. Several experiments were developed to estimate the parameters that better fit the model regarding the prediction metrics. Our best results are compared with published works, where most of the metrics (i.e., Accuracy, Precision and F-measure) were improved.

Leaks in resource transmission pipelines is a growing concern for the water transmission industry. This creates a need to prevent the threat of leaks and minimize their damages through extensive research in leak detection technology. This research work provides a thorough investigation into the history of leak detection in pipelines by surveying the web of knowledge database and visualizing the outputs using visualization software VOSviewer and CiteNetExplorer. The analysis of the web of knowledge output presents a set of the ten most used keywords in the field of leak detection in pipelines that are further described and analyzed. Additionally, in-depth analysis of a randomly selected sample of papers was conducted to draw a sense of the progress in the industry over the past four decades. This article also defines a novel approach to define the leak detection phases, i.e., the identify-localize-pinpoint approach. Furthermore, two classes of leak detection systems are identified, static leak detection systems and dynamic leak detection systems. The two systems are defined as well as their differentiative capabilities. Finally, this article provides a summary of popular leak detection technologies to provide a broad sense of understanding for the leak detection field of research.

The methods of separation of microalgae has a significant impact in the economic aspects of their cultivation. In this study, pine bark was used as a substrate for immobilization of microalgal biomass cultivated in raw municipal sewage. The experiment was conducted in cylindrical photobioreactors (PBRs) with circulation of wastewater. Biomass was cultivated for 42 days. After that time, abundant growth of the biofilm with microalgae on the surface of pine bark as well as improvement of the quality of treated sewage were observed. The efficiency of removal of nutrients from wastewater was 64–81% for total nitrogen and 97–99% for total phosphorus. Moreover, the concentration of suspended solids in sewage was reduced, which resulted in a decrease in turbidity by more than 90%. Colorimetric analysis and Volatile Matter (VM) content in the substrate showed a decrease in the Higher Heating Value (HHV) and concentration of VM due to the proliferation of biofilm.

The 1993 paper in IJAIED on evaluation methods for Intelligent Tutoring Systems (ITS) still holds up well today. Basic evaluation techniques described in that paper remain in use. Approaches such as kappa scores, simulated learners and learning curves are refinements on past evaluation techniques. New approaches have also arisen, in part because of increases in the speed, storage capacity and connectivity of com- puters over the past 20 years. This has made possible techniques in crowd sourcing, propensity-score matching, educational data mining and learning analytics. This short paper outlines some of these approaches.

From the residual biomass generated by the palm oil sector in Ecuador, kernel shell (KS) is of major importance because it has been demonstrated that its use as solid fuel could replace diesel and LPG currently subsidized by the government to be used in the industrial and commercial sectors to produce thermal energy. The implementation of a torrefaction process could improve the KS handling and transportation operations, thus promoting its domestic use. However, the mesocarp fiber (MF) generated in the mills is 2.5 times the amount of KS generated. Therefore, this work analyzes an energy system that could valorize simultaneously MF and KS by the integration of pyrolysis and torrefaction processes, to produce biochar and torrefied fuel. A numerical model is used to analyze the integration of the pyrolysis and torrefaction processes considering a temperature range between 250 and 550 °C. It is observed that biochar and torrefied fuel could be produced simultaneously from pyrolysis process temperatures of 460 °C. The maximum load capacity of the integrated pyrolysis and torrefaction system corresponds to the highest temperature considered 550 °C (1 kg of KS per each kg of MF). However, the highest energy efficiency is found at lower pyrolysis process temperatures, near the auto-thermal operation temperature. The average efficiency of the analyzed energy system is 59.7%. Thus, the use of an integrated pyrolysis and torrefaction system could be an efficient alterative to be applied in small scale mills, to improve the KS energy density and valorize MF into biochar.

Energy valorization of empty fruit bunches (EFB), via torrefaction, was investigated to stablish the best process conditions and the energy balance of an integrated plant. Differential scanning calorimetry was used, for the first time, as a new and more accurate method to determine the heat involved in the torrefaction process. This technique showed that the torrefaction of EFB is an endothermal process. A new response variable energy gain (EG) was introduced as an alternative to the customarily used variable energy yield (EY). EG was definitely a better response variable because it makes a compromise between a high mass yield and a high heating values of the solid product. On the contrary, EY has a very strong and direct (lineal) correlation with the mass yield that overshadows the effect of the heating value. Results show that torrefaction is a promising technology for the sustainable valorization of EFB because it solves the disposal problem and gives a solid and renewable biofuel that can replace coal. Besides, an important amount of electricity can be co-produced. Energy balances showed that energy self-sufficiency can be achieved by tuning the torrefaction conditions as to obtain a gaseous by-product that is used as fuel to provide the energy required in the drying and torrefaction stages. Processing 100 ton/day of EFB (dry basis), at 300 °C and 60 min, produces 37 ton/day of bio-coal (similar to sub-bituminous coal) and 0.36 MW electricity that can be exported because the process is energy self- sufficient.

Sustainable disposal of the waste is problematic due to increasing shortages of landfill space. Avocado is a common fruit that is widely consumed in many countries. This consumption results in large quantities of avocado waste being generated by the avocado processing industries. However, avocado seeds contain large amounts of starch that could be beneficiated. Starch is widely used in various industrial applications and is routinely sourced from food crops, thus competing with traditional sources of food. Alternative non-food sources of starch are needed. This work focused on ascertaining the cleaner way of extracting starch from avocado seeds for use in industrial applications. The starch was extracted from avocado seeds via a wet extraction method and tested for application in the textile industry. Optimal conditions for the extraction of starch were determined using statistically designed experiments employing a Box–Behnken design and Statistica 13 software for the experimental design, statistical analysis and optimisation of the extraction process. The analysis of variance results revealed that a quadratic model is significant for the factors and responses studied. A quadratic mathematical model was developed, and the optimum combination of a response factor was obtained by the simultaneous optimisation of the responses. The starch yield was 64% (on dry weight basis). Analysis of the extracted starch showed that it contained well over 90% starch content. Application of the starch in textile applications showed that it performed as well as a commercial starch sample. The collection and processing of waste avocado seeds can be a new source of employment and provide income generation opportunities.

Poultry litter is a waste from poultry industry that has been used for bioenergy generation and has high potential as feedstock for thermochemical processes, as pyrolysis. Kinetic parameters of poultry litter pyrolysis are paramount for techno-economic analysis of commercial scale processes. Scientific community has shown concern about the suitable application of different methods (model-free/model-fitting) for the determination of kinetic parameters. The application of an unsuitable method may lead to unreliable kinetic parameters. In this study, the performance of model-free methods for the determination of the kinetic parameters of poultry litter pyrolysis was evaluated. The characterization was performed through thermogravimetric analysis. Were applied the methods of Kissinger–Akahira–Sunose, Flynn–Wall–Ozawa and Vyazovkin. The model-free methods were not adequate to describe the kinetics of poultry litter pyrolysis throughout the whole reaction. Therefore, a model-based (five pseudo-components model) method was applied to obtain the kinetic parameters of poultry litter pyrolysis. Such model provided an adequate fit to the experimental data.

The main characteristics of coal acid mine drainage (AMD) are a low pH and high concentrations of sulfate and different metallic ions. Response surface methodology using the central composite rotatable design (CCRD) model was used to optimize the parameters for AMD remediation with aquaculture farming waste [shrimp shell (SS) and mussel byssus (MB)]. SS was chosen due to its high chitin (a metal sorbent) and calcium carbonate (an acidity neutralizing agent) content, and MB because of its potential synergistic effect for the treatment. The coefficient of determination and standard error results from the analysis of variance have shown the model to be adequate. The predicted values were in good agreement with the experimental values. The best experimental conditions established from the statistical study were 136 rpm, 11.46 g L−1 SS and 71.6 g L−1 MB. CCRD can efficiently be applied for modeling the AMD remediation with biomaterials and is an economical way of obtaining the maximum amount of information in a short period of time with the fewest number of experiments. Additionally, five kinetic models, i.e., pseudo-first-order, pseudo-second-order, intraparticle diffusion, Bangham and Elovich equation, were tested to investigate the adsorption mechanisms. The kinetic studies revealed that a 200 min contact time is sufficient to transform AMD into water suitable for non-potable reuse. The pseudo-second-order model provided the best fitting of the experimental data, indicating a chemical adsorption mechanism. This research shows the suitability of the proposed treatment, and the information is valuable for designing a low-cost remediation process for AMD.

In value-added chemical industries, use of agricultural wastes as raw materials remains to be a major challenge in commercialization due to lack of competitiveness with respect to petrochemical processes. This work presents the techno-economic analysis of a novel bioprocessing plant converting 356,400 MT/year cotton stalks into 147,000 MT/year acetic acid. A production scheme integrating lignin separation with the main bioconversion stages has been proposed. Techno-economic assessment was performed through economic feasibility and retro-techno-economic analysis (RTEA) methods. The RTEA method has been extended to include the estimation of research and development funding for improving economic feasibility. Carbon offset of the proposed technology has been estimated and carbon credit results have been incorporated into the economic feasibility metrics.

The harmful emissions from traditional organic fuels combustion cause irreparable harm to the environment, which leads to the conclusion that it is necessary to reorient the energy sector to renewable energy sources such as biomass. Traditional methods of combustion are of little use for the energy use of biomass. This fact forces us to search new efficient technologies for its processing. Pyrolysis is one of the most universal and promising areas of biomass processing. However, its implementation requires significant heat costs, which has a considerable impact on the result of the feasibility study. The aim of the work is to study the thermal effects observed in low-temperature pyrolysis and to assess the possibility of autothermal biomass processing. Straw, chips from various types of wood, pine sawdust and peat from two deposits of the Tomsk region (Russia) were considered as a biomass. A physical experiment, differential thermal analysis, gas chromatography and heat balance equations were used in the work. It has been established that low-temperature pyrolysis of biomass is accompanied by a positive value of the thermal effect in the temperature range of 220–580 °C and varies from 393 to 1475 kJ kg−1 depending on the type of raw materials being processed. The value of this effect makes it possible to organize pyrolysis of biomass in an autothermal regime with preliminary drying: maximum moisture content for straw of 19.9%, wood chips of 10.4%, sawdust of 9.7% and Sukhovskoy peat of 9.5%.

A study was carried out of the environmental and agronomic features of the sludge generated by a dissolved air flotation process applying a tannin-based coagulant in a dairy factory. First, the chemical and physical characteristics of the sludge were examined. Subsequently, a solubilization test was performed to evaluate the potential of groundwater contamination after the application of sludge on soil. The data obtained were compared to the United States Environmental Protection Agency (US-EPA) criteria for evaluation and classification of solid residues for land application. The results show that the studied sludge is a non-hazardous waste, and all evaluated parameters are lower than the maximum reference values according to international criteria. Based on the set of parameters which were evaluated, no organic pollutants were found. Additionally, the agronomic characterization shows good potential for agricultural purposes. However, in the solubilization test, chemicals such as phenols, cyanide, nitrate and fluoride were solubilized from the studied residue. As a result, the water showed concentrations above the limits required by the international criteria for drinking water established by US-EPA and World Health Organization. In conclusion, although tannin-based coagulants produce sludge with the potential for agronomic applications, some limits have to be considered to avoid environmental impacts.

Background Biomass fuel has been used to supply heat or crude materials in industry to replace the traditional fossil fuel which was one of the chief causes of climate warming. However, the large-scale utilization of biomass fuel was restricted due to the low density and high hydrophilicity of biomass, which causes the problem of transportation and storage. Therefore, pelletization of biomass was used to improve its fuel density. At present, the biomass pellet was widely used to supply heat, gas or electricity generation via gasification, which supplied clean and sustainable energy for industry. However, the energy consumption during pelletization and high hydrophilicity of pellets were still the problem for the large-scale application of biomass pellet. In this study, hydrothermal carbonization and surfactant played the role of permeation, adsorption and wetting in the solution, which was expected to improve the fuel properties and pelletization effectivity of corn stover. Results In the article, surfactant (PEG400, Span80, SDBS) was chosen to be combined with wet torrefaction to overcome the drawbacks and improve the pelletization and combustion properties of Corn stover (CS). Especially, hydrothermal carbonization (HTC) combined with surfactant improves the yield of solid products and reduces the ash content of solid product, which was beneficial for reducing the ashes of furnace during gasification. Meanwhile, surfactant promotes the formation of pseudo-lignin and the absorption for oil with low O and high C during HTC, which improves the energy density of solid product. Furthermore, the oil in solid product plays the role of lubricant and binder, which reduces the negative effect of high energy consumption, low bulk density and weak pellets strength caused by HTC during pelletization. HTC combined with surfactant improved the hydrophobicity of pellet as well as grindability due to the modification of solid product. Moreover, surfactant combined with HTC improved the combustion characteristic of solid product such as ignition and burning temperature as well as kinetic parameters due to the bio-oil absorbed and the improvement of surface and porosity. Conclusions The study supplied a new, less-energy intensive and effective method to improve the pelletization and combustion properties of corn stover via hydrothermal carbonization combined with surfactant, and provided a promising alternative fuel from corn stover, Biotechnology for Biofuels, 12 (1), ISSN:1754-6834

Environmental concerns and depletion of fossil fuels along with government policies have led to the search for alternative fuels from various renewable and sustainable feedstocks. This review provides a critical overview of the chemical composition of common commercial plant oils, i.e., palm oil, olive oil, rapeseed oil, castor oil, WCO, and CTO and their recent trends toward potential biofuel production. Plant oils with a high energy content are primarily composed of triglycerides (generally > 95%), accompanied by diglycerides, monoglycerides, and free fatty acids. The heat content of plant oils is close to 90% for diesel fuels. The oxygen content is the most important difference in chemical composition between fossil oils and plant oils. Triglycerides can even be used directly in diesel engines. However, their high viscosity, low volatility, and poor cold flow properties can lead to engine problems. These problems require that plant oils need to be upgraded if they are to be used as a fuel in conventional diesel engines. Biodiesel, biooil, and renewable diesel are the three major biofuels obtained from plant oils. The main constraint associated with the production of biodiesel is the cost and sustainability of the feedstock. The renewable diesel obtained from crude tall oil is more sustainable than biofuels obtained from other feedstocks. The fuel properties of renewable diesel are similar to those of fossil fuels with reduced greenhouse gas emissions. In this review, the chemical composition of common commercial plant oils, i.e., palm oil, olive oil, rapeseed oil, castor oil, and tall oil, are presented. Both their major and minor components are discussed. Their compositions and fuel properties are compared to both fossil fuels and biofuels.

The current research was investigated the mechanism of coal demineralization and the effect of leaching parameters on high ash coal and study the characterization of pre and post-treated coal. The two high ash Indian coal selected from Mahanadi Coalfield Limited, Odisha, pulverized to 375, 230 and 180 µm particle size were undergone simultaneous acid and alkali treatment at a different concentration, temperature and time. The percent demineralization was increased with decrease the size of the particle and rises with leaching parameters. The investigation suggested 180 µm particle size offers efficient demineralization for both coals at 30% NaOH and 30% H2SO4 concentration. The alkali leaching leads to obtaining the demineralization 46% and 42% whereas acid treatment resulted in 34% and 32% of the original coal samples. The extent of demineralization was improved the calorific value of coal. Besides, the degree of demineralization was proved from the FTIR, XRF and FESEM–EDX analysis results. FTIR analysis result showed that the peak intensity of mineral band decreased by the leaching effect and the degree of demineralization was significantly obtained to large extent by the X-ray Fluorescence spectrometer; which elucidates major minerals removed from coal by the leaching effect of acid and alkali solution.

In recent years, the use of the renewable and CO2-neutral energy carrier wood as a fuel for heat supply in domestic households increased. But as a result, the emission of particulate matter rises to a high level. Due to higher mineral content of wood (especially the content of potassium), the formation of particulate matter during combustion is much higher than that during combustion of fossil fuels like oil or gas. Therefore, the objective of the present work was the analysis of the effect of the mineral additive kaolinite on the particulate matter formation during combustion of wood pellets blended with 0, 0.5 and 1 wt% kaolinite. The examinations were conducted in two different small-scale combustion plants in cooperation between the University of Technology Hamburg (TUHH) and the Technology and Support Centre in the Centre of Excellence of Renewable Resources Straubing (TFZ). For the combustion experiments, an 8.6-kW pellet stove and a 12 kW pellet boiler were used. The results show a similar reduction effect of particulate matter emissions for both combustion devices of 46% (pellet stove) and 48% (pellet boiler) using 0.5 wt% kaolinite. The use of 1 wt% shows different results. The total particulate matter emissions of the pellet boiler were reduced of about 69% while the emissions of the pellet stove only slightly decreased about 5%.

Municipal wastewater treatment plant sludge (sewage sludge) has gained importance in biodiesel production due to its high lipid content. The oily sludges from petrochemical industry wastewater treatment plants (WWTPs) have high concentrations of phospholipids, free fatty acids, neutral lipids and can also be used as efficient feedstocks for biodiesel production. Lipid extraction is the first step of biodiesel production from sludges. Standard drying lipid extraction method necessitates expensive sludge dewatering/drying steps, holding almost 50% of overall biodiesel production cost, to remove high water content in sludge. The aim of this study was to explore lipid extraction from municipal and petrochemical industry WWTP sludges by using the novel direct liquid–liquid lipid extraction method, which does not require expensive sludge dewatering/drying steps, and to compare it to standard drying method. The study also investigated the effect of acid pre-treatment on lipid yields of the sludge samples. In both methods, hexane was used as an organic solvent. Acid pre-treatment increased the lipid yields noticeably. The highest lipid yield of 31.2% (dry sludge) was obtained from pre-acidified petrochemical industry WWTP sludge by using liquid–liquid lipid extraction method. Compared to standard drying method, direct liquid–liquid lipid extraction method resulted with 53% higher lipid and 56% higher biodiesel yields for petrochemical industry WWTP sludge sample. However, liquid–liquid lipid extraction method caused to a very slight increase in the biodiesel yield of primary municipal WWTP sludge samples.

The use of non-food materials such as agro-residues as feedstock for renewable energy production continues to generate greater interests due to the environmental challenges from the utilisation of fossil-based fuels. This study gives the first report on thermochemical characteristics, pyrolysis kinetics and pyrolysis product distribution from adzuki bean waste (pod). The pyrolysis characteristic was evaluated under a non-isothermal condition at a different heating rate (10, 15 and 20 °C/min) and kinetic parameters determined using distributed activation energy model. The result indicates that the model adequately described the pyrolysis characteristics of the feedstock with high correlation coefficient (R2 > 0.9) and apparent activation of 140.81 kJ/mol. The result of pyrolysis study revealed that adzuki bean pod could be valorised into solid, liquid (bio-oil) and gas products with maximum bio-oil yield of 46.57 wt% at 600 °C. The bio-oil collected contains high-value fuel precursors and value-added chemicals such as phenol and phenol derivatives, benzene and methyl ester. The gas product comprised of combustible gases, which can serve as an alternative energy source to the pyrolysis system. The solid bio-char product is predominately a porous carbon material with indicators of high stability. This material can also be utilised for energy application in addition to carbon sequestration. The presence of macronutrients suggests its suitability for bio-fertiliser application. This study shows that adzuki bean waste is a potential feedstock for production of alternative energy and valuable biomaterials.

BACKGROUND: Patients with diabetes lack information on which commercially available applications (apps) improve diabetes-related outcomes. We conducted a rapid evidence review to examine features, clinical efficacy, and usability of apps for self-management of type 1 and type 2 diabetes in adults. METHODS: Ovid/Medline and the Cochrane Database of Systematic Reviews were searched for systematic reviews and technology assessments. Reference lists of relevant systematic reviews were examined for primary studies. Additional searches for primary studies were conducted online, through Ovid/Medline, Embase, CINAHL, and ClinicalTrials.gov. Studies were evaluated for eligibility based on predetermined criteria, data were extracted, study quality was assessed using a risk of bias tool, information on app features was collected, and app usability was assessed. Results are summarized qualitatively. RESULTS: Fifteen articles evaluating 11 apps were identified: six apps for type 1 and five apps for type 2 diabetes. Common features of apps included setting reminders and tracking blood glucose and hemoglobin A1c (HbA1c), medication use, physical activity, and weight. Compared with controls, use of eight apps, when paired with support from a healthcare provider or study staff, improved at least one outcome, most often HbA1c. Patients did not experience improvements in quality of life, blood pressure, or weight, regardless of app used or type of diabetes. Study quality was variable. Of the eight apps available for usability testing, two were scored “acceptable,” three were “marginal,” and three were “not acceptable.” DISCUSSION: Limited evidence suggests that use of some commercially available apps, when combined with additional support from a healthcare provider or study staff, may improve some short-term diabetes-related outcomes. The impact of these apps on longer-term outcomes is unclear. More rigorous and longer-term studies of apps are needed. REGISTRATION: This review was funded by the Agency for Healthcare Research and Quality (AHRQ). The protocol is available at: http://www.effectivehealthcare.ahrq.gov/topics/diabetes-mobile-devices/research-protocol. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11606-018-4410-1) contains supplementary material, which is available to authorized users.

The current study aims to investigate the production of microalgae biomass as a function for different wet market wastewater ratios (10, 25, 50, 75 and 100%) and Scenedesmus sp. initial concentrations (104, 105, 106, 107 cells/mL) through the phycoremediation process. The biomass production, total nitrogen (TN), total phosphorus (TP) and total organic compounds (TOC) were determined daily. The pseudo-first order kinetic model was used to measure the potential of Scendesmus sp. in removing nutrients while the Verhulst logistic kinetic model was used to study the growth kinetic. The study revealed that the maximum productivity of Scenedesmus sp. biomass was recorded with 106 cells/mL of the initial concentration in 50% wet market wastewater (98.54 mg/L/day), and the highest removal of TP, TN, and TOC was obtained (85, 90 and 65% respectively). Total protein and lipid contents in the biomass yield produced in the wet market wastewater were more than that in the biomass produced in the BBM (41.7 vs. 37.4 and 23.2 vs. 19.2%, respectively). The results of GC–MS confirmed detection of 44 compounds in the biomass from the wet market wastewater compared to four compounds in the BBM. These compounds have several applications in pharmaceutical and personal care products, chemical industry and antimicrobial activity. These findings indicated the applicability of wet market wastewater as a production medium for microalgae biomass.

Replacing fossil fuels with renewable fuels derived from lignocellulosic biomass can contribute to the mitigation of global warming and the economic development of rural communities. This will require lignocellulosic biofuels to become price competitive with fossil fuels. Techno-economic analyses can provide insights into which parts of the biofuel production process need to be optimized to reduce cost or energy use. We used data obtained from a pilot biorefinery to model a commercial-scale biorefinery that processes lignocellulosic biomass to ethanol, with a focus on the minimum ethanol selling price (MESP). The process utilizes a phosphoric acid-catalyzed pre-treatment of sweet sorghum bagasse followed by liquefaction and simultaneous saccharification and co-fermentation (L+SScF) of hexose and pentose sugars by an engineered Escherichia coli strain. After validating a techno-economic model developed with the SuperPro Designer software for the conversion of sugarcane bagasse to ethanol by comparing it to a published Aspen Plus model, six different scenarios were modeled for sweet sorghum bagasse Under the most optimistic scenario, the ethanol can be produced at a cost close to the energy-equivalent price of gasoline. Aside from an increase in the price of gasoline, the gap between ethanol and gasoline prices could also be bridged by either a decrease in the cost of cellulolytic enzymes or development of value-added products from lignin.

Microalgae cultivation and biomass to biochar conversion is a potential approach for global carbon sequestration in microalgal biorefinery. Excessive atmospheric carbon dioxide (CO2) is utilized in microalgal biomass cultivation for biochar production. In the current study, microalgal biomass productivity was determined using different CO2 concentrations for biochar production, and the physicochemical properties of microalgal biochar were characterized to determine its potential applications for carbon sequestration and biorefinery. The indigenous microalga Chlorella vulgaris FSP-E was cultivated in photobioreactors under controlled environment with different CO2 gas concentrations as the sole carbon source. Microalgal biomass pyrolysis was performed thereafter in a fixed-bed reactor to produce biochar and other coproducts. C. vulgaris FSP-E showed a maximum biomass productivity of 0.87 g L−1 day−1. A biochar yield of 26.9% was obtained from pyrolysis under an optimum temperature of 500 °C at a heating rate of 10 °C min−1. C. vulgaris FSP-E biochar showed an alkaline pH value of 8.1 with H/C and O/C atomic ratios beneficial for carbon sequestration and soil application. The potential use of microalgal biochar as an alternative coal was also demonstrated by the increased heating value of 23.42 MJ kg−1. C. vulgaris FSP-E biochar exhibited a surface morphology, thereby suggesting its applicability as a bio-adsorbent. The cultivation of microalgae C. vulgaris FSP-E and the production of its respective biochar is a potential approach as clean technology for carbon sequestration and microalgal biorefinery toward a sustainable environment.

Large amounts of empty fruit bunches (EFB) are generated annually during the palm oil manufacturing process; however, they are still treated as waste. In this study, gasification experiments were conducted using EFB in a fluidized bed reactor (throughput=1 kg/hr) at an experimental temperature range of 700 to 1,000 oC to assess the use of EFB as a renewable energy resource. To overcome the issues of an unstable EFB supply, co-gasification experiments using EFB with coal were conducted. The resulting syngas yield was approximately 70 vol%, similar to that from EFB gasification. The heating value of syngas was a magnitude of three-times higher than that of EFB gasification. However, the dry gas yield and cold gas efficiency were lower than those of EFB gasification. A coal mixing rate of 20 wt% and 0.6 of ER would be appropriate conditions for continuous production of stable syngas.

Biofuels, derived from renewable biological resource, are universally recognized as viable alternatives to fossils fuels foe powering automotive internal combustion engines. In this study, fuels blends with biofuels (methanol, butanol or ethanol) and pure ultra-low-sulfur oil were used in a turbocharged diesel engine to test its performance and exhaust emission compositions. It was found that addition of 2 wt. % methanol, butanol or ethanol to fuel blends reduced exhaust emissions on average by 4.15, 5.8, and 8.89%, respectively, when compared with ultra-low-sulfur diesel. The reason for the reduced emissions is absence of sulfur and sulfuric acid in the biofuel blends.

Brewer’s spent grain (BSG) is a residue produced in large amounts by the brewing industry and may be used in bioprocesses as a source of sugar due to its chemical composition. The objectives of this work were to determine the chemical composition of BSG and to investigate its potential in obtaining fermentable sugars through enzymatic hydrolysis. For this purpose, mechanical stirring, direct and indirect ultrasound processes were studied to evaluate the efficiency of BSG enzymatic hydrolysis. Operational variables of mechanical stirring (temperature, enzyme and substrate concentrations) and ultrasound (pulse factor and amplitude) systems were analyzed. The highest sugar yield was 370.9 g kg−1 using direct sonication system at a pulse factor of 0.23 and oscillation amplitude of 50%. Sugar yield in direct ultrasound system was 2.6 and 4.9 times greater than indirect sonication and mechanical stirring systems, respectively. For BSG hydrolysis using enzymes, direct sonication presented better results than mechanical stirring and indirect sonication processes. Besides, the treatment time using direct sonication was diminished, confirming that it is a promising technology for improving the yields of fermentable sugars from BSG.

Objectives To examine older inpatients’ experiences with medical student education, their views on future interactions, and to seek their opinion on the most important curricular topics related to geriatric medicine. Methods The study involved 112 non-confused inpatients older than 65 years of age, who completed a uniformed questionnaire on the day of their discharge from a teaching hospital. Results The mean age was 81 years, with equal number of male and female participants. 57% interacted with the students during their admission, the majority being interviewed and examined. Almost all (92%) of these patients described their experience as positive, some described it as time-consuming (23%), repetitive (19%) and tiresome (9%). 92% of all participants agreed that the older patients should be part of medical students’ education. Dementia, cardiac conditions, cancer, arthritis, isolation/loneliness were highlighted as the most important topics to teach medical students related to geriatric medicine, while patience and listening were listed as important skills. They suggested practical, easily implemented advice for the improvement of the interaction between students and older patients; including allowing more time for interactions and for students to speak louder. Conclusions Older patients felt positively about their interactions with medical students, and believed that older patients should be involved in medical student education. As well as medical conditions such as dementia, cardiac disease and cancer, these patients highlighted isolation and loneliness as important topics for undergraduate geriatric medical education, implying that students should learn about broader aspects of older patients’ health and wellbeing.

Bioethanol is being promoted in Mexico to be used in a blend with gasoline. On the north of the Yucatan peninsula, bioethanol could be produced from sweet sorghum, as it can grow efficiently on this land; it can be harvested 2–3 times in a year and possesses a better agronomical stability than sugarcane with low nitrogen requirements and high productivity. In this work , the potential environmental impacts and energy efficiency of bioethanol production from sweet sorghum were evaluated using life-cycle assessment. Four scenarios were evaluated: scenario PI considered only bioethanol production from the stalk juice; scenarios PII and PIII added cogeneration from the dry-stalk biomass in single and combined cycle, respectively. Scenario PIV considered bioethanol production from both stalk juice and dry-stalk biomass. Scenario PI demanded more fossil energy than what was generated as bioethanol, while scenarios PII and PIII were fossil energy independent. Scenario PIII showed the higher net energy ratio (1.89) and a better environmental performance in all CML-IA baseline impact categories. In terms of global warming potential, the scenario PIII showed a mitigation potential of 16% with respect to the fossil reference. In the categories where the sweet sorghum scenarios represented larger emissions than the fossil reference, it was due mainly to the use of fertilizers and the conventional energy consumption in the various processing steps of the biomass. Scenario PIV showed the highest energy demand and worst environmental performance due to large demands of energy and chemicals in the bagasse pretreatment step.

The present research work deals with the application of 30% exhaust gas recirculation (EGR) in a direct injection compression ignition engine fuelled with 100% waste cooking oil methyl ester and conventional diesel. In the first phase of this research work, the performance, emission and combustion characteristics of diesel engine are investigated with the supply of fresh air–fuel mixture for conventional diesel and waste cooking oil methyl ester as fuels and in the second phase the fresh air–fuel mixture is blended with 30% exhaust gas. The study reveals that the 30% EGR addition decreased the brake thermal efficiency by 8 and 18% for conventional diesel and 100% waste cooking oil methyl ester as fuels. Nitrogen oxides emission is reduced to a great extent by 47.5% for diesel fuel and 58.9% for biodiesel fuel at full load condition. Further, the 30% EGR has substantially increased the carbon monoxide and unburnt hydrocarbon emissions for both the fuels at maximum brake mean effective pressure. In addition similar pattern of in-cylinder gas pressure, heat release rate, cumulative heat rate have been observed for fresh air fuel mixture and 30% EGR under various loading conditions.

The study treats an important and imperious worldwide problem. It deals with the production of alternative biofuels from starchy restaurants’ bio-waste. The starchy wastes of the restaurants, especially in developing countries, are produced in huge quantities that represent a sustainable substrate for ethanol production. So, we aimed to study the feasibility of the conversion of the starchy wastes to biofuel (bioethanol) using different pretreatments and new yeast strains. Our results approved the feasibility of conversion of the starchy wastes into biofuel. Using of thermo-acidic hydrolysis, we obtained 360 g of free and fermentable sugars from each dry kg of the wasted materials. Pichia barkeri and Candida intermedia were introduced as new species for the field of biofuel production in addition to the classical Saccharomyces cerevisiae. Among them, S. cerevisiae KKUY-0301 produced 11.5 g/L of ethanol from 27 g of sugars. Its transformation rate was 82% of the theoretical yield, i.e. 1 kg of the waste could produce 150 g of ethanol. Optimization of the cultural conditions approved that 4 days of incubation, pH 5, 35 °C and 5% of the yeast inoculum (108 cell/mL) were the most appropriate conditions that could induce the maximum production bioethanol. This study recommends the application of this technology on a commercial scale all over the world to benefit from all types of bio-wastes. In addition, our findings offer a crucial solution for the recycling the restaurant starchy waste materials into ecofriendly product “biofuel” that reduce the overall cost production of the bioenergy and make it a competitive to the oil-based energy.

Fossil fuels play important role in the economy of industrialized countries of the world. However, these sources of energy are not renewable and nearing the brink of extinction. Moreover, the reliance on these fuels has led to increased levels of pollution which have caused serious adverse impacts on the environment. Hydrogen has emerged as a promising alternative since it does not produce CO2 and also has the highest calorific value. The biological H2 production has an edge over its chemical counterpart mainly because it is environmentally benign. However, the major challenge limiting the transition from an oil based economy to that of biohydrogen is the low hydrogen production rate, yield and economy of the process. Biohydrogen production by dark fermentation is found most promising as compared to other biohydrogen production processes like photo fermentation process using photofermentative bacteria, microalgae, microbial fuel cell etc. Present research group has been involved in biohydrogen research for last two decades. Suitability of different organic wastes for the hydrogen production has been developed. Both pure microbial cultures and acidogenic cultures obtained from anaerobic digester are found suitable for the hydrogen production. One 10,000 L pilot plant studies are carried out for the commercial exploitation of the process. The spent medium of the dark fermentation process mostly comprises of acetic acid, butyric acid etc., which are the substrates for the biomethanation process for the generation of methane and carbon dioxide. So, maximization of gaseous energy is possible dark fermentation followed by methanation process which is known as biohythane process.

A key reason inhibiting commercialization of algal oil as biodiesel feedstock, is cultivation cost. For this reason, the usability of 19 readily available industrial effluents (autoclaved and non-autoclaved) to support heterotrophic growth and lipid accumulation was evaluated using six mixed algal cultures. Autoclaved whey effluent was the best with 14.32 g biomass L−1, 13.23% lipids, resulting in a lipid production of 1.91 g lipids L−1. Biomass production and lipid accumulation were in many cases inverse, e.g. mixed algal culture termed TUT4 accumulating 84.25% lipids on autoclaved acid mine drainage, with very little biomass produced. Biomass production was dependent on the effluent type, whereas the lipid accumulation was influenced mostly by the specific mixed algal cultures. The fatty acid composition of the algal oil (fish cannery and whey effluents) showed high saturation, leading to acceptable cetane numbers, kinematic viscosity, good oxidative stability, but poor cold flow properties.

Demand for wood pellets as a renewable alternative to fossil fuels has increased in the past decade. However, production and use of wood pellets involves several operations (biomass extraction, chipping, transport, drying, milling, pelleting, combustion) with negative impacts on e.g. the climate. In this study, the energy efficiency and climate impact of production and use of non-torrefied and torrefied wood pellets were analysed and compared. The wood pellets, produced from logging residues extracted from a boreal coniferous forest stand (Norway spruce (Picea abies (L.) H. Karst)) in northern Sweden, were assumed to be exported and finally used in a power plant. Time-dependent life cycle assessment, expressing the climate impact as global temperature change over time, was used to include annual greenhouse gas fluxes of both fossil and biogenic origin. The results showed that carbon stock changes due to extraction of logging residues contributed most of the warming effect on global temperature. Due to greater demand for raw material, a higher warming impact per gigajoule fuel was obtained for torrefied wood pellets than for non-torrefied wood pellets. However, torrefied wood pellets demonstrated a lower climate impact (per GJ electricity) when advantages such as higher electrical energy efficiency and higher co-firing rate were included. A general conclusion from this study is that replacing coal with non-torrefied or torrefied wood pellets made from logging residues can mitigate climate change. The energy output of these systems was about sevenfold the primary energy input.

Microalgae may be a potential feedstock for biogas production through anaerobic digestion. However, this process is limited by the hydrolytic stage, due to the complex and resistant microalgae cell wall components. This fact hinders biomass conversion into biogas, demanding the application of pretreatment techniques for inducing cell damage and/or lysis and organic matter solubilisation. In this study, sonication, thermal, ultrasound, homogeneizer, hydrothermal and steam explosion pretreatments were evaluated in different conditions for comparing their effects on anaerobic digestion performance in batch reactors. The results showed that the highest biomass solubilisation values were reached for steam explosion (65-73%) and ultrasound (33-57%). In fact, only applied energies higher than 220 W or temperatures higher than 80 °C induced cell wall lysis in C. sorokiniana. Nonetheless, the highest methane yields were not correlated to biogas production. Thermal hydrolysis and steam explosion showed lower methane yields in respect to non-pretreated biomass, suggesting the presence of toxic compounds that inhibited the biological process. Accordingly, these pretreatment techniques led to a negative energy balance. The best pretreatment method among the ones evaluated was thermal pretreatment, with four times more energy produced that demanded.

Non-isothermal method was used to study gasification characteristics of three coal chars and one biomass char. Four chars were made from anthracite coal (A), bituminous coal (B), lignite coal (L), and wood refuse (W), respectively. The gasification process was studied by random pore model (RPM), unreacted core model (URCM) and volumetric model (VM). With an increase in metamorphic grade, the gasification reactivity of coal char decreased, and the gasification reactivity of biomass char was close to that of low metamorphic coal char. With an increase in heating rate, the gasification of all samples moved towards high temperature zone, and the whole gasification time decreased. It was concluded from kinetics analysis that the above-mentioned three models could be used to describe the gasification process of coal char, and the RPM fitted the best among the three models. In the RPM, the activation energies of gasification were 193. 9, 225. 3 and 202. 8 kJ/mol for anthracite coal char, bituminous coal char and lignite coal char, respectively. The gasification process of biomass char could be described by the URCM and VM, while the URCM performed better. The activation energy of gasification of wood refuse char calculated by the URCM was 282. 0 kJ/mol.

This work presents a conceptual design of an integrated biorefinery using olive tree pruning as feedstock. The biorefinery combines a state-of-the-art thermochemical technology for producing high value-added antioxidants with an energy self-sufficient biochemical platform for lignocellulosic ethanol production. These plants are integrated by exchanging energy and feedstock. The process and design parameters employed in the plant designs are based on the authors’ own lab and pilot-scale data. The paper discusses the economic dilemma of using this feedstock for producing high value-added products in small amounts versus producing large amounts of low-profit biofuels. The feasibility of this production strategy at medium scale is demonstrated via a techno-economic analysis based on total production cost for each co-product. Each plant is energy integrated, and the energy performance of the bioethanol plant is assessed by calculating the end-use-energy ratio. Both analyses are parameterized with respect to plant capacity (100–1500 t dry weight (dw)/day) and raw material price (20–100 €/ton dry weight).

The aim of this paper is to present a comparative study in terms of determining general properties of four different agricultural residual substrates before and after the anaerobic fermentation process inside a pilot installation dedicated to this type of applications. The influence of anaerobic digestion can be observed from the modifications it brings to the general properties of the used materials. This work underlines positive and negative influences for pH correction agents relative to material further use in combustion process with impact on the characteristic temperatures on which the materials modify their physical properties. All used materials present a high energetic level making them useful even as residues after anaerobic fermentation.

Mathematical models have been studied and solved for evaluating an optimized process configuration for the energy intensive black liquor concentrating Kraft recovery process in paper mills. In the present study, a heptads effect evaporator system is considered and modeled first on the basis of three possible flow directions of black liquor feed and heating steam, i.e. backward, forward or mixed feed. Further, live steam split, liquor feed split, feed preheating and a hybrid of these energy saving schemes are coupled with the basic backward, forward and mixed feed arrangements. The systematically evaluated material and heat balance equations evolve into main model equations that are then represented in matrix forms, thereby, to generalize the models mathematically. The advantage of the studied models are their simplicity in linear representation of equations in matrix form and ease of numerical solution. The proposed mathematical models are iteratively solved using different numerical techniques: Gauss-Jordan, Gauss-elimination, Gauss–Seidel, Jacobi, successive over-relaxation and interior-point methods. The simulation results indicate that amongst the 15 simulated models, backward feed with the added arrangements of feed split, steam split and feed preheating showed the best steam economy. The studied models can be applied and easily extended to solve problems with different operating conditions as well once the liquor, steam and other evaporator effects parameters are known.

Cotton based textile industries are one of the major source of revenue to the Indian economy. India contributes around 30 % of world’s total cotton cultivation every year. Cotton accounts for more than 70 % of total textile production in the country. Cotton is subjected to various processes to produce cotton based textile apparels. During the processing of cotton, more amount of cotton-based wastes are generated and they are landfilled or incinerated, in general. Cotton textile industries are facing critical problems on solid-waste management, which results in environmental pollution and health hazards. These wastes comprise lignin, hemicellulose and cellulose, which can be utilized as sustainable feedstock for the production of bioethanol. Cotton based lignocellulosic biomass requires specific pretreatment strategy to efficiently remove lignin and to solubilize hemicellulose, which increases the accessibility of hydrolytic enzymes during saccharification. Till date, various pretreatment technologies such as physical, physico-chemical, acid/alkali-, ionic liquids (ILs) and biological treatment methods are widely evaluated for lignin removal, hemicellulose solubilization and cellulose crystallinity reduction in cotton wastes to enhance the enzymatic hydrolysis and fermentation process. This paper reviews about different pretreatment methods implemented and its significance for the conversion of cotton wastes to bioethanol.

The explosive growing number of data from mobile devices, social media, Internet of Things and other applications has highlighted the emergence of big data. This paper aims to determine the worldwide research trends on the field of big data and its most relevant research areas. A bibliometric approach was performed to analyse a total of 6572 papers including 28 highly cited papers and only papers that were published in the Web of ScienceTM Core Collection database from 1980 to 19 March 2015 were selected. The results were refined by all relevant Web of Science categories to computer science, and then the bibliometric information for all the papers was obtained. Microsoft Excel version 2013 was used for analyzing the general concentration, dispersion and movement of the pool of data from the papers. The t test and ANOVA were used to prove the hypothesis statistically and characterize the relationship among the variables. A comprehensive analysis of the publication trends is provided by document type and language, year of publication, contribution of countries, analysis of journals, analysis of research areas, analysis of web of science categories, analysis of authors, analysis of author keyword and keyword plus. In addition, the novelty of this study is that it provides a formula from multi-regression analysis for citation analysis based on the number of authors, number of pages and number of references.

Usability tests are a part of user-centered design. Usability testing with disabled people is necessary, if they are among the potential users. Several researchers have already investigated usability methods with sighted people. However, research with blind users is insufficient, for example, due to different knowledge on the use of assistive technologies and the ability to analyze usability issues from inspection of non-visual output of assistive devices. From here, the authors aspire to extend theory and practice by investigating four usability methods involving the blind, visually impaired and sighted people. These usability methods comprise of local test, synchronous remote test, tactile paper prototyping and computer-based prototyping. In terms of effectiveness of evaluation and the experience of participants and the facilitator, local tests were compared with synchronous remote tests and tactile paper prototyping with computer-based prototyping. Through the comparison of local and synchronous remote tests, it has been found that the number of usability problems uncovered in different categories with both approaches was comparable. In terms of task completion time, there is a significant difference for blind participants, but not for the visually impaired and sighted. Most of the blind and visually impaired participants prefer the local test. As for the comparison of tactile paper prototyping and computer-based prototyping, it has been revealed that tactile paper prototyping provides a better overview of an application while the interaction with computer-based prototypes is closer to reality. Problems regarding the planning and conducting of these methods as they arise in particular with blind people were also discussed. Based on the authors' experiences, recommendations were provided for dealing with these problems from both the technical and the organization perspectives.

Through increased interest in the use of macroalgae for biofuel production, the concept of a biorefinery approach has been developed to improve its economic viability. This paper looks at the use of seaweed residue after enzymatic saccharification of the seaweeds Saccharina latissima, Alaria esculenta and Ulva lactuca as a novel feed component for the aquaculture industry. Chemical composition analysis was used to evaluate the impact of enzymatic treatment on the nutritional aspect of seaweed residue. During saccharification, the relative ash and carbohydrate content was reduced, but total nitrogen, total carbon and lipid content increased in all three species. In addition, the saccharification of S. latissima and A. esculenta resulted in the elimination of polyphenols, further enhancing the nutritional value of the residue. The residue supported the survival and growth of bivalve spat and commercially valuable sea urchins over the course of 3-week preliminary trials.

VerbNet—the most extensive online verb lexicon currently available for English—has proved useful in supporting a variety of NLP tasks. However, its exploitation in multilingual NLP has been limited by the fact that such classifications are available for few languages only. Since manual development of VerbNet is a major undertaking, researchers have recently translated VerbNet classes from English to other languages. However, no systematic investigation has been conducted into the applicability and accuracy of such a translation approach across different, typologically diverse languages. Our study is aimed at filling this gap. We develop a systematic method for translation of VerbNet classes from English to other languages which we first apply to Polish and subsequently to Croatian, Mandarin, Japanese, Italian, and Finnish. Our results on Polish demonstrate high translatability with all the classes (96% of English member verbs successfully translated into Polish) and strong inter-annotator agreement, revealing a promising degree of overlap in the resultant classifications. The results on other languages are equally promising. This demonstrates that VerbNet classes have strong cross-lingual potential and the proposed method could be applied to obtain gold standards for automatic verb classification in different languages. We make our annotation guidelines and the six language-specific verb classifications available with this paper. Electronic supplementary material The online version of this article (doi:10.1007/s10579-017-9403-x) contains supplementary material, which is available to authorized users.

Renewable energy sources, particularly biofuels, are being promoted as possible solutions to address global warming and the depletion of petroleum resources. In this context, biodiesel is a solution to the growing demand for renewable fuels. Beef tallow is the second leading raw material after soybean oil used in biodiesel production in Brazil. Evaluating and addressing the environmental impacts of beef tallow biodiesel are of great importance for its life cycle impact assessment (LCIA). Inventory data on tallow and biodiesel production were collected from the literature and from a primary data source provided by a Brazilian biodiesel plant. The modeled system represents the Brazilian reality for the 2005–2015 decade. Subsequently, the environmental impacts of beef tallow biodiesel production were characterized for a selection of environmental impact indicators: global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), and water footprint (assessed based on blue water use (BWU) and blue water consumption (BWC) indicators). From the characterization of these environmental burdens, the main sources of environmental impact were evaluated. Sensitivity analysis was conducted to verify the influence of key parameters (emission factor, energy consumption, and prices) on changes in the environmental load of beef tallow biodiesel. Carbon flux results indicate that beef tallow biodiesel production acts as a carbon source. Namely, pasture carbon uptake (91% of all carbon input) is lower than combined biogenic and fossil CO2 emissions, which are controlled by cattle enteric fermentation as methane (72%) and by thermal energy processes (25%). Otherwise, thermal energy production accounts for 80% of total AP emissions, and cattle urine and manure are responsible for 70% of total EP emissions. The BWC and BWU water footprints of the whole process are controlled by electricity usage, which was greater than 90% for each indicator due to the high proportion of total energy (70%) derived from hydropower in Brazil. The environmental burden from transportation is minimal compared to other processes. Tallow biodiesel GWP can be improved if the carbon uptake potential from grass and low fertilizer utilization are accurately considered, as observed in the sensitivity analysis. For each MJ of beef tallow biodiesel produced, 4.6 g of CO2 is released to the atmosphere. Methane emissions, mainly due to cattle enteric fermentation, and thermal energy processes at the industrial units were the main sources of environmental GWP, AP, and EP impacts. Otherwise, water footprint indicators were associated with the high proportion of total energy derived from hydropower in Brazil.

The co-combustion characteristics of municipal sewage sludge and bituminous coal in air and O2/CO2 atmospheres were assessed by using a thermogravimetric analysis approach between heating rates of 20 and 80 K min−1. The combustion characteristics of sewage sludge/bituminous coal blend (50% blending ratio) in air were also compared with its oxy-fuel behavior. In air atmosphere, the ignition temperatures for sludge/coal blends were between those for their parent samples, which ranged from 238 to 418 °C. In O2/CO2 atmosphere with oxygen content of 30%, the ignition temperatures of 50%sewage sludge/50%coal blend were between 260 and 275 °C, which were less than those (268–280 °C) in air. The ignition and burnout indexes of the sample in 30%O2/70%CO2 atmosphere were very close to those in air. The temperatures with respect to maximum combustion rates of the 50%sewage sludge/50%coal blend in 40%O2/60%CO2 were lower than those in air. The average value of the activation energy for the 50%sewage sludge/50%coal blend in 30%O2/70%CO2 was less than that in air.

Green waste (GW) represents a large fraction of municipal solid waste (MSW) and has increased significantly with the rapid development of urban green areas in some countries. Composting is an appropriate method for the treatment and recovery of these wastes. However, the high content of lignocellulosic substances in GW is known to slow down the decomposition process. This research evaluated the effect of introducing processed food waste (PFW) and unprocessed food waste (UPFW) on composting of GW, it monitored the process itself and assessed the end-product quality. A field-scale experiment was developed using three treatments: Treatment A (100%GW), Treatment B (40%UPFW + 60%GW) and Treatment C (50%GW + 30%UPFW + 20%PFW). Treatment C reached thermophilic temperatures in a shorter time than the other treatments and maintained those temperatures for longer periods. In addition, treatment C reached ambient temperatures during curing in a shorter time compared to treatments A and B. An improved product quality was observed in treatment C compared to other treatments. For example, products from treatment C had lower ash content, higher concentrations of TOC and PTotal and lower EC values compared to treatments A and B. The final fertility index of the end-product from treatment C was 4.8–5.0, which indicates that the product can be suitable for agricultural use.

Pinewood is an abundant source of lignocellulosic biomass that has potential to be used as renewable feedstock in biorefineries for conversion into advanced biofuels and other value-added chemicals. However, its structural recalcitrance, due to the compact packing of its major components, viz. cellulose, hemicellulose and lignin, high lignin content, and high cellulose crystallinity, is a major bottleneck in its widespread use as a biorefinery feedstock. Typical chemical, thermal, and biological pretreatment technologies are aimed at removing lignin and hemicellulose fractions for improving enzyme accessibility and digestibility of cellulose. This review highlights common pine pretreatment procedures, associated key parameters and resulting enzymatic hydrolysis yields. The challenges and limitations are also discussed as well as potential strategies to overcome them, providing an essential source of information to realize pine as a compelling biorefinery biomass source.

Biodiesel was produced using waste coffee grounds (WCGs) via a two-step process comprising lipid extraction and subsequent transesterification steps. Each step was statistically analyzed, and optimum conditions for each step were suggested. WCGs were found to have 16.4% lipid content with 1.9% free fatty acid (FFA) content. The liquid-solid ratio (LSR) significantly influenced lipid extraction from WCGs, while extraction time and temperature did not; 92.7% of lipid extraction efficiency was achieved at 13.7 mL-hexane/g-WCGs, 30 min of extraction time, and 25°C. Owing to the relatively low FFA content, an alkaline catalyst (NaOH) reaction was used that requires less amount of catalyst, methanol, and shorter reaction time compared to an acid catalyst reaction. Reaction time and temperature were the major factors affecting biodiesel conversion, and 94.0% of biodiesel conversion was obtained at optimum conditions for transesterification: 0.5% catalyst, 1.5 mL-methanol/g-lipid, 45°C, and 9 h of reaction time. With the use of statistical analysis tools, high lipid extraction efficiency and biodiesel conversion were achieved at relatively mild conditions, which would reduce biodiesel production cost substantially.

The importance of date palm (Phoenix dactylifera L.) deposit could represent an interesting solution for sustainable and integrated energy valorization in Algerian oasis ecosystem. The objective of this work is to study the thermal behavior, under an oxidative atmosphere of the phoenicicole biomass main constituents related to the dominant cultivar, Deglet Nour. Thermogravimetric analysis is the approach used to study the pyrolysis behavior of this lignocellulosic biomass by the determination of the kinetic constant (activation energy, order of the reaction, pre-exponential factor) and the description of different thermal profiles. The results show that combustion process could be an interesting alternative energy recovery for the phoenicicole biomass. This is explained by the low activation energy which is estimated at an average of 29.06 k J/mol and the low residues generated by the thermoconversion. Furthermore, two types of phoenicicole waste have been identified by their combustion behavior: firstly the lif part characterized by their thermal stability due to the high lignin content and secondly the fruit bunch (ARJ) characterized by a great thermal reactivity.

Currently in South Africa, online flue gas desulphurisation (FGD) is being utilized as one of the most effective methods for total sulphur reduction in coal samples during the combustion process. However, the main disadvantage associated with FGD is the formation of its by-products (FGD gypsum). The latter is mostly formed in low grade quality, thereby bringing secondary pollution problems and extra disposal costs. Therefore, the current study describes the development of total sulphur extraction in coal under microwave heating using different dilute alkaline solutions such as NaOH, NaOH-H2O2, NH4OH, and NH4OH-H2O2. The experimental conditions were as follows: 150 °C, 5 min and 10% (m/v or v/v) for temperature, extraction time and reagent concentration, respectively. The most effective alkaline reagent for coal desulphurisation was observed to be NaOH-H2O2 with total sulphur reduction of 55% (from the inductively coupled plasma-optical emission spectrometry (ICP-OES) results). The NaOH-H2O2 reagent also showed significant morphological changes in coal as observed from the SEM images and effective demineralisation as revealed by the powder X-ray diffractometer (P-XRD) results. Additionally, desulphurisation results obtained from the developed microwave-assisted dilute alkaline extraction (MW-ADAE) method were quite comparable with the published work. The proposed total sulphur reduction method is advantageous as compared to some of the literature reported coal desulphurisation methods as it requires a short period (5 min) of time to reach its completion. Additionally, the proposed method shows excellent reproducibility (% RSD from 0.5 to 1); therefore, it can be utilized for routine analysis.