Effect of Solvent Extraction Parameters on the Recovery of Oil From Spent Coffee Grounds for Biofuel Production

Spent coffee grounds (SCG) are a potentially valuable source of lipids for sustainable production of biofuels. However, there are several feedstock properties and solvent extraction parameters that can impact on the oil yield and quality, potentially reducing the possible environmental benefits of deriving oils from this waste stream. This study presents results of laboratory and pilot plant scale experimental investigations into lipid recovery from spent coffee, determining the effects of solvent extraction variables including duration, SCG-to-solvent ratio and SCG residual moisture. SCG samples from both the industrial production of instant coffee and retail coffee shops were characterized in terms of moisture content, particle size distribution and oil content to identify the impact of these variables on the efficiency of lipid recovery by solvent extraction. The dry weight oil content of the instant SCG samples ranged from 24.2 to 30.4% w/w, while the retail SCG samples contained considerably lower amounts of lipids with their oil content ranging between 13.4 and 14.8% w/w. The highest oil yields were found at an extraction duration of 8 h, while a moisture content of ~2% w/w led to increased yields relative to completely dry samples. A pattern of increasing acidity with decreasing extraction duration was observed, suggesting preferential extraction of free fatty acids (FFA), with the fatty acid (FA) profile of the oil found to be similar to lipids commonly utilized for biofuel production

An explorative study on the adoption and dis-adoption of improved rice varieties among farmers in the Northern region of Ghana

Rice consumption in Ghana has increased steadily over the years. To enhance rice productivity to meet demand, several high-performing rice varieties have been disseminated via numerous interventions to smallholders in Northern Ghana. Nevertheless, productivity is still low at farm gate compared to research stations, due to smallholder poor adoption of the varieties. Using primary data collected from 404 farmers, the study examines the adoption levels of the main rice varieties among farmers and investigates the reasons for their adoption and dis-adoption. The empirical results revealed that rice varieties namely, Agra, Sakai, Jasmine 85, and Afife were the most adopted in the study area. Also, the study finds that GR-18, Nerica, Digang, Tox, Mandee, and Faro-15 were the most dis-adopted rice varieties. The main reasons for which farmers adopted the improved rice varieties were availability of a ready market for the produce, crop resistance to pests and diseases, consumer higher demand for rice, advice by extension staff to cultivate, and encouragement from researchers to adopt. The reasons for the dis-adoption of improved rice varieties in the study area were high input requirements, lack of ready market for the varieties, and unfavorable climatic conditions. The findings of the study give direction as to the angle from which the adoption of improved rice varieties can be stepped up while dis-adoption is reduced. Research scientists should research into rice varieties that are more suitable for the soil and climatic conditions of the study area and continue to sensitize and motivate the farmers to adopt them, while government should step up its support for the research scientists as well as the extension officers to deliver on their mandate

Influence of solvent selection and extraction temperature on yield and composition of lipids extracted from spent coffee grounds

Spent coffee grounds (SCG) are a potentially sustainable source of C16-C18 triglycerides. This study investigates known solvent extraction technologies with a wide range of solvents for lipid extraction from SCGs, and determines the effect of solvent selection and process temperature on the extraction efficiency and composition of the obtained oil. A correlation between increasing solvent boiling point, and therefore process temperature, and improved oil extraction efficiency was observed in Soxhlet extractions with a wide range of solvents. Experiments at elevated temperatures (up to 200 °C) were performed through Accelerated Solvent Extraction (ASE) and temperature increase initially improved the oil extraction efficiency when non-polar solvents were used, before decreasing it at higher temperatures. Utilization of ethanol resulted in the highest oil extraction ratio by ASE (at 165 °C), suggesting that temperature increase is more beneficial to the extraction efficiency of polar solvents. In addition, analysis of the oils was carried out to evaluate the composition of the oils extracted from SCGs using different solvents and extraction parameters. The Nuclear Magnetic Resonance (NMR) results were in agreement with the values obtained from the titrimetric determination of the free fatty acid content (FFA) of the oils in terms of the comparative trends, and also tentatively suggest that some differences in the composition of the extracted oils might be related to the type of extraction solvent used

Transesterification of high-acidity spent coffee ground oil and subsequent combustion and emissions characteristics in a compression-ignition engine

Lipids extracted from spent coffee grounds (SCG) are a potentially promising feedstock for biodiesel production if the relatively high free fatty acid (FFA) portion of the oil can be successfully converted into methyl esters, and the resulting biodiesel found to have acceptable combustion and emissions performance. This study presents experimental results obtained from transesterification of SCG-extracted oil with a FFA content of ∼30% w/w through a two-step process, followed by fuel characterization and combustion experiments with SCG-derived biodiesel, pure and blended with fossil diesel, and untreated SCG oil in a single cylinder research compression-ignition engine. The acid-catalyzed pretreatment reduced the FFA content of the oil below 1.5% w/w, with minor losses, and showed the methanol-to-FFA molar ratio to be more significant relative to the quantity of sulphuric acid used as a catalyst within the range of investigated conditions, while the subsequent base-catalyzed step converted ∼87% of the pretreated oil into biodiesel with a higher heating value (HHV) of 39.7 MJ/kg. The combustion and emission characteristics of pure and blended SCG biodiesel revealed similarities with those of commercial rapeseed and soya biodiesel samples tested. While ignition delay decreased with increasing SCG biodiesel content, the comparatively higher CO, total hydrocarbon (THC) and particulate emissions of the SCG biodiesel were attributed to higher fuel kinematic viscosity (KV). Combustion of the untreated SCG oil produced low in-cylinder peak pressure and peak heat release relative to other samples tested despite a longer ignition delay, suggesting that the oil physical properties were more important in determining combustion performance

Factors Affecting the Efficiency of Pressurized Solvent Extraction of Oil from Spent Coffee Grounds

Spent coffee grounds (SCG) are the main residues of the coffee beverage industry, and a potentially valuable source of energy-dense lipids. The present study investigates the effect of temperature, pressure and duration on the pressurized solvent extraction of lipids from dried SCG to evaluate their impact on oil extraction efficiency, composition and energy content. Solvent extraction trials at elevated temperatures performed by an Accelerated solvent extraction (ASE) unit revealed a beneficial effect of increased temperature on the crude lipid extracting efficiency of polar ethanol. Nuclear magnetic resonance (NMR) analysis showed that extraction temperature had a significant impact on the proportions of the ASE-extracted SCG oil constituents, with increasing temperature leading to lower concentration of triglycerides and higher levels of 1,2- and 1,3-diglycerides. Experiments performed in a closed pressurized vessel allowed individual selection of pressure and temperature and showed that pressure had a significant impact on oil extracting efficiency that largely depended on process temperature. There was no systematic effect of extraction temperature and pressure on the higher heating value (HHV) of SCG lipid samples, which ranged between 38.53 MJ/kg and 39.12 MJ/kg, while extraction pressure was found to have negligible effect on the free fatty acid (FFA) content of lipids extracted by pressure vessel experiments. Prolongation of pressurized extraction duration above 10 minutes was found to be counterproductive in terms of oil recovery, and consecutive short extraction static cycles with fresh solvent removed higher amounts of SCG oil relative to a single longer cycle

Integrated strategies for water removal and lipid extraction from coffee industry residues

Spent coffee grounds (SCGs) and roasted defective coffee beans (RDCBs), are a potentially sustainable source for biofuel production if the processing of these residues, and the recovery of energy-dense lipids, can be undertaken in an energy efficient way. A necessary step in solvent extraction of lipids is prior drying of the feedstock, and this can incur a significant energy cost in the case of SCGs. This study investigates solvent extraction strategies for crude lipid recovery from wet or partially dried SCG samples, with mechanical pressing used as pre-treatment and alternative to thermal drying. Dewatering of SCGs by application of pressures up to 550 bars removed 42% of the moisture present, while lipid expression from whole RDCBs was achieved, with a maximum crude lipid recovery of 77.1% relative to available oil obtained. Crude extracts removal from partially wet pressed SCGs through accelerated solvent extraction (ASE) with ethanol was not impeded by moisture presence, and the obtained extracts had high energy density (∼39 MJ/kg) comparable to hexane-extracted crude lipids. SCG and RDCB crude oil removed through solvent extraction and mechanical pressing respectively had similar fatty acid (FA) compositions, but a higher proportion of free fatty acids (FFAs) in solvent-extracted oil

A Machine to Machine framework for the charging of Electric Autonomous Vehicles

Electric Autonomous Vehicles (EAVs) have gained increasing attention of industry, governments and scientific communities concerned about issues related to classic transportation including accidents and casualties, gas emissions and air pollution, intensive traffic and city viability. One of the aspects, however, that prevent a broader adoption of this technology is the need for human interference to charge EAVs, which is still mostly manual and time-consuming. This study approaches such a problem by introducing the Inno-EAV, an open-source charging framework for EAVs that employs machine-to-machine (M2M) distributed communication. The idea behind M2M is to have networked devices that can interact, exchange information and perform actions without any manual assistance of humans. The advantages of the Inno-EAV include the automation of charging processes and the collection of relevant data that can support better decision making in the spheres of energy distribution. In this paper, we present the software design of the framework, the development process, the emphasis on the distributed architecture and the networked communication, and we discuss the back-end database that is used to store information about car owners, cars, and charging stations

SURVEY OF PLANT PARASITIC NEMATODES AND DISEASE SEVERITY OF COMMON BEAN LINES EVALUATED FOR REACTION TO ROOT KNOT NEMATODES INFESTATION

Plant parasitic nematodes are important pests in crop production in sub-Saharan Africa. The objective of this study was to identify the occurrence of nematodes associated with common bean ( Phaseolus vulgaris L.) and evaluate breeding lines for their reaction to Meloidogyne spp. in Ghana. Common bean rhizosphere soil was sampled and processed using Modified Baermann Tray method. Five nematode genera, namely Meloidogyne, Pratylenchus , Rotylenchulus , Helicotylenchus and Trichodorus were extracted. The first four genera listed above were prevalent across locations, with Trichodorus present in 30% of the fields sampled. The highest nematode population density of 319 juveniles per 200 cubic centimeter of soil was recorded for Meloidogyne spp. compared to 45 juveniles per 200 cubic centimeter, for Trichodorus. Twelve breeding lines were evaluated by inoculating roots of two-weeks-old plants with 2000 infective-stage juveniles of Meloidogyne sp. Reactions of test lines to Meloidogyne sp. infection were assessed by determining the number of egg masses and galling index (GI) on roots. Reproduction index (RI) was used to classify test lines as resistant or susceptible. Significant differences (P < 0.05) were observed in the number of eggs, GI and RI among lines tested. No resistant line was identified; however, lines SEF 47, BFS 35 and BFS 60 were moderately resistant, with RI of 13.1, 17.4 and 23.7%, respectively. Line SEF 60, although classified as slightly resistant, recorded a 100 seed weight of 26.0 g, which was 60% higher than line SEF 53 with seed weight of 16.2 g. Moderately resistant common bean lines identified could be used in common bean improvement programmes to develop elite cultivars tolerant to root knot nematodes.Les n\ue9matodes phytoparasites sont des ravageurs importants dans la production agricole. L\u2019objectif de cette \ue9tude \ue9tait d\u2019identifier la pr\ue9sence de n\ue9matodes associ\ue9s au haricot commun (Phaseolus vulgaris L.) et d\u2019\ue9valuer les lign\ue9es g\ue9n\ue9alogiques pour leur r\ue9action \ue0 Meloidogyne spp. au Ghana. Le sol de la rhizosph\ue8re du haricot commun a \ue9t\ue9 \ue9chantillonn\ue9 et trait\ue9 \ue0 l\u2019aide de la m\ue9thode du plateau de Baermann modifi\ue9. Cinq genres de n\ue9matodes, \ue0 savoir Meloidogyne, Pratylenchus, Rotylenchulus, Helicotylenchus et Trichodorus ont \ue9t\ue9 extraits. Les quatre premiers genres \ue9num\ue9r\ue9s ci-dessus \ue9taient r\ue9pandus dans tous les emplacements, avec Trichodorus pr\ue9sent dans 30% des champs \ue9chantillonn\ue9s. La densit\ue9 de population de n\ue9matodes la plus \ue9lev\ue9e de 319 juv\ue9niles par 200/cm3 de sol a \ue9t\ue9 enregistr\ue9e pour Meloidogyne spp. contre 45 juv\ue9niles par 200/cm3 pour Trichodorus. Douze lign\ue9es ont \ue9t\ue9 \ue9valu\ue9es en inoculant les racines de plantes \ue2g\ue9es de deux semaines avec 2000 juv\ue9niles au stade infectieux de Meloidogyne sp. R\ue9actions des lign\ue9es de test \ue0 Meloidogyne sp. l\u2019infection ont \ue9t\ue9 \ue9valu\ue9es en d\ue9terminant le nombre de masse d\u2019\u153ufs et l\u2019indice de galle (IG) sur les racines. L\u2019indice de reproduction (RI) a \ue9t\ue9 utilis\ue9 pour classer les lign\ue9es de test comme r\ue9sistantes ou sensibles. Des diff\ue9rences significatives (P < 0,05) ont \ue9t\ue9 observ\ue9es dans le nombre d\u2019\u153ufs, GI et RI parmi les lign\ue9es test\ue9es. Aucune lign\ue9e r\ue9sistante n\u2019a \ue9t\ue9 identifi\ue9e ; cependant, les lign\ue9es SEF 47, BFS 35 et BFS 60 \ue9taient mod\ue9r\ue9ment r\ue9sistantes, avec un RI de 13,1, 17,4 et 23,7 %, respectivement. La lign\ue9e SEF 60, bien que class\ue9e comme l\ue9g\ue8rement r\ue9sistante, a enregistr\ue9 un poids de 100 graines de 26,0 g, soit 60 % de plus que la lign\ue9e SEF 53 avec un poids de graines de 16,2 g. Les lign\ue9es de haricot commun mod\ue9r\ue9ment r\ue9sistantes identifi\ue9es pourraient \ueatre utilis\ue9es dans les programmes d\u2019am\ue9lioration du haricot commun pour d\ue9velopper des cultivars d\u2019\ue9lite tol\ue9rants aux n\ue9matodes \ue0 galles

Ecological Study of HIV Infection and Hypertension in Sub-Saharan Africa: Is There a Double Burden of Disease?

An ecological correlation study of the prevalence of hypertension with human immunodeficiency virus (HIV) prevalence in sub-Saharan Africa was conducted to determine the extent to which these conditions coincide at country level. Data on prevalence of hypertension were derived from a systematic search of literature published between 1975 and 2014 with corresponding national estimates on HIV prevalence and antiretroviral therapy (ART) coverage from the Demographic and Health Surveys and the joint United Nations Programme on HIV/AIDS databases. National estimates on gross national income (GNI) and under-five mortality were obtained from the World Bank database. Linear regression analyses using robust standard errors (allowing for clustering at country level) were carried out for associations of age-standardised hypertension prevalence ratios (standardized to rural Uganda’s hypertension prevalence data) with HIV prevalence, adjusted for national indicators, year of study and sex of the study population. In total, 140 estimates of prevalence of hypertension representing 25 nations were sex-and area-matched with corresponding HIV prevalence. A two-fold increase in HIV prevalence was associated with a 9.29% increase in age, sex and study year-adjusted prevalence ratio for hypertension (95% CI 2.0 to 16.5, p = 0.01), which increased to 16.3% (95% CI 9.3 to 21.1) after adjusting for under-five mortality, GNI per capita and ART coverage. Countries with a pronounced burden of HIV may also have an increased burden of non-communicable diseases such as hypertension with potential economic and health systems implications

Traditional values of virginity and sexual behaviour in rural Ethiopian youth: results from a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Delaying sexual initiation has been promoted as one of the methods of decreasing risks of HIV among young people. In traditional countries, such as Ethiopia, retaining virginity until marriage is the norm. However, no one has examined the impact of this traditional norm on sexual behaviour and risk of HIV in marriage. This study examined the effect of virginity norm on having sex before marriage and sexual behaviour after marriage among rural Ethiopian youth.</p> <p>Methods</p> <p>We did a cross-sectional survey in 9 rural and 1 urban area using a probabilistic sample of 3,743 youth, 15–24 years of age. Univariate analysis was used to assess associations between virginity norm and gender stratified by area, and between sexual behaviour and marital status. We applied Kaplan-Meier and Cox regression analysis to estimate age at sexual debut and assessed the predictors of premarital sex among the never-married using SPSS.</p> <p>Results</p> <p>We found that maintaining virginity is still a way of securing marriage for girls, especially in rural areas; the odds of belief and intention to marry a virgin among boys was 3–4 times higher among rural young males. As age increased, the likelihood of remaining a virgin decreased. There was no significant difference between married and unmarried young people in terms of number of partners and visiting commercial sex workers. Married men were twice more likely to have multiple sexual partners than their female counterparts. A Cox regression show that those who did not believe in traditional values of preserving virginity (adjusted hazard ratio [AHR] = 2.91 [1.92–4.40]), alcohol drinkers (AHR = 2.91 [1.97–4.29]), Khat chewers (AHR = 2.36 [1.45–3.85]), literates (AHR = 18.01 [4.34–74.42]), and the older age group (AHR = 1.85 [1.19–2.91]) were more likely to have premarital sex than their counterparts.</p> <p>Conclusion</p> <p>Although virginity norms help delay age at sexual debut among rural Ethiopian youth, and thus reduces vulnerability to sexually transmitted infections and HIV infection, vulnerability among females may increase after marriage due to unprotected multiple risky sexual behaviours by spouses. The use of preventive services, such as VCT before marriage and condom use in marriage should be part of the HIV/AIDS prevention and control strategies.</p