Fossil Sources Research Articles

Environmental impact of the main household cooking systems—A survey

The food cooking energy may represent the primary hotspot in the cradle-to-grave life cycle of several foods and drinks. It is mainly affected by the type of food and its cookery method, cooking appliance and the fuel selected as well as the number of portions to be cooked. The primary aim of this survey was to demonstrate the basic characteristics of the main cooking methods, appliances, and fuels as well as energy required for some key foods. The secondary aim was to assess the environmental impacts of a generic cooking system as a function of few household cookers fueled by different fuels (i.e., firewood, charcoal, coal, natural gas, liquefied petroleum gas, kerosene and biogas) and electricity in the Italian scenario by using the ReCiPe 2016 and product environmental footprint (PEF) standard methods and Ecoinvent v. 3.7 database. A functional unit equal to per capita useful energy delivered to the pot for cooking (1.41 gigajoule [GJ]) in 27 European Union countries in 2019 was used as the basis of comparison. The use of natural gas resulted in minimum impact in nine of the 18 mid-point impact categories of ReCiPe 2016 method and two damage categories (human health and ecosystem quality) with a minimum overall weighted damage score (OWDSR) of ~5 Pt. Thus, such a cookstove appeared to be more apt to minimize both indoor and outdoor air pollution. Even if the electric cookstove yielded a greater OWDSR (8.6 Pt) because the Italian electricity grid mix was mainly based on fossil sources, it was possible to forecast that new-generation, smart cooktops driven by hydro- and wind-power electricity would minimize OWDSR to as low as 0.9 and 1.4 Pt, respectively, thus not only avoiding the consumption of any fossil energy source but also improving people’s health.

State of the Art on the Microbial Production of Industrially Relevant Organic Acids

The industrial relevance of organic acids is high; because of their chemical properties, they can be used as building blocks as well as single-molecule agents with a huge annual market. Organic acid chemical platforms can derive from fossil sources by petrochemical refining processes, but most of them also represent natural metabolites produced by many cells. They are the products, by-products or co-products of many primary metabolic processes of microbial cells. Thanks to the potential of microbial cell factories and to the development of industrial biotechnology, from the last decades of the previous century, the microbial-based production of these molecules has started to approach the market. This was possible because of a joint effort of microbial biotechnologists and biochemical and process engineers that boosted natural production up to the titer, yield and productivity needed to be industrially competitive. More recently, the possibility to utilize renewable residual biomasses as feedstock not only for biofuels, but also for organic acids production is further augmenting the sustainability of their production, in a logic of circular bioeconomy. In this review, we briefly present the latest updates regarding the production of some industrially relevant organic acids (citric fumaric, itaconic, lactic and succinic acid), discussing the challenges and possible future developments of successful production.

Establishing the Reaction Pathways of the Catalytic Conversion of Erythrulose to Sulphides of Alpha‐Hydroxy Thioesters and Esters

AbstractSulphides of alpha‐hydroxy thioesters and esters (SAH(T)Es) are important fine chemicals and have great potential as platform molecules. SAH(T)Es are typically synthesized from fossil sources while little is known regarding their synthesis from carbohydrates. We report our findings about the one‐pot chemocatalytic conversion of erythrulose (ERU) to SAH(T)Es. Sn, Mo and W chlorides were the most selective catalysts towards the synthesis of S‐butyl‐4‐butylthio‐2‐hydroxybutanethioate (BBTHBT) in 1‐BuSH. The selectivity towards BBTHBT was impacted by the formation of different thioacetals (TAs). The addition of either KOH, H2O or MeOH was effective to decrease TAs formation and increase selectivity towards BBTHBT (or its ester). A kinetic profile, in situ 13C NMR measurements and experiments at different temperatures complement our studies to unravel the complicated reaction network involved in the conversion of ERU to SAH(T)Es. This insight provides a solid foundation for future improvements in the sustainable synthesis of SAH(T)Es.

Most relevant factors and trends in energy cooperation between Kazakhstan and China, focused on renewable energy sources (RES)

This paper analyses the good political and legal environments, mutually beneficial strategic policy, along with level of economic development and growth, superior geographical conditions and cultural integration degree of the important effecting factors of the energy cooperation between Kazakhstan and China. By using the main points listed above this article refers to related trade and investment theories, and it’s divided into two aspects: Kazakhstan's export of Chinese energy products with time series data 1998-2014 and China's investment in Kazakhstan's energy sector with time series data 1998-2016 to construct the vector autoregressive model (VAR).We selected relevant variables and data to construct an econometric model from the perspectives of trade and investment to make an empirical analysis on the influencing factors of energy cooperation between Kazakhstan and China. Our results show that China's demand for large-scale market and for opening to the outside world as well as Kazakhstan’s great energy potential are the most important factors their cooperation. It can be stated that in our days Kazakh legislation is suitable for promoting the Chinese energy investments, but in the long run it would be beneficial to mobilize national capital especially in RES investments and research. In the end, we found the most important reserves in competitiveness of electricity and heat (both from fossil and renewable energy sources) are power grid consolidation and waste heat utilization in the short run. JEL CODE: F14; Q43

Future of forest industry in carbon-neutral reality: Finnish and Swedish visions

The forest industry is a significant emitter of CO2 and thus it needs to transform toward​ a more sustainable operation in order to contribute to tackling climate change. This paper looks at the progress, tools, possibilities, and barriers of Finnish and Swedish forest industries in achieving deep decarbonization. Finland and Sweden have set ambitious national targets to reach net negative greenhouse gas emissions. The role of the forest industry in reaching national targets in these countries remains unclear even if significant fossil CO2 emission reduction and efficiency improvement has occurred. If the forest industries in these countries fulfill their planned future visions, their contribution to meeting the targets will be substantial. This study identified the largest CO2 emitting sectors in the forest industry. They are for both countries, arranged by size, transport including non-road mobile machinery, on-site energy production, fossil fuel use in processes (lime kilns and dryers), and purchased electricity. Viable decarbonization measures exist for key fossil CO2 emissions sources, but several technical, economic, and political barriers are hindering their implementation. Fuel switching from fossil energy sources to bio-based alternatives is the main tool in the decarbonization of the forest sector in both countries, but also electrification of e.g. transport, provides emission reduction opportunities. The forest industry has a high and sustainable potential to become carbon-negative by investing in bioenergy with carbon capture and storage (BECCS) but achieving net-zero emissions might not be realistic without changes in policies and suitable incentives.

Welding Technology for Liquefied Natural Gas Tanks

Liquefied natural gas (LNG) is of great importance in the energy segment of the economy. Natural gas, has a higher calorific value, better fuel efficiency and is more environmentally friendly, thereby gaining more importance compared to oil and coal. Not only does LNG offer greater flexibility in supply, it also has cost advantages for transportation starting from a distance of 2,000 km (at sea) and 4,000 km (on land) respectively. Consequently, the LNG market will grow in the coming decades compared to two other fossil sources - oil and coal. To use natural gas, it is necessary to create safe and economically profitable transportation routes from natural gas deposits to end users. One possibility is to transport gas in a liquefied state, at low temperatures. To ensure safe and reliable storage of liquefied gas at minus 163 ° C, good physical and mechanical properties of the base material and weld (corresponding tank system) are required. To meet these high requirements, appropriate welding methods and welding materials are selected. The paper presents an analysis of activities on the development of new welding materials and improvement of welding technologies for the construction of LNG tanks.

Environmental strategies for achieving a new foreign direct investment golden decade in Algeria.

While numerous studies have discussed the impact of economic growth on the environment, this paper advances in the empirical literature, aiming to validate the existence of an N-shaped environmental Kuznets curve (EKC) relationship between the ecological footprint and economic growth in Algeria during the period 1975–2014. The proposed empirical model includes as additional explanatory variables the foreign direct investment (FDI) and the electricity consumption aimed to increase the relevance of the results, correcting the lack of studies that have previously analyzed the EKC for the case of Algeria. Through the ARDL econometric approach, we confirm an N-shaped EKC between the per capita economic growth and ecological footprint in Algeria, reinforcing these results using the FMOLS and DOLS techniques. In the long run, the empirical results confirmed that the N-shaped EKC in Algeria is valid; electricity consumption and foreign direct investment directly impact ecological footprint. Even though the main objective of this study is to assess the N-shaped EKC, the novelty of the paper is the analysis of the interaction between FDI and electricity consumption. The empirical evidence reveals that FDI contributes to reducing the negative impact of fossil sources in the energy mix in Algeria through the transition to a cleaner energy mix pattern. In the final step of our analysis, we explore the causal nexus among variables by applying the Toda Yamamoto non-causality test. The Toda Yamamoto non-causality test reveals a unidirectional causality between economic growth and ecological footprint; one-run relationship flows from electricity consumption to ecological footprint, and economic growth leads to cause foreign-direct investment. These empirical results evidence the necessity of establishing suitable policies after the gold decade of the FDI in Algeria, being required to advance in this line to come back to ascending levels of FDI after the financial crisis of 2008 and the current COVID-19 crisis. In this sense, policymakers should consider the advantages of FDI for promoting clean foreign investment, necessary for reaching a transition to sustainable development in Algeria. In this sense, this study proposes a battery of environmental strategies to achieve this objective and sustainable growth in the country. Thus, policy implications and directions for future research are suggested.Graphical abstract

Modeling the Effect of Magnesia Nanoparticles on CO Hydrogenation to Light Olefins in a Continuous Flow Reactor Using Fine Gaussian Support Vector Machine

The effect of utilising energy derived from fossil sources on the environment has aroused research interest in alternative and sustainable energy sources. Synthesis gas, a mixture of carbon monoxide (CO) and hydrogen can be used as starting materials in hydrogenation reactions to produce chemical intermediates that can be used in various processes. This study investigates the robustness of applying a fine Gaussian support vector machine algorithm for predicting light olefins from catalytic CO hydrogenation using magnesia nanoparticles-based catalysts. The datasets obtained from the CO hydrogenation reaction consist of input parameters such as magnesia nanoparticles contents, reaction temperature, and reactor pressure, and the output parameters which include CO conversions and the selectivity of light olefins (CH4, C2H6, C2H4 C3H8, C4H8, and C3H6). The dataset was trained and employed for the prediction of the light olefins using a support vector machine with an inbuilt Fine Gaussian Kernel function. The performance of the support vector machine was evaluated using the coefficient of determination (R2), root mean squared error (RMSE), mean square error (MSE), and the mean absolute error (MAE). The support vector machine showed significant potential in the prediction of CO conversion, CH4 selectivity, C2H6 selectivity, and C2H4 selectivity as indicated by R2 of 0.770, 0.800, 0.730, and 0.930, respectively. While less predictive performance was obtained for the prediction of C3H8 selectivity, C4H8 selectivity and C3H6 selectivity as indicated by R2 of 0.630, 0.610, and 0.320, respectively.

Examining the impact of renewable energy technologies on sustainability development in the middle east and north Africa region

The aims of this study are two folds: First to examine the impact of renewable energy technologies on sustainability development in the Middle East and North Africa (MENA). Second to test the awareness and cultural acceptance of societies in MENA region of the need to preserve the environment and reduce pollution by paving the way for finding alternatives to energy and developing emerging energy, which in turn will contribute to sustainable development and preserve the environment from pollution due to energy produced through fossil sources. The method of the current study relied on both primary data and secondary data. Hence, a questionnaire survey was developed to collect the required data. While, secondary data sources are obtained through the Web site finance.yahoo.com. The data processing techniques were carried out using Stata 16 software and using the Multiple Linear Regression method. The sample of the study consisted of 653 people from different MENA countries, i.e. Egypt, Jordan, Algeria, Bahrain, Iraq, Kuwait, UAE, and Saudi Arabia. The results revealed two types of data, quantitative data and qualitative data. Quantitative data is excluded from the secondary data analysis that renewable energy technologies have a positive effect on sustainability development in the MENA region. Qualitative data; as the survey includes some open ended questions to give an avenue to respondents to provide further feedback regarding their experience and perception of renewable energy. The results revealed a high degree of cultural perception of Renewable Energy Technologies of the communities in the MENA. Also, people are aware and ready to afford the cost and efforts to generate clean energy that promote sustainability. This study recommends that governments should invest in renewable energy and highlights the urgent need for clean energy to emerge in the MENA region. JEL classifications Q43. Q32. O13

Emissões de gases de um motor agrícola de ignição por compressão utilizando misturas de óleo Diesel, biodiesel e etanol

ABSTRACT: Partial fuel replacement strategies arising from fossil sources used in compression ignition engines involve mixtures of mineral Diesel oil, biodiesel and ethanol to minimize the gas emissions. In this study, experimental assessments were performed on a multi-cylinder, turbocharged aftercooler, compression-ignition, agricultural tractor engine provided with electronic injection management and an exhaust gas recirculation (EGR) gas treatment system. Diesel oil containing low (BS10 -10 ppm) and high sulfur concentrations (BS500 - 500 ppm) was utilized, with 10% of biodiesel as a constituent established by Brazilian legislation, in blends with 5, 10, 15 and 20% of the total volume, made up of anhydrous ethanol with additives. Thus, there were eight fuels blends and two reference conditions (without ethanol). The emissions of CO, HC, NOx and the HC+NOx gases were estimated, corresponding to the eight operating modes (M) of the ABNT NBR ISO 8178-4 standard. From the findings, it was evident that with the rise in the ethanol concentrations in the fuel blends there was a corresponding increasing in the CO, NOx and HC+NOx emissions. The HC, on the contrary, exhibited a pattern of higher emissions for the high-sulfur fuels (BS500) at low loads. No difference was observed for the NOx emissions at high loads. In the other operation modes, different behaviors were expressed for the BS10, which sometimes showed an increase, while at other times a reduction in the NOx emissions. Regarding the BS500, the NOx emission increased when the ethanol concentrations rose. As the specific emissions of the NOx were higher than those of the HC (in g.kW-1.h-1), the behavior exhibited by the HC+NOx showed similarity to that of the NOx. When the directly analysis of the operating modes was taken into consideration, the use of ethanol triggered an upswing in the emissions, exceeding the threshold of MAR-1 and EURO V standards.

Engineering a sustainable future for point-of-care diagnostics and single-use microfluidic devices.

Single-use, disposable, point-of-care diagnostic devices carry great promise for global health, including meeting urgent needs for testing and diagnosis in places with limited laboratory facilities. Unfortunately, the production and disposal of single-use devices, whether in lateral flow assay, cartridges, cassettes, or lab-on-chip microfluidic format, also poses significant challenges for environmental and human health. Point-of-care devices are commonly manufactured from unsustainable polymeric materials derived from fossil sources. Their disposal often necessitates incineration to reduce infection risk, thereby creating additional release of CO2. Many devices also contain toxic chemicals, such as cyanide derivatives, that are damaging to environmental and human health if not disposed of safely. Yet, in the absence of government regulatory frameworks, safe and sustainable waste management for these novel medical devices is often left unaddressed. There is an urgent need to find novel solutions to avert environmental and human harm from these devices, especially in low- and middle-income countries where waste management infrastructure is often weak and where the use of point-of-care tests is projected to rise in coming years. We review here common materials used in the manufacture of single-use point-of-care diagnostic tests, examine the risks they pose to environmental and human health, and investigate replacement materials that can potentially reduce the impact of microfluidic devices on the production of harmful waste. We propose solutions available to point-of-care test developers to start embedding sustainability at an early stage in their design, and to reduce their non-renewable plastic consumption in research and product development.

Numerical analysis of vertical axis wind turbine blades in ANSYS Fluent

The limitation of the source and storage of fossil fuel and the rapid mitigation due to the rise of population, the renewable energy is the only key for the problem. Among the renewable energies, wind energy becomes the most promising potential as it is a green energy, and this research is focused on the same. The present study investigates the wind turbine blade simulation analysis for a vertical axis wind turbine blade based on the design parameters of NACA0018 airfoil. In this investigation, computational fluid dynamics analysis of vertical axis wind turbine blade is simulated by varying the angle of attack ranging from 12° to 15° while maintaining an incoming wind velocity of 8 m/s. Finite difference-based software “ANSYS FLUENT” is utilized for the simulation of this angle of attack analysis on vertical axis wind turbine considering the turbulence to be SST k-∊ model. Vertical axis wind turbine’s efficiency surely depends upon the blade profile and its orientation. Throughout the blades, velocity and pressure distribution is analyzed at different tip speed ratio with constant inlet velocity. The parameters like tip speed ratio, lift coefficient and power coefficient are reported in this study. In this study, at various angle of attack, simulation shows the uniform velocity distribution at optimum angle of attack of 15° and validation is done by drafting a graph between power coefficient and tip speed ratio, and for given angle of attack, lift coefficient is also validated via graph and feasible value of 1.689 is obtained from the simulation at angle of attack of 15° and comparison is also done by using velocity and pressure contours of blades at different angle of attack.

Carbon Analysis of Wood Composite Panels

Abstract Wood composite panels (WCP) are well known for their environmentally friendly attributes of being sustainable, renewable, biodegradable, and predominantly made from wood residues generated during lumber and plywood production. This paper focuses on the ability of WCPs to store carbon for long periods of time in nonstructural applications such as cabinets, furniture, and flooring. WCPs, include particleboard, medium density fiberboard (MDF), and hardboard–engineered wood siding and trim (EWST). These panels are anticipated to have an average service life of 25–30 years. In 2019, there was an estimated 291 million cubic meters (m3) of WCPs in use in North America that corresponds to a carbon pool of 354 million metric tons of carbon dioxide equivalents. This WCP carbon pool is enough to offset 24 years of cradle-to-gate cumulative carbon emissions (fossil and biogenic sources) emitted during production of these panels. In other words, producing and using WCPs stores carbon for long periods because the amount of carbon emitted during the production of the panels is far less than what the panels themselves are capable of storing over their lifetime of product use.

Construction of the Evaluation Index System of China's Green Economy Development Level-Based on the Dual Model of Entropy Value Method and Coefficient of Variation Method

China's economy has officially shifted from high speed development to high quality development, which means that concepts such as green development are increasingly important and the level of China's development needs to be examined from multiple perspectives. This paper applies a dual model of entropy value method and coefficient of variation method to evaluate China's green economic development level from 2016 to 2020 by selecting 12 secondary evaluation indicators based on three dimensions: economic level, social and livelihood, and green ecology. The results show that although there are fluctuations, China's overall green economic development level is on an upward trend, and there is significant progress in the economic level and social livelihood dimensions, and slight turbulence in the green ecology dimension. This paper suggests that the government should pay more attention to ecological environment, promote the reform of green mechanism and system, innovate green ecological science and technology, and promulgate relevant policies favorable to China's green development, promote the process of renewable and clean energy to replace fossil and other non-renewable energy sources, actively popularize relevant green knowledge to the nationals, and promote China's green economic development from the perspective of multiple subjects, including the state, society, and individuals.

Current state of copper-based bimetallic materials for electrochemical CO2 reduction: a review.

The increasing CO2 concentration in the atmosphere has caused profound environmental issues such as global warming. The use of CO2 as a feedstock to replace traditional fossil sources holds great promise to reduce CO2 emissions. The electrochemical conversion of CO2 has attracted much attention because it can be powered by renewable sources such as solar energy. In this review article, we provide insight into the important parameters when studying CO2RR and give a comprehensive review on the description of synthesis methods with electrocatalytic CO2 reduction over bimetallic copper-based materials. Due to the important bibliographic data on Cu bimetallic materials, we have limited this review to Sn, In, Pd, Zn and Ag. At the end of this review, challenges and perspectives for further upgrading have been included to briefly highlight the important future considerations of this rapidly growing technology.

Light absorption and source apportionment of water soluble humic-like substances (HULIS) in PM2.5 at Nanjing, China

Humic-like substances (HULIS), as important components of brown carbon (BrC), play an important role in climate change. In this study, one-year PM2.5 samples from 2017 to 2018 were collected at Nanjing, China and the water soluble HULIS and other chemical species were analyzed to investigate the seasonal variations, optical properties and possible sources. The HULIS concentrations exhibited highest in winter and lowest in summer. The annual averaged HULIS concentration was 2.61 ± 1.79 μg m−3, accounting for 45 ± 13% of water-soluble organic carbon (WSOC). The HULIS light absorption coefficient at 365 nm (Abs365, HULIS) averagely accounted for 71 ± 19% of that of WSOC, suggesting that HULIS are the main light-absorbing components in WSOC. The annual averaged Ångström absorption exponent and mass absorption efficiency of HULIS at 365 nm were 5.22 ± 0.77 and 1.71 ± 0.70 m2 g−1. Good correlations between HULIS with levoglucosan and K+ suggested biomass burning (BB) influence on HULIS. High concentrations of HULIS and secondary species (e.g., NO3−, SO42−, NH4+, C2O42−) were found in present of high relative humidity, indicating strong aqueous phase secondary HULIS formation. Secondary HULIS produced from anthropogenic and biogenic precursors were quantified based on the positive matrix factorization (PMF) model and the results showed that both fossil (55%) and biogenic (45%) emission sources made great contributions to HULIS. Fossil fuel combustion significantly contributed to HULIS formation throughout the whole year, which were enriched with more secondary HULIS (30%) than primary HULIS (25%). Strongest BB contribution (39%) was found in winter and biogenic SOA contribution (32%) was found in summer. A multiple linear regression (MLR) method was further applied to obtain specific source contributions to Abs365, HULIS and the results showed that strong light-absorbing chromophores were produced from anthropogenic precursors. Our results highlight the anthropogenic SOA and fossil fuels combustion contributions to HULIS in addition to the biggest contributor, BB, in urban area in China.

The role of consumption of energy, fossil sources, nuclear energy, and renewable energy on environmental degradation in top-five carbon producing countries

This study examines the impact of energy consumption and usage of fossil sources (e.g., oil, gas, coal), nuclear energy, and renewable energy on carbon dioxide (CO2) emission by considering the significance of the environmental degradation for countries as well as people. In this context, the top five countries that produce more than 50% of total CO2 in the world are examined. Besides, yearly data from 1965 to 2019 is used. Moreover, multivariate adaptive regression splines is applied for empirical analysis. The results indicate that (i) coefficients of determination (R2) of the best prediction models for the countries are above 99% that provide reliable results; (ii) energy consumption, coal consumption, nuclear energy, and renewable energy usage have an effect on the CO2 emission in some of these countries whereas not effective in some others; (iii) coal, oil, and natural gas consumption are the most significant indicators for the CO2 emission generally; (iv) the effects of the variables change according to different thresholds. Therefore, following a straightforward general approach for the countries in decreasing environmental degradation cannot be helpful. The results highlight the adverse effects of fossil fuels for the CO2 emission in high carbon producing countries. Policy proposals are also discussed.

Dual-carbon isotope constraints on source apportionment of black carbon in the megacity Guangzhou of the Pearl River Delta region, China for 2018 autumn season

Black carbon (BC) aerosol negatively affects air quality and contributes to climate warming globally. However, little is known about the relative contributions of different source control measures to BC reduction owing to the lack of powerful source-diagnostic tools. We combine the fingerprints of dual-carbon isotope using an optimized Bayesian Markov chain Monte Carlo (MCMC) scheme and for the first time to study the key sources of BC in megacity Guangzhou of the Pearl River Delta (PRD) region, China in 2018 autumn season. The MCMC model-derived source apportionment of BC shows that the dominant contributor is petroleum combustion (39%), followed by coal combustion (34%) and biomass burning (27%). It should be noted that the BC source pattern is highly sensitive to the variations of air masses transported with an enhanced contribution of fossil source from the eastern area, suggesting the important impact of regional atmospheric transportation on the BC source profile in the PRD region. Also, we further found that fossil fuel combustion BC contributed 84% to the total BC reduction during 2013–2018. The response of PM2.5 concentration to the 14C-derived BC source apportionment is successfully fitted (r = 0.90) and the results predicted that it would take ∼6 years to reach the WHO PM2.5 guideline value (10 μg m−3) for the PRD region if the emission control measures keep same as they are at present. Taken together, our findings suggest that dual-carbon isotope is a powerful tool in constraining the source apportionment of BC for the evaluations of air pollution control and carbon emission measures.

Latest trends and developments in microalgae as potential source for biofuels: The case of diatoms

Microalgae are microscopic plants which are found in water, snow as well as land. They are one of the major resources of biofuel. However, the phenomenon of biolipid accumulation and its downstream processing into biofuel for commercialization and industrialization has yet to be standardized at economical scale. Among microalgae, diatoms are third generation microalgae which produces abundant oil and thus serves as one of the biggest sources of fossil fuel energy. They account for more than 25% of global biomass production. Diatoms would suffice world’s energy crisis if they are milked/harvested for oil without being sacrificed. Simultaneously in order to get benefitted for crude oil the biochemical modeling of oleaginous microalgae would help in increasing its lipid accumulation to be able to be used in diatom solar panels for Diafuel™ (biofuel from diatoms) production. Such types of living algal solar panels grow in the presence of nitrogen, phosphorus, potassium, silicates, trace metals, few other micro nutrients and even in wastewater. Additionally, molecular tools like Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) offers targeted genome modification in diatoms for increasing oil production deploying specific genes. The review adds the scope to unravel such techniques in diatoms to harvest lipid for Diafuel™ production from a wide range of diatom strains. Several such genetically modified or naturally selected diatom strains rich in oil serve as an important ingredient for diatom solar panels. The main target of this review is to widen the scope of metabolic pathways for enhancing lipid and biofuel in diatoms under nutrient stress media and adapting genetic engineering tools to identify genes responsible for them. It also targets to study the quality of biofuel and life cycle assessment of lipids from diatoms.

Micropitting performance of glycerol-based lubricants under rolling-sliding contact conditions

There is a high demand for environmentally friendly lubricants in order to support a transition to sustainable transport and manufacturing since conventional mineral oils derived from fossil sources are inherently harmful for the environment. Glycerol aqueous solutions have the potential to be used as environmentally friendly base fluids, due to their high solubility in water, and non-toxicity. In this investigation a micropitting test rig (MPR), was used to study the friction, wear and micropitting behaviour of Glycerol-based lubricants in a rolling/sliding contact. Micropitting and wear profiles were analysed through optical profilometry, and the morphology and evolution of micropits were studied trough scanning electron microscopy (SEM). The results showed that the steel-steel contact lubricated with a Glycerol-water-glycol lubricant reduced mild-wear, promoting micro-pitting as a main failure mode at low sliding levels compared to a commercial fully formulated gear oil. It was also shown that friction was significantly lower for the Glycerol-water and Glycerol-water-glycol lubricants which is mainly attributed to an effect of a low pressure-viscosity coefficient.