Biofuel: A sustainable and clean alternative to fossil fuel

“While biomass is utilized for various applications, including the production of power, fuel additives, and agricultural applications, the domestic sector accounts for most of its use (75%), mostly for cooking and heating [6].”

“The steady reduction of fossil fuels and their non-biodegradable nature have prompted the search for alternate energy sources for potential future applications [10].”

“Blue-green algae, Bacillariophyceae, Eustigmatophyceae, and Chlorophyceae are the microalgae employed in the manufacture of algal biofuel [50].”

“To prepare the cellulose surface for enzymatic hydrolysis, a sophisticated pre-treatment procedure is used to fractionate various components of the cell wall found in the biomass, such as hemicellulose and lignin [56].”

“These fuels are chemically identical to conventional fuels and can be easily incorporated into engines and fuel infrastructure already in place [116].”

“The movement of goods and people via air, sea, train, and road accounts for an estimated 58% of fossil fuel consumption [4].”

“The harvested algae are subjected to an appropriate dehydration procedure to remove the water content prior to the fuel extraction[33].”

“Nonetheless, only palm oil-based biodiesel meets the renewable energy guidelines RED criteria for a 65% reduction in GWP relative to diesel [43].”

“…current ecological and economic constraints (such as carbon fixation by photosynthesis and electrochemistry, as well as the value-added product development of biowaste), and the development of designer molecules that increase performance and fuel efficiency while lowering carbon emissions [113].”

“Lignocellulosic biomasses can be converted by a variety of thermo-chemical processes to produce energy and other products like heat, syngas, liquid biofuels and solid charcoal, that depend on temperature, pressure, and heating [67].”

“…can unleash the feasibility of biofuels as clean, renewable, and scalable energy solutions by utilizing genetic engineering and biotechnology to overcome the inherent limitations of traditional biofuel manufacturing processes, such as low transformation efficiencies and substrate specificity [122].”

“They can grow easily in freshwater, saltwater, and industrial waste [47].”

“Since 1900, biofuel has been used as a fossil fuel substitute [83].”

“Advanced biofuels are second, third, and fourth-generation fuels, whereas traditional biofuels are commonly referred to as fuel from first-generation [40].”

“However, at current consumption rates, it is estimated that the worldwide supplies of petrol and oil will run out in about 50 years [3].”

“When these carbon bonds are broken, as illustrated in Figure 1, each triglyceride molecule is transformed into fatty acid ester molecules and glycerol, which can be processed to produce biodiesel[31].”

“Carbon monoxide (CO), particle matter (PM), and hazardous organic compounds are among the hazardous indoor air pollutants that are released or produced when heating or cooking with polluting fuels like coal or biomass in open flames or conventional stoves [17].”

“To make this entire process economically feasible, it is imperative to combine the algal dark fermentation process with a biorefinery approach in which the outputs are converted into useful proteins [27].”

“Algal, lignocellulosic, and plant biomass can all be used as feedstocks for the production of bioethanol [32].”

“According to some studies, governments everywhere must carefully weigh these effects before making any new investments in or plans for the use of biofuels [106].”

“Many countries diversify their energy mix to ensure the rural and regional services from indigenous biofuel production and its use [110].”

“Biofuels are classified as conventional or advanced fuels based on the materials utilized to create them, their constraints as a renewable source, and technological advancement [39].”

“…could improve the provision of several ecosystem services, such as pollination and carbon storage, as well as lower fertilizer and pesticide use compared to conventional crops, permitting the persistence of species found in grasslands or shrublands, and lessen competition with food crops [104].”

“The bioenergy sector generated almost 2.8 million employment, demonstrating its contribution to job creation [109].”

“These environmental implications are frequently assessed using LCA [93].”

“These are based on techniques that convert agricultural lignocellulosic biomass into fuels through biochemical or thermochemical [44].”

“Nonetheless, the production of biofuels for the fourth generation relies on genetically engineered organisms, altered metabolic pathways, increased CO 2 fixation capacity, and microalgae post-genome technologies [91].”

“VOCs aid in the formation of smog in addition to being health hazards [16].”

“The use of biomass has continued to be a significant source of energy and influences the environment and society locally, regionally, and worldwide [52].”

“Wastes (such as municipal solid wastes ), by-products ( such as cereal straw and forest residues), and dedicated feedstocks ( such as vegetative grasses and other energy crops), are lignocellulosic feedstocks that can be used to produce second-generation biofuels [45].”

“The process uses pyrolysis, gasification, and liquefaction to produce synthesis gas (CO + H 2 ) Table 2, which is then used to reform a variety of long carbon chain biofuels, including ethanol and synthetic diesel [66].”

“These contaminants are discharged into the soil during the drilling, hydraulic fracturing, or transport processes, frequently as a result of equipment, casing, or pipeline failures [18].”

“Biohydrogen is a highly efficient sustainable energy source that has a short half-life [25].”

“When creating standards for assessing the consequences of the biofuel industry, it is crucial to consider environmental challenges and associated difficulties such as biodiversity, soil and water resources, air pollution, GHG emissions, and sustainability [92].”

“These include biochemical and thermochemical processes [60].”

“According to Hassan et al. [88], edible food crop resources like sugarcane, potatoes, oilseeds, corn, barley, wheat, and soybeans were used to make the first generation biofuels, which included biodiesel and bioethanol.”

“Exploiting agricultural crop wastes and biomass waste to generate biofuels is anticipated to lower environmental impact and address a number of environmental concerns, such as trash management [84].”

“The concentrated ethanol is subsequently drained and converted into a fluid state by distillation, which is employed as a purification technique to eliminate water and other impurities from the diluted alcohol [35].”

“Early 20th-century bioethanol and biodiesel production involved the use of vegetable oils like sunflower, palm, and soybean oil along with cellulose or starch-based biomass such as wastes from the food sector, soybeans, and cereal grains [85].”

“The method becomes highly energy-intensive since the production of other products like acetone and ethanol limits the creation of butanol [21].”

“Agricultural and forestry waste extraction, for example, can have a detrimental influence on species that consume decomposing biomass, lower soil carbon stocks and fertility in cultivation regions, and indirectly increase deforestation as a result of rising biomass demand [103].”

“To extract biobutanol from these macroalgae, clostridial strains were utilized as feedstock [24] 1.3.”

“Therefore, the establishment of a large-scale, workable, and effective feedstock impart chain is essential to the development of liquid biofuel [112].”

“The recent exponential expansion in industrialization and population has resulted in a worldwide energy crisis and concerns about reliance on non-renewable energy sources [1].”

“Expanding the biofuel industry can improve a country's economic security, particularly by creating jobs in rural and disadvantaged areas [107].”

“To offer long-term, reliable, and affordable production systems for the biofuel sector, significant efforts must be made to incorporate social, economic, and environmental considerations in addition to addressing technological constraints [114].”

“The efficient transformation of complex biomass to biofuels is made possible by biotechnological developments like the use of genetically modified microbes and enzymes [120].”

“In contrast to grains, cellulose, lignin, and polyose are among the several chemical compositions that make up cellulosic biomass [46].”

“Biofuels classified as fourth-generation are those that are created by the genetic engineering of algae [49].”

“The generation economy of biofuel through the fermentation process depends on the nature of feedstock and hence focus is switched towards forest waste and agro-waste being non-food crops with a high proportion of cellulose and have been researched extensively in recent years [111].”

“Thus, it was anticipated that Brazil produced 17.4 billion liters of biofuel between 2005 and 2014, saving 12.9 billion US dollars in fossil fuel importation expenditures [108].”

“Biochemical conversions often happen more slowly and need less energy than thermochemical conversion techniques, Table 1 [62].”

“These sustainable feedstocks are abundant in nature and have an estimated annual production of 200 billion tonnes worldwide [86].”

“Industrial biofuel production from agricultural crops resulted in water scarcity, fast and irreversible soil degradation, excessive use of fertilizers and pesticides that contaminated the air and water, and a decline in both agricultural and wild biodiversity [98].”

“Nevertheless, other solvents are synthesized concurrently with the butanol production process, which lowers the target product's selectivity rate [23].”

“Nevertheless, the high rate of these feedstocks can have a direct influence on food supplies, and the distribution of agricultural land has contributed to the unethical and costly availability of these feedstocks [87].”

“According to the global biofuel context, the overall demand for liquid biofuel in 2035 might range from 3280 to 4350 billion liters [79].”

“The efficiency and sustainability of biofuel production are being improved by recent advancements in precision agriculture, biotechnology, and sophisticated processing methods, making biofuels a more attractive and competitive substitute for traditional fossil fuels [123].”

“The goal of sustainable biofuel production is to maximize its potential as a low-carbon substitute for traditional fossil fuels while minimizing adverse impacts on the natural environment and society [95].”

“Jat et al. [9] estimate that with recent technology and continued consumption at current rates, the total amount of oil, natural gas, and coal that can be recovered globally is approximately 100 years, 30 years, and 18 years, respectively.”

“Bio-oil functions as a source for high-value chemical compounds, such as aromatic compounds, because of its rich content of compounds produced by the decomposition of cellulosic, hemicellulosic, or lignin biomass [29].”

“Drilling for oil has the potential to contaminate groundwater and surface water when poisons and oil leak into aquifers via holes and cracks in the rock [19].”

“The production of biofuel evolved globally between 2007 and 2017 at an annual rate of 11.4% [73].”

“Enhancing feedstock properties and streamlining production methods are two ways that biotechnology and genetic engineering can transform the production of biofuels [118].”

“According to Yildiz [5] traditional biomass, primarily firewood and charcoal, supplies energy to 40% of the global population and makes up 11.5% of the world's primary energy source.”

“Thus, the issue of how biofuels affect human health is still up for debate and needs more data and research [102].”

“The effects of biofuel on the energy water food (EWF) connexion globally were examined by Chong et al. [97].”

“The disparities become more pronounced at higher percentages of biofuel, but they are minor at 5-to 20% blends and would have no detectable effects on air quality [100].”

“It involves breaking down the biomass and converting the starch into sugars, which are then mixed with water and yeast in bioreactors called fermenters [34].”

“Additionally, it is capable of projecting the biotechnological process and economic indicators, calculating the contribution of key components to the cost of producing bioethanol, and contrasting several model scenarios for co-product processing [38]”

“These fuels are derived straight from food sources [41].”

“Global CO 2 , NO x , and SO 2 emissions were reduced by 38%, 13%, and 70% in 2012 as a result of the integration of renewable energies [12].”

“Utilizing cutting-edge catalytic processes and refining techniques, advanced biofuel products such as renewable diesel, bio-based jet fuels, and biobased chemicals are being developed to provide a more sustainable and ecological option to conventional petroleum-derived fuels [117].”

“Moreover, biotechnology can help build customized microbial strains that can generate valuable biofuels and bioproducts from different feedstocks, such as waste streams and lignocellulosic materials [121].”

“Due to the anticipated need for sustainable energy, biomass's contribution as a source of renewable energy supply attracted significant attention worldwide [11].”

“However, [101] contends that because biofuel exhaust has a larger percentage of ultra-fine particles (lower than 100 nm diameter) than fossil fuel exhaust, it may be more hazardous to human health even though its PM emissions are lower.”

“Additionally, mercury, a heavy element that is beginning to pose a severe health risk, is released by coal-fired power plants [8].”

“Commonly used fossil fuel derivatives include propane, kerosene, and gasoline [7].”

“Utilizing microalgae in the production of bioethanol can help address environmental issues in situations where the conventional feedstock used in bioethanol production is found to emit more greenhouse gases during the process of manufacture and application than fossil fuels [36].”

“In this case, the microorganisms' generated enzymes are crucial in dissolving the biomass structure biopolymers into liquid or gaseous biofuels, like hydrogen, ethanol, and biogas [61].”

“Utilizing cutting-edge biofuel production methods to recover energy from biomass has significant promise for enhancing global energy security and reducing trade deficits [53].”

“This process results in the development of feedstocks that are more resilient and energy-dense, making them ideal to produce biofuels [119].”

“In the early years of the twenty-first century, biobutanol which is made from plant materials like starch and lignocellulose became more significant as a sustainable biofuel, leading to an increase in its use in the transportation and aviation sectors [20].”

“In general, biofuel emits less PM, CO, hydrocarbons, and VOCs from exhaust than fossil fuel, but more NOx [99].”

“Globally, there is a rising trend in producing biofuels from various bioresources through the incorporation of innovative technology and biological methods [115].”

“The generation of bioethanol from waste sugar beetroot pulp is modeled by [37] to use it to assess novel technologies and goods that utilize lignocellulosic raw materials.”

“The biofuel sector can keep developing and help the world move towards a more ecologically friendly and sustainable energy system by utilizing cutting-edge technologies and adopting a multidisciplinary strategy [124].”

“In 1862, Louis Pasteur became the first scientist to publish about the microbial production of biobutanol [22].”

“The generation and consumption of biofuels are potentially carbon-neutral since they are derived from biomass, which utilizes the majority of CO 2 emitted into the environment [94].”

“Dalena et al., [90] published the same finding, demonstrating that raw maize flour may be used to produce ethanol fermentation through the use of starch-digesting microorganisms such as Rhizopus sp . and Saccharomyces cerevisiae .”

“Accordingly, utilizing fungal mycelia as an enzyme during fermentation of ethanol was the initial chemical energy source created by biofuel from maize and sugarcane [89].”

“The potential of algal biomass to produce bio-oil is quite promising because of its sustainable and clean nature [28].”

“Fossil fuels, including coal, oil, petrol, diesel, natural gas, and mineral fuels partially derived from biological sources like bitumen and tar sand, account for 84% of the global primary energy consumption [2].”

“However, terrestrial U(VI) reserves are limited, and their extraction not only poses environmental risks but is also susceptible to geopolitical disruptions [2–5].”