Search Results (11)

This research work presents a techno-economic assessment of biodiesel production with non-standard waste cooking oil (WCO) (brown grease of small restaurants, yellow grease of households) and semi-open Chlorella sp. microalgal cultivation, which covers the problematic areas of scale and cost-efficiency in sustainable biodiesel production. Cost-effective biodiesel feedstock research has been motivated by the urgency of finding sustainable sources of energy. With base-catalyzed transesterification optimized by ANOVA and response surface methodology (RSM), the present study recorded biodiesel yields of up to 99.08% in household WCO (at optimum conditions; 55 °C, 3.3 mg/g NaOH, ethanol) and 96.61% in restaurant WCO (at optimum conditions; 54 °C, 1.5 mg/g NaOH, methanol) compared to 28.6% in Chlorella sp. (semi-open photobioreactors). Concerning the two types of WCO feedstocks, the obtained equations are able to compute the biodiesel viscosity and yield, in good correlation with the experimental values, in relation to the temperature and ratio of catalyst to oil/alcohol solution. The assessed household WCO has better yield and quality as it contains fewer impurities, whereas the restaurant WCO needed to be further purified, driving up the prices. Although Chlorella biodiesel is carbon neutral, its production and extraction costs are higher, making it less economically feasible for biodiesel production. Economic analysis showed that the capital costs of household WCO, restaurant WCO, and Chlorella sp. are USD 190,000, USD 220,000, and USD 720,000, respectively, based on 1,000,000 L/year as biodiesel production rate. Low capital costs as well as byproduct glycerol income of the two investigated types of WCO play a role in their low payback periods (0.23–0.91 years) and high ROI (110–444.4%). The analysis highlights the economic and environmental benefits of WCO, especially household WCO, as a scalable biodiesel feedstock, which provides new insights into process optimization and sustainable biodiesel strategies. To enhance its sustainability and cost-effectiveness and contribute to the transition to renewable biofuels globally, future studies need to emphasize energy reduction in microalgae production and purification of restaurant WCO. Full article

The most viable way to decarbonize aviation in the near term is through Sustainable Aviation Fuel (SAF), most of which is currently produced via the deoxygenation of fats, oils, and greases (FOG) followed by a separate isomerization step. Multifunctional zeolite-supported catalysts offer several advantages over existing formulations, such as enabling the use of waste FOG streams, performing their deoxygenation via decarboxylation/decarbonylation (deCO_x), and effecting the synthesis of SAF in one-pot. Previous work has shown that while supported Ni-Cu catalysts can afford excellent results in the conversion of waste FOG to fuel-like hydrocarbons via deCO_x, zeolitic materials represent promising supports in formulations employed for the synthesis of SAF. In this contribution, catalysts involving different zeolitic supports and the same Ni-Cu active phase were prepared, characterized, and tested in the conversion of brown grease to SAF to identify the carrier affording the best results. A Ni-Cu/ZSM-5 catalyst displayed the highest conversion and yield of SAF-like hydrocarbons relative to formulations supported on ZSM-22, SAPO-11, or SAPO-34 (these catalysts being referred to herein as NCZSM-5, NCZSM-22, NCSAPO-11, and NCSAPO-34). Full article

Over 80 MT of elemental sulfur, a byproduct of fossil fuel desulfurization, are generated annually. This has spurred the development of high sulfur content materials (HSMs) via inverse vulcanization as a productive pathway towards sulfur utilization. In this study, we evaluate the antimicrobial performance of SunBG₉₀, an HSM made from brown grease and sulfur, as tiles or infused into fabric squares. The static antimicrobial activity of SunBG₉₀ tiles was assessed, revealing excellent efficacy against Gram-positive bacteria, with reductions of 96.84% for Staphylococcus aureus and 91.52% for Listeria monocytogenes. The tiles also exhibited strong antifungal activity, reducing Candida auris by 96.20% and mold (fumigatus) by 83.77%. In contrast, efficacy against Gram-negative bacteria was more variable, with moderate reductions for Escherichia coli (61.10%) and Salmonella enteritidis (62.15%), lower activity against Campylobacter jejuni and Salmonella typhi, and no effect on Clostridium perfringens. Under dynamic conditions, SunBG₉₀-infused fabrics achieved a near-complete inhibition of L. monocytogenes (99.91%) and high reduction of E. coli (98.49%), along with a 96.24% inhibition of Candida auris. These results highlight the potential and limitations of SunBG₉₀ for antimicrobial applications, emphasizing the need for further optimization to achieve consistent broad-spectrum activity. Full article

Poultry slaughterhouse wastewater (PSW) is laden with fats, oil, and grease (FOG), as well as proteins. As such, PSW promotes the proliferation of filamentous organisms, which cause foam formation. In this study, the production of biological defoamers (biodefoamers) uses a consortium with antagonistic properties, i.e., 1.39 L of wastewater/mL defoamers, as reported in our previous study, toward foam formers and their application in the treatment of PSW using a bench-scale activated sludge (AS)-supported treatment system consisting of an aeration and clarification tank. The foam produced was slimy, brown, and thick, suggesting the presence of Nocardia, Microthrix, and Type 1863 species in the PSW/AS wastewater treatment system. The bio (Bio-AS) and synthetic-defoamers (Syn-AS, positive control) supplementation, i.e., at 4% v/v in the PSW/AS primary treatment stage (aeration tank) operated over ten days, resulted in 94% and 98% FOG and protein removal for the biodefoamers, respectively, when compared to 50% and 92% for a synthetic defoamer, respectively. Similarly, the Bio-AS treatment achieved 85.4% COD removal, while a lowly 51% was observed for the Syn-AS PSW treatment regime. Overall, the biodefoamers performed vehemently compared to synthetic defoamers, improving the PSW/AS system’s performance. It was prudent to hypothesize that the biodefoamers might have had FOG solubilization attributes, an assertion that needs further research in future studies. It was concluded that Bio-AS was more efficient in the removal of FOG, proteins, TSS, and COD in comparison to Syn-AS and negative control without supplementation (CAS). Full article

Ordinary Portland Cement (OPC) production consumes tremendous amounts of fresh water and energy and releases vast quantities of CO₂ into the atmosphere. Not only would an alternative to OPC whose production requires no water, releases little CO₂, and consumes less energy represent a transformative advance in the pursuit of industrial decarbonization, but the greater availability of safe drinking water would lead to significantly improved public health, particularly among vulnerable populations most at risk from contaminated water supply. For any OPC alternative to be adopted on any meaningful scale, however, its structural capabilities must meet or exceed those of OPC. An inverse vulcanization of brown grease, sunflower oil, and elemental sulfur (5:5:90 weight ratio) was successfully modified to afford the high-sulfur-content material SunBG₉₀ in quantities > 1 kg, as was necessary for standardized ASTM and ISO testing. Water absorption (ASTM C140) and thermal conductivity (ISO 8302) values for SunBG₉₀ (<1 wt% and 0.126 W·m⁻¹·K⁻¹, respectively) were 84% and 94% lower than those for OPC, respectively, suggesting that SunBG₉₀ would be more resistant against freeze-thaw and thermal stress damage than OPC. Consequently, not only does SunBG₉₀ represent a more environmentally friendly material than OPC, but its superior thermomechanical properties suggest that it could be a more environmentally robust material on its own merits, particularly for outdoor structural applications involving significant exposure to water and seasonal or day/night temperature swings. Full article

An increase in energy consumption and the extended use of nonrenewable fossil fuels raises the need to develop alternative fuels as an energy supply that can protect the environment from unwanted emissions of pollutants. One alternative renewable fuel is biodiesel. Currently, most biodiesel feed sources are edible oils, but using them leads to the dilution of global food sources. The present study aims to find an effective method of biodiesel production using food industry fatty wastes called brown grease (BG). BG contains fats, mainly linoleic and oleic free fatty acids (FFAs), that can serve as raw materials for biodiesel production using esterification reactions. The esterification and transesterification reactions for biodiesel production were studied using commercial FFAs, commercial glyceryl trilinoleate (trilinolein), soybean oil, and BG. The reactions were carried out under ultrasonic activation using BF₃ and AlCl₃ Lewis acids as catalysts in both free and immobilized forms when immobilization was performed in silica matrices using the sol-gel synthesis route. Biodiesel production was examined in batch and continuous flow reactors. The BF₃ catalyst was more efficient at the initial stages of the continuous operation, reaching a maximum conversion of 90%, with a gradual decrease in efficiency after 15 h of the process. The AlCl₃ catalyst showed better stability, reaching maximum yields of 97% and maintaining efficiency until the end of the experiment. The proposed method offers an efficient and easy way to produce biodiesel from a variety of lipids sources, including fatty wastes (BG). Full article

The effect of three kinds of fuels used to supply a diesel engine on its characteristics, fuel consumption, and emissions was studied. The fuels comprised pure diesel, a blend of diesel with 6% of methyl ester of yellow grease in the form of rapeseed oil, and a blend of diesel with methyl ester of brown grease in the form of goose fat. The chromatographic analysis was conducted for these fuels, and the results are presented. Two tests, comprising measurement of fuel consumption and engine emissions, were conducted on a vehicle with a diesel engine operating under zero load and under full load. The engine’s characteristics, including both power and torque versus speed, were determined under full engine load. The results of these tests are presented in this paper. The results indicated that the use of different methyl ester-based biodiesel blends with the same content of diesel to supply the diesel engine resulted in different fuel consumption and emissions of the engine not only in comparison to the supply of pure diesel but between biodiesels analyzed. Full article

Among the renewable energy sources is biodiesel. This fuel is usually produced by catalytic transesterification of vegetable oils and animal fats under heating and pressure. Brown grease is a mixture of oils, fats, solids and detergents from food industry wastes that is captured in grease traps. Brown grease is classified as waste and must be treated and disposed of appropriately. It contains oils and fats that can be converted into biodiesel. However, the high concentration of free fatty acids in brown grease does not enable the use of conventional biodiesel production schemes. This study proposes a new scheme for biodiesel production from brown grease. In addition, conditions for the effective separation of a fat phase from brown grease were tested, and the composition of a fatty phase was determined for several grease traps. Esterification and transesterification of brown grease lipids were carried out with methanol, where the Lewis acids BF₃ and AlCl₃ were used as catalysts and the reaction was activated by ultrasound. The results show that biodiesel can be obtained from brown grease by esterification and transesterification within several minutes under ultrasonic activation at room temperature. These results open prospects for the development of efficient, low-cost and environmentally friendly biodiesel production. Full article

Empty fruit bunches (EFB) are waste products in the palm oil industry. Upon pressing of EFB, a liquor is produced which contains low grade fats, oils, and greases (FOG). These are the least valuable products of palm oil production, and are often discarded as waste. It is shown here that the EFB pressed liquor can be thermally transformed at or below 350 °C to produce a series of hydrocarbons in the range of kerosene and diesel fuel. This is distinctly different from other studies of biofuels from palm oil, which were based entirely on biodiesel (fatty acid methyl ester (FAME)) and biogas production. Furthermore, this transformation takes place without addition of an external catalyst, as was shown by comparison to reactions with the potential Lewis acid catalysts, ferric sulfate, and molecular sieves. The product distribution is similar to that obtained from brown grease, another waste FOG stream obtained from the sewage treatment industry, although the products from palm oil waste are less sensitive to reaction conditions. Full article

While commercial hydrodeoxygenation (HDO) processes convert fats, oils, and grease (FOG) to fuel-like hydrocarbons, alternative processes based on decarboxylation/decarbonylation (deCO_x) continue to attract interest. In this contribution, the activity of 20% Ni-5% Cu/Al₂O₃ in the deCO_x of waste free fatty acid (FFA)-based feeds—including brown grease (BG) and an FFA feed obtained by steam stripping a biodiesel feedstock—was investigated, along with the structure-activity relationships responsible for Ni promotion by Cu and the structural evolution of catalysts during use and regeneration. In eight-hour experiments, near quantitative conversion of the aforementioned feeds to diesel-like hydrocarbons was achieved. Moreover, yields of diesel-like hydrocarbons in excess of 80% were obtained at all reaction times during a BG upgrading experiment lasting 100 h, after which the catalyst was successfully regenerated in situ and found to display improved performance during a second 100 h cycle. Insights into this improved performance were obtained through characterization of the fresh and spent catalyst, which indicated that metal particle sintering, alloying of Ni with Cu, and particle enrichment with Cu occur during reaction and/or catalyst regeneration. Full article

Cassava processing produces by-products such as brown bark, between bark, disposal, bran, fiber and bagasse. Cassava bagasse is characterized as a source of starch that can be converted into sugars to obtain biofuels. The objective of this work was to produce ethanol from this cassava processing residue and to evaluate its contribution potential in the Brazilian energy matrix. Cassava processing residues were obtained from four different starch manufacturers in Brazil. Analysis of the chemical compositions of these samples provided the content of starch, sugar, crude grease, moisture, ash and also their pH values. For the ethanol process, the samples were submitted to enzymatic hydrolysis using the alpha-amylase and amyloglucosidases enzymes, followed by fermentation and distillation. The samples showed high starch indices, approximately 64% on average. The average yield of ethanol obtained was 30% after treatment of the sample like this. Considering the estimated volume of cassava bagasse in Brazil, it is possible to produce an average of 789 million cubic meters per bagasse, replacing about 24% of the first generation ethanol. Cassava bagasse can be considered an interesting biomass for the production of biofuels, contributing to the expansion of the energy matrix. Full article