Liquid Biofuels Research Articles

Pyrolysis pretreatment and low-temperature liquefaction: Developing rice straw biochar-based clean liquid biofuel

To overcome the challenges of high oxygen content and low energy density in converting biomass into liquid biofuels, this study proposes an efficient and eco-friendly method: first pyrolyzing rice straw biomass, then converting it into liquid biofuel. It was found that: (1) Characterizing the elemental composition, higher heating value (HHV), thermogravimetric properties, and functional groups of rice straw-biochar-liquid fuel (RS-C-LF), along with analyzing the mass and energy balance of the liquefaction process, revealed that 150 °C was the optimal low liquefaction temperature. (2) The HHV, O and S content, mass and energy yield of RS-C-LF150 were significantly enhanced compared to direct biomass-to-liquids and met the biodiesel standard, with values of 42.16 MJ/kg, 0.82 %, 0 %, 67.49 %, and 69.42 %, respectively. (3) The feasibility and commercial potential of this research was further demonstrated through economic and SWOT analysis of this study liquid biofuel (the total production expenditure is only $171.29/bbl), and the design of the zero-waste and self-circulating preparation system.

Estimation of kinetic and thermodynamic parameters during thermal decomposition of raw, boiled, and torrefied banana peel through arrhenius and CR methods

The objective of the present manuscript was to investigate the bioenergy generation potential of banana peel as solid or liquid biofuel, by examining physicochemical, kinetic, as well as thermodynamic parameters. Raw banana peel, boiled banana peel, and torrefied banana peel were subjected to a thermal decomposition environment. BBP was prepared by boiling RBP in a hot plate at 120 °C using 600 rpm, for 150 min. Besides, RBP was torrefied at 225 °C (nitrogen atmosphere), at 15 °C/min and a residence time of 30 min, to prepare TBP. Pyrolysis of all three materials was carried out at 10 and 15 °C /min using thermogravimetric analysis. The kinetic and thermodynamic parameters were evaluated using Arrhenius and CR methods. The overall activation energy at 15 °C/min was 107.04, 106.88 and 74.85 kJ/mol, for RBP, BBP, and TBP, respectively.

Evaluation of the Energy Potential of Agro-industrial Waste from Mangifera indica L. in Zamora, Mexico: Perspectives for the Management of Solid and Liquid Biofuels

Evaluation of the Energy Potential of Agro-industrial Waste from Mangifera indica L. in Zamora, Mexico: Perspectives for the Management of Solid and Liquid Biofuels

Lignosulfonate-Based Carbon-Supported Pellets Catalyst to Enhance Sustainable Biofuel Production from Waste Cooking Oil.

In this study, a cost-effective and stable heterogeneous acidic carbocatalyst (CZnLS950) derived from Na-lignosulfonate (LS), a side product of the paper industry, was employed to produce hydrocarbon fuels through the pyrolysis of waste cooking oil (WCO) and crude natural-oil extracted from sunflower seeds, aligning with the principles of the circular economy. To enhance its practicality in industrial settings, the catalyst was synthesized in pellet form, enabling easy separation from the biofuel produced during the reaction. CZnLS950 exhibited remarkable catalytic efficiency in the pyrolysis of WCO, resulting in a 71 wt. % liquid biofuel yield under mild conditions. This performance is attributed to the unique synthesis procedure of acidic carbocatalyst, which utilizes LS and nano ZnO (20 nm) to create a hierarchical pore structure with acidic properties (1.1 mmol of NH3 g-1). Stability and reusability of the carbocatalyst were evaluated, and the results showed excellent stability with small catalytic deactivation (~5 wt. %) after the fourth use. Attempts at distinct catalytic mechanisms for WCO and sunflower seeds crude natural-oil pyrolysis were provided to understand the processes involved in obtaining the two different biofuels produced. Overall, this study sets the stage for exploring Lignosulfonate-based materials to achieve renewable biofuel from recycling streams.

Biofuel production from macrophytes

The depletion of natural resources and minerals is leading to slower economic growth in many countries. Sustainable economic development requires rational resource management and waste reduction, as disposal or incineration pollutes fertile soils, the atmosphere, and water bodies. This study aimed to develop methods for obtaining the technology of liquid biofuel (bio-oil) production by hydrothermal revitalization of the biomass of macroalgae and aquatic macrophytes. The thermal properties and caloric content of aquatic plant biomass, specifically Phragmites australis, Scirpus lacustris, Typha angustifolia L., and Sparganium erectum L., were investigated, and the optimal parameters for hydrothermal revitalization of their biomass were identified. The biomass of P. australis and S. lacustris was shown to have optimal thermal properties, having an ash content of 7.6% and 6.6%, respectively, and a maximum mass loss temperature of 351 °C and 345 °C, respectively. The production regimes for liquid biofuel (bio-oil) were established. The properties of fuel derived from P. australis biomass were evaluated, including the content of easily boiling fractions and coke residue. The magnitude of fuel yield from biomass P. australis was found to be correlated with the quality of bio-oil. Thus, obtaining biofuels from aquatic plants is one of the promising areas of plant biomass processing.

Ultrasound Assisted Pre-treatments for the Efficient And Sustainable Conversion of Biomass Into Biofuels

The growing focus on sustainable and efficient biomass-to-biofuels conversion, driven by environmentalconcerns and the demand for eco-friendly processes has become a key area of research. Biomass, a vitalrenewable energy source, harbors the potential for direct transformation into liquid biofuels such as ethanoland biodiesel, signifying a noteworthy progression in biofuel technology. Persistent challenges, includingsuboptimal biofuel yields and heightened production costs arise from incomplete cellulose digestion shieldedby lignin. In response, various pretreatment methods have been investigated to augment cellulose andhemicellulose accessibility by disrupting lignin cross-links. Among these strategies, ultrasonic irradiation orsonication emerges as a promising eco-friendly pretreatment for the efficient conversion of lignocellulosicbiomass into biofuels.This article explores the prerequisites of effective pretreatments, highlighting the significance of dualapplication, minimal energy consumption, the use of economically viable chemicals, and consideration ofmoderate temperatures and pressures. By delving into the mechanism of ultrasound irradiation, the studyelucidates how ultrasound waves generate cavitation bubbles, initiating both physical and chemicaltransformations in biomass. In-depth discussions encompass factors influencing sonication, includingduration, frequency, power, temperature, liquid medium, and suspended solids. Critical considerations foroptimizing pretreatment efficiency are outlined in the design aspects of sonochemical reactors, coveringreactor configuration, ultrasonic frequency, power dissipation, duration, and temperature. The articleconcludes by underscoring the evolving potential of ultrasound-assisted pretreatments in biofuel productionand encourages further detailed advancements and comprehensive studies to actualize their full-scaleindustrial applications.

Selective hydrogenation of 5-hydroxymethylfurfural triggered bya high Lewis acidic Ni-based transition metal carbide catalyst

The high-efficiency conversion of biomass resources to biofuels has attracted widespread attention, and the active sites and synergistic effect of catalysts significantly impact their surface arrangement and electronic structure. Here, a nickel-based transition metal carbide catalyst (Ni/TMC) with high Lewis acidity was prepared by self-assembly of transition metal carbide (TMC) and nickel, which exhibited excellent performance on synergistic hydrogenation and hydrogenolysis of 5-hydroxymethylfurfural (HMF) into liquid biofuel 2,5-dimethylfuran (DMF). Notably, Ni/WC with the highest Lewis acidity (4728.3 μmol/g) can achieve 100% conversion of HMF to 97.6% yield of DMF, with a turn-over frequency of up to 46.5 h−1. The characterization results demonstrate that the rich Lewis acid sites yielded by the synergistic effect between Ni species and TMC are beneficial for the CO hydrogenation and C–O cleavage, thereby accelerating the process of hydrodeoxygenation (HDO). Besides, a kinetic model for the HDO of HMF to DMF process has been established based on the experimental results, which elucidated a significant correlation between the measured and the predicted data (R2 > 0.97). Corresponding to the adsorption configuration of Ni/WC and substrate determined by in-situ FTIR characterization, this study provides a novel insight into the selective conversion of HMF process for functional biofuel and bio-chemicals.

Determination of Some Physicochemical Properties of Binary Biodiesel and Binary Biodiesel-Diesel Blend Fuels Obtained from Waste Pumpkin Seed- Camelina Oils

The primary aim of utilizing biodiesel is to reduce dependency on fossil fuels, decrease harmful emissions, and promote the use of renewable energy sources. Studies on biodiesel commonly revolve around singular biodiesel-petroleum diesel blends. Binary biodiesel is generally obtained by mixing different types of biodiesel or blending these mixtures with petroleum diesel. The combination of these diverse feedstocks with distinct properties can offer varying characteristics and benefits. Many studies regarding liquid biofuels primarily focus on blends of singular biodiesel with diesel. Raw materials constitute a substantial portion of the cost in biodiesel production. Hence, efforts have been made to favor non-edible and waste products as raw materials. Additionally, products that are suitable for cultivation in Turkey and easy to obtain as raw materials, supporting domestic biofuel production, have been chosen. Biodiesels obtained from waste pumpkin seeds and linseed oils through the transesterification method were blended at volumetric ratios of 1:1 and 1:3 to obtain binary biodiesel fuels (C50P50, C25P75, and C75P25). The binary biodiesel-diesel blend fuels were achieved by blending different volume ratios of binary biodiesel fuels (C25P25D50 and C10P10D80) with traditional petroleum diesel after their preparation. Subsequent analyses focused on determining the physicochemical properties (density, kinematic viscosity, flash point, water content, calorific value, cold filter plugging point, and copper strip corrosion) of the prepared binary biodiesel and binary biodiesel-diesel blend fuels. Compliance with biodiesel standards (EN 14214, ASTM D-6751) was observed for all fuels, and the results were compared with the reference fuel, diesel (petroleum). According to the analysis results, all the tested fuels met the standards, with the C10P10D80 blend fuel displaying the closest resemblance to diesel.

Comparative study of a two-step enzymatic process and conventional chemical methods for biodiesel production: Economic and environmental perspectives

The urgent need to address greenhouse gas (GHG) emissions underscores the significance of biodiesel as a key liquid biofuel. Compared to chemical biodiesel production, enzymatic technology offers a more sustainable alternative. This article presents a comparative study between a two-step enzymatic biodiesel production technology, already successfully industrialized, and conventional chemical technologies utilizing soybean oil (SBO) and waste cooking oil (WCO) as feedstock, respectively. The economic analysis demonstrates significant cost savings with the enzymatic process resulting in reductions of 16.33% and 36.54% for SBO and WCO, respectively. Enzymatic technology also exhibits substantial reductions in energy consumption, with a decrease of 86.8% and 60.2% for SBO and WCO, respectively. LCA findings indicate that enzymatic technology diminishes environmental impacts and GHG emissions are less than 78.86% and 63.05% for SBO and WCO, respectively. This study provides crucial insights for decision-makers, marking a significant paradigm shift in biodiesel production.

Possibilities of Utilising Biomass Collected from Road Verges to Produce Biogas and Biodiesel

Grass collected as part of roadside maintenance is conventionally subjected to composting, which has the disadvantage of generating significant CO2 emissions. Thus, it is crucial to find an alternative method for the utilisation of grass waste. The aim of this study was to determine the specific biogas yield (SBY) from the anaerobic mono-digestion of grass from road verges and to assess the content of Fatty Acid Methyl Esters (FAMEs) in grass in relation to the time of cutting and the preservation method of the studied material. The biochemical biogas potential (BBP) test and the FAMEs content were performed on fresh and ensiled grass collected in spring, summer, and autumn. The highest biogas production was obtained from fresh grass cut in spring (715.05 ± 26.43 NL kgVS−1), while the minimum SBY was observed for fresh grass cut in summer (540.19 ± 24.32 NL kgVS−1). The methane (CH4) content in the biogas ranged between 55.0 ± 2.0% and 60.0 ± 1.0%. The contents of ammonia (NH3) and hydrogen sulphide (H2S) in biogas remained below the threshold values for these inhibitors. The highest level of total FAMEs was determined in fresh grass cut in autumn (98.08 ± 19.25 mg gDM−1), while the lowest level was detected in fresh grass cut in spring (56.37 ± 7.03 mg gDM−1). C16:0 and C18:0, which are ideal for biofuel production, were present in the largest amount (66.87 ± 15.56 mg gDM−1) in fresh grass cut in autumn. The ensiling process significantly impacted the content of total FAMEs in spring grass, leading to a reduction in total saturated fatty acids (SFAs) and an increase in total unsaturated fatty acids (USFAs). We conclude that grass biomass collected during the maintenance of road verges is a valuable feedstock for the production of both liquid and gaseous biofuels; however, generating energy from biogas appears to be more efficient than producing biodiesel.

Kinetic Modelling of Biomass Pyrolysis Processes

Pyrolytic conversion is the only biomass exploitation route capable of providing solid and liquid biofuels, as well as platform biomolecules for sustainable energy sources and raw materials for bio-based products [...]

Enhancing Biodiesel Production: A Review of Microchannel Reactor Technologies

The depletion of fossil fuels, along with the environmental damages brought by their usage, calls for the development of a clean, sustainable and renewable source of energy. Biofuel, predominantly liquid biofuel such as biodiesel, is a promising alternative to fossil fuels, due to its compatible direct usage within the context of compression ignition engines. However, the industrial production of biodiesel is far from being energy and time efficient, which contributes to its high production cost. These inefficiencies are attributed to poor heat and mass transfer of the transesterification reaction. The utilisation of microchannel reactors is found to be excellent in escalating heat and mass transfer of the reactants, benefitting from their high surface area-to-volume ratio. The microchannel also intensifies the mixing of reactants via the reactor design, micromixers and the slug flow patterns within the reactor, thus enhancing the contact between reactants. Simulation studies have aided in the identification of mixing regimes within the microchannel reactors, induced by various reactor designs. In addition, microwave irradiation heating is found to enhance biodiesel production by localised superheating delivered directly to the reactants at a molecular level. This enables the reaction to begin much earlier, resulting in rapid biodiesel production. It is postulated that the synergy between microchannel reactors and microwave heating would catapult a pathway towards rapid and energy-efficient biodiesel production by enhancing heat and mass transfer between reactants.

Determination of some fuel properties of binary biodiesel and binary biodiesel – diesel blend fuels obtained from camelina oil and waste frying oils

In today's studies on liquid biofuels, it is observed that many of them focus on blends of single biodiesel with diesel. These studies have shown that biodiesel produced from different feedstocks exhibits similar properties to traditional diesel fuel in terms of fuel characteristics and engine performance, indicating the potential of biodiesel to replace diesel fuel. However, recent research has shown limited studies involving the blending of dual biodiesel with traditional diesel fuel.
 In this study, high oil content camelina plant, which has an important place in ensuring sustainability in human food production, in other words, it is not suitable for human food and has the potential to significantly increase our domestic biofuel production, and domestic waste frying oil, which significantly reduces the cost of biodiesel raw material production, were selected as biodiesel feedstock. Binary biodiesel fuels (D0C50WF50, D0C75WF25, and D0C25WF75) were obtained by mixing the biodiesel fuels produced from camelina and domestic waste frying oil by transesterification method in the ratio of 1:1 and 1:3 by volume. Binary biodiesel-diesel blend fuels were obtained by blending binary biodiesel fuels (D75C12.5WF12.5, D50C25WF25 and D25C37.5WF37.5) with conventional diesel fuel (diesel) after blending at 1:1 ratio by volume. As a result of the research, the physicochemical properties (density, kinematic viscosity, flash point, water content, calorific value, cold filter plugging point, cloud and pour point, copper strip corrosion) of the prepared binary biodiesel and binary biodiesel+diesel blend fuels were determined. The results of the analyses of the blend fuels were determined in accordance with the relevant biodiesel standards (EN 14214, ASTM D-6751) and the results were also compared with the reference fuel, diesel fuel.

Physicochemical exploration of castor seed oil for high-quality biodiesel production and its sustainable application in agricultural diesel engines

In Thailand, castor seeds often classified as weeds are locally distributed in every region of the country and not fully utilized. Therefore, this research aimed to study the physicochemical properties of castor seed oil as a raw material for the production of liquid biofuels. The study of extracting oil from castor seeds using various methods revealed that the Soxhlet extraction technique, a circulatory extraction method, yielded the highest amount of extracted oil at 52.45 wt%, compared to the dry weight of the castor seed. In the study of the physicochemical properties of castor seed oil, the results revealed that the major components were 89.71% ricinoleic acid, 3.96% linoleic acid, and 3.09% oleic acid, respectively. The kinematic viscosity of castor seed oil was as high as 164.68 cSt. However, when converted into castor seed oil biodiesel, the kinematic viscosity decreased to 10.36 cSt, still two times higher than that of the standard biodiesel oil. Therefore, blending castor seed oil biodiesel with petroleum diesel oil to obtain B30 and B40 revealed that the fuel properties met the qualifications of both ASTM D6751 and EN 14214 standards. The initial tests on agricultural diesel engines found that the gas emissions of CO2, CO, HC, and NO2 from biodiesel blends B30 and B40 tend to be lower than those from using only petroleum diesel oil and biodiesel oil derived from castor seeds. Therefore, blending biodiesel oils B30 and B40, derived from castor seed oil, not only results in good biofuel liquid qualities but also proves to be efficient for use in agricultural diesel engines. It is suitable to encourage the community to adopt it for agricultural purposes in the future.

Lipidomic analysis of microalgae and its application in microalgae cultivation and alternative liquid biofuel production

Lipidomic analysis of microalgae and its application in microalgae cultivation and alternative liquid biofuel production

Multi-objective optimization of syngas production for Fischer-Tropsch synthesis based on biogas catalytic reforming and upgrading

The conversion of biogas into synthesis gas, for its subsequent application in Fischer-Tropsch synthesis, is one of the most studied processes for the production of liquid biofuels. However, this conversion still has economic and environmental disadvantages. This study evaluated the technical feasibility of a syngas production plant from biogas upgrading and reforming, through water scrubbing and bi-reforming processes. Aspen Plus modeling and a multi-objective optimization (MOO) were used to minimize CO2 emissions and maximize profitability. The multi-objective differential evolution with tabu list method was used to resolve the MOO design problem. The results reveal inherent trade-offs between both objectives. In particular, certain process parameters exerted a notable influence on the outcomes. Keeping a low water flow in the absorption column is essential to reduce environmental impact, but this also results in a lesser removal of impurities from biogas. Conversely, a higher water flow in the reactor promotes methane conversion, but concurrently raises the environmental impact. Nevertheless, the profitability of the Pareto front ranged from 5,200 to 6,500 k$ with a 1,000 Nm³/h biogas feed and the calculated CO2 equivalent net flow values varied between -11,900 and -11,550 kg/h. Therefore, it was successfully validated that calculated solutions of the Pareto allowed to demonstrate the feasibility of the proposed process.

Production of Renewable Hydrocarbon Biofuels with Lignocellulose and Its Derivatives over Heterogeneous Catalysts.

In recent years, the issues of global warming and CO2 emission reduction have garnered increasing global attention. In the 21st Conference of the Parties (convened in Paris in 2015), 179 nations and the European Union signed a pivotal agreement to limit the global temperature increase of this century to well below 2 K above preindustrial levels. To fulfill this objective, extensive research has been conducted to use renewable energy sources as potential replacements for traditional fossil fuels. Among them, the production of hydrocarbon transportation fuels from CO2-neutral and renewable biomass has proven to be a particularly promising solution due to its compatibility with existing infrastructure. This review systematically summarizes research progress in the synthesis of liquid hydrocarbon biofuels from lignocellulose during the past two decades. Based on the chemical structure (including n-paraffins, iso-paraffins, aromatics, and cycloalkanes) of hydrocarbon transportation fuels, the synthesis pathways of these biofuels are discussed in four separate sections. Furthermore, this review proposes three guiding principles for the design of practical hydrocarbon biofuels, providing insights into future directions for the development of viable biomass-derived liquid fuels.

Radiating biofuel-blended turbulent nonpremixed hydrogen flames on a coaxial spray burner

The low radiant intensity and luminosity of hydrogen flames can be enhanced by the addition of a small portion of sooting biofuels. To achieve higher effectiveness, the impact of blending turbulent nonpremixed hydrogen flames with liquid biofuels, by gas-assist atomisation, is investigated and compared with the introduction methods of prevapourisation and ultrasonic spray. The flame appearance, luminosity, radiant fraction, centreline temperature, and the near-field spray characteristics of four biofuel surrogates (eucalyptol, D-limonene, guaiacol, and anisole) blended into hydrogen flames are measured experimentally. Radiating biofuel/hydrogen flames are achieved on a coaxial needle spray burner by the addition of 0.1–0.3 mol% biofuel surrogates. Compared with the unblended hydrogen flame, the luminosity and radiant fraction are enhanced by 30%–500% and 2%–15%, respectively, with the addition of biofuel surrogates. The results show that adding the biofuel surrogates by gas-assist atomisation is more effective than prevapourisation and ultrasonic atomisation in luminosity and radiant fraction enhancement. It is found that the local fuel-rich conditions, which are beneficial for soot formation, are further facilitated by the larger droplets and spray objects generated by gas-assist atomisation. Of the additives tested, anisole is the most effective for luminosity and radiant fraction enhancement of a hydrogen flame while exhibiting the largest flame temperature drop due to the enthalpy of vapourisation and the radiative loss from the promoted soot formation. The viscosity and surface tension greatly influence the spray characteristics which in turn impacts the flame characteristics. Guaiacol, the representative of lignin, appears to have the lowest effectiveness in radiant fraction enhancement due to the presence of a hydroxy group, a higher bond dissociation enthalpy, and a coarser spray ascribed to higher viscosity and surface tension.

Proteinaceous Microsphere-Based Water-in-Oil Pickering Emulsions for Preservation of Chlorella Cells.

Microalgae are highly regarded as ideal materials for the creation of liquid biofuels and have substantial potential for growth and utilization. However, traditional storage and culture methods for microalgae are plagued by challenges such as uncontrolled growth, bacterial contamination, and self-shading among algae. These issues severely impede the photosynthetic process and the efficient extraction of biomass energy. This study tackles these problems by utilizing magnetic hydrophobic protein particles to stabilize water-in-oil Pickering emulsions. This allows for the micro-compartment storage and magnetic transfer of algae. Additionally, the successful encapsulation of Chlorella cells in high-internal-phase water-in-oil Pickering emulsions effectively mitigates the settling problem of Chlorella cells in the liquid phase, thereby enabling the potential use of Pickering emulsions for the confined cultivation of microalgae.

Detailed speciation of biomass pyrolysis products with a novel TGA-based methodology: the case-study of cellulose

Pyrolysis of waste biomass represents a key route for the circular economy and a promising solution for the generation of valuable chemicals and liquid biofuels. The complex multi-component and multi-phase nature of the process, however, poses a challenge in acquiring comprehensive experimental data on biomass devolatilization. These data are essential for refining kinetic schemes and optimizing technology. This work presents a novel experimental methodology suitable for the collection of kinetically relevant data on biomass devolatilization combined with a complete characterization of the product slate. This methodology consists of a thermogravimetric analyser employed to carry out pyrolysis experiments, useful for the accurate monitoring of mass loss dependencies at varying heating rate, for the control of reaction temperatures and for the suppression of secondary gas-phase reactions as well as of transfer limitations. Multiple analytical methodologies and sampling protocols were combined for product speciation – downstream online MS for gases and H2O, sorbing traps for integral offline GC–FID/MS measurement of heavy oxygenates, point vapour collection for instant GC–FID/MS analysis of light oxygenates – and allowed to independently determine the integral mass yield of each pyrolysis product, closing mass balances with very high accuracy. Experiments of cellulose pyrolysis at varying heating rate were carried out to tune and validate the methodology. Speciation protocols allowed to identify and individually quantify 31 species among pyrolysis products, including gases, condensable oxygenates, H2O and char. The comparison of experimental findings with predictions from a state-of-art lumped model has highlighted the significance of the present methodology in unravelling the kinetics governing both devolatilization and product distribution.