Biofuel Yield Research Articles

The potential for bioenergy generated on marginal land to offset agricultural greenhouse gas emissions in China

Rational use of marginal land for cultivation of bioenergy crops is an effective means to solve land use competition and is an important way to reduce greenhouse gas (GHG) emissions and improve energy supply. This study conducted an evaluation of the suitability of marginal land for growing energy crops in China during 1990–2020 using the GIS and multi-factor analysis method and revealed the quantitative relationship between bioenergy produced by marginal land energy crops and carbon reduction potential. The Intergovernmental Panel on Climate Change (IPCC) coefficient method and life cycle method were applied to measure the biofuel yield of the Jatropha curcas and assessed its potential to offset agricultural greenhouse gas emissions. The findings are: (1) The marginal land area available for energy crops in 2020 is 1.63 × 106 km2, which is 8.35 % lower than the area planted in 1990. (2) When the reclamation index is 60 %, all suitable marginal land can be used to grow energy crops, and biofuels can replace 3.31 × 1011 tons of conventional energy. (3) In 2020, agricultural greenhouse gas emissions will be 9.02 × 108 tons, and the potential of bioenergy crop cultivation to offset agricultural greenhouse gas emissions amounts to 4.31 × 108 tons, or 47.88 %. In the future, the pressure of agricultural GHG emission reduction will be further exacerbated by population growth and agricultural land supply, etc. Rational use of marginal land and development of bioenergy crops are effective ways for China to cope with climate change and realize its renewable energy strategy.

A Review on Potential Biofuel Yields from Cover Crops

Millions of hectares of cover crops are planted in the U.S. and European Union to manage soil erosion, soil fertility, water quality, weeds, and climate change. Although only a small percentage of cover crops are harvested, the growing cover crop planting area provides a new biomass source to the biofuel industry to produce bioenergy. Oilseed crops such as rapeseed, sunflower, and soybean are commodities and have been used to produce biodiesel and sustainable aviation fuel (SAF). Other cover crops such as cereal rye, clover, and alfalfa, have been tested on small or pilot scales to produce cellulosic ethanol, biogas, syngas, bio-oil, and SAF. Given the various biofuel products and pathways, this review aimed to provide a comprehensive comparison of biofuel yield from different cover crops and an overview of the technologies that have been employed to improve biofuel yield. It was envisioned that gene-editing tools might be revolutionary to the biofuel industry, the work on cover crop supply chain will be critical for system scaleup, and high-tolerant technologies likely will be needed to handle the high compositional heterogeneity and variability of cover crop biomass for biofuel.

High-silica faujasite zeolite-tailored metal encapsulation for the low-temperature production of pentanoic biofuels

Zeolite-encapsulated metal nanoclusters are at the heart of bifunctional catalysts, which hold great potential for petrochemical conversion and the emerging sustainable biorefineries. Nevertheless, efficient encapsulation of metal nanoclusters into a high-silica zeolite Y in particular with good structural integrity still remains a significant challenge. Herein, we have constructed Ru nanoclusters (∼1 nm) encapsulated inside a high-silica zeolite Y (SY) with a SiO2/Al2O3 ratio (SAR) of 10 via a cooperative strategy for direct zeolite synthesis and a consecutive impregnation for metal encapsulation. Compared with the benchmark Ru/H-USY and other analogues, the as-prepared Ru/H-SY markedly boosts the yields of pentanoic biofuels and stability in the direct hydrodeoxygenation of biomass-derived levulinate even at a mild temperature of 180 °C, which are attributed to the notable stabilization of transition states by the enhanced acid accessibility and properly sized constraints of zeolite cavities owing to the good structural integrity.

Edible waste oil to biofuel using reclaimable g-C3N4/HAp/Fe3O4/K2CO3 nanobiocomposite catalyst: Toxicity evaluation and optimization

In the current work, the new heterogeneous nonobiocomposite of g-C3N4/HAp/Fe3O4/K2CO3 was made from chicken bone and melamine and used in biofuel generation from edible waste oil (EWO). FTIR, SEM, Map-EDX, BET, VSM, and XRD techniques confirmed that the catalyst was synthesized. The magnetic saturation number and the BET value of g-C3N4/HAp/Fe3O4/K2CO3 were determined to be 8.89 emu.g−1 and 3.95 m2.g−1, respectively. The impact of temperature, time, catalyst mass, and the ratio of methanol: Oil (MeOH: Oil) on biofuel production was explored using response surface method-central composite design. The maximum yield of biofuel from EWO (98.52 %) achieved at contact time of 150 min, temperature of 65 °C, catalyst amount of 3 wt%, and MeOH: Oil ratio of 15:1. Activation energy and k0 for the transesterification process were computed to be 58.91 kJ.mol−1 and 3.24 × 107 min−1, respectively. The values of ΔH and ΔG were determined positive for the biofuel production process, which indicates that the biofuel production process is exothermic and non-spontaneous. The value of the environmental factor (E) also showed that biofuel production has negligible harmful effects on the environment. The heterogeneous catalyst can be effectively reused many times in the transesterification process. The produced biofuel was in good compliance with famous standards and can serve as a suitable fuel source.

(Invited) Utilization of Bio-CO2 and Bio-Methane for Fuel Production: Integration Solid Oxide Electrolyzer, Low Energy Plasma Reformer with Fischer-Tropsch Synthesis

Transition to renewable energy is essential to achieve climate protection objectives. Besides storing electricity for later use, fuel production using renewable energy is an essential part of reducing fossil dependance. The highest value application in current markets is the production of liquid transportation fuels such as sustainable aviation fuels (SAF) from sustainable, ideally biogenic carbon resources. A system is presented for processing anaerobic digester gas for liquid hydrocarbon production. Bio-CO2 is processed through a solid oxide electrolysis cell and bio-CH4through a low energy plasma reformer. The combined synthesis gas is supplied to a Fischer-Tropsch reactor for the production of liquid hydrocarbons. The combination of technologies nearly doubles the yield of biofuel by utilizing the bio-CO2 in addition to the bio-CH4. The product fuel is all bio-carbon but it also embodies renewable electric energy in a high-value, storable and transportable liquid hydrocarbon.

Integrated hydropyrolysis and vapor-phase hydrodeoxygenation process with Pd/Al2O3 for production of advanced oxygen-containing biofuels from cellulosic wastes

This study focuses on developing advanced oxygen-containing biofuels with high furan, cyclic ketone, and ethanol content from holocellulose and cellulosic wastes. To achieve this, we employed an integrated process that combined hydropyrolysis and vapor-phase hydrodeoxygenation using Pd/Al2O3 as a catalyst. In the first stage, the non-catalytic hydropyrolysis of hemicellulose resulted in furfural and acetic acid fractions that were effectively converted into furans, cyclic ketones, and ethanol in the second-stage reactor over Pd/Al2O3 under 0.3 MPa H2. We found that a hydropyrolysis temperature of 440 °C in the first stage reactor resulted in the highest yield of oxygen-containing biofuels (171.1 mg/g) with 89.2% hemicellulose conversion. However, increasing the hydrodeoxygenation temperature in the second stage reactor reduced the yield of oxygen-containing biofuels, and at 400 °C, excess deoxygenation led to hydrocarbon production. The Pd/Al2O3 catalyst demonstrated high stability during the vapor-phase hydrodeoxygenation of primary furfural and acetic acid intermediates, with only 2.1% coke formation after three reaction cycles. This scalable process enables the conversion of various cellulosic wastes into advanced oxygen-containing biofuels, with considerable total yields. Our findings suggest that this integrated process holds great promise for converting biomass waste into advanced oxygen-containing biofuels.

Application of pharmaceutical waste as a heterogeneous catalyst for transesterification of waste cooking oil: biofuel production and its modeling using predictive tools

In this study, for the first time, pharmaceutical waste was used as a heterogeneous catalyst to produce biofuel from waste cooking oil (WCO). An efficient and low-cost heterogeneous catalyst was prepared from waste tablets of calcium carbonate (CaCO3) and magnesium oxide (MgO). A certain amount of alumina nanoparticles (Al2O3) was added to the pharmaceutical waste to participate in the transesterification of the WCO, which positively affected mass yield. The mentioned catalysts were identified by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), field-emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) analyses. According to the BET analysis, the specific surface of the catalysts increased. Also, the effects of various reaction parameters such as temperature, time, catalyst loading, and the oil: methanol ratio were investigated and optimized by response surface methodology (RSM). Furthermore, an adaptive neuro-fuzzy inference system (ANFIS) was coupled with a firefly optimization algorithm to predict biofuel yield. Under optimum conditions (Al2O3 0.952 wt%, catalyst 4.978wt%, oil:methanol ratio 0.5 vol:vol, reaction time 120 min, and reaction temperature 69.6 °C), the mass yield of MgO and CaO catalysts was 95.6 and 90.4 wt%, respectively. The composition of biofuel was identified using gas chromatography–mass spectrometry (GC-MS).

Valorization of food waste for biogas production; effect of co-ensiling with maize straw at different C/N ratios

Food waste (FW) contribute to emission of greenhouse gases as well as environmental pollution. One way of reducing the impact of FW on the environment is by using it for biofuel production. The yield of biofuel from FW can be improved if the substrate is pretreated. In this study, ensiling was used as a cost effective method of pretreating FW for biomethane production. Co-ensiling of FW and maize straw (MS) was carried out at carbon to nitrogen ratios (C/N) of 20, 25, 30 and 35 for 210 days at ambient temperature. Thereafter, the biomethane potential (BMP) of the silages was determined using an automatic biomethane potential test system. Results showed that ensiling reduced both structural and non-structural carbohydrate components of the silages. BMPs of 385.58, 497.39, 520.53, 551.37, 542.16 and 517.29mL/gVS from the unensiled FW, ensiled FW without MS, co-ensiled FW at C/N ratio of 20, co-ensiled FW at C/N ratio of 25, co-ensiled FW at C/N ratio of 30 and co-ensiled FW at C/N ratio of 35 respectively were obtained. A kinetic evaluation showed that the dual pool model gave a better prediction of the experimental BMP of all substrates than the first-order model and the modified Gompertz model.

Nanotechnology based technological development in biofuel production: Current status and future prospects

Depleting fossil fuels and net carbon emissions associated with their burning have driven the need to find alternative energy sources. Biofuels are near-perfect candidates for alternative energy sources as they are renewable and account for no net CO2 emissions. However, biofuel production must overcome various challenges to compete with conventional fuels. Conventional methods for bioconversion of biomass to biofuel include chemical, thermochemical, and biological processes. Substrate selection and processing, low yield, and total cost of production are some of the main issues associated with biofuel generation. Recently, the uses of nanotechnology and nanoparticles have been explored to improve the biofuel production processes because of their high adsorption, high reactivity, and catalytic properties. The role of these nanoscale particles and nanocatalysts in biomass conversion and their effect on biofuel production processes and yield are discussed in the present article. The applicability of nanotechnology in production processes of biobutanol, bioethanol, biodiesel, biohydrogen, and biogas under biorefinery approach are presented. Different types of nanoparticles, and their function in the bioprocess, such as electron transfer, pretreatment, hydrolysis, microalgae cultivation, lipid extraction, dark and photo fermentation, immobilization, and suppression of inhibitory compounds, are also highlighted. Finally, the current and potential applications of nanotechnology in biorefineries are also discussed.

Preparation of rich hydrocarbon biofuels from cracking of waste cooking oil by CaO@Zn-KIT-6

The preparation of biofuel from bio-oils is of great importance to the development of renewable energy and to alleviate environmental pollution problems. In this work, acidic mesoporous silica Me-KIT-6 (Me = Zn, Al, Zr, Sn, Mn) were prepared and coated with basic metal oxides, and the CaO@Me-KIT-6 catalyst was obtained, and tested in the catalytic cracking reaction of waste oils and fats. The structure of the catalyst was characterized by X-ray diffraction, N2 physical adsorption and transmission electron microscopy (TEM), the acidity/basicity was characterized by chemisorption (NH3-TPD/CO2-TPD), and the structure-performance relationship in waste cooking oil catalytic cracking was investigated in detail. The results showed that CaO@Zn-KIT-6 catalyst had a good catalytic performance with a liquid biofuel yield of 66.30% and an acid value of about 23.35 mg KOH/g. The carbon distribution of the liquid biofuel concentrated in the range of C13-C18 with 67.80% of hydrocarbon products. The synthesized core-shell catalysts displayed multifunctional role resulting from tailored acid-base synergy.

Yield prediction and optimization of biomass-based products by multi-machine learning schemes: Neural, regression and function-based techniques

Pyrolysis, as a thermochemical conversion of biomass, is a superior biofuel production procedure. The determining procedure for the optimal operational parameters, biomass characteristics, and types is outstandingly complex. Machine learning (ML) models were applied to enhance the predictive performance of three biofuel yields (bio-char, bio-oil, and syngas). This study aimed to establish seven ML models by utilizing the extracted experimental datasets of various pyrolysis routes of biomass (walnut shells and seed cake). The yields of three biofuels are mostly estimated at 0.95 to 0.99 of R-squared. Moreover, the sensitivity analysis displayed that species of biomass and pyrolysis conditions exhibited high errors (5.26–5.62% and 2–4.63% of MAPE) by excluding them from the input set for yield predictions. The generalizability of the ML technique is observed. The radial basis function (RBF) is highly capable of estimating biofuel yield. Genetic algorithms based on radial basis function (GA-RBF) optimization are applied in two ways: single bio-fuel and biomass species. The optimal yields achieved 36.04, 45, and 54.16% for the three biofuels, respectively. Three types of ML demonstrated the high feasibility of biofuel yield prediction. The findings provide strong evidence for using the potential of ML as an assistant along with desirable biofuel production.

Can biomass structural composition be predicted from a small dataset using a hybrid deep learning approach?

The accurate determination of biomass composition can enhance the efficacy of biofuel yield evaluations and provide valuable estimates for process economic viability. This study proposes a generative adversarial algorithm (GAN)-based machine learning (ML) model (hybrid deep learning method) for predicting the composition of lignocellulosic biomass, which includes cellulose, hemicellulose, and lignin content. The model employs proximate and ultimate analyses of biomass as input features, while comparing the performance of three different ML models, with random forest (RF) outperforming all other models). The implementation of the GAN significantly enhanced the model's performance. For the test dataset, the R2 values experienced an increase across all biomass components, with cellulose demonstrating the most noteworthy improvement, elevating from 0.7233 to 0.854. To further enhance the predictive capabilities of the model, hyperparameter optimization was performed. Before optimization, the RF model displayed strong correlations between predicted and actual values. However, post-optimization improvements were relatively minimal, with Grid Search and Bayesian Optimization yielding only marginally better results than Randomized Search. Additionally, an interpretable analysis was conducted to provide a deeper understanding of the relationship between proximate and ultimate analysis, and the structural composition of biomass. The findings presented in this study could prove useful in assessing the potential of biomass for the production of bio-based chemicals and biofuels.

Recent Advances in Biomass Pyrolysis Processes for Bioenergy Production: Optimization of Operating Conditions

Bioenergy has emerged to be among the primary choices for the short- and medium-term replacement of fossil fuels and the reduction in greenhouse gas (GHG) emissions. The most practical method for transforming biomass into biofuel is thermochemical conversion, which may be broken down into combustion, torrefaction, pyrolysis, hydrothermal liquefaction, and gasification. In this study, producing biofuels using a biomass pyrolysis process was investigated. This study explored the pyrolysis process and operating conditions to optimize the process parameters to maximize the desired product yields and quality. The pyrolysis process produces three main products, which are bio-oil, bio-char, and gas. There are three classifications for the pyrolysis method, with each of them producing a majority of a certain product. First, slow pyrolysis is conducted in the temperature range of 300–950 °C and residence time of 330–550 s. It produces around a 30% oil yield and 35% char yield, and thus, the majority yield of slow pyrolysis is char. Second, fast pyrolysis produces around 50% oil, 20% char, and 30% gas yields with a temperature range of 850–1250 °C and a residence time of 0.5–10 s. The average yield of flash pyrolysis was found to be 75% bio-oil, 12% bio-char, and 15% gas, which is conducted within less than 1 s. It was reported that the pyrolysis of biomass was simulated using ASPEN Plus, where the effects of several parameters, such as the temperature, heating rate, and residence time, on the product yield and composition were investigated. Pyrolysis was performed under different conditions ranging from 400 to 600 °C. The effects of different catalysts on the pyrolysis process were studied. It was found that the addition of a catalyst could increase the yield of bio-oil and improve the quality of the product. The optimal operating condition for the pyrolysis process was determined to be a temperature of 500 °C, which resulted in a higher bio-oil yield. It was found that the biofuel yield was enhanced by selecting appropriate raw materials, such as rice husk, along with the pyrolysis temperature (e.g., 450 °C) and particle size (350–800 µm), and using a low residence time and pressure.

Algae biogas production focusing on operating conditions and conversion mechanisms – A review

Global warming is the result of traditional fuel use and manufacturing, which release significant volumes of CO2 and other greenhouse gases from factories. Moreover, rising energy consumption, anticipated limitations of fossil fuels in the near future, and increased interest in renewable energies among scientists, currently increase research in biofuels. In contrast to biomass from urban waste materials or the land, algae have the potential to be a commercially successful aquatic energy crop, offering a greater energy potential. Here we discuss the importance of Anaerobic Digestion (AD) for enhanced biogas yield, characterization, and comparisons between algae pretreatment methods namely, mechanical, thermal, microwave irradiation, and enzymatic and catalytic methods. The importance of anaerobic digestion enhances biogas yield, characterization, and comparisons between mechanical, thermal, microwave irradiation, and enzymatic and catalytic treatment. Additionally, operational aspects such as algal species, temperature, C/N ratio, retention period, and particle size impact biofuel yield. The highest algal biogas yield reported was 740 mL/gVS, subtracted from Taihu de-oiled algae applying thermos-chemical pretreatment under conditions of temperature, time, and catalyst concentration of 70 °C, 3 h, and 6%, respectively. Another high yield of algal-based biogas was obtained from Laminaria sp. with mechanical pretreatment under temperature, time, and VS concentration of 38 ± 1 °C, 15 min, and 2.5% respectively, with a maximum yield of 615 ± 7 mL/g VS. Although biofuels derived from algae species are only partially commercialized, the feedstock for biogas might soon be commercially grown. Algae and other plant species that could be cultivated on marginal lands as affordable energy crops with the potential to contribute to the production of biogas are promising and are already being worked on.

Recent Advances of Triglyceride Catalytic Pyrolysis via Heterogenous Dolomite Catalyst for Upgrading Biofuel Quality: A Review.

This review provides the recent advances in triglyceride catalytic pyrolysis using heterogeneous dolomite catalysts for upgrading biofuel quality. The production of high-quality renewable biofuels through catalytic cracking pyrolysis has gained significant attention due to their high hydrocarbon and volatile matter content. Unlike conventional applications that require high operational costs, long process times, hazardous material pollution, and enormous energy demand, catalytic cracking pyrolysis has overcome these challenges. The use of CaO, MgO, and activated dolomite catalysts has greatly improved the yield and quality of biofuel, reducing the acid value of bio-oil. Modifications of the activated dolomite surface through bifunctional acid-base properties also positively influenced bio-oil production and quality. Dolomite catalysts have been found to be effective in catalyzing the pyrolysis of triglycerides, which are a major component of vegetable oils and animal fats, to produce biofuels. Recent advances in the field include the use of modified dolomite catalysts to improve the activity and selectivity of the catalytic pyrolysis process. Moreover, there is also research enhancement of the synthesis and modification of dolomite catalysts in improving the performance of biofuel yield conversion. Interestingly, this synergy contribution has significantly improved the physicochemical properties of the catalysts such as the structure, surface area, porosity, stability, and bifunctional acid-base properties, which contribute to the catalytic reaction's performance.

The Potential of microalgae for cellulose degradation and utilization for biofuel application

As society is becoming more reliant on fuels, a more sustainable form of energy must be investigated. Another presiding issue is the output of cellulose left over from other plants that are used for biofuels, such as corn. However, the microalgae, Chlamydomonas Reinhardtii, a unicellular organism, is an ideal source of energy, as there is evidence that it contains the genes that are responsible for the encoding of Cellulases, which allow for the degradation of cellulose, such as endoglucanases. Chlamydomonas Reinhardtii typically lives in both soil and water environments, a photosynthetic organism that utilizes light as an energy source. The uncommon trait for microalgae to express cellulase allows for external sources of carbon to be utilized by the microorganism, which could affect the biological output of macromolecules common in biofuels such as lipids and carbohydrates. The study aims to compare not only the cellulase expression levels of Chlamydomonas Reinhardtii, but also see how the lipid output of the microalgae compares to other microorganisms used in the biofuel industry such as Chlorella Vulgaris, another phototrophic microalgae, which is used for direct fuel. Additionally, Trichoderma Reesei will also be compared, which is another microorganism that is used for biofuel production. However, the industry utilizes Trichoderma Reesei’s ability to produce cellulase, rather than just taking directly from the microorganism. The conclusions unfortunately did not show any cellulase expression, and biofuel output favored algae

High efficiency lipid production, biochar yield and chlorophyll a content of Chlorella sp. microalgae exposed on sea water and TiO2 nanoparticles

This study explores the challenges facing microalgae biofuel production, specifically low lipid content and difficulties with algal cell harvesting. The purpose of the research is to investigate the effect of seawater content and nanoparticle concentration on freshwater microalgae growth and biofuel production. The principal results of the study show that increasing the proportion of seawater and nanoparticles enhances the lipid content and cell diameter of microalgae, while excessive concentrations of nanoparticles and low seawater content lead to reduced microalgae growth. Furthermore, an optimal cell diameter was identified at a nanoparticle concentration of 150 mg/L. The study also reveals that increasing seawater content can decrease zeta potential and increase chlorophyll a content due to the concentration of dissolved organic matter. Increasing the seawater content from 0% to 25% decreased zeta potential by 1% owing to the instability and aggregation of the cells. Chlorophyll a for the 0% seawater was 0.55 which is increased to 1.32 only due to the increase in the seawater content. This significant increase is due to the concentration of dissolved organic matter in seawater. Additionally, the presence of seawater positively affects microalgae metabolic activity and biochar yield. The findings of this study offer valuable insights into the potential for optimizing microalgae biofuel production. The use of seawater and nanoparticles has shown promise in enhancing microalgae growth and biofuel yield, and the results of this study underscore the scientific value of exploring the role of seawater and nanoparticles in microalgae biofuel production. Further research in this area has the potential to significantly contribute to the development of sustainable energy solutions.

A Membrane Biophysics Perspective on the Mechanism of Alcohol Toxicity.

Motivations for understanding the underlying mechanisms of alcohol toxicity range from economical to toxicological and clinical. On the one hand, acute alcohol toxicity limits biofuel yields, and on the other hand, acute alcohol toxicity provides a vital defense mechanism to prevent the spread of disease. Herein the role that stored curvature elastic energy (SCE) in biological membranes might play in alcohol toxicity is discussed, for both short and long-chain alcohols. Structure-toxicity relationships for alcohols ranging from methanol to hexadecanol are collated, and estimates of alcohol toxicity per alcohol molecule in the cell membrane are made. The latter reveal a minimum toxicity value per molecule around butanol before alcohol toxicity per molecule increases to a maximum around decanol and subsequently decreases again. The impact of alcohol molecules on the lamellar to inverse hexagonal phase transition temperature (TH) is then presented and used as a metric to assess the impact of alcohol molecules on SCE. This approach suggests the nonmonotonic relationship between alcohol toxicity and chain length is consistent with SCE being a target of alcohol toxicity. Finally, in vivo evidence for SCE-driven adaptations to alcohol toxicity in the literature are discussed.

Ex Situ Catalytic Pyrolysis of Invasive Pennisetum purpureum Grass with Activated Carbon for Upgrading Bio-Oil

Energy demands keep increasing in this modern world as the world population increases, which leads to a reduction in fossil fuels. To resolve these challenges, Pennisetum purpureum, an invasive grass in Brunei Darussalam, was examined as the feedstock for renewable energy through a catalytic pyrolysis process. The activated carbon was applied as the catalyst for a simple and economical solution. The catalytic pyrolysis was executed at 500 °C (the temperature for the highest biofuel yield) for both reactors to produce the highest amount of upgraded biofuels. The biochar produced from the non-catalytic and catalytic pyrolysis processes showed a consistent yield due to stable operating conditions, from which the activated carbon was generated and used as the catalyst in this work. A significant amount of improvement was found in the production of biofuels, especially bio-oil. It was found that for catalysts, the number of phenolic, alcohol, furans, and ketones was increased by reducing the amount of acidic, aldehyde, miscellaneous oxygenated, and nitrogenous composites in bio-oils. The highest amount of phenolic compounds was produced due to a number of functional groups (-C=O and -OH) in activated carbon. The regenerated activated carbons also showed promising outcomes as catalysts for upgrading the bio-oils. The overall performance of synthesized and regenerated activated carbon as a catalyst in catalytic pyrolysis was highly promising for improving the quality and stability of bio-oil.

Improving bio aviation fuel yield from biogenic carbon sources through electrolysis assisted chemical looping gasification

The second-generation bio aviation fuel production via Chemical Looping Gasification (CLG) of biomass combined with downstream Fischer-Tropsch synthesis is a possible way to decarbonize the aviation sector. Although CLG has a higher syngas yield and conversion efficiency compared to the conventional gasification processes, the fraction of biogenic carbon which is converted to biofuel is still low (around 28%). To increase carbon utilization and biofuel yield, incorporation of two types of electrolyzers, Polymer Electrolyte Membrane (PEM) and Molten Carbonate Electrolysis Cell (MCEC), for syngas conditioning has been investigated. Full chain process models have been developed using an experimentally validated CLG model in Aspen Plus for Iron sand as an oxygen carrier. Techno-economic parameters were calculated and compared for different cases. The results show that syngas conditioning with sustainable hydrogen from PEM and MCEC electrolyzers results in up to 11.5% higher conversion efficiency and up to 8.1 % higher biogenic carbon efficiencies in comparison to the syngas conditioning with water gas shift reactor. The study shows that the lowest carbon capture rates are found in the configurations with the highest biogenic carbon efficiency which means up to 14% more carbon ends up in FT crude compared to the case with conventional WGS conditioning. Techno-economic analysis indicates that syngas conditioning using PEM and MCEC electrolyzers would result in an increase of the annual profit by a factor of 1.4 and 1.7, respectively, when compared to using only WGS reactors.