Preliminary techno-economic analysis of biodiesel production over solid-biochar

Technoeconomic and carbon footprint analysis of simulated industrial scale biodiesel production process from mixed macroalgal and non-edible seed oil using sulphonated zinc doped recyclable biochar catalyst

The present research explored the sustainable production of biodiesel from mixed oils of marine macroalgae and non-edible seeds using a sulphonated Zinc doped recyclable biochar catalyst derived from coconut husk. The maximum biodiesel conversion of 94.8 % was yielded with optimized conditions of 10:1 methanol to oil molar ratio, 4.8 % biochar catalyst concentration, 54.5 ℃ temperature and 87.4 min reaction time. A techno-economic assessment provided a favourable return on investment (ROI) of 21.59 % and 4.63 years of reimbursement period, with a calculated minimum selling price of 0.81 $/kg of produced biodiesel. The carbon footprint analysis results estimated an annual emission of 752.07 t CO2 which corresponds to 0.088 kg CO2 emission per kg of biodiesel produced from the simulated process. The study on economic viability and environmental consciousness of biodiesel production not only paves the way for a greener and sustainable future while also contributing to low carbon footprint.

Chemoenzymatic indican for light-driven denim dyeing

Blue denim, a billion-dollar industry, is currently dyed with indigo in an unsustainable process requiring harsh reducing and alkaline chemicals. Forming indigo directly in the yarn through indican (indoxyl-β-glucoside) is a promising alternative route with mild conditions. Indican eliminates the requirement for reducing agent while still ending as indigo, the only known molecule yielding the unique hue of blue denim. However, a bulk source of indican is missing. Here, we employ enzyme and process engineering guided by techno-economic analyses to develop an economically viable drop-in indican synthesis technology. Rational engineering of PtUGT1, a glycosyltransferase from the indigo plant, alleviated the severe substrate inactivation observed with the wildtype enzyme at the titers needed for bulk production. We further describe a mild, light-driven dyeing process. Finally, we conduct techno-economic, social sustainability, and comparative life-cycle assessments. These indicate that the presented technologies have the potential to significantly reduce environmental impacts from blue denim dyeing with only a modest cost increase.

Recent advancements and challenges in emerging applications of biochar-based catalysts

The sustainable utilization of biochar produced from biomass waste could substantially promote the development of carbon neutrality and a circular economy. Due to their cost-effectiveness, multiple functionalities, tailorable porous structure, and thermal stability, biochar-based catalysts play a vital role in sustainable biorefineries and environmental protection, contributing to a positive, planet-level impact. This review provides an overview of emerging synthesis routes for multifunctional biochar-based catalysts. It discusses recent advances in biorefinery and pollutant degradation in air, soil, and water, providing deeper and more comprehensive information of the catalysts, such as physicochemical properties and surface chemistry. The catalytic performance and deactivation mechanisms under different catalytic systems were critically reviewed, providing new insights into developing efficient and practical biochar-based catalysts for large-scale use in various applications. Machine learning (ML)-based predictions and inverse design have addressed the innovation of biochar-based catalysts with high-performance applications, as ML efficiently predicts the properties and performance of biochar, interprets the underlying mechanisms and complicated relationships, and guides biochar synthesis. Finally, environmental benefit and economic feasibility assessments are proposed for science-based guidelines for industries and policymakers. With concerted effort, upgrading biomass waste into high-performance catalysts for biorefinery and environmental protection could reduce environmental pollution, increase energy safety, and achieve sustainable biomass management, all of which are beneficial for attaining several of the United Nations Sustainable Development Goals (UN SDGs) and Environmental, Social and Governance (ESG).

Economic analysis of the circular economy based on waste plastic pyrolysis oil: a case of the university campus

Recently, the concept of a circular economy for carbon neutrality is emerging. In particular, waste plastics are one of the key wastes, and efforts are being made to recycle them as energy rather than dispose of them. Accordingly, the technology of producing and utilizing pyrolysis oil from waste plastics attracts attention. As it is an early stage of technology development, however, there are not many demonstrations and papers that analyze the technology broadly. The goal of this study is to propose building a circular economy on a university campus through waste plastic pyrolysis oil technology. To show its feasibility, waste plastic pyrolysis oil technology is analyzed comprehensively from economic, environmental, and policy perspectives using the scenario analysis technique on the university campus level. A methodology of the scenario analysis technique enables predicting the uncertainties. Since plastic pyrolysis oil technologies and carbon neutrality are accompanied by many uncertainties, this technique is expected to be an appropriate methodology for this study. First, the amount of pyrolysis oil production from waste plastics from the campus is estimated. Then, the cost and carbon emissions from waste plastics are estimated if the pyrolysis oil technology is used instead of the traditional waste disposal process. As a result, the total economic profits of up to 425,484,022 won/year (354,570.01 $/year) are expected when a circular economy is built using waste plastic pyrolysis oil. In addition, it is also confirmed that greenhouse gas (GHG) emissions can be reduced by up to 840,891 kgCO2eq/year. The waste plastic pyrolysis oil satisfies Korea's gas pollutant standards and is consistent with the GHG reduction policy. It can be concluded that building a circular economy at the university campus level using waste plastic pyrolysis oil technology is suitable from economic, environmental, and policy perspectives.

Review of Advances in the Utilization of Biochar-Derived Catalysts for Biodiesel Production

Biochar, obtained from the thermal decomposition of different biomass sources, can be used in various scientific technologies by virtue of its distinguishing performance. Recent developments in advanced biochar synthesis methods have led to continuous growth in the literature related to bulk biochar products and synthesized biochar substrates. This review specifically summarizes the current advanced methods for the synthesis of functional biochar catalysts and applications in (trans)esterification. Herein, first the method and design of synthesized biochar substrate catalysts are briefly introduced. Second, the applications of these synthesized biochar substrate catalysts upon (trans)esterification are comprehensively discussed. Finally, the current research status and the future perspectives of the synthesized biochar substrate catalyst are presented. It is expected that this summary will provide perspectives and instructions for future work on synthesized biochar catalysts for biodiesel products.

Biodiesel Production from Waste Plant Oil over a Novel Nano-Catalyst of Li-TiO2/Feldspar

A novel Li-impregnated TiO2 catalyst loaded on feldspar mineral (Li-TiO2/feldspar) was synthesized via a wet impregnation method and was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) analysis. Using these techniques, it was possible to confirm the catalyst’s structural organization with a high crystallinity. This catalyst was used in the transesterification of five waste plant oils of Citrullus colocynthis (bitter apple), Pongamia pinnata (karanja), Sinapis arvensis (wild mustard), Ricinus communis (castor) and Carthamus oxyacantha (wild safflower). The catalytic tests were performed at temperatures ranging from 40 to 80 °C, employing a variable methanol/ester molar ratio (5:1, 10:1, 15:1, 20:1 and 25:1) and different catalyst concentrations (0.5%, 1%, 1.5%, 2% and 2.5%) relative to the total reactants mass. Conversion of 98.4% of fatty acid methyl esters (FAMEs) was achieved for Pongamia pinnata (karanja). The main fatty acids present in bitter apple, karanja, wild mustard, castor and wild safflower oils were linoleic acid (70.71%), oleic acid (51.92%), erucic acid (41.43%), ricinoleic acid (80.54%) and linoleic acid (75.17%), respectively. Li-TiO2/feldspar produced more than 96% for all the feedstocks. Fuel properties such as iodine value (AV), cetane number (CN), cloud point (CP), iodine value (IV), pour point (PP) and density were within the ranges specified in ASTM D6751.

Carbon credit reduction: A techno-economic analysis of "drop-in" fuel production

The current study elucidates the fundamentals of technical, financial, and environmental viability of the processes used for sustainable "drop-in" fuel generation. At present, the price of producing "drop-in" fuels is around two times as costly (5-6 USD/gallon) as the cost of fossil fuels (3 USD/gallon), especially when using second-generation feedstocks. Hence, this necessitates a comprehensive techno-economic understanding of the current technologies with respect to "drop-in"-fuel. This entitles technical-economic viability, and environmental sustainability to make the processes involved commercially viable. In this context, the present review addresses unique contrasts among the various processes involved in "drop-in" fuel production. Furthermore, principles and process flow of techno-economic analysis as well as environmental implications in terms of reduced carbon footprint and carbon credit are elucidated to discuss fundamentals of techno-economic analysis in terms of capital and operational expenditure, revenue, simulation, cash flow analysis, mass and energy balances with respect to evidence-based practices. Case specific techno-economic studies with current developments in this field of research with emphasis on software tools viz., Aspen Plus, Aspen HYSIS, Aspen Plus Economic Analyser (APEC) Aspen Icarus Process Evaluator (AIPE) are also highlighted. The study also emphasis on the carbon foot print of biofuels and its carbon credits (Carbon Offset Credits (COCs) and Carbon Reduction Credits (CRCs)) by leveraging a deep technical and robust business-oriented insights about the techno-economic analysis (TEA) exclusively for the biofuel production.

A comparative physicochemical property assessment and techno-economic analysis of biolubricants produced using chemical modification and additive-based routes

Several edible and non-edible oil sources are currently being developed as renewable basestocks for biolubricant production. However, these feedstocks possess undesirable physicochemical properties limiting their lubricant applications. Chemical modification and additive-based routes could be used to modify their properties -suitable for different biolubricant applications. The first part of this study compares how the selected modifications affect the properties of the basestocks. Next, the techno-economic analysis (TEA) was conducted to study 4 selected biolubricants and a potential biolubricant derived from marine microalgae biomass. Oxidative stabilities of chemically modified biolubricants followed the order of epoxidation> triesterification> estolide. Pour points of triesters showed minimal increments and reduced for estolides, whereas epoxidation increased pour points. Estolides exhibit maximum kinematic viscosity increment among chemical modification routes, followed by TMP-transesterification and epoxidation. The oxidative stability of chemically modified biolubricants was higher than additized biolubricants; conversely, the viscosity increments and pour point reductions for additized biolubricants were higher than chemically modified biolubricants. TEA results show that the unit cost for producing 1-kg estolide was the highest among the chemical modification routes. The unit cost per kilogram of jatropha biolubricant produced using the additive-based route was lower than chemically modified biolubricants. Due to a high microalgal oil feedstock cost, the unit cost per kilogram of additized microalgae oil biolubricant was more than the unit cost of additized Jatropha oil. The techno-economic feasibility of biolubricant production from marine microalgal oil could be improved by adopting a biorefinery approach.

Production of biodiesel from non-edible feedstocks using environment friendly nano-magnetic Fe/SnO catalyst

Environmental problems associated with chemical catalysts to fulfil an ever-increasing energy demand have led to the search for an alternative environment friendly heterogeneous catalyst. If a catalyst being used in the biodiesel production is not environment friendly, then the environment is being contaminated in another way while trying to avoid pollution caused by burning of fossil fuels. The present study reports the use of nano-magnetic catalyst Fe/SnO supported on feldspar for the transesterification of various non-edible feedstocks oil, including Pongamia pinnata (karanja), Carthamus oxyacantha (wild safflower), Citrullus colocynthis (bitter apple), Sinapis arvensis (wild mustard) and Ricinus communis (castor). The optimized transesterification parameter was oil to methanol ratio (1:5, 1:10, 1:15, 1:20 and 1:25), catalyst amount (0.5, 1, 1.5, 2, 2.5%), temperature (40, 50, 60, 70 and 80 °C), and reaction times (30, 60, 90, 120 and 150 min). The biodiesel yield was found to be more than 97% for all the tested feedstocks with a maximum biodiesel yield of 98.1 ± 0.6% obtained for bitter apple seed oil under optimum conditions (oil to methanol ratio of 1:10, catalyst amount of 1% at 50 °C for 120 min). The catalysts used for transesterification were magnetically extracted after completion of the reaction. Different physico-chemical parameters like pour point, density, cloud point, iodine value, acid value, saponification and cetane number were determined and the quality of all the biodiesel samples were found to be in the standard range (ASTM D6751 and EN 1404). Different techniques like XRD, FTIR, SEM and EDX were used to characterize the prepared nano-magnetic (Fe/SnO/Feldspar) catalyst.

Exploring agricultural waste biomass for energy, food and feed production and pollution mitigation: A review

Globally agricultural production system generates a huge amount of solid waste. Improper agri-waste management causes environmental pollution which resulted in economic losses and human health-related problems. Hence, there is an urgent need to design and develop eco-friendly, cost-effective, and socially acceptable agri-waste management technologies. Agri-waste has high energy conversion efficiency as compared to fossil fuel-based energy generation materials. Agri-waste can potentially be exploited for the production of second-generation biofuels. However, composted agri-waste can be an alternative to energy-intensive chemical fertilizers in organic production systems. Furthermore, value-added agri-waste can be a potential feedstock for livestock and industrial products. But comprehensive information concerning agri-waste management is lacking in the literature. Therefore, the present study reviewed the latest advancements in efficient agri-waste management technologies. This latest review will help the researchers and policy planners to formulate environmentally robust residue management practices for achieving a green economy in the agricultural production sector.

Sulfur heterogeneity: A non-negligible factor in manipulating growth and lipid accumulation of Scenedesmus obliquus at a relatively high ratio of carbon to nitrogen

Algal biodiesel has been becoming a focus in the field of bioenergy worldwide. In this study, effects of heterogeneous sulfur (SO₄^2-, SO₃^2- and S^2-) on growth and lipid accumulation of Scenedesmus obliquus cultured in wastewater with a C/N ratio of 30 were investigated, respectively. The results shown that SO₄^2-, the optimal sulfur source, could trigger cell growth in a concentration-dependent manner. However, SO₃^2- was superior to the others in boosting carbon uptake of cells, which was subject to NH₄⁺-N concentration. Only SO₄^2- could simultaneously increase lipid content and productivity of cells with a dominant component of oleic acid (C18:1n9c) occupying approximately 40% in fatty acid profile. Additionally, the genes encoding enzymes such as CDIPT, ADPRM, DPP1, pmtA and BTA1 involved in the uppermost lipid-related pathway (glycerophospholipid metabolism) were identified facing different sulfur source regardless of the concentration changes. These findings may facilitate nutrition management efforts to enhance microalgae-based biofuel production.

Catalytic pyrolysis of lignocellulosic biomass for bio-oil production: A review

Catalytic pyrolysis has been widely explored for bio-oil production from lignocellulosic biomass owing to its high feasibility and large-scale production potential. The aim of this review was to summarize recent findings on bio-oil production through catalytic pyrolysis using lignocellulosic biomass as feedstock. Lignocellulosic biomass, structural components and fundamentals of biomass catalytic pyrolysis were explored and summarized. The current status of bio-oil yield and quality from catalytic fast pyrolysis was reviewed and presented in the current review. The potential effects of pyrolysis process parameters, including catalysts, pyrolysis conditions, reactor types and reaction modes on bio-oil production are also presented. Techno-economic analysis of full-scale commercialization of bio-oil production through the catalytic pyrolysis pathway was reviewed. Further, limitations associated with current practices and future prospects of catalytic pyrolysis for production of high-quality bio-oils were summarized. This review summarizes the process of bio-oil production from catalytic pyrolysis and provides a general scientific reference for further studies.

Techno-economics of coconut coir bioadsorbent utilization on free fatty acid level reduction in crude palm oil

The quality of crude palm oil (CPO) is generally determined by the levels of free fatty acids (FFA). This helps in balancing the level of acidity during transportation and storage processes. However, high FFA in CPO is not good for consumer health. One of the methods for adsorbing FFA is adsorption, which is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface. Therefore, this study aims to analyze the effect of contact time (40, 80 and 120 min) and Coconut Coir (CC) bioadsorbent concentrations of 1, 2 and 3 (%, w/v) on the reduction of CPO FFA levels. This began with the activation of CC biochar synthesis by using NaOH and HCl, which produced CC-NaOH and CC-HCl bioadsorbents based on the product of NaOH. Furthermore, the adsorption process was carried out by mixing CPO with CC-NaOH and CC-HCl bioadsorbents in a three-necked flask. After this, the filtrate product was obtained and analyzed for its FFA levels. The results showed that the largest percentage reduction for the effect of bioadsorbent concentration was 3% (w/v) at a contact time of 120 min. It also indicated that this study enabled lower levels of FFA in CPO. Based on the detailed cost estimate, the production cost of the CC-NaOH bioadsorbent was USD 481,874, sold at USD 95/ton with annual sales and net profit (after tax) at USD 684,000 and USD 141,188, respectively. This profit after tax and rate of return on investment was found to be 20.68 and 39.49% of the entire estimation, respectively. It also had a payback period of 2.95 years and a break-even point at a capacity of 43.16%. In addition, the prepared adsorbent showed significant ability as an inexpensive, reproducible and environmentally friendly compound used in reducing the FFA levels of CPO.

Biochar as environmental armour and its diverse role towards protecting soil, water and air

Biochar has been of considerable importance for various environmental applications in recent years. It has exhibited substantial advantages like favourable structural and surface properties, easy process of preparation and widely available feedstocks. These set of exceptional properties make it an efficient, cost-effective and environment friendly source for diversified elimination of pollutants. The heterogeneity of physico-chemical properties offers a possibility for biochar to optimize its efficacy for targeted applications. This review aims to highlight the critical role that biochar plays in various environmental applications, be it in soil, water or air. In particular the article offers a comprehensive review of the recent research findings and updates related to the diversified role of biochar. Also, the interaction of pollutants with biochar functional groups and the impact of variation of parameters on biochar attribute relevant to specific pollutant removal, modifications, mechanisms involved and competence for such removal has been discussed. Different technologies for production of biochar have also been summarized with an emphasis on post treatment of biochar, such as modification and doping. In addition to this, the underlying gaps in the studies carried out so far and recommendations for future research areas in biochar have also been deliberated.

Silica Coating of Metal-Loaded H-ZSM-22 to Form the Core-Shell Nanostructures: Characterization, Textural Properties, and Catalytic Potency in the Esterification of Oleic Acid

In this study, ZSM-22 was synthesized using N,N-diethylaniline as a template through a hydrothermal method. The proton and various metals such as zirconium, strontium, and iron were immobilized on the surface of obtained zeolites through the ion exchange method. The catalysts were studied by Fourier-Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption isotherms, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) elemental analysis, and Temperature-Programmed Desorption of ammonia (TPD-NH3) technique for determining the number of acid sites. In the esterification reaction of oleic acid, the operating conditions such as catalyst dosage, temperature, molar ratio of methanol to oil, and reaction time were optimized and adjusted at 11 wt%, 70°C, 10 : 1, and 48 h subsequently. The maximum yield% of 48.07% was achieved in the presence of Zr-H-ZSM-22 at optimum conditions. In order to improve the efficiency of three zeolites Zr-H-ZSM-22, Fe-H-ZSM-22, and Sr-H-ZSM-22, the core-shell structures with SiO2 coating were prepared. Zr-H-ZSM-22@SiO2 was less active than Zr-H-ZSM-22 due to the SiO2 coverage of Lewis active sites.

A Quantitative Sustainability Assessment of Food Waste Management in the European Union

In an endeavor to make Europe carbon-neutral, and to foster a circular economy, improving food waste management has been identified by the European Union (EU) as a key factor. In this study, we consider 21 pathways, covering: (i) prevention; (ii) reuse for both human consumption and animal feed; (iii) material recycling as an input into the food and chemical industries; (iv) nutrient recycling; and (v) energy/fuel recovery. To include all types of impact, a sustainability assessment, encompassing environmental, economic, and social pillars, is performed and complemented with societal life cycle costing. The results indicate that after prevention, reuse for human consumption and animal feed is the most preferred option, and, in most cases, nutrient recycling and energy recovery are favored over material recycling for chemical production. While highlighting that the food waste management hierarchy should be supported with quantitative sustainability analyses, the findings also illustrate that biochemical pathways should be improved to be competitive despite the fact that food waste valorization has the potential to satisfy the EU demand for the chemicals investigated. Yet, the results clearly show that the potential benefits of improving emerging technologies would still not eclipse the benefits related to food waste prevention and its redistribution.

Techno-economic evaluation and sensitivity analysis of a conceptual design for supercritical water gasification of soybean straw to produce hydrogen

This paper proposes a conceptual design for the catalytic supercritical water gasification of soybean straw. The design consists of four process units for pretreatment, gasification, separation, purification and combustion. The economic feasibility of hydrogen production was evaluated based on a comprehensive cash flow analysis. The economic analysis suggested a minimum selling price of U.S. $1.94/kg for hydrogen. The cost of hydrogen produced is relatively lower compared to that of other biomass conversion processes. Besides, the net rate of return (NRR) estimated was 37.1%. A positive NRR value indicates that the project is profitable from an economic perspective. Sensitivity analysis indicates that the minimum selling price of hydrogen is affected by the feedstock price, utility cost, tax rate and labor cost. Moreover, feedstock price and labor cost show the greatest effect. Other factors such as land cost, working capital and utility cost showed the least effect on the minimum selling price.

Heterogeneously catalyzed biodiesel production from Azadiricha Indica oil: Predictive modelling with uncertainty quantification, experimental optimization and techno-economic analysis

This study presents predictive modelling with uncertainty analysis, optimization and techno-economic feasibility of Bio-catalyzed Biodiesel Production from Azidirica Indica Oil (BCBPAIO). Central Composite Design (CCD) predictive model and optimum conditions for BCBPAIO were developed in Design Expert software. The model uncertainty analysis was performed using Monte Carlo simulation. The BCBPAIO simulation and economic analysis were conducted in ASPEN Batch Process Developer V10. The correlation coefficient (R²) and adjusted R² value of the CCD model were 0.9922 and 0.9780 respectively. CCD model certainty gave 73.51% with 100,000 trials; the oil transesterification optimum conditions gave 87.04% conversion with 3.62 wt% of catalysts; and methanol to oil molar ratio of 8:1 at 59 °C for 4 h. The annual production cost, total capital investment, payback time and internal rate of returns are $ 3537105, $ 5243784, 2.67 and 43% respectively. This study shows that the production is profitably feasible.

Modelling and process optimization for biodiesel production from Nannochloropsis salina using artificial neural network

In the present investigation, calcium oxide solid nanocatalyst derived from the egg shell and Nannochloropsis salina were used for the production of biodiesel. The morphological characteristics and functional groups of synthesized nanocatalyst was characterized by SEM and FTIR analysis. Process variables optimization for biodiesel production was studied using RSM and ANN. The R² values for RSM and ANN was found to be 0.8751 and 0.957 which showed that the model was significantly fit with the experimental data. The maximum FAME conversion for the synthesized nanocatalyst CaO was found to be 86.1% under optimum process conditions (nanocatalyst amount: 3% (w/v); oil to methanol ratio 1:6 (v/v); reaction temperature: 60 °C; reaction time 55 min). Concentration of FAME present in biodiesel was identified by GC-MS analysis.

Simulation of ethanol recovery and economic analysis of pectin production on an industrial scale

Taking into account that the industrial processing of passion fruit generates significant amounts of waste (only the peels represent 51% of the total mass of the fruit), in the present study an economic analysis was conducted to evaluate industrial line viability for pectin extraction from passion fruit peels. Knowing that absolute ethanol (99.50% purity), used in the precipitation and washing steps, has a higher cost, a simulation of extractive distillation was performed using solvents ethylene glycol and glycerol, in the software Aspen Plus v.11, being possible to recover 99.63% of ethanol for both solvents. The results of the economic evaluation showed that the process using ethylene glycol has an advantage, mainly due to its higher profitability (1.13 times higher), lower production cost (94.86% of the price using glycerol), and a lower breakeven point (around 3% smaller). The financial indicators showed profitability and attractiveness for the implementation of this processing line.

Lipid bioproduction from delignified native grass (Cyperus distans) hydrolysate by Yarrowia lipolytica

In the present study, native grass (Cyperus distans) was utilized for the production of lipid using Yarrowia lipolytica MTCC 9519. Initially, pretreatment methods using hydrothermal and alkaline delignification were performed to obtain cellulose rich liquid fractions. Delignified native grass biomass was enzymatically hydrolyzed to convert non fermentable sugars in to fermentable sugars. The growth of Y. lipolytica MTCC 9519 by utilizing pretreated native grass hydrolysate was evaluated. The yield and concentration of total reducing sugars after enzyme hydrolysis were found to be 378 ± 35 mg/g of pretreated biomass and 28.64 g/L ± 1.25 g/L, respectively. When pretreated, delignified native grass hydrolysate was used with (NH₄)₂SO₄ (30C/N ratio) and sodium n-octanoate (0.4% w/w), the dry cell weight and lipid accumulation of Y. lipolytica MTCC 9519 reached about 19.88 ± 1.54 g/L and 53.62% (w/w) respectively after 96 h. Thus, native grass could become a promising substrate for biolipid production.

Economic analysis on sewage sludge drying and its co-combustion in municipal solid waste power plant

Co-treatment in municipal solid waste power plant has been deemed to one of the most suitable ways to handle sewage sludge. Economy of the co-treatment process is very concerned in the waste incineration plant. Thermal calculation of sewage sludge co-combustion was done. Four common sludge drying schemes was compared: flue gas drying, steam drying, electric heating drying in the waste incineration plant and in situ electric heating drying in the sewage treatment plant. Sensitivity analysis was also performed. When the water content was 30-40% and the absolute-dry sludge ratio was 2-3%, the boiler efficiency was reduced by 0.56-1.12% compared with the case without mixing sludge, and the power generation decreased by 0.2568-0.3767 MW in steam drying scheme and by 0.0037-0.0094 MW in other schemes. Net present value (NPV) of flue gas drying was the highest among the four sludge drying schemes, which was more than 20 ¥ million, while the scheme of electric heating drying in the waste incineration plant had the lowest NPV, which can't recoup the initial investment. Sensitivity coefficient of flue gas drying was smallest among different schemes, showing that the risk of this program was the smallest. Absolute-dry sludge ratio and unit subsidy for sludge treatment were sensitive factors for NPV in flue gas scheme, which had a sensitivity coefficient of 1.123-1.171 and 1.232, respectively. Operating parameters optimization of co-combustion of sludge was done and ways to improve economic efficiency was discussed.

Process optimization, green chemistry balance and technoeconomic analysis of biodiesel production from castor oil using heterogeneous nanocatalyst

In the present work, zinc doped calcium oxide was used as a nanocatalyst for biodiesel production from castor oil. The optimal conditions of biodiesel conversion and green chemistry balance were obtained with response surface methodology. Five green chemistry parameters like carbon efficiency, atom economy, reaction mass efficiency, stoichiometric factor and environmental factor were optimized. The sustainable biodiesel yield 84.9% and green chemistry balance 0.902 was achieved at methanol to oil molar ratio 10.5:1, temperature 57 °C, time 70 min, and catalyst concentration 2.15%. The synthesized biodiesel was characterized by GCMS and FTIR, and physic-chemical properties were determined. Based on experimental study annually 20.3 million kg capacity plant was simulated using SuperPro designer. The sensitivity analysis of oil purchase cost and biodiesel selling price on ROI, payback period, IRR and NPV were investigated. The optimization and technoeconomic analysis provided a sustainable platform for commercial based biodiesel production.

Optimization and techno-economic analysis of biodiesel production from Calophyllum inophyllum oil using heterogeneous nanocatalyst

The present research work is aimed at reducing the consumption of reactants by process optimization and economic analysis of large-scale commercial plant using techno-economic analysis. The statistical optimization of biodiesel production from Calophyllum inophyllum oil using Zn doped CaO nanocatalyst was used to optimize the conversion efficiency and green chemistry value. The environmental studies on transesterification reaction were done using green chemistry parameters like carbon efficiency, atom economy, reaction mass efficiency, stoichiometric factor and environmental factor. The biodiesel conversion 91.95% was achieved when maintaining the methanol to oil ratio 9.66:1, concentration of catalyst 5% (w/v), time 81.31 min and temperature 56.71 °C with green chemistry value of 0.873. Techno-economic analysis of biodiesel production from Calophyllum inophyllum oil was executed used optimized lab-scale data. The techno-economic analysis of 21 million kg/year biodiesel production plant was investigated. The annual biodiesel revenue of 15,224,000 $/yr and the payback period was about 1.15 years.

Pineapple (Ananás comosus) leaves ash as a solid base catalyst for biodiesel synthesis

Homogeneous catalysts used for biodiesel synthesis have several limitations, including non-recoverability/reusability, saponification, emulsification, equipment corrosion, and environmental pollution. To overcome these limitations, we synthesized a novel catalyst via calcination of pineapple leaves waste. This catalyst was characterized by X-ray powder diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and soluble alkalinity measurements. The catalyst's activity with regards to soybean oil transesterification was analyzed, and multiple process parameters (temperature, catalyst amount, reaction time, and methanol:oil molar ratio) were examined. A high catalytic activity, probably related to the 85 wt% content of alkali/alkali metals (K, Ca and Mg), was observed after a 30 min reaction time, 60 °C, 4 wt% of catalyst, oil to methanol molar ratio of 1:40, reaching an oil to biodiesel conversion above 98%. We conclude that the novel catalyst presented here is efficient, cost-effective, and sustainable, while simultaneously abundant waste is reduced.