scholarly journals Biodiesel production from microalgae by enzymatic transesterification

2015 ◽  
Author(s):  
◽  
Abhishek Guldhe
Keyword(s):  
Energy Consumption ◽  
Production Process ◽  
Lipid Extraction ◽  
International Standards ◽  
Biodiesel Production ◽  
Enzymatic Conversion ◽  
Microalgal Biomass ◽  
Whole Cell ◽  
Immobilized Lipases ◽  
Microalgal Lipids

Main focus of this study is to investigate the enzymatic-conversion of microalgal lipids to biodiesel. However, preceding steps before conversion such as drying of microalgal biomass and extraction of lipids were also studied. Downstream processing of microalgae has several challenges and there is very little literature available in this area. S. obliquus was grown in the pilot scale open pond cultivation system for biomass production. Different techniques were studied for biomass drying and extraction of lipids from harvested microalgal biomass. Effect of these drying and extraction techniques on lipid yield and quality was assessed. Energy consumption and economic evaluation was also studied. Enzymatic conversion of microalgal lipids by extracellular and whole cell lipase application was investigated. For both applications, free and immobilized lipases from different sources were screened and selected based on biodiesel conversion. Process parameters were optimized using chosen extracellular and whole cell lipases; also step-wise methanol addition was studied to improve the biodiesel conversion. Immobilized lipase was studied for its reuse. Final biodiesel was characterized for its fuel properties and compared with the specifications given by international standards. Enzymatic conversion of microalgal lipids was compared with the conventional homogeneous acid-catalyzed conversion. Enzymatic conversion and chemical conversion were techno-economically investigated based on process cost, energy consumption and processing steps. Freeze drying was the most efficient technique, however at large scale economical sun drying could also be selected as possible drying step. Microwave assisted lipid extraction performed better compared to sonication technique. Immobilized P. fluorescens lipase in extracellular application and A. niger lipase in whole cell application showed superior biodiesel conversion. The extracellular immobilized P. fluorescens lipase showed better biodiesel conversion and yields than the immobilized A. niger whole cell lipase. Both the enzyme catalysts showed lower biodiesel conversion compared to conventional chemical catalyst and higher processing cost. However, techno-economic analysis showed that, the reuse potential of immobilized lipases can significantly improve the economics. Fewer purification steps, less wastewater generation and minimal energy input are the benefits of enzymatic route of biodiesel conversion. Microalgae as a feedstock and lipase as a catalyst for conversion makes overall biodiesel production process environmentally-friendly. Data from this study has academic as well as industrial significance. Conclusions from this study form the basis for greener and sustainable scaling-up of microalgal biodiesel production process.

scholarly journals Physical Methods of Microalgal Biomass Pretreatment

2014 ◽  
Vol 28 (3) ◽  
pp. 341-348 ◽  
Author(s):  
Agata Piasecka ◽  
Izabela Krzemińska ◽  
Jerzy Tys
Keyword(s):  
Alternative Energy ◽  
Lipid Extraction ◽  
Physical Method ◽  
Extraction Methods ◽  
Biodiesel Production ◽  
Biomass Pretreatment ◽  
Microalgal Biomass ◽  
Alternative Energy Sources ◽  
Wet Biomass ◽  
Microwave Techniques

Abstract The prospect of depletion of natural energy resources on the Earth forces researchers to seek and explore new and alternative energy sources. Biomass is a composite resource that can be used in many ways leading to diversity of products. Therefore, microalgal biomass offers great potential. The main aim of this study is to find the best physical method of microalgal biomass pretreatment that guarantees efficient lipid extraction. These studies identifies biochemical composition of microalgal biomass as source for biodisel production. The influence of drying at different temperatures and lyophilization was investigated. In addition, wet and untreated biomass was examined. Cell disruption (sonication and microwave) techniques were used to improve lipid extraction from wet biomass. Additionally, two different extraction methods were carried out to select the best method of crude oil extraction. The results of this study show that wet biomass after sonication is the most suitable for extraction. The fatty acid composition of microalgal biomass includes linoleic acid (C18:2), palmitic acid (C16:0), oleic acid (C18:1), linolenic acid (C18:3), and stearic acid (C18:0), which play a key role in biodiesel production.

Computer-aided exergo-environmental analysis of biodiesel production process from microalgal biomass

2018 ◽  
Vol 11 (44) ◽  
pp. 2201-2209
Author(s):  
Maria Ochoa-Garcia ◽  
Luis Tejeda-Lopez ◽  
Karina Ojeda-Delgado ◽  
Angel Gonzalez-Delgado ◽  
Eduardo Sanchez-Tuiran
Keyword(s):  
Production Process ◽  
Environmental Analysis ◽  
Biodiesel Production ◽  
Microalgal Biomass ◽  
Computer Aided

scholarly journals Influence of Light Intensity and Photoperiod on the Photoautotrophic Growth and Lipid Content of the Microalgae Verrucodesmus verrucosus in a Photobioreactor

2021 ◽  
Vol 13 (12) ◽  
pp. 6606
Author(s):  
Laura Vélez-Landa ◽  
Héctor Ricardo Hernández-De León ◽  
Yolanda Del Carmen Pérez-Luna ◽  
Sabino Velázquez-Trujillo ◽  
Joel Moreira-Acosta ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Accumulation ◽  
Growth Parameters ◽  
Methyl Esters ◽  
Lipid Extraction ◽  
Growth Conditions ◽  
Biodiesel Production ◽  
Microalgal Biomass ◽  
Bg11 Medium ◽  
Gas Chromatography Mass Spectroscopy

Microalgal biomass has the capacity to accumulate relatively large quantities of triacylglycerides (TAG) for the conversion of methyl esters of fatty acids (FAME) which has made microalgae a desirable alternative for the production of biofuels. In the present work Verrucodesmus verrucosus was evaluated under autotrophic growth conditions as a suitable source of oil for biodiesel production. For this purpose BG11 media were evaluated in three different light:dark photoperiods (L:D; 16:08; 12:12; 24:0) and light intensities (1000, 2000 and 3000 Lux) in a photobioreactor with a capacity of three liters; the evaluation of the microalgal biomass was carried out through the cell count with the use of the Neubauer chamber followed by the evaluation of the kinetic growth parameters. So, the lipid accumulation was determined through the lipid extraction with a Soxhlet system. Finally, the fatty acid profile of the total pooled lipids was determined using gas chromatography-mass spectroscopy (GC-MS). The results demonstrate that the best conditions are a photoperiod of 12 light hours and 12 dark hours with BG11 medium in a 3 L tubular photobioreactor with 0.3% CO2, 25 °C and 2000 Lux, allowing a lipid accumulation of 50.42%. Palmitic acid is identified as the most abundant fatty acid at 44.90%.

scholarly journals Bioenergy II: Modeling and Multi-Objective Optimization of Different Biodiesel Production Processes

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Giovanni Di Nicola ◽  
Matteo Moglie ◽  
Marco Pacetti ◽  
Giulio Santori
Keyword(s):  
Energy Consumption ◽  
Production Process ◽  
Minimum Energy ◽  
Biodiesel Production ◽  
High Price ◽  
Optimization Analysis ◽  
Trade Off ◽  
Multi Objective ◽  
Optimal Configurations ◽  
Pareto Frontiers

One of the most promising renewable fuels proposed as an alternative to fossil fuels is biodiesel. The competitive potential of biodiesel is limited by the price of vegetable oils, which strongly influences the final price of biofuels. An appropriate planning and design of the whole production process, from the seed to the biodiesel end product, is essential in order to contain the fallout of energy inefficiencies in the high price of the end product. This study focuses on the characteristics of the production process currently used to produce biodiesel.Refined vegetable oil can be converted into biodiesel by means of a great variety of techniques and technologies, many of which are still not suitable for application on an industrial scale. The solution of greatest interest is homogeneous alkaline transesterification with KOH and methanol. Even when dealing with this type of conversion, it is impossible to establish a universal pattern to describe the conversion or purification stages because there are various possible solutions that make each system different from another. When we look more closely at the state of the art in industrial biodiesel production plants, we also encounter the potential problems introduced by the type and characteristics of the raw materials.Comparing some of the reference solutions that have inspired numerous installations, an optimization analysis was conducted using ASPENPLUS 2006, for the modeling of the process, and modeFRONTIER 4.1 for the optimization procedure. The optimization analysis was carried out using a multi-objective genetic algorithm optimization in order to define the configuration of the main parameters that guarantee the best trade-off between the maximization of the purity of some important compounds and the minimization of energy requirements in the process. The results of this analysis were Pareto frontiers that identify a family of configurations which define the best trade-off between the objectives. Using the Pareto frontiers we then selected the configuration that requires the minimum energy consumption. Among these optimal configurations there is one which guarantees the lowest specific energy consumption while all the optimal configurations obtained respected the requirements of EN 14214, in terms of biodiesel quality.

scholarly journals OPPORTUNITIES FOR REDUCTION OF ENERGY CONSUMPTION IN THE LIFE CYCLE OF BIODIESEL OBTAINED FROM MICROALGAE SCENEDESMUS SP.

2014 ◽  
Vol 46 (1) ◽  
pp. 94-103
Author(s):  
Virginija Skorupskaite ◽  
Violeta Makareviciene
Keyword(s):  
Life Cycle ◽  
Energy Consumption ◽  
Biodiesel Production ◽  
Growth Media ◽  
Total Energy Consumption ◽  
Microalgal Biomass ◽  
Microalgae Oil ◽  
Reduction Of Energy Consumption ◽  
Fossil Energy Ratio ◽  
Liquid Biofuel

The article considers the opportunities for reduction of energy consumption in the life cycle of biodiesel obtained from microalgae oil. Results show that by introducing technical glycerol and substrate leftover after production of biogas into the microalgae growth media energy consumption can be significantly reduced. Production of biogas from de-oiled microalgae improves the energy balance of the life cycle of biodiesel obtained from microalgae oil. It is impossible to obtain fuel containing more energy than would be used in the process of production if microalgae for biodiesel production are cultivated in conventional growth media. Only by subjecting microalgal biomass for production of gaseous and liquid biofuel (biodiesel and biogas) the total energy consumption is lower and equals to 65802.03 MJt-1 than energy value of biofuel, i.e. 79083.32 MJt-1. In this case the fossil energy ratio (FER) for biodiesel reaches 1.2.

scholarly journals Effect of Devices and Driving Pressures on Energy Requirements and Mass Transfer Coefficient on Microalgae Lipid Extraction Assisted by Hydrodynamic Cavitation

2020 ◽  
Vol 9 (3) ◽  
pp. 467-473
Author(s):  
Martomo Setyawan ◽  
Panut Mulyono ◽  
Sutijan Sutijan ◽  
Yano Surya Pradana ◽  
Laras Prasakti ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Energy Consumption ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Lipid Extraction ◽  
Driving Pressure ◽  
Hydrodynamic Cavitation ◽  
Biodiesel Production ◽  
Experimental Result ◽  
Process Conditions

Previous studies of biodiesel production from microalgae have concluded that microalgal biodiesel is not profitable at an industrial scale due to its excessive energy consumption for lipid extraction. Hydrodynamic cavitation lipid extraction is one of the extraction methods which has lower energy consumption. Thismethod enables a fast extraction rate and low energy consumption for cell disruption. In order to achieve optimum process conditions, several influential parameters, which are cavitation generator geometry and driving pressure, need to be scrutinized. The experimental result showed that the maximum yield was obtained at 5 bar driving pressure. The lowest specific extraction energy was obtained at 4.167 bar driving pressure while using one side concave cavitation generator geometry with the ratio of the reduced cross-sectional area of 0.39. The value of the energy extraction requirement 17.79 kJoule/g lipids is less than the biodiesel heating value, and the value of the volumetric mass transfer coefficient is almost 20 times fold greater than the conventional extraction method, therefore this method is promising to be further developed.

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