Download Free Energy Efficient And Cost Effective Microalgae Disruption For Extraction Of Lipids For Biodiesel Production Book in PDF and EPUB Free Download. You can read online Energy Efficient And Cost Effective Microalgae Disruption For Extraction Of Lipids For Biodiesel Production and write the review.

Microalgae appear to be a promising source of biodiesel as they have high photosynthetic rates and can accumulate substantial amount of lipids in their biomass (up to 77% of dry cell mass in some species). Unlike oilseed crops (such as rapeseed, soybean, and corn) which require freshwater and arable land for their cultivation, many of the marine microalgal strains can be cultivated in saltwater on non-arable lands. As such, large-scale microalgal cultivation should pose minimal interfere with valuable agricultural resources. The development of an effective and sustainable process to isolate intracellular lipids from the microalgal biomass is critical for an economically viable up-scaling of microalgal technologies. The primary objective of this thesis was to examine the mechanism underlying the lipid extraction process. We investigated the use of two types of laboratory-scale lipid extraction technologies: supercritical carbon dioxide (SCCO2) extraction and organic solvent extraction. In addition to the optimization of the lipid extraction process, the study examined the auxiliary cell disruption step which assisted lipid extraction by liberating lipids from the encapsulation of microalgal cells. SCCO2 extraction was found to produce a higher lipid yield than traditional organic solvent extraction using hexane (0.058 g lipid / g dried microalgae after 80 min vs 0.032 g lipid / g dried microalgae after 330 min). Lipid yield of the SCCO2 extraction process increased with decreasing temperature and increasing pressure. By increasing the ratio of water adsorbent (diatomaceous earth) to microalgal biomass in the extraction column, the SCCO2 process was able to extract lipids from wet microalgal paste (water content = 70 wt% of biomass) as effectively as it did from dried biomass. This modification, however, reduced the capacity of the extraction vessel by 88%. Commercial-scale use of the SCCO2 extraction must consider the high cost associated with its infrastructure and operation. Despite the routine use of classical Folch (chloroform/methanol) protocol for the determination of microalgal lipid content, the variables that affect organic solvent extraction of microalgal lipids are not well understood. A first-order kinetic model that described the microalgal organic solvent lipid extraction process as an equilibrium-driven phenomenon was developed and fitted to experimental results (0.68 ≤ r2 ≤ 1.00). The model was the first of its kind ever reported and provided a novel perspective in understanding the mechanism underlying the lipid extraction process. According to this model, the amount of intracellular lipid that can be transferred to the extraction solvent was governed by the equilibrium constant, K (unitless), while the rate of lipid mass transfer across the cell membrane was jointly controlled by the overall mass transfer coefficient, k (1/min), and the equilibrium constant. The efficiency of organic solvent extraction of microalgal lipid with either a methanol-based system or a hexane-based system was shown to increase with a rise in the cell concentration of the extraction mixture, a rise in the speed of agitation, a rise in the extraction temperature, and a rise in the degree of cellular disruption. The presence of water up to 20 vol% of the extraction solvent did not appear to adversely affect the efficiency of the extraction process. The tolerance of the extraction process to relatively large amounts of water demonstrated that the extraction process can be applied to wet microalgal paste or even concentrate solution with minimal loss of efficiency. This finding was crucial for the economics of the extraction process as it removed the necessity for an energy-intensive drying process prior to the lipid extraction step. An increased presence of water in excess of the aforementioned threshold level, however, rapidly decreased extraction efficiency. Cell disruption assists lipid extraction by releasing intracellular lipids from microalgal cellular structures. The use of high-pressure homogenization (HPH), ultrasonication, bead beating, and sulfuric acid treatment as laboratory-scale disruption methods were investigated for microalgal cells. The disruption efficiency of each method was evaluated through percentage reduction of intact cell concentration. With an average disruption efficiency of 73.8 % of initial intact cells, HPH was found to be the most efficient cell disruption method. Sulfuric acid treatment, bead beating, and ultrasonication followed HPH with an average disruption efficiency of 33.2, 17.5 and 4.5 % of initial intact cells, respectively.The use of HPH and ultrasonication as microalgal cell disruption methods were examined in further detail. The kinetics of cell disruption under both methods appeared to follow a first-order decay model whereby disruption rate was shown to decrease with time. The disruption rate constant for either method was found to increase linearly with parameter that affected the level of energy input (operating pressure for HPH and power for ultrasonication). On the other hand, initial cell concentration appeared to affect the disruption rate constant of both methods in a non-linear fashion. Disrupting microalgal cells with either HPH or ultrasonication prior to lipid extraction increased both lipid and triglyceride yields by respectively 590 - 786 % and 358 - 484 %.
Microalgae Cultivation for Biofuels Production explores the technological opportunities and challenges involved in producing economically competitive algal-derived biofuel. The book discusses efficient methods for cultivation, improvement of harvesting and lipid extraction techniques, optimization of conversion/production processes of fuels and co-products, the integration of microalgae biorefineries to several industries, environmental resilience by microalgae, and a techno-economic and lifecycle analysis of the production chain to gain maximum benefits from microalgae biorefineries. Provides an overview of the whole production chain of microalgal biofuels and other bioproducts Presents an analysis of the economic and sustainability aspects of the production chain Examines the integration of microalgae biorefineries into several industries
This book presents an authoritative and comprehensive overview of the production and use of microalgal biomass and bioproducts for energy generation. It also offers extensive information on engineering approaches to energy production, such as process integration and process intensification in harnessing energy from microalgae. Issues related to the environment, food, chemicals and energy supply pose serious threats to nations’ success and stability. The challenge to provide for a rapidly growing global population has made it imperative to find new technological routes to increase the production of consumables while also bearing in mind the biosphere’s ability to regenerate resources. Microbial biomass is a bioresource that provides effective solutions to these challenges. Divided into eight parts, the book explores microalgal production systems, life cycle assessment and the bio-economy of biofuels from microalgae, process integration and process intensification applied to microalgal biofuels production. In addition, it discusses the main fuel products obtained from microalgae, summarizing a range of useful energy products derived from algae-based systems, and outlines future developments. Given the book’s breadth of coverage and extensive bibliography, it offers an essential resource for researchers and industry professionals working in renewable energy.
Downstream bioprocesses have a significant role to play in the creation of a sustainable bio-based economy, enabling the creation of new products and systems from the more sustainable bioprocessing of natural products. Liquid Biphasic System: Fundamentals, Methods, and Applications in Bioseparation Technology explores in detail the fundamental processes and applications of this new separation system, aiding understanding of the basic principles of the technique and offering constructive criticisms on the latest findings. Including coverage of the background, principles, mechanisms, and applications, Liquid Biphasic System addresses how to adapt the technology for the purification of useful compounds with greater cost efficiency and greener processing. It is essential reading for bioprocess engineers, biochemical engineers, biosystem engineers, chemists and microbiologists working in the fields of bioprocessing. Researchers, scientists, and engineers concerned with the selection and evaluation of alternative bioseparation processes will find the book particularly useful. Provides information and examples of advanced separations in a single source Includes detailed descriptions of novel bioseparation systems Covers the latest technologies related to advanced liquid–liquid separation and their applications in various industries
Microalgae can be future resource for industrial biotechnology In current energy crisis era, microalgae are under tremendous research focus for the production of biodiesel due to their high photosynthetic efficiency, growth rate and high lipid content compared to territorial plants. However, the large-scale production of algal biomass and downstream processing of harvested algae towards bio-fuels are facing several challenges from economic viability perspective. Apart from bio-fuels, the microalgae synthesize number of bio-molecules such as pigments (e.g., chlorophyll, carotenoid), protein (e.g., lectin, phycobiliprotein), and carbohydrates (e.g., agar, carrageenan, alginate, fucodian) which are available in the various forms of microalgal products. Therefore, developing a strategy for large-scale production and use of algal biomass for the co-production of these value-added macromolecules is thus imperative for the improvement of the economics of algal biorefinery. In the above context, this book covers three major areas (i) commercial-scale production of bio-molecules from microalgae, (ii) sustainable approach for industrial-scale operation, and (iii) optimization of downstream processes. Each of these sections is composed of several chapters written by the renowned academicians/industry experts. Furthermore, in this book, a significant weightage is given to the industry experts (around 50%) to enrich the industrial perspectives. We hope that amalgamate of fundamental knowledge from academicians and applied research information from industry experts will be useful for forthcoming implementation of a sustainable integrated microalgal biorefinery. This book highlights following. Explores biomolecules from microalgae and their applications Discusses microalgae cultivations and harvesting Examines downstream processing of biomolecules Explores sustainable integrated approaches for industrial scale operations Examines purification techniques specific for microalgal proteins, Omega 3 fatty Acids, carbohydrates, and pigments
This Brief provides a concise review of the potential use of microalgae for biofuel production. The following topics are highlighted: the advantages of microalgae over conventional biofuel-producing crops; technological processes for energy production using microalgae; microalgal biomass production systems, production rates and costs; algae cultivation strategies and main culture parameters; biomass harvesting technologies and cell disruption; CO2 sequestration; life cycle analysis; and algal biorefinery strategies. The conclusions section discusses the contribution of the technologies described to environmental sustainability and future prospects.
Algal biofuels have gained increased attention over the past decade due to its potential for substituting fossil fuels and sequestering carbon dioxide in the atmosphere. One of the major obstacles for producing biofuels from microalgae is extracting intracellular lipids, which requires penetration of solvents into the cell wall and membrane. Lipid extraction and the algae concentration processes combined account for the majority of the energy input required to make algal biofuels. Improvements in both of these steps are necessary for making algal biofuels production a net-positive energy process. The goal of this study was to improve the energy efficiency of lipid extraction from microalgae by either decreasing the amount of drying necessary for lipid extraction, or increasing the amount of lipids extracted via pretreatment methods. To achieve the goal, the following objectives were completed: (1) the effects of biomass concentration on solvent extraction yields with chloroform and n-hexane was investigated, (2) the efficiencies of chloroform and n-hexane as an extracting solvent were examined, and (3) the impact of pretreatment of microalgae with ultrasonication, microwaves, and electroporation on extraction yields was investigated. The microalgae Chlorella vulgaris (C. vulgaris) was grown in the laboratory in batch bioreactors. The microalgae was concentrated to different biomass concentrations and the lipids were extracted using two solvent systems: chloroform/methanol/water and n-hexane/ methanol/water. For the chloroform/methanol/water solvent system, the highest total lipid yield of 0.248 g per g of dry C. vulgaris was achieved at algal biomass concentration of about 15% on weight basis. On the other hand, the total lipid yield of 0.139 g per g of dry C. vulgaris was obtained at about 24% algal biomass concentration for the n-hexane/ methanol/water solvent system. Extraction of lipids with n-hexane was 76% of the yield of the extraction with chloroform. Electroporation, ultrasonication, and microwaves were studied for their potential pretreatment methods to increase lipid extraction from C. vulgaris. The yield for lipid extraction increased from 0.246 to 0.311 g per dry g of C. vulgaris when the cells were pretreated with ultrasonication, which is equivalent to a 26.4% increase. Pretreatment with microwaves resulted in a lipid yield of 0.317 g per dry g of C. vulgaris, which is a 28.9% increase. Electroporation resulted in a lipid yield of 0.259 g per dry g of C. vulgaris, which is a low increase of 5.3%, but electroporation was the most efficient in terms of energy requirements. It was also found that pretreatment of the algae does have the potential to replace polar solvents in lipid extraction for cell disruption, however improvements need to be made in the process in order to gain the same yield as a combined chloroform/methanol extraction.
Bioenergy Systems for the Future: Prospects for Biofuels and Biohydrogen examines the current advances in biomass conversion technologies for biofuels and biohydrogen production, including their advantages and challenges for real-world application and industrial-scale implementation. In its first part, the book explores the use of lignocellulosic biomass and agricultural wastes as feedstock, also addressing biomass conversion into biofuels, such as bioethanol, biodiesel, bio-methane, and bio-gasoline. The chapters in Part II cover several different pathways for hydrogen production, from biomass, including bioethanol and bio-methane reforming and syngas conversion. They also include a comparison between the most recent conversion technologies and conventional approaches for hydrogen production. Part III presents the status of advanced bioenergy technologies, such as applications of nanotechnology and the use of bio-alcohol in low-temperature fuel cells. The role of advanced bioenergy in a future bioeconomy and the integration of these technologies into existing systems are also discussed, providing a comprehensive, application-oriented overview that is ideal for engineering professionals, researchers, and graduate students involved in bioenergy. Explores the most recent technologies for advanced liquid and gaseous biofuels production, along with their advantages and challenges Presents real-life application of conversion technologies and their integration in existing systems Includes the most promising pathways for sustainable hydrogen production for energy applications
This book is designed with the objective of studying microalgae and its application in the widest sense. Microalgae offer various inherent advantages as they are capable of accumulating lipids (20–70%), and able to aid with the production of pigments, carbohydrates, and proteins. The book comprehensively covers microalgae isolation techniques, their cultivation, and wastewater treatment by microalgae as well as the impact on biomass, lipid extraction, biofuel, and utilization of residual biomass focusing on biorefinery approach. The volume discusses the conversion of defatted oiled microalgae biomass for different applications. Acknowledging these challenges, this book discusses the limitations, outcomes, and economic aspects