Advanced Bioprocessing for Alternative Fuels, Biobased Chemicals, and Bioproducts

Technologies and Approaches for Scale-Up and Commercialization

Majid Hosseini

• Publisher: Woodhead Publishing
• Year: 2019
• ISBN:
  9780128179420
• Topic: Ciencias físicas
• Subtopic: Energía

Advanced Bioprocessing for Alternative Fuels, Bio-based Chemicals, and Bioproducts: Technologies and Approaches for Scale-Up and Commercialization demonstrates novel systems that apply advanced bioprocessing technologies to produce biofuels, bio-based chemicals, and value-added bioproducts from renewable sources. The book presents the use of novel oleaginous microorganisms and utilization strategies for applications of advanced bioprocessing technology in biofuels production and thoroughly depicts the technological breakthroughs of value added bioproducts. It also aides in the design, evaluation and production of biofuels by describing metabolic engineering and genetic manipulation of biofuels feedstocks.

Users will find a thorough overview of the most recent discoveries in biofuels research and the inherent challenges associated with scale up. Emphasis is placed on technological milestones and breakthroughs in applications of new bioprocessing technologies for biofuels production. Its essential information can be used to understand how to incorporate advanced bioprocessing technologies into the scaling up of laboratory technologies to industrial applications while complying with biofuels policies and regulations.

• Presents the use of novel oleaginous microorganisms and utilization strategies for the applications of advanced technologies in biofuels production
• Provides a basis for technology assessments, progress and advances, as well as the challenges associated with biofuels at industrial scale
• Describes, in detail, technologies for metabolic engineering and genetic manipulation of biofuels feedstocks, thus aiding in the design, evaluation and production of advanced biofuels

Chapter 1

A Perspective on Bioprocessing for Biofuels, Bio-Based Chemicals, and Bioproducts

Majid Hosseini, Manufacturing and Industrial Engineering Department, The University of Texas Rio Grande Valley, Edinburg, TX, United States

Abstract

The global search for renewable fuels has sparked fervent curiosity in both bioproducts and biofuels. This is in part to the growing concerns over global warming with the thought that carbon dioxide emission can be curbed through the implementation of sustainably converted biomass into biofuels and value-added bioproducts that are in high demand. By implementing calculated strategies alongside appropriate regulatory frameworks, renewable fuels could be monumental in impeding the progress of global warming while augmenting energy security, furthering diversity in international agricultural efforts, and raising the incomes of the rural communities. In addition, the production of renewable fuels can be supplemented by integrating specific genetic engineering practices, thus yielding a feasible component of the total energy makeup. The optimization of biomass production may be achieved by implementing genetic engineering techniques in energy crops, along with crop modifications that enhance their fuel conversion potential. Furthermore, genetic engineering also presents an opportunity to aid in the downstream processing of biomass into fuel. While the promise of genetic engineering is alluring, it also comes with uncertainties as such products created via this technology may raise international concerns. This chapter intends to provide an overview of recent trends in the creation and exchange of advanced bioprocessing for biofuels, bio-based chemicals, and bioproducts. Moreover, a discussion on the impact that bioprocessing and biotechnological routes may have on enhancing biofuels production, bioeconomy, and improving its viability in the marketplace is also provided.

Keywords

Bioprocessing; biofuels; bio-based chemicals; bioproducts; genetic modification

1.1 Introduction

Given the dire global consequences that higher temperatures and unstable climate changes could trigger, intensified in the developing countries, there is an urgent need for progressive policy amendments. The consensus is that this century’s energy goal, providing sufficient affordable energy to meet and exceed demand while mitigating undue environmental impacts, is not achievable without a massive innovative effort on a global level. Although it would be naive to believe that biofuels would resolve all of the current global energy problems and concerns, investing in their development could yield solutions to climate change while decreasing fossil fuel dependence for those countries that import energy. Thus, investing in novel energy technologies could be fruitful economically, environmentally, and in geopolitical terms.

The most recent analysis conducted by the International Energy Agency in 2017 [1] projects that by 2040, global primary energy demand is on track to increase by 30% and oil demand continues to grow to 2040, while the share of direct and indirect renewable use in final energy consumption rises globally from 9% today to 16% in 2040. Still fossil fuels account for a large portion of the projected expansion in demand by 2040. Although modest in nature, the demand for natural gas is also expected to experience growth and natural gas use rises by 45% to 2040. The increasing global demand for energy will also impose a credible threat to the world’s energy security. Further exacerbating the interim security risks is the disproportionate amount of countries that produce oil compared to ever growing demand from those that rely on importing oil and gas.

A plentiful supply of biomass is critical for a bio-based industry. Biofuels are defined as fuels which are derived from biomass, with the most prolific liquid biofuels being bioethanol and biodiesel. Ethanol, an alcohol, can fuel cars designed to operate on either pure ethanol or a blend of gasoline and ethanol dubbed “gasohol.” In its blended form, ethanol can become an octane booster, an additive that can reduce pollution when combined with unleaded gasoline replacing the more commonly used methyl tertiary-butyl ether additive. Another biofuel is biodiesel that can also be used in its pure or blended (with petroleum diesel) form. Although the focus of biofuels is typically within the transportation sector, their cooking capability could prove to hold great global significance, specifically in the rural communities of the developing countries. Comparatively, the amount of pollutants and emissions created by biofuels in cooking applications is drastically lower than that of its traditional solid-fuel counterparts. As such, biofuels as a whole could improve the quality of life for billions across the world.

Future energy security and reduced greenhouse gas emissions may be achieved through advances in biofuels and bioproducts, freeing the global economy from the constraints of fossil fuel dependence. Specifically, increases in the forestry and agricultural sectors alongside a boost to rural economies are some of the benefits of adopting the use of biofuels and bioproducts while also creating new opportunities for growth via biorefineries and their production of various consumer products (e.g., bio-based chemicals, biofuels, and value-added products).

In order to totally replace petroleum and its derived products, the production of biofuels requires a plentiful, renewable, and eco-friendly feedstock, such as biomass. A potential solution lies in the implementation of an integrated biorefinery where the main feedstock for biofuel and bio-based chemicals can have the nutritional components extracted while the byproducts are converted into profitable materials (i.e., animal fodder).

Furthermore, by utilizing both macro- and microalgae, arable land usage concerns would be mitigated while global fuel demands are met [2]. By pursuing new technologies and discoveries within aquaculture, genetic engineering, energy crops, and conversion methodologies, sustainable eco-friendly biorefineries will significantly impact the world’s energy, biofuel, bioproducts, and renewable chemical supplies. Biorefineries also have no shortage of obstacles to overcome.

Virgin fossil fuels may ultimately be replaced by the production of renewably sourced bio-based chemical, value-added bioproducts, and biofuels. Concurrently, attempts at making alternative fuels readily available in the market must be done along with ensuring environmental and economic sustainability. The integration of producing value-added bioproducts alongside energy outputs in a biorefinery may yield systematic improvements to both productivity and profitability. Economic success lures shareholders and corporations into investing in new biorefineries, thus increasing the domestic bioenergy supply. A biorefinery’s efficiency and productivity can be optimized by conserving energy usage as well as utilizing feedstocks, waste, and byproduct streams to their fullest extent while employing economies of scale to reduce operating expenditures.

The economics of lignocellulosic biorefineries are not yet viable due to the difficulties and cost associated with cellulose’s processing, pretreatment, and enzymatic hydrolysis. In addition, microalgae-based processes also face hurdles associated with scale up, making the production process far from cost effective [3]. To surmount these challenges, advancements in biomass conversion via genetics, bioprocessing, and metabolic engineering will be needed in order to support an economical and sustainable bio-based future. As such, all elements of the biomass must be fully utilized so as to maximize profit while minimizing waste generation when producing biofuels and bioproducts. The incorporation of various improvements across a multitude of disciplines including less costly enzymes for hydrolysis, newly synthesized catalyst for biomass to biofuel conversion, and enhanced bioprocessing techniques will allow the goal of a bio-based future to become fully realized commercially and globally.

Foreign petroleum dependence is anticipated to diminish in the wake of widespread adoption of biofuels and bioenergy production. In order to develop the necessary infrastructure and technology prior to implementation, renewable resource processing must be given scientific priority. Yet another significant opportunity lies in environmental protection via bioprocessing. An overall reduction in industrially generated and municipal waste streams could be realized through feedstock bioconversion to biofuels in place of toxic hydrocarbon production.

The enduring goal of the scientific community is to create carbon neutral bioprocesses that efficiently use a wide range of renewable resources to produce energy and chemicals with the intent to make technological and scientific gains in meeting the emergent bioeconomy’s demands.

Incremental efficiency improvements as well as rapid analytical characterization of renewable fuel have led to developments in robust, stable, and even automated bioprocessing technologies and systems. Recent development of specially adapted separation and purification technologies for the recovery of bio-based products and the progress made in bioprocessing technologies will facilitate the economic conversion of renewable feedstocks into biofuels, bio-based chemicals, and value-added bioproducts. Microorganisms that have been genetically modified (GM) and are capable of transforming biomass into biofuels, bio-based chemicals, and value-added bioproducts along with development of bioproducts’ biomanufacturing processes that are highly regulated, controlled, and have foreseeable performance may provide means in an earlier adoption of biofuels production from renewable resources.

1.2 Challenges and Prospect of Bioprocessing for Biofuels and Bioproducts

The advanced technologies used for bioprocessing face obstacles not only in recognizing industry needs but also in furthering the transfer of technology while teaching the next generation of engineers and scientists that will support growth within the field. This includes supporting innovative alternative fuels technologies that will fully harness that potential of contemporary bioprocessing.

Essentially, the tenants of industrial bioprocessing are understanding the biocatalysts or microorganisms employed, maintaining product quality and safety no matter the operation’s size, exercising environmental stewardship, and promoting process innovation to maintain a competitive edge within the industry as well as with consumers. Specific bioengineered processes of note include bioreactor design, concentrating and purifying diluted product streams, and applying cost-effective engineered solutions to biofacilities from cradle to grave [4]. In order to nurture growth in the understanding of how to produce a growing and wide array of biofuels, bio-based chemical, and bioproducts, a sustained and internationally agreed upon policy is paramount. A selected few of more than 72,000 algae species have been thoroughly evaluated [5], and even fewer have been used on an industrial scale. The latest attempts in laboratory and pilot scale phototrophic, heterotrophic, and mixotrophic microalgae cultivation have unveiled novel organisms that have yet to be exploited. While renewable energy is already being used in many different forms, microalgae-derived carbon-neutral biofuels are desirable candidates due to their sustainability, large carbon dioxide sequestration capacity, large lipid production, and their ability to grow in a multitude of environments (e.g., brine, brackish, and wastewaters) [6–9]. The cheap and economical extraction of lipids form microalgae continues to be a major hurdle in its commercial biofuel adoption. Fervent studies are currently ongoing to ascertain the capability of microalgae as both a biofuel and in carbon dioxide fixation. While a promising biofuel feedstock, microalgae are not yet utilized on an adequate industrial scale for bulk commodities. The final cost of the extraction process can also be aided by a comprehensive techno-economic analysis, which will also provide guidance by means of a cost/benefit analysis for future process improvement (e.g., increased lipid yields). However, relevant breakthroughs in technology (e.g., genetic modification, metabolic engineering techniques, and biorefining) indicate that further developments will yield a suitable process that is both economical and sustainable in the near future. Future industrial processes may rely upon the novel chemicals yet to be unlocked within microalgae.

Existing examples of modern bioprocessing technologies demonstrate the vast variety of manufacturing methodologies required to create bioproducts and biofuels. A singular step has the potential to greatly skew the cost, quality, and properties of the resulting product. Transforming microorganisms and creating new biocatalyst necessitate the use of many different types of advanced bioprocessing techniques. Something that is often neglected is the variety of engineering skills, specifically those for bioprocessing that are required when dealing with bio-based products. Specific bioengineering challenges in the field today are as follows: ensuring that regulatory and biological standards are met in equipment design while remaining economical; ensuring bioproducts processes are environment friendly and sustainable; and demanding consistent high-quality bioproducts by implementing robust and rapid purification processes. Highly specialized bioproducts are often the result of dilute solution fermentation, a process that can be optimized by improving energy usage and efficiency which can be done by driving down costs in handling, synthesis, and downstream processing. Other areas of improvement include bioreactor design and making conditions more conducive to cultivating and creating microorganisms and their products. Advanced bioprocessing techniques also can make advances in fermentation (i.e., submerged, solid substrate) while cellular and genetic manipulation can make strides in the field by changing the physical properties of microbe membranes to negate the toxicity caused by extracellular fermentation products.

The three dominant products of biofuels and bioenergy are presently bioethanol, biodiesel, and biogas. Synthesized via the fermentation of soluble sugars or starches (e.g., sugarcane, corn), bioethanol is considered to be a first-generation biofuel. Within the scientific community, there is a push toward the development of second-generation bioethanol, derived from the lignocellulosic biomass of plants, with the initial results showing great promise. Comprising lignin polymers, hemicelluloses, and cellulose, lignocellulosic biomass is a renewable resource and can be used to manufacture biofuels and value-added bioproducts. Unfortunately, the molecular structure and heterogeneity of lignocellulose may prove to be problematic. The lignin’s resistance to enzymatic degradation, preventing the conversion of the plant’s available polysaccharides into sugars, is the overwhelming recalcitrant factor for biofuels production. Furthermore, as a nonlinear polymer that is inherently chemically diverse and composed of weak reactive linkages along with multiple monomer units, the lignin’s phenolic polymer within its cell wall component is to blame for overall biomass recalcitrance. As such, lignin degradation is cost prohibitive, requiring pretreatment to access the polysaccharide content required for biomass conversion to biofuel. Genetic manipulation techniques have attempted to facilitate plant biomass processing by employing a methodology that, while in its infancy, would create plant that either accumulates less lignin or yields lignin that is readily decomposable. Conventional techniques utilize genetic engineering in such a way that modifies the enzyme expression used for lignin biosynthesis.

1.3 Bioprocessing Routes for the Production of Biofuels and Bioproducts

The developments of advanced biotechnology and bioprocesses for the production of biofuels and bioproducts have been selected as topics to be discussed at length herein. Biotechnology was first used by Karl Ereky in 1919, in reference to the science and methodologies that create products from raw materials while aided by living organisms [10]. Genetic engineering (or recombinant DNA technology) utilizes biotechnology to manipulate the cellular structure genetically through the introduction or elimination of specific genes. The use of these techniques yields GM organisms (GMOs), organisms altered by inserting at least one transgene frequently from a different species than that of the recipient. The 1970s gave way to the first genetic modification experiments, combining synthetic human genes with bacterial genes. Ten years later, research could insert genes into fungi and yeast as well as otherwise foreign genes into plant and limited animal cells. In regards to the biofuels sector, both biotechnology and genetic engineering hold great promise in advancing agricultural production and converting biomass. Such gains may come in the form of energy crop production optimization, increasing crop yield per acre, modifying feedstock to aid in ease of fuel conversion, and the novel creation of enzymes that support downstream biofuel processing [11]. Although genetic engineering appears quite alluring at present, it is not clear if it will deliver on its promises, be overshadowed by new technologies, or become cost prohibitive in the future.

Although selective breeding methods will continue to influence agricultural a...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of Contributors
• Preface
• Chapter 1. A Perspective on Bioprocessing for Biofuels, Bio-Based Chemicals, and Bioproducts
• Chapter 2. Metabolic Engineering and Genetic Manipulation of Novel Biomass Species for Biofuel Production
• Chapter 3. Subcritical Hydrolysis Contribution in the Holistic Biorefinery Concept: Obtaining Bioproducts and Biofuels From Renewable Natural Resources for a Novel Bioeconomy
• Chapter 4. Thermochemical, Biological, Biochemical, and Hybrid Conversion Methods of Bio-derived Molecules into Renewable Fuels
• Chapter 5. Biological Production of Alcohols
• Chapter 6. Biobutanol Production
• Chapter 7. Uses of Enzymes for Biodiesel Production
• Chapter 8. Recent Trends and Advances in Glycerol-Free Biodiesel Production
• Chapter 9. Lignin: Understanding and Exploring Its Potential for Biofuel Production
• Chapter 10. Bioconversion and Chemical Conversion of Biogas for Fuel Production
• Chapter 11. An Approach Toward Cellulase Production, Bioconversion, and Utilization
• Chapter 12. Bioconversion of Agricultural Wastes From the Livestock Industry for Biofuel and Feed Production
• Chapter 13. Producing Animal Feed as a Coproduct of Biorefining
• Chapter 14. Electro-Fermentation—Microbial Electrochemistry as New Frontier in Biomass Refineries and Industrial Fermentations
• Chapter 15. Biohydrogen Production From Renewable Resources
• Chapter 16. Multipurpose Use of Microalgae to Treat Municipal Wastewater and Produce Biofuels
• Chapter 17. Algae as a Source of Microcrystalline Cellulose
• Chapter 18. Liquid Biofuels From Microalgae: Recent Trends
• Chapter 19. Assessing Microalgae Sustainability as a Feedstock for Biofuels
• Chapter 20. Production of Microalgae-Derived High-Protein Biomass to Enhance Food for Animal Feedstock and Human Consumption
• Index