Genetically Engineered Algae and Microbes have the Potential to Produce Compounds that may be easier to Process into Biofuels

The use of genetically engineered microorganisms such as yeasts, algae and bacteria have the potential to produce a variety of biofuel compounds which are easier to extract since they are excreted from the microbes as is the case with ethanol. There are four different classes of compounds that are being currently developed by genetically altered microorganisms, this essay attempts to outline the main types under development as outlined by scientific literature and current company projects. The most common type of biofuel under current use is ethanol, which are one of the many types of alcohols that could be used as future biofuels. A company called Algenol has screened and altered a variety of algae that are able to excrete ethanol, as yeasts cells do. Algae have the advantage in that carbon dioxide and sunlight are used to produce biofuels. Algenol has developed a process called Direct to Ethanol which helps optimize the production of ethanol from the algae. In the future, other types of alcohols may be beneficial for biofuels, these include propanol and butanol derivates. There are a variety of metabolic pathways that have been discovered which make butanol or propanol. Pathways from the bacteria Clostridrium are known to produce good amounts of butanol. In fact, genes have been taken from Clostridrium and put into E. Coli which have produced several grams per liter of either 1-butanol, isopropanol and isobutanol [ 1. Radakovits et al 2010 ]. Algae have also been targeted genetically to produce modified alkanes or fatty acids which are excreted from the cells of algae, this allows the non-invasive extraction of biofuel related compounds.

In algae, genes that breakdown lipids can be targeted in order to produce free fatty acids, triacylglycerides (TAGs) and even alkanes. Genetic modification of these genes in algae also concentrates towards the increased excretion of these compounds from within the cells. Such work is being done by the company Synthetic Genomics. Their goal is to generate algae that can continuously excrete oil (ie fatty acids, alkanes). This production model is one of the promising ways to produce biofuels from genetically altered microorganisms since the compounds are more similar to diesel and gasoline type compounds and their extraction may be much easier since oil type compounds separate from aqueous solutions much easier than others such as alcohols. One type of algae called Botyrococcus Brauni produces very large chain hydrocarbons which may already be suitable for biofuel use. It would be interesting if genes from this algae could be transferred to other types in order to produce these large hydrocarbons. Another class of compounds receiving a great deal of attention recently is the production of isoprenoids from sources such as yeasts or genetically altered bacteria. One company called Amyris genetically engineers strains of yeasts that can produce various isoprenoids for applications related to chemical and biofuel production. Currently they have developed methods to produce an isoprenoid compound called farnesene and are planning to scale up this process for large scale production. This isoprenoid may be a type which could be used for biofuel use. E. Coli bacteria have also been targeted to host genes which can produce other types of isoprenoids such as isopentenol or pinene and terpinene which compounds have been claimed to be suitable jet fuel substitutes [ 2. Peralta-Yahya et al 2010 ]. Isoprenoid compounds are common in plants and other organisms and constitute a large set of compounds. Many of the genes which produce these biofuel type compounds have already been isolated and targeted. It is still a challenge to optimize these pathways in the correct microorganism for high yield biofuel production. However, in the short upcoming years we should be seeing the right types of host organisms with the right type of genetic and metabolic modifications for optimum biofuel production.

REFERENCES

1. "Genetic Engineering of Algae for Enhanced Biofuel Production", Eukaryotic Cell Vol 9 No 4 pgs 486-501 [2010] by R. Radakovits, RE Jinkerson, A. Darzins, M. Posewitz

2. "Advanced Biofuel Production in Microbes", Biotechnology Journal Vol 5 No 2 pgs 147-162 [2010] by PP Peralta-Yahya, JD Keasling

Photos taken from the Picassa Web Album

KEYWORDS: Ethanol from Algae, Clostridrium bacteria Butanol Production, Botyrococcus Brauni, Extracellular excreted fatty acids - lipids, Isoprenoid biofuel compounds, Genetic strains of Escheria Coli, Farnesene, Free Fatty Acids, Triacylglycerides, Propanol - Butanol alcohol derivate biofuel compounds

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The Need for our Natural Gas Vehicle Infrastructure to Expand through Continued Government Support and Training

Natural Gas or CNG (compressed natural gas) vehicles could provide a large amount of alternative fuel vehicles in the future as the proper training and facilities exist that allow companies to setup their own natural gas vehicle fleets. A large number of natural gas vehicle fleets already exist in the US, many are applied toward heavy duty vehicles which include buses and large trucks. In fact, one third of newly made transit buses are natural gas powered. Over 100,000 natural gas vehicles are on the road and the goal is to increase the number to over 1.6 million natural gas powered vehicles. The setup and maintainance of natural gas vehicle fleets require major infrastructure setups which oftentimes includes the conversion of gasoline or diesel engines into natural gas or propane based engines. Vehicle fleets can also require the set up of in-house natural gas service fill stations, which are very convenient for government and certain business locations that could possibly setup service stations in their own parking lot. In fact several types of natural gas service station fills for vehicle fleets can be setup using the existing natural gas lines near the businesses and organizations with the addition of equipment such as compressors, dryers, vaporizers & separators. The Department of Energy has a very nice website that includes publications that help companies setup natural gas service fill stations through their Alternative Fuels & Advanced Vehicle Data Center [ Link to NREL Publication ]. Across the country there are over 1300 natural gas fueling stations with half of them being available for public use. The DOE also has a NGV Station Locator.

Many NGV stations are private because they are fueling stations for government, school or business natural gas vehicle fleets as was discussed previously. In the future there should be a demand for automotive technicians who are certified in conversion/installation and maintenance of natural gas vehicles. There is also a need for Inspectors of the critical natural gas component systems in vehicles such as CNG (compressed natural gas). CNG vehicle components have to be inspected every 36,000 miles. There are basically three choices for natural gas systems that a vehicle can operate on, those being CNG (compressed natural gas), liquefied natural gas (LNG) and propane or LPG (liquefied petroleum or propane gas). Since common gasoline or large sized vehicles can be converted into natural gas systems, training should be needed for technicians who can convert light duty or heavy duty into natural gas based vehicles using one of the three types of natural gas fuels. Training technicians to set up and manage natural gas vehicle refueling stations as well as servicing these type of vehicle fleets should be needed in the future. In order to convert a regular gasoline engine based vehicle to run on natural gas, system components such as the fuel tank and carbuerator/fuel injection systems must be modified. Vehicles can even operate on a combination of CNG and gasoline. Organizations such as the National Alternative Fuels Training Consortium offer certified training courses and workshops concerning natural gas vehicles for those seeking to become automotive technicians in this discipline.

Special thanks for photo contributors from Picasa Web Album

KEYWORDS: Natural Gas Engine Conversion, Natural Gas Vehicle Station Locator, Setup of Natural Gas Filling Stations, CNG - LNG - LPG Vehicles, Light or Heavy Duty Natural Gas Vehicles, Natural Gas Vehicle Automotive Technicians, Natural Gas Vehicle Certification or Inspection, Natural Gas Vehicle Fleets

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Regenerative Redundant Electrical Generation in Electric Vehicles could Aid in Vehicle Efficiency

Power efficiency in Electrical Vehicles that includes electrical power regeneration should be a major consideration when designing these type of vehicles. The type and size of the rechargable vehicle battery is already one of the most important considerations when refering to overall vehicle efficiency. The two more important processes that require higher amounts of electrical energy in these vehicles are the air conditioning system and the battery recharing system. In many plug in electric vehicle designs, some of the power generated by the combustion engine is used to recharge the vehicle battery when its capacity gets lower than a certain charge level. In non plug-in electric vehicles (HEV's), regenerative electric power that is applied to the battery is produced by taking advantage of the braking and coasting functions that produce electric power near the wheels. This type of system would also be advantageous for plug in electric vehicles. In theory, a redudant electrical power generation system obtained from several regenerative power sources could help future electric vehicle designs. Redudant systems could be useful in plug-in electric hybrids since regeneration of battery power is not always needed and can be applied towards other electrical systems in the car such as air conditioning and lights. The type of regenerative power sources include roof top solar PVs, wind turbines, waste heat to electricity systems and also the aforementioned regenerative braking system.

Alternative power sources such as solar and wind power have already been developed and designed as regenerative power sources for electric hybrid vehicles. One example includes a possible wind turbine that can fit on the top of a vehicle roof that would be designed to recharge the battery. Such a system may be considered by Automobile manufacturers from individual(s) who have designed wind turbine & electric generator patent. The use of solar roof top PV panels have also been designed by companies and are currently being used in selected vehicle models for battery recharge capability. One of the more important functions of vehicle use that takes large amounts of electrical power is the air conditioning system. It is estimated that normal sized vehicles use up to 400 Watts of power just to run the air compressor used for air conditioning, waste heat generated from the vehicle is one regenerative power source that could be utilized to run an air compressor. Waste heat generated by the engine block could be taken advantage of also. The waste heat from the engine block could be recovered by placing semiconductor like chips on the engine itself and possibly converting the waste heat directly into electrical energy. There are many options to regenerate electrical energy to assist with it's many needed uses in a vehicle that many times is provided for by the battery itself. The size and weight of the vehicle battery itself also affects engine performance.

Photos taken from Picasa Web album

KEYWORDS: Redundant Electrical Power Generation, Regenerative Braking and Coasting, Waste Heat to Electrical Generation from Computer Chips, Vehicle Wind Turbine Generator, Vehicle Roof top Photovoltaic Panels

Dimethyl Ether is Becoming a Viable Diesel Fuel Alternative in Europe and Asia

In the future, there should be a need for more efficient heavy duty vehicles used for mass transit and transporting goods across a country. In addition these vehicles should be able to perform better (ie increased gas mileage and lowered emissions). One fuel that has been tested since 1995 in diesel type vehicles is Dimethyl Ether, which has been proven to meet fuel emissions standards and perhaps fuel efficiency ones as well. DME (dimethyl ether) can operate in diesel engines with minor modifications to the fuel injection system. Just as interesting, DME can also be mixed with LPG (Liquefied Petroleum Gas) to operate in ignition combustion engines (ie gasoline based). DME can be mixed at 30 % as an additive to LPG and engine modifications might also be needed such as new engine designs that incorporate spark and compression ignition (called Homogeneous Charge Compression Ignition Engine - HCCI [ 1. K. Yeom et al 2009 ]. The chemical structure of DME is shown in the image above. DME has favorable engine performance characteristcs because of its chemical/physical properties such as a low boiling point & high cetane number. DME also combusts very clean or in other words it is Sootles, meaning little to no smoke or particulates are emitted. DME also has projected lower combustion emissions of carbon dioxide, since it has a high oxygen content, it also more easily meets 2007 nitric oxide diesel engine standards due to more exhaust recirculation [ 2. L. Savadkouhi et al year ]. Another interesting fact is that DME can be produced at affordable prices using synthesis gas obtained from natural gas. According to the International DME Association, DME maybe at least 1.5 times cheaper to produce than diesel fuel and can also be simulataneously produced with methanol or converted directly from methanol.

The need to have a fuel distribution network and a good heavy duty vehicle infrastructure based on DME in Europe created a joint effort collaboration called the AFFORHD Project. In fact, there should also be heavy demands for DME trucks and buses in Japan and China. This has prompted companies like Nissan and Volvo to built diesel vehicles that can operate on DME. Nissan based trucks have already been built and have been tested by the National Traffic Safety and Environmental Laboratory where they passed US 2010 heavy duty vehicle emission standards. Increased pressure to have cleaner burning vehicles across the world has already got Europe and Asia pivoted to mass produce DME vehicles between the years 2015 - 2020. Dimethyl ether also has other similar uses to the petrochemical industry where it can serve as a energy production fuel or used as a chemical feedstock for making plastics. DME can be combusted in Gas Turbines for Electric Power Generation. It can be used as chemical feedstock to produce Polypropylene plastics. DME can also be mixed with LPG in order to be used a heating fuel in homes. It is usually mixed at about 20 % with LPG. Other physical properties that make DME a favorable fuel for multiple uses is its low viscosity, high cetane number and low octane number. Overall, DME can serve as a legitimate diesel fuel substitute with the advantage of having better fuel characteristics, performance and lower emissions. Vehicles such as these on the American Highways would be favorable since they may more easily pass more recent American fuel efficiency and emission standards as mentioned above.

REFERENCES

1. "Knock Characteristics in Liquefied Petroleum Gas (LPG) - Dimethyl Ether (DME) Homogeneous Charge Compression Ignition Engine", Energy Fuels vol 23 no 4 pgs 1956-1964 [2009] by K. Yeom and C. Bae

2. "Performance and Combustion Characteristics of OM314 Diesel Engine Fueled with DME : A Theoretical and Experimental Analysis" Journal of Engineering for Gas Turbines and Power vol 132 no 9 pgs 92801-92806 by L. Savadkouhi, S.A. Jazayeni, N. Shahangian, J. Tavakoli

Photos taken from the Picassa Web Album

KEYWORDS: Dimethyl Ether, Diesel Fuel Substitutes, Nitric Oxide Emission Standards, Liquefied Petroleum Gas, Simultaneous Methanol and Dimethyl Ether Production, Cetane Number, Viscosity, Homogeneous Charge Compression Ignition Engine, Gas Turbine Fuel, Home Heating Fuel, National Traffic Safety and Environmental Laboratory, AFFORHD, Nissan & Volvo DME trucks, Sootless emissions, low carbon dioxide emission fuels

Yeast Cultivation can also Produce Biodiesel from Renewable Waste Resources

The production of biodiesel from algae and microorganisms is a viable alternative to the usual methods of production which include crushed oilseeds and waste vegetable oil (WVO). Most people already know about the use of algae that is currently being developed for a number of different types of biofuels, another possible source of fatty acids for biodiesel that hasn't received much attention can be cultivated using microorganisms or yeast cells. Microorganisms or algae could be the favorable choice in biofuel production due to the theoretical high yield amount of biomass per acre as compared to conventional energy crops which usually include oilseeds such as soybeans. It is estimated that alternative biomass sources such as algae produce 30 times more energy value than these conventional crops. Several yeast cell varieties that have been experimented in with in the past can produce high fatty acids amounts per cell and along with high lipid yeilds. Three types of yeast varieties, those being Cryptococcus Curvatus, Lipomyces Starkeyi & Rhodotorula Glutinis can attain a cell lipid percentage of up to 60 - 70 % [ 1. X. Meng et al 2009 ]. An advantage with the cultivation of yeast cells for biofuels is that they can be grown using dark fermentation. Dark Fermentation is a term that usually applies mostly towards the production of biohydrogen from microrganisms. However, similar fermentation conditions and even carbon feedstocks work for the cultivation of yeasts even though they are not the same choice of microorganisms that usually make hydrogen. However, the same type renewable waste resources used for biohydrogen production can also be applied towards the cultivation of yeast cells towards lipid production. These type of renewable waste sources include wastewater sources, dairy wastes, starch hydrosylates, lignocellulosic wastes and even biodiesel glycerine waste.

Yeast cells also have the advantage of attaining high biomass yields in a short period of time. The growth rate of yeast as well as the actual conversion rate of a carbon source into lipids are very good. For example, with batch style fermentation, yeasts attain cell density yields of around 100 - 150 grams cells per liter, while lipid production rates are around 0.2 - 0.5 grams lipid per liter * hour and a carbon conversion rate of up to 30 % [ 2. P. Measters et al 1996 ]. High lipid yields can be attained by providing an excess amount of carbon feedstock as well as providing a lower nitrogen content in the growth media. In other words having a high carbon to nitrogen (C/N ratio) - (a similar concept in producing a good compost) and other factors such as favorable Temperature, pH and oxygen content provide higher lipid yields [ 3. L. Azocar et al 2010 ]. Companies are already using yeasts to produce biofuels although not towards the manufacture of lipids. One company currently cultivates yeast cells to make isoprenes. Isoprenes represent a large class of natural compounds produced by many organisms, of which plants usually produce a large subset of these compounds called terpenoids. Isoprene, which is a related compound can also be produced by microorganisms. It is used to make materials like rubber. The cost of producing biofuels from microorganisms or algae have some obstacles to overcome, such as processing and refining methods, costs and associated technology improvement needs. Production of biofuels from algae, microorganisms or yeasts may still be a favorable method of choice due to the possible availability of renewable waste resources as carbon sources to produce lipids. The production of biodiesel itself has the potential to manufacture even more biodiesel from the cultivation of yeast cells from the glycerine waste that may accumulate in large quantities as more biodiesel is produced. For example, it is estimated that for every 10 kg of biodiesel produced from certain oilseeds around 1 kg of waste glycerine is made. It is also estimated that even at the current production rate, the pharmaceutical industry only needs 1/3 of the glycerine produced to help manufacture drugs.

REFERENCES

1. "Biodiesel Production from Oleaginous Microorganisms", Renewable Energy vol 34 pg 1-5 [2009] by Xin Meng, J. Yang, Xin Xu, L. Zhang, Q. Nic, M. Xien

2. "High Density Cultivation of the Lipid Accumulating Yeast Cryptococcus Curvatus using Glycerol as a Carbon Source", Applied Microbiology & Biotechnology vol 45 pgs 575-579 [1996] by PAEP Measters, GNM Huijbents

2. "Biotechnological Processes for Biodiesel Production Using Alternative Oils", Applied Microbiology & Biotechnology vol 88 No 3 pg 621-626 by L. Azocar, G. Ciudad, HJ Heipieper, R. Navia

Photos taken from the Picasa Web Album

KEYWORDS: Cryptococcus Curvatus, Lipomyces Starkeyi, Dark Fermentation, Renewable Waste Resources, Biodiesel Glycerine, Isoprenes, High Production Biomass, Yeast based Biodiesel, High Lipid Percentage per cell, Rhodotorula Glutinis, Starch & Whey Hydrosylates

Photos taken from the Web Album of Picasa

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