Frequently asked questions
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1Q: What’s an enzyme?
A: An enzyme is a protein able to catalyze a specific chemical reaction that converts a molecule into another molecule. All living organisms, bacteria, yeasts as well as plants and mammals, contain thousands of enzymes that perform simultaneously and cooperatively all chemical reactions necessary to live.
Most enzymes bear at their surface specific sites and reactive groups to trap a molecule (the substrate) and process it into a new molecule (the product). Once the product is released, these specific sites are free to bind another identical substrate molecule so that the entire cycle can start again.
2Q: What’s a metabolic pathway?
A: A metabolic pathway is a complex series of chemical reactions catalyzed sequentially by several enzymes that lead to the synthesis of a target molecule. Most nutrients essential for the growth and survival of microorganisms are synthesized from environmental sugars by hundreds of metabolic pathways.
3Q: What makes Global Bioenergies’ metabolic pathway to isobutene “artificial?”
A: Global Bioenergies’ exclusive process is referred to as an “artificial” metabolic pathway. Compared to other approaches already in use, Global Bioenergies processes do not simply rely on the optimization or exploitation of naturally occurring metabolic pathways but rely on enzymatic activities and on metabolic intermediates that are not found in nature. These only occur in the microbial strains engineered by the Company. By engineering new functions into natural enzymes, we have created enzymes with specificity towards non-natural substrates that lead to the synthesis of target molecules.
Furthermore, isobutene is not naturally produced in nature. No microorganism produces significant amounts of isobutene, a molecule that is currently exclusively extracted from crude oil.
4Q: Which microorganism is used in Global Bioenergies’ process?
A: Several micro-organisms can in principle host our artificial metabolic pathway that converts carbohydrates (sugars) into isobutene. These micro-organisms include bacteria, such as Escherichia coli, or yeasts such as Saccharomyces cerevisiae. We are currently focusing our research work on the construction of Escherichia coli production strains.
5Q: Are these microorganisms GMO?
A: These microorganisms are indeed classified as GMO (genetically modified organisms): their genetic material has been altered so that they can express the enzymes responsible for our metabolic pathway. It is important however to distinguish our production strains that will be used in the strictly confined environment of a closed industrial fermenter from, for example, genetically modified plants growing unrestricted in fields. Even in the event of their accidental release in the environment (an event considered as extremely unlikely because of the safety measures and strict regulations in application), these GMO are harmless as they are laboratory-trained strains unable to survive in the natural environment.
6Q: What does fermentation mean?
A: Fermentation refers to the use of microorganisms to convert a raw material into a new product. For example, the transformation of sugars into alcohol using Brewer’s Yeast (Saccharomyces cerivisae) is called alcoholic fermentation. Our isobutene production process could therefore be described by analogy as “isobutenic fermentation.”
7 Q: What is a hydrocarbon?
A: Hydrocarbons are molecules composed exclusively of carbon and hydrogen atoms. Hydrocarbons are characterized by their unmatched energy density (around 45MJ/Kg), hence their preferential use in the transportation industry.
8Q: What are olefins?
A: Olefins, also called alkenes, define a subclass of the hydrocarbon family, characterized by the presence of at least one carbon to carbon double bond. Since double bonds are chemically reactive and thanks to these double bonds, olefins can be readily converted into many products and are hence often described as product trees in the field of fuel and materials production. Amongst the olefins group, several molecules are of significant industrial interest, they are: ethylene, a two-carbon molecule which is the basic constituent of the plastics used in packaging; propylene, a three-carbon molecule used to make hard plastics; isobutene, a four-carbon molecule found in many fuels and materials; and butadiene, a four-carbon molecule with two double bonds, which is principally used in making the synthetic rubber found in tires.
9Q: What are the advantages of these gaseous fermentation processes compared to traditional fermentation processes leading to the production of liquids?
A: The production of gaseous olefins using a biological process has two significant advantages:
- Fermentation of liquids stops as soon as the toxicity threshold is reached (13% in the case of ethanol, and it is why wine does not contain more alcohol than this percentage). Most chemical products have a much lower toxicity threshold (one or a few percent), which results in complex production processes as extraction must be carried out during fermentation. Fermentation of a gas avoids product accumulation in the fermentation medium. Limits linked to product toxicity for the production strain are therefore entirely avoided.
- When olefins leave the fermentation medium in the presence of air, water vapor, and CO2, the light olefins are already partly purified. This environment is indeed much less complex than the fermentation medium which contains thousands of different compounds. Downstream purification efforts will therefore be drastically reduced.
10Q: Why is isobutene a key component of fuels?
A: Most products of the petrochemical industry are repeats of four carbon atoms: the main component of gasoline derived from crude oil is octane, an eight-carbon molecule; Jet fuel’s main components are twelve carbon molecules and diesel contains mainly molecules composed of 16 carbons.
Isobutene, a reactive four-carbon molecule can be readily converted to 8, 12 and 16-carbon molecules that are all fully compatible and interchangeable with the current fuel products extracted from crude oil.
Iso-octane, in particular, is used as a standard in the octane rating scale: 100% pure iso-octane would be “unleaded 100.”
Iso-octane has many other benefits over ethanol: it is a hydrocarbon with a high energetic density (approx. 44MJ/Kg). One Kg of ethanol only contains 27MJ, or a third less, and the distance covered by a car using this Kg of ethanol is reduced by the same factor.
Finally, ethanol requires dedicated infrastructure for its storage and distribution since it is highly corrosive to engines and pipelines (transport of ethanol is carried out by trucks). In contrast, hydrocarbons derived from Global Bioenergies’ isobutene process are fully compatible with products derived from crude oil: they can be readily mixed without any limitation in terms of quantities added and neither costly changes in the infrastructures already in place, nor alteration of motor engines and consumers habits are required.
11Q: What else can be done with isobutene?
A: Isobutene forms the basic ingredient for many products derived from the petrochemical industries: it is a central component in the making of tires, organic glass (Plexiglas®), lubricants and some plastics.
The first market foreseen as profitable will be that of biomaterials derived from isobutene, where cost pressure is less than in the field of fuels
12Q: How do you transform isobutene into these products?
A: Isobutene is converted into the target products using chemical processes which are often already in use in the petrochemical industry. Using these processes, millions of tons of isobutene derived from crude oil is being converted into iso-octane every day. Similarly, organic glass, synthetic rubber and plastics are already being produced in several factories. In theory, an isobutene production unit using renewable resources and the GBE process could be attached to these existing factories.
Other applications, such as the production of jet fuels and pET, are yet to be industrialized on the basis of processes already existing at a laboratory scale.
13Q: How do we discriminate between the different generations of biofuels?
A: There is no easy answer to this question since no official nomenclature on biofuel names has yet been established. Generally speaking, the first generation of biofuels are based on the use of carbohydrates originally produced for human consumption such as sugars (from sugar canes or sugar beets) or starch from cereals that can be easily converted into glucose syrup.
The second generation of biofuels refers to biofuels derived from agricultural and forestry wastes products composed primarily of cellulose fibers. Similarly to starch, cellulose is a polymer of glucose. This polymer is, however, extremely resistant and its conversion into glucose syrup is difficult. Numerous companies are working on developing this process and a successful outcome is expected in the coming years. Several full-size factories are being built or about to start production.
The third generation of biofuels is still in development and aims at using photosynthesis to convert the carbon dioxide present in the air into biofuels. Many research scientists argue that micro-algae are the microorganisms that will be able to carry out this photosynthesis-based process in an economically viable way.
14Q: Which sustainable raw material can be used in your process?
A: Today the process uses glucose derived from cereals. The process is on the other hand not dependent on one specific resource as our metabolic pathway can be introduced in a range of micro-organisms. Some of these micro-organisms are more adapted to process saccharose extracted from sugar canes and sugar beets while others are more adapted to using glucose derived from starch in cereals. It will also be possible to use sugars derived from agricultural and forestry waste products (second generation biofuels) as soon as these are available in a manner that makes economic sense. We can also consider using photosynthetic microorganisms (third generation biofuels) by inserting our metabolic pathway in their genomes and thus enabling the conversion of the carbon dioxide present in air into hydrocarbons. This last method is, however, still in its infancy and will require a number of years of development before becoming operational.
15Q: Is Global Bioenergies currently developing new methods to process lignocellulose material?
A: Global Bioenergies has a keen interest in all new methods currently in development that can be used to extract sugars from lignocellulose material, those same sugars that are used by microorganisms during fermentation. Several industrial groups are actively exploring and industrializing a range of new methods and the first industrial scale successes are currently emerging. A successful outcome in the development of these methods will provide a new sustainable source of raw materials to be used in our production process.
Research aimed at extracting cellulose from plants is not carried out by Global Bioenergies as the company remains firmly focused on developing new strategies to convert sugars into olefins.
16Q: And what about the risk of competition between the production of food and that of biomaterials and biofuels?
A: With regards to biomaterials, these represent intrinsically large markets but which remain extremely limited when compared to global agricultural output and the issue is therefore limited. Dedicating a few percent of agricultural output to the production of materials is in continuity with today’s non-food agriculture (coton, rubber,etc.)
With regards to fuels, the question is real. There is still a little leeway in the short term: the FAO (Food and Agriculture Organization) has shown that 40% of agricultural resources are wasted (http://www.fao.org/docrep/014/mb060e/mb060e02.pdf). Reducing this waste and further increasing agricultural output are short term realistic objectives.
For the long term, the use of forestry and agricultural waste will increase the amount of sugar resources available and avoid any risk of direct competition between agriculture for biofuel production and agriculture for food supply.
17Q: Which countries have the best prospects for implementing and using bioprocesses?
A: Countries located in temperate and equatorial zones have good prospects regarding biofuels but the highest crop yields (defined in Kg of sugar per hectare and taking into account by-products such as hay and bagasse) are obtained with sugar cane plantations in tropical regions. Countries like India and Pakistan situated on the Tropic of Cancer or Brazil and South Africa on the Tropic of Capricorn have the distinct prospect to become one day for biofuels production what the Middle East is nowadays to crude oil production. Implementing biological processes represents a unique chance for the development of these countries. It is worth noting that Brazil is so far the world biofuels industry leader.
18Q: Can we have a progress update on Global Bioenergies' isobutene bioproduction process?
A: The development of such a complex process, from concept to the first commercially produced kilogram of material, requires approximately seven years based on current estimates. It can be split in several stages. The first stage consisted of obtaining a proof of concept. In our case, this step was extremely difficult since a major scientific breakthrough was required to build artificial metabolic pathways. This first step has been successfully completed for several of the Companies’ programs. These processes are now at the development stage which combines activities aiming at optimizing the metabolic pathway, at constructing production strains and at developing a lab-scale fermentation process. The industrialization of the overall process still remains to be achieved by gradually scaling up the size of fermenters to an industrial size (hundreds of m3).
19 Q: Can you already estimate the cost of one kilogram of “biohydrocarbons”?
A: The production cost of biological olefins would be of $1.6/Kg using cereals derived glucose as feedstock. This cost is lower than current isobutene and butadiene market price. The processes would therefore be profitable in today’s market environment. These conditions are bound to evolve positively in the coming years as it is expected that isobutene and butadiene price will increase faster than that of plant based resources.
20Q: What is the expected impact of the isobutene bioproduction process on employment once it is commercialized?
A: Bioprocesses create jobs that cannot be relocated since the production plants must be situated close to the supply of raw materials. These bioprocesses will have a positive impact on employment in France, the leading agricultural country in Europe, as well as for countries with a highly developed agricultural sector.
21Q: Can we expect the isobutene bioproduction process to have a positive impact on the environment?
A: Olefins derived from plants are expected to have a more positive environmental impact than their homologues derived from crude oil. This is estimated when looking at the overall process from start to finish: the isobutene production process from crude oil can be considered as a linear process. Crude oil is extracted, converted into a range of products such as fuels and materials and they all end up eventually as CO2 in the atmosphere.
On the other hand, the plant-derived olefins production processes can be pictured as a cycle: the olefins are produced from plants and used as fuels or to make products. After use and combustion the carbon also ends up as CO2 in the atmosphere but it is then re-absorbed by the plants themselves as the starting point for a new cycle of olefin production.
If this cycle was perfect, CO2 emission would be reduced by 100%. Unfortunately this is not the case and CO2 emission is only expected to be decreased by 20 to 80% depending on the type of plants used as starting material for the production process. These first estimates will be validated through trials on an industrial pilot.