Latest Discoveries and Breakthroughs

Cellulosic ethanol is a relatively new research domain within the biofuels industry. For this reason, there are a significant number of new developments that happen in the industry on a continuous basis. This page provides inputs on the innovations and breakthroughs in Cellulosic ethanol along its entire value chain.

Inputs are provided on the following aspects:

Feedstock Innovations and Breakthroughs
Pretreatment Innovations and Breakthroughs
Production Process Innovations and Breakthroughs
Production Facility Innovations and Breakthroughs
Hydrolysis Innovations and Breakthroughs
- Enzymatic Hydrolysis Breakthroughs
- Acid Hydrolysis Innovation and Breakthroughs
- Fermentation Innovations and Breakthroughs
- Ethanol Recovery Innovations and Breakthroughs
- Gasification Innovations and Breakthroughs

Feedstock Innovations and Breakthroughs

Agave as a Potential Ethanol Feedstock, February 2011

Agave, the perennial monocot genus of Mexican origin which is currently known for its use in the production of alcoholic beverages (Tequila) and fibers, would soon be evaluated for its potential to serve as a sustainable biofuel feedstock.

Agave is very much known to thrive in semi-arid regions where it is less likely to conflict with food and feed production. Also it is considered a unique feedstock because of its high water use efficiency and its ability to survive without water between rainfalls, even for extended period of time.

The current issue of Global Change Biology Bioenergy claims that Scientists have found through 14 independent studies that the yields of two Agave species greatly exceeded the yields of other biofuel feedstocks, such as corn, soybean and sorghum. The issue also gives additional information that even more productive Agave species which have not yet been evaluated do exist.

Agave is very much promising mainly because the biomass can be harvested as a co-product of tequila production without additional land demands. Also the abandoned Agave plantations in Mexico and Africa that previously supported the natural fiber market could be reclaimed for this bioenergy feedstock. More research on Agave species is essential though, to determine the tolerance ranges of the high yielding varieties that would be most viable for bioenergy production in semi-arid regions of the world.

With the raising interest towards bioenergy crops that have a low risk of unintended land use change, it can be expected that Agave could come under lime light in alternative energy market very soon.

Pretreatment Innovations and Breakthroughs

Xylan Delignification Process

An extrusion process melded with alkaline peroxide chemical pretreatments allows the lignin and hemicellulose in biomass to be solublized, and the cellulose component to be made available for enzymatic breakdown. This process is called the Xylan Delignification Process (XDP). In this paper, some results of the XDP on promoting enzymatic breakdown and SSF of corn stalks switch grass and straw are reported. It was found that the XDP process allowed quick (6 hour) and reasonably complete (85--88%) hydrolysis of the cellulose fraction of cornstalks, but was less effective in allowing utilization of the switch grass with 76% yield noted in 24 hours. Solubilization of the lignin and hemicellulose were not achieved on a first set of corn stalk, switch grass, and straw samples, but was noted on a second straw sample.

Production Process Innovations and Breakthroughs

Natural Bioreactors used for Cellulose degradation, February 2011

Microbiologists at the Technische Universitaet Muenchen (TUM) were worried about the food vs fuel crisis and have now turned their heads towards cellulosic ethanol. The scientists are not using any valuable crops for the ethanol production. Instead, they have decided to use the sugar that is stored in these plants, as cellulose. Since breaking down of cellulose would affect the stability of the plant, they have narrowed down to use bacteria tat, by nature, are capable of breaking down cellulose. These bacteria are mainly found in the bovine digestive tract and act as natural “bioreactors”.

The research group at TUM, headed by Dr.Schwarz, is presently working with Clostridium thermocelium, which is the most promising soil bacterium. This bacterium has been found to use about 70 enzymes that break down different parts of the cell wall in plants, making it extremely adaptive. The bacterium literally acts like a Chameleon, as it adapts its enzyme producing capabilities based on the part of the plant it thrives in and produces suitable enzyme complexes to degrade cellulose.

Dr.Schwarz’s lab is now concentrating on using the bacterium’s enzymes to find suitable enzyme combinations for the industrial degradation of cellulose.

Production Facility Innovations and Breakthroughs

New Patent for Enzymatic Hydrolysis of Cellulosic Ethanol, February 2011

Dyadic International Inc, USA, has been issued a U.S.Patent titled “Construction of Highly Efficient Cellulase Compositions for Enzymatic Hydrolysis of Cellulose”, by the United States Patent and Trademark Office (USPTO).

The patent is all about the use of enzymes from newly identified and isolated strains of Chrysosporium lucknowense, which when used in combination with other enzymes, demonstrates an extremely high ability to convert lignocellulosic biomass into fermentable sugars like glucose, xylose, arabinose, galactose, mannose, rhamnose, sucrose and fructose. These sugars are the key ingredients in the formation of biofuels.

C. lucknowense is a fungus, capable of producing cellulases, hemicellulase and other such enzymes. Dyadic identified various new enzymes including two new cellobiohydrolases (CBH Ib and IIb, or Cel7B and Cel6B), an endoglucanase (EG VI),a beta-glucosidase (BGL), and a xylanase (Xyl II) through the genome annotation project conducted in conjunction with Scripps Florida.. The research group at Dyadic was keen on using at least on of the two new cellobiohydrolases in conjunction with a BGL and EG VI.

Enzymatic Hydrolysis Breakthroughs

Abengoa to build ethanol plant, February 2011

Technology provider for the energy and environment sectors Abengoa will implement its enzymatic hydrolysis process technology to produce bioethanol at a commercial-scale in the US. The news comes after the company's second generation bioethanol pilot production plant, located in Salamanca, Spain, produced successful results.

The project, which received financing for its construction and start-up through the European Commission's 5th Framework Program, currently, produces 5 million litres of the biofuel from wheat and maize straw. Since it was launched in 2009, the plant has operated for over 5,500 hours, yielding 200 litres per tonne of straw, fermenting exclusively from the cellulose.

Now Abengoa will use its technology in a 100 million gallon-a-year plant, which it will build in Hugoton, Kansas. The project is being developed in conjunction with the US Department of Energy and will be the largest commercial bioethanol production plant using biomass to date. The plant will save approximately 135,000 tonnes of CO2 every year, equivalent to the annual emissions from 35,000 cars.

Abengoa aims for the large-scale production facility to achieve a yield higher than 300 litres per ton. The company has made major investments in enzymatic hydrolysis, including establishing a focused research line (the Enzyme Development Technological Program) to create more effective enzymes, which are key to the production of ethanol from biomass.

Acid Hydrolysis Innovations and Breakthroughs

Process and installation for obtaining ethanol by the continuous acid hydrolysis of cellulosic materials

The invention refers to a process and installation for obtaining ethanol as a liquid Fuel by continuous acid hydrolysis of cellulosic materials, such as wood, forest residues, agricultural residues, urban garbage and others, thus making possible the industrial utilisation of said cellulosic materials in high yield and productivity and with low investment, the latter being particularly true of agricultural residues, to produce ethanol, single cell protein, lignin coke, furfural, methanol and acetic acid.

United States Patent 4529699, 1985

Fermentation Innovations and Breakthroughs

Ethanol fermentation using oxidation reduction potential

This invention discloses the monitoring and controlling of oxidation reduction potential (ORP or redox) during the fermentation process for the production of ethanol. This novel process is intended for the burgeoning fuel ethanol industry, where both measurement and control of oxidation reduction potential is not currently practiced. With tighter controls on ORP, the new ethanol process will deliver higher yields, shorter fermentation times, and decreased byproduct formation.

United States Patent 7078201, 2006

Ethanol Recovery Innovations and Breakthroughs

Ethanol recovery process

A process for producing and recovering light alcohols, particularly ethanol, alcohol mixtures containing ethanol, and ABE mixtures (alcohol mixtures containing acetone, butanol and ethanol), using a combination of steps including fermentation, first membrane separation, dephlegmation and dehydration by second membrane separation.

United States Patent 7732173, 2010

Gasification Innovations and Breakthroughs

Fuel gasification system

The invention provides a fuel gasification furnace including a gasification chamber (1) for fluidizing a high-temperature fluidizing medium therein to form a gasification chamber fluidized bed having an interface, and for gasifying a fuel in the gasification chamber fluidized bed, a char combustion chamber (2) for fluidizing a high-temperature fluidizing medium therein to form a char combustion chamber fluidized bed having an interface, and for combusting char generated by gasification in the gasification chamber in the char combustion chamber fluidized bed to heat the fluidizing medium, and a first energy recovery device for using gases generated by the gasification chamber as a fuel. The gasification chamber and the char combustion chamber are integrated with each other. The gasification chamber and the char combustion chamber are divided from each other by a first partition wall for preventing gases from flowing there between, and which extends vertically upward from the interfaces of the respective fluidized beds. The first partition wall has a first opening provided in a lower portion thereof, and the first opening serves as a communication between the gasification chamber and the char combustion chamber, for allowing the fluidizing medium heated in the char combustion chamber to move from the char combustion chamber via the first opening into the gasification chamber.

United States Patent 7390337, 2008

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