A number of companies are gearing up to finally start-up commercial cellulosic ethanol plants in the US this year, using enzymes to extract sugar from biomass.
Abengoa is weeks away from starting up the ethanol portion of its cellulosic complex in Kansas, an executive with the company said on 18 February.
Abengoa is among three companies that plan to start commercial-scale production of cellulosic ethanol this year. All three plants use enzymes to extract sugar from biomass.
A new biomass fuel revolution is set to begin
By the end of this year, DuPont should start operations at a 30m gal/year cellulosic ethanol plant in Iowa. Earlier in 2013, INEOS Bio started cellulosic ethanol production at an 8m gal/year plant in Florida. However, this plant relies on a gasification process to produce ethanol from biomass. It does not use enzymes.
For years, cellulosic-based production has been a goal for the industry. It could create a potentially large and low-cost source for sugars that would not compete with food-based raw materials such as corn.
A PIVOTAL YEAR
“How many years have we all sat around and said: ‘In five years we’re going to see commercial production’?” said Christopher Standlee, executive vice president of Abengoa Bioenergy New Technologies. Standlee made his comments at the National Ethanol Conference.
“Ladies and gentleman, I am thrilled to finally say that this is a pivotal year for second generation ethanol in the US, perhaps in the world,” Standlee said.
Abengoa has already started a 21 MW plant at the site that is powered by biomass, Standlee said. The Spain-based multinational company started selling electricity produced from the plant to the grid last year.
The ethanol portion of the complex will use wheat straw and corn stover collected from a 50-mile (80km) radius, Standlee said.
Over the years, Abengoa has improved the efficiency of its production process, he said. At one point, the company was producing 55 gal of ethanol for each ton of biomass. Standlee did not specify if the biomass was measured in metric tonnes or short tons.
The company has since reached 80 gal/ton, he said.
Enzyme costs have fallen from $1.50/gal to 30 cents/gal, Standlee said. Overall production costs have fallen to about $2/gal from $4/gal.
Abengoa is now considering different feedstock for its process, such as municipal solid waste, Standlee said.
POET-DSM START-UP IN Q2
POET-DSM Advanced Biofuels expects to complete the start-up process for its US cellulosic ethanol complex by the end of the second quarter, an executive with the company said on 18 February. The plant should be mechanically completed by the start of Q2, said Steve Hartig, general manager, licencing for POET-DSM. He made his comments on the sidelines of the National Ethanol Conference.
The plant is being built in Iowa, and it should have a capacity of 25m gal/year, he said.
POET-DSM is a joint venture between US ethanol producer POET and the Dutch chemical and life sciences firm DSM.
COMPETITIVENESS VS CORN
Companies, though, have struggled to develop a biomass-based process that can compete with corn, the main US feedstock for ethanol.
Right now, the POET-DSM plant will not immediately make ethanol at the same cost as corn-based product, Hartig said.
However, that could change once companies gain more experience and learn lessons in operating this first wave of commercial-scale cellulosic ethanol plants, he said.
POET-DSM purposely used materials and employed designs that likely exceeded the requirements for the plant. This was done as a precaution to avoid having to remake or redesign units, all of which would be costly. “We were conservative on everything,” Hartig said.
Future plants would not need to take such cautious steps, he said.
In addition, the experience that POET-DSM gains from operating a commercial-scale plant can be used to design a second plant that can operate at a lower cost, he said.
Biomass has three main components: lignin, hemicellulose and cellulose.
Cellulose is a source of six-carbon sugars (C6), while hemicellulose is a source of five-carbon sugars (C5).
POET-DSM has engineered yeast that can consume both types of sugars to produce ethanol, Hartig said. That ensures that little sugar remains unused.
Looking ahead, the sugars extracted from biomass can be used to produce materials other than ethanol, Hartig said.
New fermentation technology could give ethanol producers several alternatives, such as farnesene, isobutanol, succinic acid, butanediol (BDO) and acrylic acid.
In fact, DSM and Roquette Freres created a joint venture called Reverdia that is producing renewable succinic acid from a 10,000 tonne/year plant near Genoa, Italy.
Cellulosic ethanol complexes could use a portion of their sugars to produce high-margin specialty chemicals while using the bulk for fuel, Hartig said.