GM Announces New Cellulosic Ethanol Partnership with Mascoma Corp.

Mascoma Cellulosic Ethanol

General Motors announced today it would be entering into a strategic relationship with Mascoma Corp., a second-generation biofuel company with the technology to produce cellulosic ethanol from non-food sources via a single-step biochemical conversion.

The undisclosed equity share aims to contribute to joint research and development along with technology exchange, plant siting, and rapid commercialization of cellulosic ethanol technology and infrastructure. This is GM’s second investment in a cellulosic ethanol company, after announcing partnership with Coskata back in January.

Mascoma is a 3 year old energy biotech company based in Boston. Their proprietary production process, called Consolidated Bioprocessing, limits the use of chemicals and enzymes required by other biochemical methods to make cellulosic ethanol. There are two basic processing methods: biochemical treatment and gasification (see post on Coskata).

How Does Mascoma’s Cellulosic Ethanol Process Work?

During a conference call today, I asked Chairman and CEO of Mascoma Bruce Jamerson how their process differs from standard biochemical production processes. He described it like this:

Cellulosic ethanol feedstocks are usually broken down by some kind of pre-treatment, like a mild acid bath. At that point, the cellulose (which is basically a chain of glucose sugar molecules) is clipped apart into C5 and C6 sugars by enzymes. Those sugars are then fermented into ethanol by other microbes. Each of these steps take time, and money. The first step after pre-treatment, called hydrolysis, typically requires purchasing expensive enzymes. The best way to reduce the cost and throughput time would be to eliminate some of these steps.

Mascoma’s proprietary microorganims do all of the post pre-treatment steps at once, without the need for separate batches. The advantage of this is decreased throughput time, lower capital cost, and higher yields.

The other big difference about Mascoma is their pretreatment step, which essentially chops up plant material and uses a proprietary process involving heat, water, temperature, and mechanical action to prepare the plant material for digestion. Since it doesn’t use acids or bases to break down cellulose, it avoids chemical use and decreases waste materials.

Mascoma can make cellulosic ethanol out of any non-grain feedstock like switchgrass, corn stover, wood chips, waste wood material.

What are Mascoma’s Plans for Commericalization?

Mascoma is building a demonstration facility in New York, and hopes to have it operating by end of the year. The company is looking at 2010 or beyond before commercial scale facilities are operating.

Mascoma, like Coskata, is backed by Khosla Ventures, and has raised about $90 million in investments.

Is Mascoma Competing with Coskata for Biofuel Supremecy?

During a conference call today, Mary Beth Stanek of GM said that Coskata and Mascoma aren’t really competing with one another, since they offer complimentary approaches to producing ethanol. Bruce Jamerson commented that they’re glad GM is investing in both Coskata and Mascoma because there is such a demand for low greenhouse gas fuels.

How does Mascoma’s Ethanol Compare?

Mascoma said their fuel would incur approximately $1.00 to $1.50 per gallon production cost, completive with gasoline.

GM said they’ve thoroughly evaluated Mascoma’s environmental metrics, which include:

  • Greenhouse gas savings: 90-95% reduction when compared to gasoline.
  • Commercial stage water use: 2-3 gallons water per gallon ethanol produced (compared to Coskata’s 1 gallon).
  • Commercial stage net energy balance: around 1:8-10 (8 to 10 units of energy produced for each put in). Mascoma says they’re currently getting an energy return of 1:5.5 in the lab.

Why Does GM Care so much About Cellulosic Ethanol?

It’s no mystery why GM is interested. They’ve already got 4 million Flex Fuel vehicles (those that can run on 85% ethanol) on the road, and any effort to rapidly commercialize cellulosic ethanol will help them in the long term.

For more on this topic, see GM’s Grand Plan For Solving America’s Oil Dependence.

Update: Mascoma receives $10 million in equity investment from Marathon Oil.

Posts Related to Cellulosic Ethanol, GM, and Coskata:


In a past life, Clayton was a professional blogger and editor of Gas 2.0, Important Media’s blog covering the future of sustainable transportation. He was also the Managing Editor for GO Media, the predecessor to Important Media.