Green Options » renewable fuel

Low Cost Gas Engine Innovation Doubles Fuel Economy

Nick Chambers — Thu, 26 Jun 2008 15:15:02 +0000

Revetec, a little known company from the Gold Coast region of Australia, may be on to something huge: they’ve created an engine that is 50% smaller, 50% lighter, has 50% lower emissions and is cheaper to manufacture than a conventional internal combustion engine of the same horsepower. Oh yeah, did I mention that it doubles the fuel economy too.

What that means is a car like the 2007 Toyota Yaris, which is rated at 40 mpg on the highway, would get 80 mpg with a Revetec engine.

This isn’t some hoax… They have a prototype which has been attached to an actual vehicle and independently tested to substantiate their claims.

In personal communication with Mr. Brad Howell-Smith, the Chairman, Inventor and CAD Designer for Revetec, he says “road tests have estimated that [the engine] uses around 50% less fuel than a conventional engine” and if it were converted to run on diesel, that performance gain could be much higher.

Also, because the engine delivers higher torque, and can perform and operate well at much lower rpm’s than a conventional one, the noise levels are lower.

To illustrate how serious he is, Mr. Howell-Smith said that since 2001 his company has been in touch with the US Military Head of R&D for the Southern Hemisphere on a “regular basis” for the purpose of developing one of their engines for light aircraft.

The current prototype engine, the X4v2, is what Revetec calls a “controlled combustion engine.” The meat of the engine comprises two counter rotating multilobate cams, which are acted upon by two pairs of diametrically opposed pistons which are rigidly interlinked by connecting rods.

If that sounds like complete gibberish to you, you’re not alone. Which is why I included an animation of the process to the left. A more simplified animation of the general motion of an engine of this sort is also included below.

Mr. Howell-Smith said that “if [the engine] uses 50% less fuel given that it has the same top end as a conventional engine, emissions would be reduced by 50% if the bottom end was utilized.”

What does all that stuff about “bottom end” and “top end” mean? The X4v2 has a huge amount of torque over a much larger range of rpm’s than a conventional internal combustion engine.

If a person were to drive a vehicle fitted with this engine in a non-aggressive fashion and keep the rpm’s at the “bottom end” (meaning no “jack-rabbit” starts) they could expect to see a 50% reduction in emissions.

Alternatively, according to Mr. Howell-Smith, a person could see a 30% reduction in fuel use and a 30% reduction in emissions if they used the full acceleration power of the X4v2 all the time. This would provide a 20% increase in acceleration capabilities.

We could debate about whether or not the internal combustion engine has a place in the future of transportation or whether it’s going to be all-electric or fuel cell or whatever… but in the meantime, Revetec has a product that could revolutionize the the transportation industry now, and provide a much needed large reduction in fuel consumption and emissions.

Just imagine a bunch of 80 mpg Toyota Yarises (Yarisi??) running around all over the place. A little scary, I know, but… an 80 mpg conventional automobile? I must be dreaming, wake me up before I get too excited.

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Image Credits: Revetec

Turbine Engine: No Pistons, No Lube, 30% Better Fuel Economy

Nick Chambers — Mon, 09 Jun 2008 16:58:03 +0000

There are more than 5,000,000 heavy duty trucks running up and down US highways each day. Every one of those trucks gets an average of 7 mpg, carries upwards of 200-300 gallons of diesel, and spews out potentially harmful emissions.

Like it or not, we depend on them to bring us our food, fuel, and products for everyday living. It’s a connection that most of us often forget about, only remembering it long enough to curse them as they slow us down on the highway.

It’s also an industry that has recently been hit hard by soaring fuel prices, and now, with the average price of diesel in the US at $4.70/gallon and climbing, it’s sure to get worse.

Needless to say, there’s a rising cacophony of voices within the trucking industry clamoring for relief. Most of this noise currently comes in the form of wanting a break in fuel prices, but really that’s just a temporary fix. Any solution with sticking power would have to offer both economic and environmental benefit — you know, win-win.

Enter Turbine Truck Engines. The company has developed an engine for heavy duty trucks called the Detonation Cycle Gas Turbine (DCGT). Key features of this engine technology include:

Uses over 30% less fuel than current heavy duty engines
30%+ fewer emissions including nitrogen oxide (NO, NO₂, N₂O₂) and carbon monoxide (CO)
Operates on all fuels and mixtures of fuels: biofuels, hydrocarbon fuels, hydrogen and synthetic
Has few moving parts, requiring much less maintenance
Has no pistons or valves, and uses no lube oil, filters or pump
Is air cooled and lightweight (less than 2 lbs. per hp)

The company has been aggressively seeking investors recently and last year won the prestigious Frost and Sullivan Award for Technology Innovation.

Currently Turbine Truck Engines holds several patents and has a few prototypes under its belt. When (and if) their technology finally reaches the market, the combined savings on maintenance and fuel, as well as environmental benefits, could make this engine extremely popular with truck drivers and trucking companies worldwide.

What do you think? Is it worthwhile to invest in this type of technology, or should we move past fuel altogether and focus on other things such as our rail infrastructure for movement of goods? Is that even possible? Are big rigs a permanent feature of our society? Is there any way to run them entirely on electricity?

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Image Credit: Turbine Truck Engines

The Ultimate Green, Renewable Fuel (and Food): Algae, Possibly

Shirley Siluk Gregory — Tue, 03 Jun 2008 01:13:44 +0000

Across the U.S., researchers, startup companies and investors are exploring the potential of creating large amounts of green, renewable fuel from the humblest of sources: algae.

If you think the energy/food potential for hemp is underutilized, wait’ll you get a gander at algae. This little microorganism really packs a punch.

According to The Book of General Ignorance: Everything You Think You Know is Wrong (2006, Harmony Books) (I highly recommend it, by the way — it’s packed with fascinating information and weird insights), algae breathes out more oxygen than all the world’s land-based plants and trees combined. Certain types of algae also deliver a whopping amount of protein and nutrients per farmed acre (20 times more than soy beans, in the case of spirulina).

It’s the energy potential, minus the downsides of corn-based ethanol, though, that’s currently got many projects going full-steam ahead. San Diego-based Sapphire Energy, for example, recently announced it had successfully produced a 91 octane fuel using only carbon dioxide, sunlight and algae. And the Cambridge, Massachusetts firm GreenFuel Technologies Corp. expects to achieve commercially viable production of algae-based biofuel (at least 247 acres’ worth) in the “next few years.” It’s already set up pilot operations at six locations in Massachusetts, Arizona, Kansas, Louisiana, New Mexico and New York.

Less than two months ago, researchers at the University of Texas at Austin announced they had created a new “super” variety of fuel-producing algae by inserting the cellulose-making genes of a non-photosynthesizing bacteria into cyanobacteria, also known as blue-green algae.

Where will it all lead? While commercial production of algae-based fuel isn’t upon us yet, a new research-trade organization, the Algal Biomass Organization, recently went into full swing. It’s planning its second-ever Algae Biomass Summit this coming October in Seattle.

GM Announces New Cellulosic Ethanol Partnership with Mascoma Corp.

Clayton B. Cornell — Thu, 01 May 2008 19:38:51 +0000

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.

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Scania’s Ethanol Diesel-Engine, Runs On Biodiesel Too

Clayton B. Cornell — Tue, 15 Apr 2008 20:26:28 +0000

Scania (part of Volkswagen) builds modified, heavy-duty diesel engines designed to run on almost pure ethanol (E95, or 95% ethanol, with a 5% ignition improver).

If that sounds weird, that’s because it is. US auto manufacturers make a big deal out of converting cars and trucks to run on ethanol/gasoline blends of up to 85% ethanol. Scania has done better than that for 15 years, and guess what, their engines can run on 100% biodiesel too, without any modification.

Scania’s compression-ignition (CI) ethanol engine is a modified 9-liter diesel with a few modifications. Scania raised the compression ratio from 18:1 to 28:1, added larger fuel injection nozzles, and altered the injection timing. The fuel system also needs different gaskets and filters, and a larger fuel tank since the engine burns 65% to 70% more ethanol than diesel (whoa! see below). The thermal efficiency of the engine is comparable to a diesel, 43% compared to 44%.

While Scania originally introduced this technology for “heavy commercial vehicles in urban operation” (city buses), they’re now extending it to trucks as well. Scania maintains that with existing technology, the transition to renewable fuels can be painless. Since in the last 15 years they’ve put 600 ethanol buses on the road (mostly in Sweden), the company seems to know what it’s talking about.

Scania is also working to develop ethanol refueling infrastructure, which should make it easier for smaller transport companies to invest in ethanol-powered vehicles.

But why not use biodiesel, since ethanol requires about 1.5x more fuel usage? Scania’s answer may raise a few eyebrows: “the farming capacity [for biodiesel] is insufficient for the huge need foreseen for the transport industry.”

Unless you take EU spokesman Michael Mann’s comments seriously (he said that Europe can grow enough fuel to meet 10% of it’s transportation fuel), Scania must be betting on cellulosic ethanol. The intensifying food vs. fuel debate isn’t taking this issue lightly, as I’ve written about here and here.

In any case, Scania’s work seems to indicate it might not be as hard to create engines that run on alternative fuels as auto manufacturers maintain.

Posts related to Ethanol and Biodiesel:

European Union Defends Biofuel Targets As Food Prices Soar
Biodiesel Myth (Or Fact?) #23: Biodiesel is Raising Food Prices
Mercedes 40-MPG Diesel Hybrid: Cleanest SUV on the Planet
How Biodiesel Fuel-Cells Could Power The Future (And Your Car)

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