Commercial Solar Rooftop Installation

Commercial solar rooftop installation is installing solar panels on the roof of a commercial building to generate electricity. Commercial solar systems are typically larger than residential ones, ranging in size from a few kilowatts to several megawatts.

The installation process typically begins with a site assessment to determine the suitability of the roof for solar panels. Factors such as roof orientation, shade, structural integrity, and available space are all considered. Once the site is deemed suitable, the solar installer will design and install a system that meets the specific needs of the building owner.

There are two main mounting systems for commercial solar panels: ballasted and attached. Ballasted systems use heavy weights, such as concrete blocks, to secure the panels to the roof. Attached systems use roof-penetrating hardware to attach the panels to the roof.

Once the mounting system is installed, the solar panels are attached. The panels are wired together in series and then connected to a solar inverter. The inverter converts the direct current (DC) electricity produced by the panels to alternating current (AC) electricity, which can power the building's electrical needs.

The final step in the installation process is to connect the solar system to the building's electrical grid. This allows the building owner to return excess electricity to the utility company.

Here is a more detailed overview of the commercial solar rooftop installation process:

1. Site assessment: The solar installer will visit the site and assess the roof for suitability. This includes checking the roof orientation, shade, structural integrity, and available space.
2. System design: The solar installer will design a system that meets the specific needs of the building owner. This includes considering the building's energy consumption, budget, and desired payback period.
3. Mounting system installation: The solar installer will install the mounting system supporting the solar panels.
4. Solar panel installation: The solar installer will attach the solar panels to the mounting system.
5. Solar inverter installation: The solar installer will install the solar inverter, which converts the DC electricity produced by the panels to AC electricity.
6. Grid interconnection: The solar installer will connect the solar system to the building's electrical grid.

Commercial solar rooftop installations can be completed in a few weeks, depending on the system's size and the installation's complexity.

Commercial solar rooftop installations offer several benefits to businesses, including:

• Reduced energy costs: Solar panels can generate electricity for free, significantly reducing a business's energy costs.
• Increased energy independence: Solar panels can help businesses become more independent and reduce their reliance on the utility grid.
• Improved environmental performance: Solar energy is a clean and renewable energy source, which can help businesses reduce their environmental impact.
• Increased property value: Commercial solar installations can increase the value of a business's property.

If you are a business owner considering a commercial solar rooftop installation, several resources are available to help you get started. You can contact local solar installers for quotes and consultations. You can also search for government and utility incentives that may be available to help offset the installation cost.

The general steps to compress syngas ,System and method for syngas clean-up

 Syngas, or synthesis gas, combines carbon monoxide (CO), hydrogen (H2), and other trace gases. The compression of syngas involves reducing its volume while increasing its pressure. Here are the general steps to compress syngas:

Understand the requirements: Determine the desired pressure level and the flow rate of syngas that needs to be compressed. This information will help you select the appropriate equipment.

Select a compressor: Choose a compressor that is suitable for handling syngas. Centrifugal compressors and reciprocating compressors are commonly used for gas compression. Consider factors such as the required pressure ratio, flow rate, gas properties, and efficiency when selecting a compressor.

Prepare the syngas: Syngas may contain impurities and contaminants that could damage the compressor or affect its performance. Pre-treat the syngas to remove particulates, moisture, sulfur compounds, or other impurities. This may involve using filtration, scrubbing, or drying equipment. Gasification of municipal solid waste (MSW) with subsequent utilization of syngas in gas engines/turbines and solid oxide fuel cells can substantially increase the power generation of waste-to-energy facilities and optimize the utilization of wastes as a sustainable energy resource. However, purification of syngas to remove multiple impurities such as particulates, tar, HCl, alkali chlorides and sulfur species is required. This study investigates the feasibility of high-temperature syngas purification from MSW gasification, focusing on catalytic tar reforming and desulfurization. Syngas produced from a downdraft fixed-bed gasifier is purified by a multi-stage system. The system comprises a fluidized-bed catalytic tar reformer, a filter for particulates and a fixed-bed reactor for dechlorination and desulfurization with overall downward cascading of the operating temperatures throughout the system. Novel nanostructured nickel catalysts supported on alumina and regenerable Ni-Zn desulfurization sorbent loaded on honeycomb are synthesized. Complementary sampling and analysis methods are applied to quantify the impurities and determine their distribution at different stages.

Compressor setup: Install the selected compressor in a suitable location, following the manufacturer's instructions and safety guidelines. Ensure the compressor is connected to the syngas source and any necessary pre-treatment equipment.

Compress the syngas: Start the compressor and adjust its settings to achieve the desired compression ratio. The compression process will reduce the volume of syngas while increasing its pressure. The specific procedures and controls will depend on the type of compressor used.

Cooling: Compressing syngas generates heat, which needs to be dissipated to avoid damage to the compressor and ensure efficient operation. Employ cooling mechanisms, such as intercoolers or heat exchangers, to remove excess heat during compression.

Storage and distribution: Once the syngas is compressed, it can be stored in suitable containers, such as high-pressure cylinders or tanks. If the compressed syngas needs to be transported, ensure proper safety measures and follow applicable regulations.

It's important to note that compressing syngas can be a complex process, and the specific requirements and equipment may vary depending on the scale and application. It is recommended to consult with experts or engineers experienced in gas compression to ensure safe and efficient syngas compression.

The most reliable source of renewable energy& the world's first smart river turbine.

A new alternative

We estimate that 1.4 billion individuals across the world are without electricity, most living in rural and distant areas inaccessible to the national or regional electricity grid. The most common energy solution available is the use of gas generators which are polluting and can be expensive to maintain in the long term. As an alternative, the use of green technologies is rapidly growing.
Renewable energy solutions are gaining popularity especially in the residential market. Billions of dollars are invested every year on solar and wind systems. However these renewable energy products do not represent optimal solutions for meeting individual needs due to intermittent production of energy resulting in weather variations. In consequence, these systems are only used to 12% to 35% of their capacity implicating an over sizing of installations and storage systems to accumulate the energy when produced. However one regular and predictable energy source is unexploited: the river.

The ideal source of renewable energy

Among all renewable energy sources, only the river can provide a predictable and reliable source of energy, 24 hours a day. Idénergie’s turbine is the solution of choice to fully benefit from the continuous  production of energy offered by the river. This allows, among other advantages, the use of less batteries than the standard norm since the energy produced is uninterrupted and less subject to weather variations. Idénergie’s river turbine is the only water driven technology that meets the needs of a residence by directly supplying household appliances and recharging batteries. It equally represents an excellent emergency backup system because of the endless supply of energy it provides.

Easy to install

Our turbine can be dismantled in separate pieces in order to facilitate shipping to the the most remote locations and is ready to assemble on site. This allows for a simple and fast installation which requires only 2 individuals in less than a 24 hour period. The turbine is attached to a stable pillar from the front with a steel cable and is deposited on the river bed, self positioning in the fluid like a kite. Electrical DC connections are simplified by the presence of our embedded electrical converter. All that’s left to do is connect the output cable to your batteries, without any additional electric equipment.

The first smart river turbine

Idénergie’s river turbine has an embedded smart converter that allows the conversion of the energy harnessed from the water current into electricity to recharge batteries and power home appliances. In addition, it allows the user to have better control by automatically regulating the rotational speed of the turbine thus extracting maximum power from the current; it has a built-in motor mode to enable automatic start-up and emergency disconnect of the turbine on demand. In case water speed is very low, the smart turbine can use the generator in motor mode to initiate sufficient movement in order to produce electricity. The output power is set to DC current, from 24 to 48 and more in order to allow the transport of electricity over long distances.

Low maintenance

Idénergie’s river turbine uses a new type of electric generator which Idénergie is the inventor and sole manufacturer. The generator is very efficient at low water velocity and provides an energy production equivalent of 4 to 10 solar panels (between 2 and 6 kWh/day).  Our unique patented shaftless technology prevents any water intrusions within the generator’s electric casing, allowing an almost maintenance free subwater generator.

Robust design

 

Idénergie’s river turbine is composed of two Darrieus turbines. This model was chosen for its simplicity of manufacturing and installation. It accommodates a water depth of only two feet and with a minimum of 1,2 m/s water velocity, the turbine can produce 2.4 kWh/day. This represents the energy production equivalent of 16 x 250W solar panels. In addition the blades are inexpensive to produce, easy to replace and ship in case of damage. The structure and envelope of the generator are made ​​of aluminum chosen for its lightweight characteristics, structural rigidity and its resistance to corrosion. Free hanging turbines and upward rotational mechanism descreases the chances of debris accumulation. Its robust design has been proven to resist even heavy loads as trees.

In harmony with the river ecosystem

Mostly made of noble metals such as aluminium and other environmentally friendly components, the turbine is the greenest amongst all available renewable energy products. These material do not react to the environment and are easily recyclable ensuring a subtantial end of life value. In addition, the river turbine does not require a permanent structure reducing its impact on aquatic fauna.
By taking into account numerous studies estimating the interactions of the turbines with the ecosystems, Idénergie designed its product in order for it to have minimal impact on the aquatic fauna and its housing environment. Studies carried out by the Alden laboratories, an american entity, have proven that the Darrieus Turbines, used by Idenergie, represent no harm to the river’s ecosystem. In fact, extracting energy from a fluid tend to slow it down, resulting in faster velocity on the side of the turbine thus floating objects and debris, as well as fish, tend to naturally avoid the turbine resulting in 98% survival rate.
source http://idenergie.ca

Production of(fuel) Diesel From Non-Recyclable Waste Plastics

Thermal technique makes clean crude replacement from mixed plastic waste. 

Waste plastic could become a more valuable commodity after developing a process that turns mixed plastic waste into a hydrocarbon-based product. 

This is the assessment of Adrian Haworth, sales and marketing director of Recycling Technologies. This company has developed WarwickFBR, a recycling system that converts mixed plastic waste (MPW) into PlaxOil, a heavy fuel alternative that can be sold or used in localised on-demand combined heat and power (CHP) plants.

Haworth explained that its WarwickFBR system produces the PlaxOil following pyrolysis of MPW. To do this, the system first shreds and dries the MPW. It then injects blended product into a fluidised bed where the long hydrocarbon chains in the polymers are broken down by pyrolysis - a multi-step process in which organic materials are decomposed by heat in the absence of oxygen - to form an energy-rich gas. This gas is then filtered to remove contamination, cooled and condensed to provide PlaxOil.

“Pyrolysis is a fairly simple process, it starts by drying plastics to be processed. They are then shredded into smaller pieces and heated in a thermal chamber. The melted plastic is continually heated until it boils and produces vapours. The vapour is passed into cooling pipes and distilled into a liquid chemically identical to regular fuel.”

The art of refining liquid hydrocarbons (crude oil) into diesel, gasoline, and fuel oils was commercially scaled decades ago. Unfortunately, refineries are technologically limited to accepting only a narrow range of liquid hydrocarbons with specific properties and minimal contaminates. Hydrocarbon streams that fall outside of accepted refinery standards have traditionally been landfilled or melted into products of low value. Unrecyclable, hydrocarbon-based waste is a significant environmental problem increasing every year. According to the Environmental Protection Agency’s 2010 Facts and Figures report, over 92% of waste plastic is not recycled. With a growth rate of approximately 8% per year, a critical need for a viable and environmentally sound, general-purpose hydrocarbon-based recycling process exists. 

The barriers and challenges are so significant that previous attempts to refine waste plastics into fuel resulted in unviable batch-based machines producing low-value, unstable mixed fuels. However, for three years, JBI, Inc. (“JBI”) has broken through these barriers and has designed and built a viable commercial-scale continuous refinery capable of processing a wide range of hydrocarbon-based waste into ASTM specification fuels. 

Research and testing of scale-up through 1-gallon, 3000 gallon, multi-kiln, and 40 ton/day processors in a plant in Niagara Falls, NY. Technical challenges encountered and lessons learned during process development will be explained in detail. 

In 2009, our technology was “molecularly audited” by IsleChem, LLC (“IsleChem”) of Grand Island, NY. In 2012, SAIC Energy, Environment & Infrastructure, LLC (“SAIC”). Numerous sources of waste plastic and users of the resulting fuel products conducted extensive audits of the technology, process, and plant. However, this technology can be applied to other waste hydrocarbon-based materials such as contaminated monomers, waste oils, lubricants and other composite waste streams.

Plastic Fuel

All around the globe, companies and individuals are starting to produce fuel from waste plastic. As only 8% of waste plastic is recycled in the US, 15% in Western Europe, and much less in developing countries, this reuse of plastic could potentially keep enormous amounts of plastic out of landfills and out of the oceans. Over 500 billion pounds of new plastic is manufactured each year, and roughly 33% of that is single-use and thrown away. As so little plastic is recycled, we need to reframe plastic waste as an underused resource vs landfill destined. If all plastic waste made it into the dump, it would indeed be mined in the future, but currently, all plastic waste does not make it into our landfills. The United Nations estimates plastic accounts for four-fifths of the accumulated garbage in the world’s oceans. We need to stop polluting our oceans with plastic before it is too late and start collecting all plastics suitable for this new fairly simple technology, a technology that is available now.

Image via: coastalcare.org

The technology is not overly complicated; plastics are shredded and then heated in an oxygen-free chamber (known as pyrolysis) to about 400 degrees celsius. As the plastics boil, gas is separated out and often reused to fuel the machine itself. The fuel is then distilled and filtered. Because the entire process takes place inside a vacuum and the plastic is melted - not burned, minimal to no resultant toxins are released into the air, as all the gases and or sludge are reused to fuel the machine.

 

For this technology, the type of plastic you convert to fuel is essential. If you burn pure hydrocarbons, such as polyethene (PE) and polypropylene (PP), you will produce a fuel that burns pretty clean. But burn PVC and large amounts of chlorine will corrode the reactor and pollute the environment. Burning PETE releases oxygen into the oxygen-deprived chamber, thereby slowing the processing, and PETE recycles efficiently at recycling centres, so it is best to recycle PETE traditionally. HDPE (jugs) and LDPE (bags and films) are polyethene, so usable as fuel as well, just slightly more polluting as a thicker, heavier fuel is created. But additional processing can turn even HDPE into clean diesel.

 Source (Plastic To Fuel • Insteading)

“Polyethylene and polypropylene are pure hydrocarbons, only they are arranged in long chains. If you chop those chains into shorter ones, you get oil, if you chop them even shorter, you get diesel, and if you chop them again, you get gasoline and eventually burnable gas.” 

www.energeticforum.com

In Niagara Falls, NY, John Bordynuik’s ‘Plastic Eating Monster’ can even vaporise thick HDPE plastic into a cleaner-burning number 2 fuel. Put plastic in one end of the machine, and out the other end comes diesel, petroleum distillate, light naphtha and gases such as methane, ethane, butane and propane. The machine accepts unwashed, unsorted waste plastics, composites and commingled materials and returns about 1 gallon of fuel from 8.3 pounds of plastic. And the processor uses its off-gases as fuel, therefore using minimal energy to run the machine. John currently has two massive steel processors up and running, with financing secured for three more to be built shortly. 

In the Philippines, Poly-Green Technology and Resources Inc. was started by Jayme Navarro whose sister asked him to come up with a way to recycle plastic bags. A plant is being built that will produce 5,000 kilos of fuel per day. www.polygreen.com.ph 

Cynar in the UK likes to call their product ‘End of Life Plastic to Diesel’ or ELPD. Their technology converts mixed Waste Plastics into synthetic fuels that are cleaner, low in sulphur and in the case of the diesel, a higher cetane than generic diesel fuel. They have a plant running in Ireland , with another to open in Bristol, UK in January and many more in the planning stage. Each Cynar plant can process up to 20 tons of End of Life Plastic per day, producing 5,000 gallons (19,000 litres) of high quality liquid fuels at a conversion rate of 95%.

Cynar will be supplying Jeremy Rowsell, a British insurance industry executive who lives in Australia, with all the plastic waste fuel he needs to fly a single-engine Cessna from Sydney to London this winter. Fuel will be in place at about 10 locations along the 10,500-mile route. The solo journey dubbed ‘On Wings of Waste’ is intended to heighten awareness of this new fuel.

Of course, it would be best if widespread environmentally friendly plastics were in use, but in the meantime, recycling existing plastics into fuel would keep the plastics out of our waterways. This process is also excellent for difficult to recycle PP and PE plastics like bottle caps, appliance plastics, nursery planters and dirty plastics such as meat wrappings. This process is not suitable for PVC or polystyrene (styrofoam). This technology could also reduce carting issues, as companies that deal with plastic waste could build mini-burners on location. 

Companies:

Japan. Sells International: e-n-ergy.com

UK: Cynar produces a synthetic fuel suitable for all internal combustion engines: cynarplc.com

Washington, DC: www.envion.com
Boosts easy installation, high efficiency, no second-time pollution.
The plant converts 6,000 tons of plastic into nearly a million barrels yearly.

Circle Pines, MN and International:  polymerenergy.com
They have a modular unit that produces 775 litres of fuel for every ton of plastic waste processing. System capacity is rated at 185 tons per month.

New York/Canada: JBI, Inc. www.plastic2oil.com
20-ton processor, 4,000 lbs. of plastic feedstock per machine per hour.

Philippines: www.polygreen.com.ph
5,000 kilos of fuel per day

Hong Kong: Ecotech Recycling Social Enterprise
A prototype machine can process three tons of plastic waste into 1,000 litres of fuel oil per day.

Las Vegas, NV: general@quadraprojects.net

 

Resources:

UNEP Policy Brief on Plastic Waste: unep.org.pdf

Northeastern University turns plastic waste into energy to drive generators: phys.org

DIY for under $800.: energeticforum.com

Peswiki Plastic and Energy page: peswiki.com
This homemade device converts around 25 kg of shredded plastic into 24 litres of diesel in 4 hours. www.emuprim.lv

 

New solar device converts Sun's energy to hydrogen more efficiently than ever New solar device converts Sun's energy to hydrogen more efficiently than ever

An international team of scientists has invented a cheap solar device that can store energy from the Sun more efficiently than anything on the market.

One of the biggest problems with solar power becoming a more viable and cost effective alternative to fossil fuels is what to do when the sun isn’t shining. An international team of scientists has figured out a solution, and it just might be the most promising one yet.

Led by Michael Graetzel, director of the Laboratory of Photonics and Interfaces at the Ecole Polytechnique in Switzerland, the team has created a device that can collect energy from sunlight and convert it to hydrogen, which can be stored and burned as fuel or fed through a fuel cell to generate electricity.

Named a ‘water splitter’, the device has been tipped as the next big thing in solar technology, says Kevin Bullis at MIT’s Technology Review, because it meets three of the four criteria needed to create a practical device. Firstly, it’s highly efficient. It’s made from a new type of material called perovskite, which was discovered in 2009 and found to absorb light much more efficiently than silicon, which is what solar cells are currently made from. According to Bullis, it can store 12.3 per cent of the energy in sunlight in the form of hydrogen, which is pretty huge, seeing as 10 per cent is the accepted benchmark for efficient solar-hydrogen converters.

Secondly, it’s cheap to produce, using only inexpensive materials. And thirdly, these materials are abundant to source, so the device is also easy to make. On top of perovskite, the device uses cheap nickel and iron to act as catalysts in its two 'water-splitting' electrodes - one that produces hydrogen and one that produces oxygen when they react with water.

"The catalysts built on previous work showing that nickel hydroxide is a promising catalyst, and that adding iron could improve it. The researchers added iron to nickel hydroxide to form a layered structure, and put the catalyst on a porous nickel “foam” to increase the area across which reactions can take place, speeding them up,” says Bullis.

The fourth criteria needed for a practical device is reliability, which the team is now working on increasing. Right now, it only lasts for a few hours before the solar cell's performance starts to decrease. This is because perovskite degrades much faster than silicon. But the team, including researchers from Switzerland, Singapore and Korea, has figured out how to extend this lifespan to over a month by adding a layer of carbon. They’ve published their results in the journal Science. They're now working on increasing this further.

What the device in action below:

What If Electric Cars Were Better?

Improving the energy density of batteries is the key to mass-market electric vehicles.

• BY DAVID ROTMAN

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Electric vehicles are still too expensive and have too many limitations to compete with regular cars, except in a few niche markets. Will that ever change? The answer has everything to do with battery technology. Batteries carrying more charge for a lower price could extend the range of electric cars from today's 70 miles to hundreds of miles, effectively challenging the internal-combustion motor. 

To get there, many experts agree, a major shift in battery technology may be needed. Electric vehicles such as the all-electric Nissan Leaf and the Chevrolet Volt, a plug-in hybrid from GM, rely on larger versions of the lithium-ion batteries that power smart phones, iPads, and ultrathin laptops. Such gadgets are possible only because lithium-ion batteries have twice the energy density of the nickel–metal hydride batteries used in the brick-size mobile phones and other bulky consumer electronics of the 1980s. 

Using lithium-ion batteries, companies like Nissan, which has sold 20,000 Leafs globally (the car is priced at $33,000 in the U.S.), are predicting that they've already hit upon the right mix of vehicle range and sticker price to satisfy many commuters who drive limited distances.

The problem, however, is that despite several decades of optimization, lithium-ion batteries are still expensive and limited in performance, and they will probably not get much better. Assembled battery packs for a vehicle like the Volt cost roughly $10,000 and deliver about 40 miles before an internal-combustion engine kicks in to extend the charge. The battery for the Leaf costs about $15,000 (according to estimates from the Department of Energy) and delivers about 70 miles of driving, depending on various conditions. According to an analysis by the National Academy of Sciences, plug-in hybrid electric vehicles with a 40-mile electric range are "unlikely" to be cost competitive with conventional cars before 2040, assuming gasoline prices of $4 per gallon.

Estimates of the cost of assembled lithium-ion battery packs vary widely (see "Will Electric Vehicles Finally Succeed?"). The NAS report put the cost at about $625 to $850 per kilowatt-hour of energy; a Volt-like car requires a battery capacity of 16 kilowatts. But the bottom line is that batteries need to get far cheaper and provide far greater range if electric vehicles are ever to become truly popular. 

Whether that's possible with conventional lithium-ion technology is a matter of debate. Though some involved in battery manufacturing say the technology still has room for improvement, the NAS report, for one, notes that although lithium-ion batteries have been getting far cheaper over the last decade, those reductions seem to be leveling off. It concludes that even under optimistic assumptions, lithium-ion batteries are likely to cost around $360 per kilowatt-hour in 2030.

The U.S. Department of Energy, however, has far more ambitious goals for electric-vehicle batteries, aiming to bring the cost down to $125 per kilowatt-hour by 2020. For that, radical new technologies will probably be necessary. As part of its effort to encourage battery innovation, the DOE's ARPA-E program has funded 10 projects, most of them involving startup companies, to find "game-changing technologies" that will deliver an electric car with a range of 300 to 500 miles.

The department has put $57 million toward efforts to develop a number of very different technologies, including metal-air, lithium-sulfur, and solid-state batteries. Among the funding recipients is Pellion Technologies, a Cambridge, Massachusetts-based startup working on magnesium-ion batteries that could provide twice the energy density of lithium-ion ones; another ARPA-E-funded startup, Sion Power in Tucson, Arizona, promises a lithium-sulfur battery that has an energy density three times that of conventional lithium-ion batteries and could power electric vehicles for more than 300 miles.

The ARPA-E program is meant to support high-risk projects, so it's hard to know whether any of the new battery technologies will succeed. But if the DOE meets its ambitious goals, it will truly change the economics of electric cars. Improving the energy density of batteries has already changed how we communicate. Someday it could change how we commute.

Use of Supercritical Water Could Cut Costs for Ethanol

ENERGY

A startup says it can make sugar for biofuel from wood chips at a fraction of the normal cost.

• BY KEVIN BULLIS

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Renmatix, a startup based in Kennesaw, Georgia, is using water at high pressure and temperature to transform wood chips into sugar, which can then be fermented to make biofuels and other chemicals. The company says the process can produce sugar for the same price as making it from sugarcane, which has led to profitable biofuels production in Brazil.

Renmatix is addressing the most difficult step in producing ethanol from abundant cellulosic materials such as wood chips, instead of from corn or sugar crops. Once the sugar is made, the same technology employed in a conventional corn or sugarcane ethanol plant can be used to produce ethanol.

So far, Renmatix has only demonstrated the technology on a small scale, using a facility that can process three tons of wood chips a day. As with all advanced biofuels companies, one of the biggest challenges will be convincing investors to hand over the money needed to build a larger commercial facility to prove the venture is commercially viable. The U.S. Environmental Protection Agency has been forced to waive requirements for cellulosic ethanol because commercial plants for converting cellulosic material to ethanol haven't yet been built. By lowering the cost of producing sugar from cellulosic materials, Renmatix hopes to at last break this logjam.

Researchers and companies have tried many methods of turning cellulose into sugar. Some involve breaking the biomass down using acids or specially tailored enzymes. Others involve using heat and pressure to turn biomass into hydrogen and carbon monoxide, which can be converted to biofuel using inorganic catalysts. Each method has drawbacks: enzymes are expensive; acids are toxic. Both processes are slow, and they require expensive equipment. The processes that use high heat and inorganic catalysts also have relatively low yields of the desired fuels.

Instead of using enzymes or acids, Renmatix employs supercritical water—water at very high temperatures and pressures. Under these conditions, cellulose will dissolve and very quickly break down into sugar molecules. The reactions take seconds, compared to days for some other processes. Because of the high speed of the reaction, a relatively small amount of equipment can produce a large amount of sugar, keeping capital costs down. Smaller equipment could also make it possible to distribute the production of biofuels, thereby decreasing the cost of transporting biomass.

However, working with supercritical water comes with challenges. The materials that can be used with supercritical water are limited—it will dissolve glass, for example. The extremely fast reactions also make it difficult to ensure that the chemistry doesn't go too far and produce undesirable by-products. In past attempts, the supercritical water has dehydrated some of the sugar produced, resulting in compounds that can poison the yeast used to convert sugar to ethanol. Typically, the process also yields a relatively small amount of sugar from a given amount of biomass.

Fred Moesler, Renmatix's vice president of process technology, says the company has overcome these problems. The company hasn't said how it does this, but Gary Aurand, a research scientist at the University of Iowa who is familiar with the company from its early days (when it was known as Sriya Innovations) suggests the company may be using supercritical water in only part of its process.

Turning biomass into sugar using supercritical water involves first grinding biomass into small particles, then dissolving cellulose in water. Without dissolving it, only the cellulose molecules at the surface of the particles will be broken down, resulting in low sugar production. After the cellulose is dissolved, further exposure to high temperatures and pressure will break the cellulose molecules down into sugar.

Aurand says that water only needs to be supercritical for the dissolving step. If Renmatix could engineer a system to move the dissolved material into an area of lower temperature and pressure, it could slow down the process of breaking down the cellulose into sugar, preventing the formation of the unwanted compounds.

All Renmatix has said is that it uses two steps to break down cellulose and a similar material, hemicellulose. Breaking down cellulose produces glucose, the sugar that yeast can readily use to produce ethanol. Breaking down hemicelluloses produces another sugar called xylose, which doesn't work with conventional fermentation, but which can be used in some advanced biofuels and biochemicals processes. The economics of the process will depend on the market for xylose.

Renmatix has raised some of the money for a plant capable of producing 100,000 tons of sugar per year—large enough to show that the process has commercial potential, it says. But the company is still working to obtain the loans needed to go forward. In the past, using supercritical water to process biomass has been seen as uneconomical, so it may prove difficult to get banks to sign on. "Little is known about the technology," says Andy Aden, manager of biorefinery analysis at the National Renewable Energy Laboratory in Golden, Colorado. Based on prior calculations, he says, "it is likely to be expensive."