Several molecular systems have been constructed that mimic various aspects of photosynthesis. Two of these utilize molecular systems that are derived from natural photosynthesis but that incorporate chemically based modifications to produce artificial photosynthetic devices. These devices use artificial photosynthetic pigments to drive chemical reactions across lipid bilayers or use noble metal catalysts to change the function of the photosynthetic process to produce hydrogen and oxygen instead of sugars ethanol and oxygen. Neither of these systems are sufficiently robust to be operated for extended periods of time as energy unit conversion devices, but they have shown that it is possible to produce artificial photosynthetic assemblies that function well in a laboratory setting. (more…)

With ethanol’s future uncertain, many commentators see the transportation debate evolving into a war between two other technologies—hydrogen-powered fuel cells and battery powered electric vehicles. Some alternative fuel advocates are putting their support behind hydrogen, the most abundant element on Earth. Water, for example, is composed of hydrogen and oxygen molecules. Hydrogen can be produced from water by electrolysis, which separates the oxygen from the hydrogen. It can be used to power hydrogen fuel cells for vehicles (or to provide heat and electricity for buildings). Hydrogen fuel cells work by recombining hydrogen and oxygen—a process that produces electricity, heat, and water. Hydrogen-powered cars, therefore, could be an ideal transportation solution—nonpolluting, zero-emission vehicles that release only water, a natural and completely safe waste product. Also, fuel cells are highly efficient and powerful, and unlike typical batteries, fuel cells will never lose their charge as long as hydrogen fuel is supplied.

Hydrogen fuel cell technologies, however, must overcome many stubborn challenges before they can become a practical source of energy. Perhaps the biggest obstacle is cost; it currently takes more energy to make hydrogen than is produced, and production relies on expensive catalysts made from platinum, a scarce metal. And like biofuels, hydrogen is currently made using fossil fuels, so it is not emissions-free. In addition, liquid hydrogen fuel is highly flammable and must be stored at very low temperatures or under very high pressure, making transport and storage difficult. Switching vehicles to hydrogen fuel cell power also would require building a whole new infrastructure similar to the chain of gas stations that currently dot the landscape. Researchers are hoping to find answers to these problems by searching for other types of catalysts, studying other ways to improve production, and developing better hydrogen storage options.

Hydrogen researchers, however, have been promising breakthroughs since the 1990s with little progress to show for their efforts. Many observers are thus coming to the conclusion that the hydrogen fuel cell is a technology that will not be perfected in the near future. As physicist and climate expert Joe Romm explains, “Neither government policy nor business investment should be based on the assumption that these technologies will have a significant impact in the near or medium-term.” The Obama administration apparently agrees; it submitted a budget for 2010 that sharply cut back on government support for hydrogen projects. U.S. Energy Secretary Steven Chu explained the administration’s problems with hydrogen technology:

Right now, the way we get hydrogen primarily is from reforming [natural] gas. That’s not an ideal source of hydrogen. . . . The other problem is, if it’s for transportation, we don’t have a good storage mechanism yet. Compressed hydrogen is the best mechanism [but it requires] a large volume. We haven’t figured out how to store it with high density. What else? The fuel cells aren’t there yet, and the distribution infrastructure isn’t there yet. So . . . to get significant deployment, you need four significant technological breakthroughs. That makes it unlikely

Congress promptly reversed President Obama’s decision, however, restoring more than $200 million to 190 hydrogen projects around the country.

Microtechnology-Based Energy and Chemical Systems will most likely employ combustion for driving processes such as vapor generation and vapor barrier, endothermic chemical reactions, and (most notably) fuel reforming. Both fuel reformers and combustors will be of a miniature design relying on embedded catalysts for promoting chemical reactions at moderate temperatures (350–7501C). Many potential configurations exist depending on the application and constraints on the design. Microchannel arrays are a potential configuration; mesh and post architecture is another to achieve the desired surface area and small diffusional lengths necessary. (more…)

It is progress in the development of hydrogen-air PEM stacks that has made fuel cells a contender for powering automobiles of the future. For many years, the energy and power densities of PEM cells were so low and the amount of platinum catalyst required was so high that most commercial applications seemed out of the question. For example, the platinum requirements for the PEM cells used on Gemini space missions of the 1960s were on the order of 100 g/ kW, for a cost factor of $1500/kW (assuming a platinum cost of $15/g). A typical automotive fuel cell stack would be 80 kW, implying a cost of $120,000 for the catalyst material alone. By comparison, current automotive catalytic converters require roughly 0.05 g/ kW of platinum-group metals, costing on the order of $100 for an average car. More stringent emissions standards are pushing precious metal requirements higher, so that future gasoline vehicles may need 0.1 to 0.2 g/kW of platinum group metals. (more…)

Fuel cells are typically classified according to type of electrolyte. While many varieties of fuel cells have been demonstrated in the laboratory, five major types are seeing development for commercial applications:

* Polymer electrolyte membrane (PEM) cells use a plastic (polymer) membrane that becomes electrically conducting when hydrated (saturated with water); they operate near 1001C.
* Alkaline fuel cells use a caustic electrolyte such as potassium hydroxide (KOH); they also operate near 1001C. (more…)

A fuel cell is an electrochemical device that directly converts a fuel to electricity by means of reactions on the surfaces of electrodes and transport of ions through an electrolyte. A fuel cell can be thought of as a chemical battery whose reactants are fed from external sources rather than packaged as part of the battery. A key feature of a fuel cell is transformation of the chemical potential energy of a fuel directly into electricity, a high-value form of energy that can be put to many uses from electricity conversion. The fuel cell’s direct energy unit conversion process occurs without an intermediate step of heat generation, as involved in combustion engines. (more…)

Researchers at the Institute of Chemical Technology have developed a new catalyst that allows to obtain, from bioethanol, hydrogen for direct use in fuel cells.

According to the researchers note the ITQ, the new catalyst is a new step towards the sustainable production of hydrogen with “interesting applications”, for example, buses, trains or trams based fuel cells.

It is an active catalyst at low temperatures, high selectivity to hydrogen production water and low carbon monoxide and methane. These three features can improve both energy and economic efficiency of hydrogen production process. “Hydrogen is currently produced by steam reforming of natural gas that operates at 900 º C, compared to 350 º C to working our catalyst, leading to a major energy savings,” said Antonio Chica, a researcher at the ITQ.

Likewise, the catalyst developed by the ITQ produced “very little” carbon monoxide, which means “breakthrough”, mainly to ensure optimal performance of the fuel cell because the CO is causing the malfunction of the batteries.

Also get “significant benefit” to the process of producing high purity hydrogen because it would involve the partial or total removal of one of the most expensive in the process units (units that use catalysts that are fairly expensive and aimed at the removal of CO by water displacement reactions and preferential oxidation). Similarly, the final stage of purification is simplified both in terms of energy and technology, which would mean “a considerable cost savings,” he said.

“The catalyst that we have developed could have interesting applications in industrial production of hydrogen. It has proven its efficiency in the laboratory, through the study of plant-level scale pilot will have to confirm the good results obtained so far, “said Girl.

If you are not up-to-date with scientific developments, you probably have not have heard of the process of converting gas to liquids. It might not sound like it could apply to many people, but in fact it should appeal to everyone. This newer method of using our natural resources to our advantage could be the key to less reliance on foreign energy sources, resulting in lower natural gas prices. (more…)

All of today’s hydrogen conversion products, demonstration models, and prototypes possess some deficiencies; they cannot yet provide, at an affordable cost, the level and quality of energy services, and hydrogen delivery system demanded by a broad base of consumers. While fuel cell technologies have generated much excitement, they are still in various stages of maturity. Most have not been manufactured in large quantities and numerous performance issues—including durability, (more…)

The internal combustion engine has dominated the car and light-truck market for over 100 years. Although remarkable improvements have been made over the past 30 years to reduce air pollution problems to nearly zero and to almost double vehicle efficiency, increasing concerns about global warming and energy security are pushing vehicles toward even greater energy efficiency improvements. (more…)