New Year ushers in new hopes and sets aggressive targets. 2014 is no different. Toyota, the Japanese auto giant unveiled the concept version of a hydrogen car or the FCV (fuel cell vehicle) at the Consumer Electronics show currently being held at Las Vegas. The cars will be marketed in California next year and even the blueprint for Hydrogen gas stations are ready The car, it is claimed can reach a maximum speed of 100mph and accelerate to 60mph in 10 seconds.Moreover a fulltank run of about 300 miles is assured. Toyota didn't specify a price , but a humble guess is:anywhere between 50,000 -100,000 USD. (1). Hyundai and Honda motors are also fast catching up
Hydrogen,is the simple, unassuming numero uno of the periodic table. Henry Cavendish, the eighteenth century chemist was the first to identify this colorless odorless gas and realize that upon combustion it yielded water. That is why Lavoisier later named it Hydrogen that which yields water. With just one electron and one proton, how complex can it chemistry get? Sure it is simple but explosive too. It can burst into flames at the slightest provocation. Now combustibility is the hallmark of fuels, and naturally questions popped up among scientific circles. Could hydrogen be the ultimate fuel, because the product of its combustion is the benign and benevolent Water. Can there be a greener fuel? However easy combustibility, though highly desirable for a fuel, makes its storage and handling extremely difficult and dangerous. Scientists have been trying for decades to tame hydrogen. Indeed there are success stories, but the price tags are so exorbitant that hydrogen as a fuel isn't a commercial success yet .If storage, handling and transportation of hydrogen become cheaper and viable (on par with that of the crude oil,) then FCVs, will soon be within common man's reach. Persistent efforts at all levels are on to tackle issues. It is in this context that we must once again acknowledge help from the lowly microbes.
In a recent issue of Science magazine Schuchmann and Muller (Molecualr Microbiology and Bioenergetics, Institute of Molecular Biosciences, Wolfgang Goethe University Frankfurt Germany) report (2,3)a clever way of restraining this mischievous molecule. The method may even be economically viable. Schuchumann and Muller found a perfect ally in Acetobacterium woodii. These microbes thrive at room temperature , need no oxygen (or in more scientific terms they are anaerobic. It contains an enzyme Hydrogen Dependent Carbon dioxide Reductase,(HDCR) which can chemically link hydrogen (hydrogenase ) to carbon dioxide or peel them off (dehydrogenase) if necessary. In other words the reaction is reversible. The reaction as depicted below is quite simple, and devoid of the usual complexities of enzymatic catalysis. Earlier Reda et al(4) reported the use of an electroactive enzyme to bring about the reversible reaction of formate , but hydrogen molecule did not play any direct role there.
Formic acid is a liquid,and noncombustible which solves the problem of storage , handling and transportation. Schuchmann and Muller point out an additional advantage; possibility of using syngas, as the input stream. Syn gas is a mixture of carbon monoxide, carbon dioxide and hydrogen. (CO, CO2 and H2,) and is produced in bio gas generators.
Hydrogen,is the simple, unassuming numero uno of the periodic table. Henry Cavendish, the eighteenth century chemist was the first to identify this colorless odorless gas and realize that upon combustion it yielded water. That is why Lavoisier later named it Hydrogen that which yields water. With just one electron and one proton, how complex can it chemistry get? Sure it is simple but explosive too. It can burst into flames at the slightest provocation. Now combustibility is the hallmark of fuels, and naturally questions popped up among scientific circles. Could hydrogen be the ultimate fuel, because the product of its combustion is the benign and benevolent Water. Can there be a greener fuel? However easy combustibility, though highly desirable for a fuel, makes its storage and handling extremely difficult and dangerous. Scientists have been trying for decades to tame hydrogen. Indeed there are success stories, but the price tags are so exorbitant that hydrogen as a fuel isn't a commercial success yet .If storage, handling and transportation of hydrogen become cheaper and viable (on par with that of the crude oil,) then FCVs, will soon be within common man's reach. Persistent efforts at all levels are on to tackle issues. It is in this context that we must once again acknowledge help from the lowly microbes.
In a recent issue of Science magazine Schuchmann and Muller (Molecualr Microbiology and Bioenergetics, Institute of Molecular Biosciences, Wolfgang Goethe University Frankfurt Germany) report (2,3)a clever way of restraining this mischievous molecule. The method may even be economically viable. Schuchumann and Muller found a perfect ally in Acetobacterium woodii. These microbes thrive at room temperature , need no oxygen (or in more scientific terms they are anaerobic. It contains an enzyme Hydrogen Dependent Carbon dioxide Reductase,(HDCR) which can chemically link hydrogen (hydrogenase ) to carbon dioxide or peel them off (dehydrogenase) if necessary. In other words the reaction is reversible. The reaction as depicted below is quite simple, and devoid of the usual complexities of enzymatic catalysis. Earlier Reda et al(4) reported the use of an electroactive enzyme to bring about the reversible reaction of formate , but hydrogen molecule did not play any direct role there.
Formic acid is a liquid,and noncombustible which solves the problem of storage , handling and transportation. Schuchmann and Muller point out an additional advantage; possibility of using syngas, as the input stream. Syn gas is a mixture of carbon monoxide, carbon dioxide and hydrogen. (CO, CO2 and H2,) and is produced in bio gas generators.
The concept of trapping hydrogen in carbon dioxide is not new (4,5). There are chemical methods to do it, however they all suffer in one way or the other either by way of low yields, high temperature requirements or expensive catalysts. Schuchumann and Miller are hopeful that their discovery could be a biotechnological breakthrough.
But there are more road blocks in the path of FCVs :for example industrial scale manufacture of hydrogen may not be so green.
But there are more road blocks in the path of FCVs :for example industrial scale manufacture of hydrogen may not be so green.
References:
2.Direct and reversible Hydrogenation of CO2 to formate by a bacterial carbon dioxide:
Schuchmann and Muller, Science Vol 342, p 1382-1385 , 2013
3.An enzymatic route to H2 storage Pereira Science 342, p,1329-30, 2013
4.Reversible Interconversion of Carbon dioxide and formate by an electroactive enzyme: Reda et al Proceeeding of the National academy of Scienes (USA) Vol. 105(31) pages 10654-10658, 2008
5..Reversible hydrogen storage using CO2 and a proton switchable iridium catalyst in
aqueous media under mild temperatures and pressures: Hull etal Nature Chemistry :
Vol.4, pages 383- 388, 2012
