Carbon dioxide turned into hydrocarbon fuel

     Global CO₂ emissions from sources such as car exhausts and industry are predicted to double between now and 2050. More CO₂ means that trees will grow faster and lock up more carbon. This led some to hope that plants might mop up all the extra gas.

    But forests will be less effective at slowing climate change than scientists thought, because they will mop up less carbon dioxide than expected.

      The results should hammer home the message that the world cannot rely on trees to solve the problem of CO₂ emissions,

The team involved in advanced experiments, simulating the future atmosphere, found that the trees in the 2050 atmosphere converted more carbon dioxide into plant matter, locking up 27 per cent more carbon than at control sites. However, even if this extra growth occurs in existing temperate forests all over the world in 2050, the trees will only absorb 10 per cent of human-generated CO₂.

Results warn us that forests cannot solve the problem of global warming, and emissions need to be reduced.

"Eventually we have to deal with the root cause."

 A New Solution

A way to turn   carbon dioxide into hydrocarbons   has caused a big stir at an industrial chemistry conference in New Brunwick, New Jersey. Nakamichi Yamasaki of the Tokushima Industrial Technology Center in Japan says he has a process that makes propane and butane at relatively low temperatures and pressures.

The work suggests the tantalizing prospect that CO₂, the main greenhouse gas, could be recycled instead of being pumped into the atmosphere.

While this work still needs independent verification, if we can make even heavier hydrocarbons, it might be possible to make petrol. It has carbon chains that are between five and 12 atoms long - butane is four atoms long.

Many people have tried before to make hydrocarbons by mixing carbon with hydrogen gas in a reaction chamber at very high temperatures, but yields have always been pitiful. Yamasaki has used hydrochloric acid as his source of hydrogen ions.

He bubbles the CO₂ into a reaction vessel (see graphic) where it is heated to about 300 °C at 100 times atmospheric pressure. The heat and pressure are low enough, says Yamasaki, to make it feasible to scale up the reaction so it can run on a power station's waste heat.

Iron powder

Using iron powder as a catalyst, Yamasaki says he has made substantial amounts of methane, ethane, propane and butane, which he was able to vent off as gases when the mixture cooled. If he can improve the catalyst's performance he is hopeful of making heavier hydrocarbons such as petrol, too.

Some suggestion for the improvement of the catalyst

As evidenced by the FISCHER-TROPSCH  synthesis,  the potassium (and other alkalis to a smaller extent) affect both the molecular weight distribution of the products (and indirectly the hydrocarbon production) and the amount of alkenes in each carbon number fraction. In general, a  higher potassium content produces higher weight products. Thus, whereas the value of alpha (the ratio of chain propagation to chain termination) is about 0.7 for unprompted iron or a catalyst containing up to about 0.5 wt.% potassium, the value of alpha can be increased to greater than 0.9 with catalysts containing higher amounts of Potassium.

    Thus we can utilize this property of potassium to boost the performance of iron powder catalyst and can hope for getting the hydrocarbon chain with higher carbon number which in turn take us near the aged nourished   dream of  making petrol from some waste like Carbon dioxide.  

 To conclude this I want to say that," The Stone Age didn’t end because we run out of stones, similarly the Oil Age won’t end because of the lack of the oil. ”

REFERENCES :--

1. H. Kölbel and M. Ralek, Catal. Rev.-Sci. Eng., 21  225 (1980).

    2.  New scientist  02 Aug 2002