The recent edition of the journal Science contains a report that scientists working at the DOE/Pacific Northwest National laboratory have directly converted sugars ubiquitous in nature to an alternative source for those products that make oil so valuable
We have taken a step closer towards a goal that has long eluded chemists everywhere; how to replace crude oil as the root source for plastic, fuels and scores of other industrial and household chemicals by using an inexpensive, nonpolluting renewable plant matter.
A research team working for the Institute for Interfacial Catalysis (IIC) which is based at the Pacific Northwest National Laboratory (PNNL) reported in the journal Science that have directly converted sugars
Scientists took a giant step closer to the biorefinery today, reporting in the journal Science, that they have directly converted sugars, which are everywhere in nature, with an alternative source..
"What we have done that no one else has been able to do is convert glucose directly in high yields to a primary building block for fuel and polyesters," said Z. Conrad Zhang, senior author.
The building block the group found is called HMF, which stands for hydroxymethylfurfural. HMF is a chemical that is derived from carbohydrates such as glucose and fructose. HMF may be a viable successor to petroleum-based chemicals.
Glucose, in plant starch and cellulose, is nature's most abundant sugar. Until now is has been challenging to obtain a commercially workable yield.
Zhang said. "In addition to low yield until now, we always generate many different byproducts," including levulinic acid, making product purification expensive and uncompetitive with petroleum-based chemicals.
The research team was able to obtain HMF yields that are upward of 70 percent from glucose and nearly 90 percent from fructose while leaving only traces of acid impurities.
They were able to reach these levels due to the experiments that they conducted with a novel non-acidic catalytic system which contained metal chloride catalysts in a solvent capable of dissolving cellulose. The solvent is known as an ionic liquid and this ionic liquid enabled the metal chlorides to convert the sugars to HMF.
A positive side-effect of the ionic liquid; it is reusable. This means that there is no wastewater produced as there is in other methods that convert fructose to HMF.
Zhang and his team, discovered that a particular metal — chromium chloride — was by far the most effective at converting glucose to HMF with few impurities and, as such reactions go, at low temperature, 100 degrees centigrade.
"This, in my view, is breakthrough science in the renewable energy arena," said J.M. White, IIC director and Robert A. Welch chair in materials chemistry at the University of Texas. "This work opens the way for fundamental catalysis science in a novel solvent."
The next step, according to Zhang, step is to experiment with ionic solvents and metal halides combinations to see if he can increase HMF yield from glucose while reducing separation and purification cost.
"The opportunities are endless," Zhang said, "and the chemistry is starting to get interesting."
There is still someway to travel along this path and I am uncertain about the long term impacts of and our ability to produce sufficient material to replace the volume of for plastic, fuels and scores of other industrial and household chemicals that we use.
The danger of this research is that people will assume they do not have to conserve but can keep on consuming as usual as science will save the day. Discovery is important and that research can and often does turn up the unexpected which is one of the main reasons we need to keep on looking.
However, let’s not forget that we can make a difference by reducing our use and taking responsibility for meeting our own needs.
