Thursday, February 12, 2009

Bioenergy Momentum

Although the cost of oil is currently low, it will eventually rise again. It is important to develop bioenergy sources such as ligno-cellulosic fuels and algal fuels before oil rises again into the "demand destruction" levels of summer 2008. Fortunately, research into several forms of bioenergy continues due to momentum built over the past few years.

UW Madison researchers have developed an interesting two-step process to produce furans from lignocellulose.
The key to the new process is the first step, in which a novel solvent system converts cellulose into the renewable platform chemical 5-hydroxymethylfurfural (HMF), from which a variety of valuable commodity chemicals and fuels can be made. A paper describing the process was published in the 11 Feb issue of the Journal of the American Chemical Society.

Professor Ronald Raines and graduate student Joseph Binder, a doctoral candidate in the chemistry department, developed the unique solvent system—N,N-dimethylacetamide (DMA) containing lithium chloride (LiCl)—that enables the single-step synthesis of HMF with “unprecedented yield” from untreated lignocellulosic biomass, as well as from purified cellulose, glucose, and fructose.

...In step two, Raines and Binder convert HMF into DMF. Starting by applying the solvent to corn stover, the team then removed the chloride ions from the resulting crude HMF by ion-exclusion chromatography in water. This separation step prevented the chloride from poisoning the copper hydrogenolysis catalyst. They then subjected the crude HMF from corn stover to hydrogenolysis in 1-butanol with a carbon-supported copper-ruthenium catalyst and obtained a 49% molar yield of DMF, similar to that obtained by Dumesic and his colleagues using HMF that contained trace chloride. _GCC
Until now, cellulose has been resistant to breaking down into its constituent sugars. This quick one step method for cellulose to HMF, then the quick second step from HMF to DMF -- a potentially useful biofuel -- may bring about an important shift in the treatment of cellulosic waste from forests, cities, and farms.

The process of converting the "black liquor" waste product from pulp/paper works into useful energy is being expedited by a Swedish company with a US subsidiary.
Chemrec’s black liquor gasification (BLG) technology converts the black liquor waste stream from the paper pulping process into synthesis gas. The synthesis gas can then be processed into a variety of fuels—likely dimethyl ether (DME) and methanol (MeOH), although fuels such as Fischer-Tropsch diesel (FTD), Synthetic Natural Gas (SNG), or hydrogen are also possible. _GCC
And don't forget the promise of algal biofuels. Plans to incorporate algal bioreactors into the overall energy scheme of Scottish distilleries may give algal fuels the push they need to break through into the mainstream.
The bioreactors are glass panels that contain water and algae. When carbon dioxide is percolated through the panels, the algae strips out the carbon atoms, which are made into biodiesel.

The process also produces proteins that could be used to enrich spent grain from the distillery so that it is suitable for sale to fish farmers. _Bioenergy
Notice that the distillers are trying to maximise the utility of byproducts of the main processes. Combining spent distillers grains with the protein from spent algae would make a more valuable fish and animal feed. Even more elaboration in the use of waste byproducts is coming, to increase efficiencies and profits.



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