Archive for the ‘bioelectricity’ Category

The Bioelectricity And Bioethanol Synergy

The global race for alternative energy solutions has been quite keen as is expected of cutting-edge technologies. So rapid is the evolution that barely a week goes by without a technological update. Second generation bioethanol programs for example use lignocellulosic biomass such as miscanthus and switchgrass for feedstock; but just as these programs were making progress, a report was published last week by researchers from Stanford University and the University of California, Merced. The report indicated that burning such feedstock to produce electricity for battery-powered vehicles was more energy efficient than using the same in producing ethanol for traditional internal combustion engines. Specifically, it held that across a wide range of lignocellulosic biomass feedstock and vehicle classes, bioelectricity produced on average, 81% more transportation kilometers and 108% more emissions offsets than bioethanol per unit area cropland. According to the report, ethanol produced from an acre of switchgrass can power a small-sized SUV a distance of about 9,000 highway miles (14,484 kilometers) compared to about 14,000 (22,531 kilometers) for bioelectricity, which also substantially avoids more greenhouse gas emissions.

A note or two just before celebrating battery-powered automobiles. Only a tiny fraction of vehicles in the United States for example are battery-powered. The infrastructure (recharging stations etc) is not well established. Forecasts for the proportion of hybrid electric vehicles by the year 2015 are in the 10% range with an even smaller value for battery-powered ones. Appropriate pricing for these may also not have been settled. The process of substituting current internal combustion-engine vehicles with electric ones will therefore be slow and protracted if indeed plausible.

There is however a measure which will utilize the synergies between bioelectricity and bioethanol in a lignocellulosic energy program.
The process of ethanol production from biomass such as miscanthus or switchgrass involves fermentation to produce the solution which is then distilled to obtain ethanol. In Brazil, widely acclaimed as the model of ethanol excellence, ethanol is produced from sugarcane. The milling residue known as bagasse is burnt to produce auxiliary power just like in the afore-mentioned report. For most of these ethanol milling plants, the power so-generated is sufficient to power the whole production process with a lot to spare. The excess power is sold to utilities with proceeds in the millions of United States dollars. Two points are worthy of note here. The first is that the power is generated from the residue of the ethanol production process, that means after ethanol milling. The second is that even then, the said power is in excess of production requirements. In Brazil, synergies between ethanol and sugar (both products of the sugarcane feedstock) have sustained the milling plants.

The same crop of switchgrass for example can therefore be used for production of both ethanol (for blending with gasoline in traditional internal combustion engines) and electricity (for charging battery-powered vehicles). The inherent synergies would deliver on two key pillars of current energy policy thrust, more efficient and reliable energy source as well as greater greenhouse gas offsets. That the electricity-powered engine is more efficient than its internal combustion counterpart is not in doubt but due to the current impassioned and implacably polarized ethanol-gasoline arguments it would be necessary to add that the United States Department of Agriculture has determined that ethanol has 81% greater energy efficiency than gasoline.

When other countries’ automobile companies were improving on fuel efficiency and emissions standards, those of the United States, with brazen state support skimped. Today, the same US automobile companies are teetering on the brink of collapse while the Toyotas and Hondas even with the current recession are better off. There is no current evidence that bioelectricity or bioethanol will replace gasoline any time soon, as the fuel for automobile transportation. However, in the current energy quest, this process will provide for a much-desired, cleaner, efficient and more reliable addition to the transportation energy mix.

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