A recent posting on EIA’s Today in Energy web page (May 13, 2015) highlighted the ethanol industry’s productivity improvement over the past two decades and noted that it is using 7% less corn to make the same amount of ethanol which then reduces ethanol’s land use requirements.
Reducing land use for cultivating corn also reduces water requirements, potential wetlands conversion to crop land, and fertilizer usage (reducing aquatic dead zones).
This is all good and it is what we expect from the efforts of engineers working diligently to improve industrial processes – continual improvement. In the ethanol industry the seven percent reduction in feedstock (corn) requirements has resulted from “better process technology, such as finer grinding of corn to increase starch conversion and improved temperature control of fermentation to optimize yeast productivity… [and] the development of better enzymes and yeast strains for improved output per bushel of corn.”
So what has the petroleum refining industry done over the same time period (1997-2014)? We can look at EIA’s data on refining yields to see if there have been improvements in refinery yields, i.e. how much transportation fuel is yielded from each barrel of crude oil.
In 1997, the yield of principal transportation fuels (gasoline, jet fuel, and diesel fuel) from refining crude oil was 78.9% on a volume basis. In 2014 the yield for those fuels was 84.3 percent, an increase of 6.8 percent which is almost as much as the increase in ethanol yield over that time period. This improvement has resulted from improvements in catalysts, equipment, and process automation as well as investments in conversion processes that upgrade less desirable products to transportation fuels.
Another way to evaluate yield improvement in petroleum refining is to look at total yield. On a volume basis (the EIA data are presented on this basis), the total yield from a petroleum refinery is greater than 100 percent because transportation fuels are not as dense as crude oil. In 1997, the total yield for the refining industry was 105.6% and in 2014 the total yield had increased to 106.7 percent. That 1.1 percent increase in yield gain results in an additional 170,000 barrels per day of transportation fuels in the US from the same volume of crude oil. And this yield improvement was achieved while the industry was also reducing the amount of sulfur in transportation fuels significantly.
As in other industries, hundreds of engineers are working diligently to improve petroleum refining processes and deliver continual improvements and they are succeeding.