Engineering in an Age of Limits

Discusses the role of engineers as society enters an Age of Limits — particularly with oil supplies.

Monthly Archives: September 2013

The Exponential Function

Albert Bartlett

The first set of posts at this site to do with Process Safety Management (PSM) has been to do with the impact of the likely decline in world-wide petroleum supplies over the coming decades. These declines will lead not only to shortages of raw materials but also unpredictable interruptions in the supply chains. These issues will in turn pose both serious challenges and opportunities for process safety professionals.

However, I would first like to recognize the contributions of Dr. Albert Bartlett, professor emeritus at the University of Colorado, who passed away a few days ago at the age of 90. Dr. Bartlett became very well known through his explanation of how the exponential function affects us; in particular, his lecture on “Arithmetic, Population & Energy” has been widely viewed on the Internet. His famous quotations include, “The greatest shortcoming of the human race is our inability to understand the exponential function”, and “Sustainable growth is an oxymoron”.

An earlier post in this series discussed the remarkable forecasts made by Dr. M. King Hubbert in the year 1956. At that time world-wide oil production of oil was increasing at a rate of about 7% per year but Hubbert predicted that first the United States and then the world would reach an upper limit (the top of the Hubbert Curve). And this is what has happened; world-wide production rose steadily until the year 2005. Then, as Dr. Bartlett pointed out, because continuous exponential growth is not possible the production rate has flattened out, and has remained on a bumpy plateau since.

A further issue that needs is to be considered, and one that we may cover in more detail in a future post, is that of ERORI (Energy Returned on Energy Invested). When Dr. Hubbert was making his predictions it took very little energy to produce energy. It has been estimated that the early Texas and Saudi Arabian fields had an ERORI of around 100. In other words, it took one barrel of oil to produce 100 barrels. Modern facilities such as deepwater platforms and tar sands have a much lower value (probably in the 15-30 range). Therefore, even if we could produce the same amount of oil as we did in the 1950s, the net production would be less because so much of that oil would be used simply to find, produce and ship the new oil.

Although the consequences of these predictions appear to be rather gloomy, they provide an opportunity for process safety professionals. Most of their current work is reactive. Someone such as an operations manager or an investment analyst suggests that a new activity, such as building an offshore platform, be carried out. The PSM function is largely to serve as a necessary brake. HAZOPs have to be performed, operating procedures written, MOC procedures developed, and so on. Although the other groups on the project will recognize the necessity and importance of this work, they will still see it as an effort that takes time and adds cost.

However, if the supply of raw materials, equipment and spare parts becomes less reliable as a result of restricted energy supplies, PSM professionals can assume more of a “take charge” role. They can develop management systems that not only keep the facility safe, but that also help management keep things running in difficult times. They can move from their current reactive mode to a role that is much more pro-active.

We will develop this theme in future posts.