coal production

The formation of modern society has been dominated by coal and oil, and together these two fossil fuels account for nearly two thirds of all primary energy used by mankind. This makes future production a key question for future social development and this thesis attempts to answer whether it is possible to rely on an assumption of ever increasing production of coal and oil. Both coal and oil are finite resources, created over long time scales by geological processes. It is thus impossible to extract more fossil fuels than geologically available. In other words, there are limits to growth imposed by nature.

The concept of depletion and exhaustion of recoverable resources is a fundamental question for the future extraction of coal and oil. Historical experience shows that peaking is a well established phenomenon in production of various natural resources. Coal and oil are no exceptions, and historical data shows that easily exploitable resources are exhausted while more challenging deposits are left for the future.

For oil, depletion can also be tied directly to the physical laws governing fluid flows in reservoirs. Understanding and predicting behaviour of individual fields, in particularly giant fields, are essential for understanding future production. Based on comprehensive databases with reserve and production data for hundreds of oilfields, typical patterns were found. Alternatively, depletion can manifest itself indirectly through various mechanisms. This has been studied for coal.

Over 60% of the global crude oil production is derived from only around 330 giant oilfields, where many of them are becoming increasingly mature. The annual decline in existing oil production has been determined to be around 6% and it is unrealistic that this will be offset by new field developments, additional discoveries or unconventional oil. This implies that the peak of the oil age is here.

For coal a similar picture emerges, where 90% of the global coal production originates from only 6 countries. Some of them, such as the USA show signs of increasing maturity and exhaustion of the recoverable amounts. However, there is a greater uncertainty about the recoverable reserves and coal production may yield a global maximum somewhere between 2030 and 2060.

This analysis shows that the global production peaks of both oil and coal can be expected comparatively soon. This has significant consequences for the global energy supply and society, economy and environment. The results of this thesis indicate that these challenges should not be taken lightly.

Published in: Uppsala University, doctoral thesis
Available from: Uppsala University

A model capable of projecting mineral resources production has been developed. The model includes supply and demand interactions, and has been applied to all coal producing countries. A model of worldwide coal production has been developed for three scenarios. The ultimately recoverable resources (URR) estimates used in the scenarios ranged from 700 Gt to 1243 Gt. The model indicates that worldwide coal production will peak between 2010 and 2048 on a mass basis and between 2011 and 2047 on an energy basis. The Best Guess scenario, assumed a URR of 1144 Gt and peaks in 2034 on a mass basis, and in 2026 on an energy basis.

Published in: Fuel, Volume 88, Issue 11, November 2009, Pages 2059-2067
Available from: ScienceDirect

By applying the multi-Hubbert curve analysis to coal production in the United States, we demonstrate that anthracite production can be modeled with a single Hubbert curve that extends to the practical end of commercial production of this highest-rank coal. The production of bituminous coal from existing mines is about 80% complete and can be carried out at the current rate for the next 20 years. The production of subbituminous coal from existing mines can be carried out at the current rate for 40–45 years. Significant new investment to extend the existing mines and build new ones would have to commence in 2009 to sustain the current rate of coal production, 1 billion tons per year, in 2029. In view of the existing data, we conclude that there is no spare coal production capacity of the size required for massive coal conversion to liquid transportation fuels. Our analysis is independent of other factors that will prevent large-scale coal liquefaction projects: the inefficiency of the process and either emissions of greenhouse gases or energy cost of sequestration.

Published in: Natural Resources Research, article in press
Available from: SpringerLink