Coal Gasification: The Clean Energy Of The Future?
Dirty it may be, but coal is cheap. For this simple reason, it remains the world’s main source of power, providing a quarter of our primary energy and more than 40% of our electricity. And it will continue to do so for many years to come.
The challenge, then, is how to harness coal’s energy more cleanly. While global attempts to develop carbon capture and storage (CCS) have stalled, a number of countries are looking at different ways to exploit their abundant coal reserves.
Not all are motivated by environmental concerns, but are driven instead by economics and a desire for energy independence.
Old and new
The main technology being used is coal gasification – instead of burning the fossil fuel, it is chemically transformed into synthetic natural gas (SNG).
The process is decades old, but recent rises in the price of gas mean it is now more economically viable. The US has dabbled in the technique, but China is going all out in a bid to satisfy its soaring demand for power and reduce its dependency on imported liquefied natural gas (LNG).
The country’s National Energy Administration has laid out plans to produce 50 billion cubic metres of gas from coal by 2020, enough to satisfy more than 10% of China’s total gas demand.
Not only does it make economic sense, but it allows China to exploit stranded coal deposits sitting thousands of kilometres from the country’s main industrial centres. Transporting gas is, after all, a lot cheaper than transporting coal.
Coal gasification can also help address local pollution problems that have in recent months brought parts of the country to a virtual standstill.
But there are two big problems. First, coal gasification actually produces more CO2 than a traditional coal plant; so not only will China be using more coal, it will be doing so at a greater cost to the environment.
As Laszlo Varro, head of gas, coal and power markets at the International Energy Agency (IEA), says: “[Coal gasification] is attractive from an economic and energy security perspective.
“It can be a nice solution to local pollution, but its overall carbon intensity is worse [than coal mining], so it is not attractive at all from a climate change point of view”.