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Speech on Gasification at Yorkshire Coal Taskforce Clean Coal Seminar, March 2001: David White, Chair of Institution of Chemical Engineers Committee on Gasification Technology said we were in danger of missing the boat, others were taking seriously the response to change, they were always assuming it was natural gas |
It could be natural gas or synthetic gas, gasification had a very important role. Restructuring and deregulation of the power and gas industries was now a world wide situation. There were pressures also in Europe and the US, environmental constraints, CO2 reduction had come through fuel switching, but also needed to come through efficiency and technology. There was global growth and power demand, more reason to look at power generation technology. The power section was vulnerable, large volume produced at source. Reassessment at technical level, how to handle these emissions, we had to look at FGD. But if taking new plant and talking about a combination of efficiency, nox, dust, was it right to take it out after combustion? Or could you remove it at another point of the cycle, more efficiently? That step was going to be influenced by the efficiency of the technology that generates the electric power. Economic constraints, how could we best get to the levels that had been imposed on us? This linked back to technological advances. The key for coal is that you can no longer afford to combust the fuel and clean up after, we had to convert that fuel, then combust that efficiently.
The technological advances had been significant. On a global survey, the efficiency was 30% maximum – Drax was 36-37%, but a lot of other plants around the world reached barely 25%. China less than that, billions of tonnes of coal burned inefficiently, vast quantities of CO2. That was 70% of energy going to waste. The best steam was 43-47%, but current combined cycle system was 58%, that was twice the efficiency by using combined cycle. The gas turbine was the friend of coal. The enemy had been natural gas, and the price. But that had changed. Combined cycle plants were essential for the efficiency of power generation in the future. We had to see how we could harness the benefits. Changes in time – jet engines replaced liners. Many gas turbines were just big jet engines, and would burn any clean gas.
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In efficiency terms, plants had come up into 390 Megawatt on one machine from 159 Megawatt in 1991. Gas turbines were very versatile, could run on many different types of fuel, but would also run on synthesis gas. We could eliminate sulphur, would also have spare nitrogen, more environmentally friendly than natural gas. CO2 had been one of the key things that people had been talking about, efficiency, fuel and CO2 all combined together, the global average of emissions. There were benefits even without sequestration, growth in demand for gas, in order to meet regulations, using clean gas, low cost turbine, quick build. |
Looking at natural gas prices, we were becoming dependent on external sources, less than half way up that curve, it was attractive to gasify coal. In the US, the rise was fivefold not threefold, and the US is moving as fast as possible into gasification. This was gaining favour, they could convert any material, particularly coal, could get up to 95% conversion efficiency, getting very substantial conversion of energy in the raw material. It was a fully proven technology, primarily in the chemical industry, 160 projects up and running in the world, 450 gasifiers, many in South Africa. We had seen a scale up of gasifiers to fit with new gas turbines for the new power sector, most technological challenges had been overcome, operations going extremely well.
The other thing that was important, any discussion on the environment, what was contributed by the power sector, but they could not separate it from the transport sector. The new directives on quality of diesel and gasoline being produced, some concern now about pollution from planes, changes were taking place in fuel quality that were requiring the refiners to re process a lot of that transport fuel into better quality material. That change was coming about at the same time as pressure from operators to become cleaner. Also there was a falling market for heavy residual fuel that could be combusted without FGD.
| One solution was to start gasifying that heavy residue, he showed a chart of how gasifying took place. Taking a range of fuels, putting into a reactor, a solid material comes out as crude glass. The gases are then cleaned, systems used by the oil industry, the clean gas can then be used in gas turbines. If you wanted to make other things, it could be done on a hydrogen stream, they could make more CO2 in the stream, and it could be captured. Why integrate? He tended not to like the term, what one was doing, in simple terms, providing a CCGT with its own gas supply. In integration, they could improve efficiency by various levels of integration, always at cost, they could have heat recovery, but there was a cost in doing it. | 
Gascoigne Wood Mine from Leeds/Hull railway line |
He preferred to say, we were supplying a gas turbine with its own source of gas, it could be used to repower a coal station, by retaining steam turbines. He had put a gas turbine in, and a gasifier, in Indiana, off site, and pumped over the fence, could re-power a CCGT that was running on natural gas at the moment. What was also happening in the power industry, the oil companies were getting interested in power generation, seeing high availability in the US and Holland, availability of gas turbines and gasifiers. General Electric were using synthetic gas, it was fully commercial, coal, waste, residue.
He gave figures on synthetic gas, and spoke of projects, in Tampa, asked the community which technology they wanted to choose, they chose the IGCC because it was the cleanest. New projects – Global, Texas – 500 Megawatt, burning petcoke. Studies showed capital costs were falling, they had been looking at how it could be packaged and costs reduced. He spoke of his concern, in this country, we had not been looking to see what the others were doing, they were getting on faster than us - $450 million per year in the US, it was here. We don’t need cleaner coal technology, it is here, and doing well. It was being pushed, or drawn in by very high gas prices in the US. CO2 , the technology to do it was fully proven.
To summarise, he believed gasification was fully proven, it had never been in a stronger position. They needed to stimulate an interest in following this route in this country. CO2 capture and sequestration, cheaper than renewables, off shore wind, which cost between 6˝ and 10 p. Although governments supported renewables to a certain level, they couldn’t support a 10% level they were asking for, the renewables obligation directive. The concern was, here was a guaranteed method of removing CO2 at a reasonable cost, could support the use of coal, should be the way we should be going forward.
Coal remains a vital feedstock, gas becomes the salvation of the coal industry.