The regulatory measures to reduce greenhouse gases are creating a billion dollar per year market for CO2 mitigation equipment and services. However, the amount to be spent for sequestration will be far less than for improving efficiency of existing combustors. This is the conclusion reached by the McIlvaine Company in its continually updated report Utility Carbon Dioxide Mitigation Markets.
From the perspective of an oil company looking for ways to enhance recovery, coal is ideal. Large amounts of CO2 can be generated at low cost. Sask Power is building a CO2 capture system at its Boundary Dam plant. Due to the proximity of depleted oil fields, the cost of the capture system can quickly be offset by oil revenue increases.
The balance between the need for enhanced oil recovery and the availability of power plant CO2 is also favourable. The need far exceeds the present CO2 generation. The problem is that much of the need is remote from the generation. The result is that CO2 sequestration will be too expensive for all but a few sites.
McIlvaine Company adds that one solution is a new global strategy that marries coal-fired power generation and enhanced oil recovery. Coal could be economically shipped to Saudi Arabia and coal-fired power plants which are constructed there could economically furnish the CO2 for recovery. The gas and oil which would no longer be burned to generate Saudi power would be exported. The problem is that this solution requires a degree of coordination among the countries of the world which is unlikely.
The concept of quickly replacing coal with other fuels is impractical, costly and not the best environmental option. In some circumstances, coal is the greenest of fuels. An existing coal-fired power plant emits 1 unit of greenhouse gases while a gas turbine emits only 0.6 units of greenhouse gases. A solar or wind generator will emit close to 0 units. A coal-fired power plant burning 20% biomass and using oxycombustion and sequestration will emit -0.2 units of greenhouse gases. For each unit of energy produced, CO2 is being removed from the atmosphere. The biomass absorbs CO2 when it grows. When it is burned and then sequestered, it is no longer in the environment. When pure oxygen is the gas intake there is no stack and no emission. All the gases are sequestered.
The problem with widespread use of this technology is the limited availability of biomass and the lack of proximity between combustion source and depleted oil fields.
The biggest opportunity is the increased efficiency at existing coal-fired power plants. Utilising gravimetric rather than volumetric coal feed, upgrading the combustion system, utilising optimisation and other renovations can cause large CO2 reductions. An ultra-supercritical power plant generates 30% less CO2 than an old sub-critical power plant.
McIlvaine concludes that this is only the beginning. Co-generation combined with higher efficiency can cut the CO2 emissions by 50%. A power plant with a steam plume is a power plant which needs co-generation. Rather than unproductively evaporating large amounts of water, the power plant can supply the energy for an ethanol plant or even to a co-located sewage treatment plant or fish farm.
There is a revolution in fish farming with Recirculating Aquaculture Systems (RAS). These sophisticated tank systems can be located anywhere and are more cost effective than ponds or wild capture.
