Advanced Clean Coal Technology for Power Generation-

An Opportunity for Southeast Asia

Miro R. Susta,  IMTE AG, Switzerland

Dr. Sohif Bin Mat, Transtherm Engineering & Construction Sdn Bhd, Malaysia

IMTE AG

Power Consulting Engineers

Switzerland

MALAYSIA POWER 2003, KUALA LUMPUR, MALAYSIA

April 2003

ABSTRACT

On a worldwide basis, the prospect for Advanced Clean Coal Technology (ACCT) for power generation is extremely good, especially in rapidly developing markets such as Asia, Africa and South America. ACCT will pay considerable contribution not only to efficiency improvement but also to emissions decrease to the environment.

ACCT is defined as technology designed to enhance both the efficiency and the environmental acceptability of coal extraction, preparation and use.
This technology reduces emissions and waste, and increase the amount of energy gained from each tonne of coal.

It is expected that Supercritical Steam (SC), Ultra-SC (USC) technology, Pressurized Fluidized Bed Combustion (PFBC), Integrated Gasification Combined Cycle (IGCC), Hybrid Combined Cycle (HCC), Direct Coal fired Combined Cycle (DCCC), Molten Carbonate Fuel Cell (MCFC) and Magneto Hydrodynamics (MHD) power generation will realize high thermal efficiencies in this order and be put into practical use in the reverse order.

Both, PFBC and IGCC represent a unique partnership between coal gasification and the most efficient Combined Cycle Gas Turbine (CCGT) cycle for power generation.

The primary goal of leading power generation industry and many governmental bodies worldwide is successful introduction of ACCT into the energy marketplace.

The gasification, which utilizes coal, residual heavy oils and other low value feedstocks in the cleanest possible way, is not new.

The first coal gasification process was developed in Germany more than 65 years ago. Coal remains one of the most abundant primary energy sources for electric power generation worldwide. Currently, coal is used to generate around 40% of the electricity worldwide and is projected to supply over 50% of power generation plants worldwide beyond 2015.

For example, during the first 10 months of the year 2002, only in USA the total net generation of electricity was 3,222 billion kWh, 1% above what was reported for the corresponding period in 2001. 

In USA, more than 55% of the generation was produced by coal-fired power plants (burning around 580 millions tons of coal annually).

Wide application of gasification for power generation purposes was mainly delayed by its economics. The installed IGCC kW-price is much higher comparing to conventional CCGT using natural gas (NG) fuel.

When linked with modern CCGT, IGCC is one of the few technologies that significantly increase efficiency of coal fired power plant and have a beneficial environmental effect in reducing emissions of CO₂.

Additionally, an IGCC power plant produces marketable by-products, rather than large volumes of solid wastes typical of scrubber-equipped or fluidized bed combustion power plants using coal or petroleum-based heavy fuels.

The Present experience in USA and Europe shows that coal based IGCC power plant technology is ever closer approaching commercial status.

As such, IGCC is a technology that may be used not only in industrial but also in developing countries in the long term.

Current IGCC coal gasification projects would not have been economically viable, unless amply subsidized under various national & international entities and supporting programmes like the Clean Coal Technology (CCT) programme sponsored by the US Department of Energy or some programmes like THERMIE sponsored by European Countries (EC).

But to be truly competitive with conventional, NG fired CCGT cycles, NG prices need to raise and larger gas turbines (GT) to be used.

Since IGCC technology has remarkable implications for energy conservation and environmental protection, indirect economic and social benefits are substantial.

If the predicted growth in coal-fuelled power generation continues without widely applied pollution-suppressing technologies, emissions levels would increase by 350% within the next double-decade, and by 1000% by the year 2035. Such estimates have been issued by the World Bank.

As worldwide air emissions standards become stricter, the superior environmental performance of IGCC will take on added economic benefits because the technology can achieve greater emissions reductions at lower cost than less advanced technologies.

According to World Bank statistics, the greenhouse emissions increased in Malaysia from 3.8 tonnes per capita in 1994 to 5.7 tonnes in 1998.

Among ASEAN countries this is the third highest after Brunei and Singapore.

Modern IGCC power generation technology will make an important contribution to the improvement of the global environment.

For example, a coal plant without environmental controls generates 1000 to 1500 ppm of NOx, compared to about 20 ppm for NG fired CCGT power plant.

State-of-the-art, IGCC power plants generate as little as 20 ppm of NOx, or about the same as NG fired power plants.

Similarly, an uncontrolled coal power plant generates 2500 ppm of SO₂, while a state-of-the-art IGCC power plant generates as little as 10 ppm SO₂.

This paper presents review and technical / commercial analysis of several most important IGCC projects with their basic economical indicators and benefits for global environment. SC, USC, PFBC, HCC, DCCC, MCFC and MHD technologies are also briefly introduced.