Case study

Stable operation and cost reduction in existing plants using optimal catalyst replacement plans

Industry: Coal-fired power plants

ISSUE

The issues surrounding the usage of biomass fuel for the decarbonization of plants

Large investments for building new infrastructure and other facilities are needed to reach decarbonization, which is considered a global issue. Against this background, as the implementation of renewable energy takes place, its supply depends on the climate and usage conditions. Therefore, in terms of the balance between supply and demand, coal-fired power generation remains an essential power source. Currently, coal-fired power plants have no choice but to consider biomass fuel and low-load operations to reduce CO2 emissions. To continue operating coal-fired power plants, it is necessary to minimize CO2 emissions and supply low-cost, stable power. Appropriate maintenance plans for the denitration system, i.e. SCR system, are key for the stable operation of the plant.

Effect of SCR performance of AQCS equipment

SOLUTION

KEY POINTS TO THE SOLUTION

  • Investigating the performance variations of SCR catalysts over time and optimizing the catalyst replacement date and volume
  • Estimating the effect of switching fuels on SCR catalysts to prevent loss of power generation profit
  • Estimating the optimal catalyst volume based on the operating conditions of the plant to reduce excess catalyst volume

Investigating the performance variations of SCR catalysts over time and optimizing the catalyst replacement date and volume

Maintaining and operating a SCR system require setting the catalyst replacement date and investment in advance. Optimal catalytic replacement plans greatly contribute to the reduction of maintenance costs of existing plants by reducing the investment for new catalysts and disposing of spent catalysts. At Mitsubishi Power, we collect a catalyst sample from your SCR reactor, then investigate its residual performance on a laboratory scale using a catalyst evaluation system. Based on the results, we are able to create a diagram for the catalyst deactivation rate over time and plan the optimal catalyst replacement date and volume.

Mitsubishi Power’s operation and maintenance support

Estimating the effect of switching fuels on SCR catalysts to prevent loss of power generation profit

One of the initiatives toward realizing a carbon-neutral society is switching to biomass fuel. However, compared to coal fuel, biomass fuel has a high concentration of substances that adversely affect the performance of catalysts. Biomass fuel is produced in various areas and has multiple types and has different properties. The effect of biomass fuel on the performance of catalysts varies based on such different properties. At Mitsubishi Power, we analyze the components of the fuel and estimate the deterioration performance of SCR catalysts. This enables you to replace the right volume of catalyst at the right time. This can also help avoid unplanned plant stop due to performance issues and prevent loss of power generation profit.

Estimating the optimal catalyst volume based on the operating conditions of the plant to reduce excess catalyst volume

Generally speaking, the catalyst volume that fills the SCR system is designed to accommodate the performance requirements of 100% plant load exhaust gas conditions. Therefore, the plant operating under low load normally requires less catalyst volume. At Mitsubishi Power, we give you recommendations for reducing excess catalyst volume by estimating the required volume based on your plant operation plan, which contributes to the reduction of running costs.

EXPECTED OUTCOME

  • Minimizing the catalyst volume to be replaced, contributing to the reduction of the plant's maintenance costs
  • Avoiding unplanned plant stop due to performance issues that can occur when switching fuels and preventing loss of power generation profit
  • In the future, if the NOx emission regulation become significantly stricter or if exhaust regulations of new substances, such as Hg, are applied, Mitsubishi Power's performance agency service can offer you an optimal catalyst plan.

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