Ammonia Desulfurization: Breaking the Traditional Coal-Type Barrier

For years, ammonia desulfurization was often considered a solution mainly suited to high-sulfur coal, while calcium-based systems were regarded as sufficient for low-sulfur coal. Changing environmental requirements and rising operating costs are challenging this conventional view.

As emission standards become more stringent and carbon costs receive greater attention, power plants using low-sulfur coal are also reassessing their long-term flue gas treatment strategies. Compared with traditional calcium-based desulfurization, ammonia desulfurization offers strong adaptability to different coal qualities and operating conditions.

The difference starts with the reaction mechanism. Calcium-based desulfurization relies on gas-solid-liquid reactions, where limestone dissolution and mass transfer can affect system performance. Ammonia desulfurization is based primarily on gas-liquid reactions, allowing sulfur dioxide to react rapidly with ammonia and reducing the risk of reaction-rate limitations.

Advanced ammonia-based systems can maintain desulfurization efficiencies above 95% across low-, medium-, and high-sulfur coal applications, while ammonia recovery rates of 97% or higher help support economical operation.

For plants considering a transition from calcium-based systems to ammonia-based technology, the benefits go beyond sulfur dioxide removal. Reduced gypsum handling requirements, lower solid-waste pressure, and the potential value of ammonium sulfate by-product can all influence overall operating economics.

At MirShine Group, decades of chemical engineering experience and multiple generations of technology development have supported the application of ammonia desulfurization across a wide range of coal qualities.

The question is no longer simply whether a plant burns high- or low-sulfur coal. The more important question is whether its current desulfurization system remains the right solution for the environmental and economic requirements ahead.