What is the primary function of a black liquor recovery boiler?

The primary function of a black liquor recovery boiler is to process black liquor, which is a byproduct of the pulping process in the paper industry. Black liquor consists of organic materials and inorganic chemicals that are separated from wood during the production of pulp. The recovery boiler plays a crucial role in this process by burning the black liquor to recover energy and materials necessary for the pulping process, such as sodium, which is essential for making new pulping chemicals.

During combustion in the recovery boiler, the organic components of black liquor are converted into heat, which is used to produce steam. This steam can subsequently be used to generate electricity or provide heat for various industrial processes, but the boiler's primary function remains the efficient processing and energy recovery from black liquor. The recovery of these materials helps in minimizing waste output and supports the sustainability of the paper production process.

Other options, while related to the broader functions of industrial boilers, do not specifically align with the key role of a black liquor recovery boiler. The focus on processing black liquor highlights the unique operational characteristics of these boilers within the pulp and paper manufacturing context.