A significant part of hard coal production (15–19% in the years 2010–2017, i.e. 1.0–1.3 billion

tons per year) is traded on the international market. The majority of coal trade takes place by sea,

accounting for 91–94% of the total coal trade. The article discusses the share of coal in international

seaborne trade and the largest coal ports. Coal is one the five major bulk commodities (in addition

to iron ore, grain, bauxite, alumina, and phosphate rock). In the years 2010–2016, the share of coal

in international seaborne trade and major bulk commodities was 36–41% and 11–12%, respectively.

Based on the analysis of coal throughput in different ports worldwide, the ports with the

largest throughput include the ports of Qinhuangdao (China), Newcastle (Australia), and Richards

Bay (South Africa). For 2013–2017, their throughput amounted to a total of 411–476 million tons

of coal. The largest coal exporting countries were: Australia, Indonesia, Russia, Colombia, South

Africa, and the US (a total of 85% share in global coal exports), while the largest importers are

Asian countries: China, India, Japan, South Korea and Taiwan (a 64% share in global imports). In

Europe, Germany is the largest importer of coal (54 million tons imported in 2016). The article also

discusses the freight costs and the bulk carrier fleet. Taking the price of coal at the recipient’s (i.e.

at the importer’s port) into account, the share of freight costs in the CIF price of steam coal (the

price of a good delivered at the frontier of the importing country) was at the level of 10–14%. In

the years 2010–2016, the share of bulk carriers in the world fleet was in the range of 11–15%. In

terms of tonnage, bulk carriers accounted for 31–35% of the total tonnage of all types of ships in

the world. The share of new (1–4 years) bulk carriers in the total number of ships on a global scale

in the years 2010–2016 was 29–46%.

The paper presents the method of on-line diagnostics of the bed temperature controller for the fluidized bed boiler. Proposed solution is based on the methods of statistical process control. Detected decrease of the bed temperature control quality is used to activate the controller self-tuning procedure. The algorithm that provides optimal tuning of the bed temperature controller is also proposed. The results of experimental verification of the presented method is attached. Experimental studies were carried out using the 2 MW bubbling fluidized bed boiler.