Fossil Fuel Supply for India's Coal-fired Power Plants

Related Vendors

DÜPERTHAL Sicherheitstechnik GmbH & Co. KG

Glatt Ingenieurtechnik GmbH

EDL Anlagenbau Gesellschaft mbH

Tata Consulting Engineers

Sea or Rail Transportation

Receipt and unloading of imported coal does not necessarily mean unloading at a captive port or at a captive coal terminal near the plant. At times imported coal is received through rail also depending upon the contract with the coal supplier. Similarly, indigenous coal does not mean only rail or road transportation. Indigenous coal can also be received through sea and unloaded at a port or at a terminal. Thus it can be seen that there are varieties of solutions to meet the project requirements, some of which could be purely non technology related and some of which can be purely technology related.

Setting aside all such issues discussed in the above paragraphs, which are project specific and therefore outside the scope of this article, we can consider and discuss cases where the coal is received and unloaded either at a captive port or at a captive terminal or at a unloading berth inside an existing port and transported to a power plant. In this context it may also be noted that transportation on sea for long distance transportation has been the most reliable and dependent method and will continue to remain so in future as well.

Gallery

Gallery with 7 images

The whole system of unloading and transportation of coal can be split in to two parts: (i) receipt, unloading and storage of coal at the port or at the terminal which can generally be called seaborne coal handling system, and (ii) transportation of coal from the port or the unloading terminal to the power plant site.

Seaborne Cargo Handling

Seaborne coal handling system in the parlance of power plant engineers and consultants means transportation of coal using ships or using ships and barges, unloading at a port or a coal terminal and storage near the port or the terminal for further transportation to the power plant site.

Ships can be unloaded using mechanized systems or non mechanized systems. One example of non mechanized unloading is at Mithapur where coal is received by 40 000 dwt ships and coal is unloaded on to the berth using cranes travelling on the berth. The unloaded coal is transported by trucks to a storage area for further distribution to various customers. It is said that about 10 000 tonnes of coal can be unloaded in a 24 hour day this way. Imported or indigenous coal is transported by ships from the port of dispatch on the seas on a prefixed voyage route to the port of receipt for unloading or to a coal terminal meant for unloading for the project. Depending upon the draft at the unloading location, large, medium, or small ships can directly call at the unloading berth or can be lightered mid stream from where coal is further transported through barges up to the unloading berth.

The decision to adopt direct unloading of large or medium sized ships or to have the mother ships lightered and then transport the coal up to the unloading berth is based on the quantity required to be unloaded and available draft, ability for movement during high tide etc. If draft available can allow large sized ships to berth at the port or at the terminal there is no need for adopting barges. Examples for this are the New Tuticoirn Port, Mangalore Port , Adani Port, Ennore satellite Port etc. If however adequate draft is not available as in the case of the Trombay terminal, large ships will have to be lightered mid stream and then coal will have to be transported using barges.

Sizes of ships are classified as Handimax (up to 50 000 dwt capacity), Panamax (over 50 000 dwt up to 75 000 dwt capacity) and Cape Size vessels (over 75 000 dwt capacity). This is a general classification and a more detailed classification is available which is not very relevant for coal transportation as discussed in this article. There are self unloading type and ships which are unloaded using berth mounted unloaders. Self unloading vessels are also generally called geared vessels. Geared vessels can be fitted with simple grab bucket type unloading cranes or can be fitted with sophisticated belt conveying systems for continuous unloading. Barges do not have unloading systems fitted in to them and are unloaded using berth mounted machinery only.

(ID:35459490)