3.2 Process Flow Diagram

Fig. 4 is a process flow diagram of the onboard ammonia production unit for SCR applied to PANAMAX 74BC.

　

Fig. 4 Process Flow Diagram

　

3.3 Equipment Layout

Fig. 4 shows the equipment layout of the onboard ammonia production unit for the PANAMAX 74BC. Fig. 5 shows the layout of the unit on the deck near the chimney of the PANAMAX 74BC. Ammonia produced with this unit is utilized for SCR. Required space is about 5mL x 3mW x 4mH, which is easily available on the deck of the ships.

　

Fig. 5 Equipment Layout

Fig. 6 Layout of the Unit on the Deck

　

3.4 Raw Material and Utility Consumption

Raw material hydrogen is produced by water electrolysis from distillate for boiler water. Nitrogen is produced by Pressure Swing Adsorption (PSA) from ambient air. Electric power used for electrolysis and the motors of rotating machines is fed from the power generator equipped to supply all electric power for the ship. Electrical power cost is calculated as cost for fuel for the diesel engine generator. As for the above, all raw materials and utilities required for ammonia production are common and their consumption figures are small enough to be obtained in ships without any additional equipment. Raw material and utility consumption figures are as follows:

　

Table 3 Raw material and utility consumption

　

3.5 Ammonia Production Cost

Based on the conditions shown in Tables 2 and 3, ammonia production cost is calculated at JPY150,000 per ton of ammonia, which is higher than the price of ammonia produced in large ammonia plants, such as 1,000 t/d or bigger facilities. The major reason for the high ammonia cost by this system is the size (capacity). A 50kg/h production capacity is 1/833 of commercial ammonia plants of 1,000t/d class.

　

4. ADVANTAGEOUS FEATURES OF THIS SYSTEM

　

This onboard ammonia production system has many advantageous features, described in the following:

1) Risks in transportation of ammonia across towns are avoided. Ammonia is usually transported from ammonia production factory to users via distribution stations by lorries or trucks. Traffic accidents involving these vehicles are not uncommon and pose a toxic and flammable danger.

2) Eliminate loading facilities at ports. Loading facilities at each of the 1,000 ports in Japan are required to load ammonia from tanks on the port into the tanks onboard. Loading facilities include loading arms, tanks, compressors and/or pumps which are an additional cost to ammonia itself.

3) Large capacity ammonia tanks are required for voyage from one port to another. More than twice volume of ammonia must be stored if the port of destination is not equipped with ammonia loading facilities. This is not only a problem of space for tanks but also safety of crew and passengers of the ship.

4) This unit requires air, water and electricity as raw materials and utilities, all of which are available on ships. No other materials are required. In collaboration with the Tokyo Institute of Technology, NKK and NSS have developed a new ruthenium.

5) Ammonia synthesis pressure and temperature of this system are 1 MPa[gauge] and 350℃ which are dramatically lower than those of conventional technologies of which pressure and temperature are 15 to 30 MPa[gauge] and 500℃.

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