Objective
Replacing the process heat generated by the combustion of natural gas by process heat liberated by the combustion of phosphorus into phosphorus acid. The innovative character of this project resides in the fact, that the heat which is created by the combustion of phosphorus is used by means of a newly developed border plant. In the old situation the process heat of the phosphorus acid plant was evacuated through cooling systems into the sea. In the new situation the newly developed border plant recycles the process heat in order to use it in other plants instead of process heat generated by the combustion of natural gas. The expected energy savings are about 13.950 TOE/yr. Because of todays relative low prices of natural gas the project has momentary no payback.
Because of many technical problems, the operational readiness of the boiler was delayed with about one year. Because of this no energy savings were made. Lack of income : 2.5 mio HFL. Extra energy costs were because at first the process heat wasn't generated by burning phosphorus but by burning natural gas. Costs : 0.4 mio HFL. Due to the fact that the uspcaling of the pilot plant appeared to be more difficult than expected, the expenses will exceed the budget with more than 1.0 mio HFL.
The system is operational after some alterations in order to optimize the process. The output increased to 90 % of the original design. A new type of burner is developed and is expected to bring the output to the desired level. Capacity experiments are held with the air drier.
A new fuel pump should make an end to the necessity of a weekly maintenance stop.
A stainless steel boiler with a pressure of 170 bar was built as an upscaling of 14 times a pilot plant with which preliminary experiments have been taken place. (Height 20 M, Bore 4 M) the phosphorus is burnt in this boiler.
The boiler has a closed pipe wall off stainless steel. No phosporic acid is allowed to form in this boiler as it affects the material at temperatures above 83 deg.C. For this reason the phosphorus is sprayed with dried compressed air and the required combustion air must also be dried in an air drier. The process heat is transported through a closed steam condensation system (bore 150 MM) 170 bar with a length of more than 2 km. This closed system is directly linked with the processes of the other plants. In the other plants synthetic oil is heated by the energy from the boiler. In this way the process heat generated by the combustion of natural gas is replaced by the process heat of the boiler. This gives an energy saving of approximately 13600 TOE/YR. Thereis also a steam condensation system between the boiler and a steam convector (170 bar) which serves as a control unit. Thus the residual heat is discharged into the central network as 20 bar steam. While the process heat of the phosphoric acid plant isn't evacuated into the sea anymore, there is no need for the pumps which pumped the cooling water. This gives an energy saving of approximately 350 TOE/YR. The concept of using phosphorus as fuel in a boiler is completely new, so it can't be compared with existing technologies. So there are some technical risks:
- stainless steal and high pressure
- corrosion admittance
- up-scaling 14 x pilot plant
- very long transport of heat with a pressure of 170 bar
- investment is useless when application appears not to be possible
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
4380 Vlissingen
Netherlands