| Press material

Global sulfur limit comes into force - giants under pressure


Shipping companies around the world are currently under pressure to get their ships afloat under the new regulations of the International Maritime Organization (IMO). Thousands of water boilers that have been used to heat heavy oil have become redundant - although steam could still be used efficiently. For this purpose, Orcan Energy offers waste heat solutions that can be used to save nearly 12 million liters of fuel and 40 million tons of CO2 worldwide for the protection of the environment.

From January 2020, the sulfur limit in fuel worldwide will be reduced from 3.5 to 0.5 percent. So far, heavy oil (HFO) has generally been heated on the high seas, which remains as a residue in crude oil refining. The viscous mass contains high levels of sulfur, ash and heavy metals and must first be heated before firing so that it is liquid enough to be injected. With the tightening of the limit values, however, the burning of heavy fuel oil is no longer possible.

Shipowners now have three realistic options: they switch from heavy oil to marine diesel or another fuel; They put into the ships a cleaning system, a so-called scrubber or convert the entire ship to liquefied natural gas (LNG) as fuel.

Since switching to marine diesel is the easiest, it is first implemented on the vast majority of

more than 90 percent of the ships, which is approximately 60.000 ships worldwide.

This eliminates the need for thousands of boilers to heat heavy fuel oil on most vessels, although water vapor can be efficiently used to power an on-board electric generator that can easily be connected to all existing boilers. This has two advantages for shipping companies: First, the electricity that is produced results in lower fuel costs that partially offset the higher fuel price of low-sulphur fuels. Second, the fossil-free power drops the overall emissions. The efficiency PACK can make use of any waste heat source, whether it is extracted from exhaust gas directly or indirectly, via a steam or thermal oil boiler. It’s simply a matter of installing a small steam-to-water or oil-to-water heat exchanger that transports the waste heat with an intermediate hot water loop to the efficiency PACK.

How does Orcan’s efficiency PACK work?

The Orcan technology is based on the so-called Organic Rankine Cycle (ORC), a physical principle in which an organic refrigerant (instead of water in a normal Rankine Cycle) completes a cycle and continuously converts waste heat into mechanical work. This waste heat can come from various sources like exhaust gases, jacket cooling water, steam or thermal oil. The heat is extracted from the heat source via a heat exchanger and transferred to the efficiency PACK by means of an intermediate hot water loop. Jacket cooling water is fed into the efficiency PACK directly. The waste heat enters the cycle via the evaporator and drives the ORC in the efficiency PACK. In the evaporator the refrigerant is vaporized and routed to the expansion machine as superheated vapor. Here the highly pressurized refrigerant is expanded, thus releasing mechanical work and driving the rotary screws in the expansion machine. This rotational energy is in turn used to drive a generator that produces electricity. After the expansion machine the still gaseous refrigerant is liquefied again in the condenser and then repressurised by the feed pump. The refrigerant has now completed the cycle and again enters the evaporator to absorb waste heat.

How big is the efficiency PACK?

The efficiency PACK has 1096 x 1396 x 1982 mm (w x l x h); it requires 1.5 square meters of floor space on a vessel; it can best be compared to the size of a shower cubicle.

Are the efficiency PACKs better geared towards a certain type/size of ship?                 

The efficiency PACKs can be installed on all types of ships. Several design requirements like compactness and modularity have been made in order to make it suitable for many types of ships. We now have a product that is compact enough to be installed on inland waterway vessels, but due to its modularity we can also combine multiple units for ships that produce greater quantities of waste heat, e.g. cruise vessels, hopper dredgers and fishing trawlers.

What reductions in C02 emissions can be generated? And what cost savings can shipowners achieve?

This is very case-specific. A typical case is where we install 4 units and save around of 350 to 400 tonnes of fuel annually and reduce CO2 emissions by 1000 to 1200 tonnes. One fully utilized efficiency PACK can reduce fuel costs with around €75.000 annually at current prices. With a typical project with four modules, the total fuel savings amount to approx. €220.000 to €250.000 annually.