[Quotation p35]
DTEC (Discharged Thermal Energy Conversion) technology offers a similar outcome. The process is a modification of ocean thermal energy conversion technology (OTEC), which is based on the temperature differences between deep and shallow seawater. Instead of seawater, DTEC uses the wasted heat and warm effluent wastewater to evaporate ammonia, the vapors of which can power turbines to generate electricity at little cost and without pollution. The ammonia gas is then cooled using cold seawater to allow the ammonia to be re-used.
The amounts of electricity and water generated through this process are not huge, but they are significant. On an average world-scale refinery, the installation of DTEC technology can generate 1,000 - 10,000 kW of electricity and 1,000 - 10,000 cubic meters a day of drinking water, depending on the configuration. This amounts to a reduction of up to 100,000 tonnes of CO2 a year.
"We are looking at incorporating an IGCC plant with a refinery"
Khalad al-Mushailah, KNPC
Unlike IGCC, DTEC is in the process of being implemented. Under the terms of a memorandum of understanding signed in April, Japan’s Xenesys, which has pioneered the technology, is designing a DTEC plant at the Mina al-Ahmadi refinery owned by KNPC. The facility will use the cooling processes at the refinery to create electricity and desalinated seawater.
"The Middle East has a lot of waste heat discharged, without it being utilized," says Michinaga Takeda, head of Xenesys’s overseas business division. "We have had lots of enquiries from the region about the technology."
According to Takeda, DTEC may be easier to implement than the more tired and tested OTEC technology because the high temperature of the discharged heat from the refinery means there is a greater temperature differential, and therefore higher pressure.
Electricity shortfall
In theory, a technology such as DTEC makes sense for Kuwait. The state is undergoing a power crisis, with regular electricity outages during the summer months. By using the wasted heat and returning it in the form of electricity to the refinery, DTEC can help reduce the total demand load. If it is replicated at the state’s two other existing and one planned refineries, and at the Equate petrochemicals facility, it could potentially reduce demand by up to 30 MW - a significant amount.
Again, the technology is not cheap and requires an outlay of about $10 million - 20 million to install. But its proponents claim the savings on power and water will return that investment in five years. Al-Mudhsilsh says if the Mina al-Ahmadi experience is a good one, then the technology can be rolled out to KNPC’s other facilities. Other Gulf states may follow Kuwait’s example.
