Economic analysis of using refinery vacuum residue in a green
power production cycle (Integrated Gasification Combined Cycle)
Mousa Meratizaman, Sina Monadizadeh, Majid Amidpour
Abstract:
A major portion of the energy produced in the world today comes from burning
liquid heavy hydrocarbon fuels. The combustion of residual heavy fuel oils has
been extensively used and studied for a number of years. As a result of the refining
process, these oils contain higher levels of molecular weight (MW) coke precursor
compounds such as asphaltenes, with concomitant increases in the emission of
stack solids during combustion. Heavy fuel oil is particularly used in industries
which require a great deal of heat and in electric power stations. However, there
could be environmental problems associated with burning these used heavy fuel
oils. As a result of gas pressure drop in natural grid pipeline in the cold seasons,
the feedstock of steam power plant is changed from natural gas into heavy fuel oil.
Sometime this change is happening for the whole winter and causes lots of
environmental problems for the cities near the big power plant in the country same
as Arak. Gasification is a technologically advanced and environmentally friendly
process of disposing heavy fuel oil and coal by converting them into usable gas
products named Syngas which mainly consists of CO and H2. The generated
syngas after treatment can be used instead of heavy fuel oil in the steam cycle
boiler same as natural gas. Heating value of syngas is related to gas composition.
In some cases, it is reported that the heating value of natural gas is about four times
of typical syngas. Economic analysis of different feedstock application in a 1000
megawatt steam power plant (six units of a 165 megawatt steam turbine) is
considered in this article. Natural gas, heavy fuel oil and syngas (generated from
gasification of fuel oil) are selected as steam power plant feedstock. The main parts
of natural gas and heavy fuel oil steam cycle are boiler feed pump, three pressure
level boiler and steam turbine but for syngas feedstock cycle, preheater, gasifier
and gas treatment unit are added to previous instruments. Annualized cost of
system (ACS) is chosen as an economic analyzing approach.
Keywords:
Gasification, Fuel oil, Syngas feedstock, Steam cycle power plant, Annualized cost
of system