Remedies to utilize public sector units and not relying on IPPs

By S. Muhammed Anis
August 16 - 22, 1999

The power generating units in public sector are converting about 10-15% of energy contained in fuel to electrical energy. The rest of energy obtained by the burning of fuels is merely wasted through heating of river waters, sea water or air. Heat recovery units need to be installed without any further delay to reduce the cost of power generation. The energy rejected can safely be reduced to half of the existing rate easily. Consequently the cost of thermal power generation can be reduced to 50% of present rate through installation of heat recovery units. The invested money can be recovered back in 1-2 years time through reduction of cost of generation of electricity.

The Power Plants presently being operated in the country in public sector are loosing their generating capacity by manifold. The causes are purely technical one. The solution to this problem is of grave nature and is mainly of specialized nature and not managerial alone.

These plants have been designed for continuous operation on 24-hour basis, and not at all as standby and for intermittent operation. Due to the present policy of top management in the power generation sector and pressure of IPP's, these plants are being operated intermittently. Moreover, the public sector has opened its power plants for the disposal of refinery tars and retort residues, disposed of all over the world. These dirts are burnt under boilers, and huge amounts are paid for the heat available in imported waste oils. This is at the cost of damage of our national plants and pollution of environment. The foreign and local oil companies and their agents are making huge profits through disposal of the wastes oils by their burning under boilers in power generating sector, which has no sale price elsewhere.

The result is that, the life span of public sector plants is being reduced manifold due to hot corrosion and condensed acid generated by the combustion of sulphur. As per thumb rule, combustion of 3% sulphur bearing fuel oil results in generation of about 10% sulphuric and nitric acids in the combustion exhaust gases. One can easily judge the eventualities of burning these waste oils as fuel for power generation and intermittent shut downs of steam / power generating units in the public sector. This policy, not only results in undue drain of precious foreign exchange, which of course is scarce, but is also indiscriminately polluting the environment. This environmental pollution is too hazardous for human being, agriculture, as well as general deterioration due to free showers of sulphuric and nitric acids. Any treatment of waste fuel oils before combustion is not the actual remedy / solution of acid neutralization.

The general strategy should be that, the public sector power generating plants should be operated up to their optimum generating capacity on continuous basis, while IPPs should be on standby in case of any accidental break down / short supply etc. Instead, at present the situation is reverse. The IPPs are presently operating on their maximum output, whereas public sector plants are operating on standby basis. Due to this general policy, being adopted by public sector, most of these plants are either lying idle or loosing their designed generating capacity. The eventual result is that, due to their design, huge deposits of clays, salts, and sulphur tri-oxide powdery ashes etc. are accumulated on the heating surfaces. Henceforth, heat transfer phenomenon is badly hampered by the accumulations and corrosion due to sulphur tri-oxide (Sulphuric Acid). The result is that, steam generating out put is adversely affected and consequently the power generation is reduced manifold. About 100 kg of Sulphuric Acid in addition to Nitric Acid is among products of combustion of one ton of 3% sulphur bearing waste oil / residual oil (Furnace Oil). The destruction due to these acids inside the plant as well as in the environment may well be imagined. The raising of heights of boiler chimneys is not a solution for burning of such large quantities of fuel oil.

The remedial measures should be that, these plants should be operated on continuous basis instead of intermittent one. Secondly, the huge accumulated deposits, adversely affecting the output of boilers and turbines,, should be taken care of by chemical means and not by any mechanical methods.

Local crude, obtained directly from the oil fields, can be burnt in a better way under the boilers instead of imported waste oils misnomered as furnace oils. The local crudes are very low in ash, high in calorific value, better in combustion properties, which are all recommended factors for a good fuel. The local crude is rejected on the plea of having wax. The wax burns smoothly in candles, it is surprising, why it is rejected for burning under boilers on grounds of having wax.

Henceforth the strategy should be, to use indigenous crude for burning under boilers. The utilization of local waste oils is no problem. They may be utilized for blending with local crude to cover any shortage of fuel oil and disposal of local retort waste.

The valuable foreign exchange, presently expended on the import of hazardous waste oils, thus should be saved. The local crude may also safely be used in turbines and diesel engines with minor cleaning of fuel, easily manageable, on the site of use.