In general, Indian industry is highly energy-intensive and its energy efficiency is well below that of other industrialized countries. There is considerable scope for improvement of energy efficiency in industries which are energy-intensive, such as chemicals, cement, plastics, metals, etc.
Efforts to promote energy conservation by such industries could lead to substantial reduction of their cost of production, making them more competitive globally. The majority of electricity is consumed by energy-intensive industries like aluminium, iron and steel, textiles, chemicals and pulp and paper. As 1 kW/h saved at the user end could mean a relief of 2 to 4 KW of the generation capacity depending on the plant load factor, transmission and distribution losses and end-use efficiency, energy conservation offers the least cost option for bridging the ever-widening gap between demand and supply of energy. Significant energy savings could be achieved through better housekeeping, improved capacity utilisation, development of cogeneration facilities, industrial waste and heat management and arrangements for improving the quality of electricity supply. For new plants, the goal should be to adopt energy-efficient technologies right at the inception stage. The following energy-intensive industries have been
focused upon for a more detailed analysis-fertilizer, aluminium, textile, cement, iron and steel, pulp and paper, petrochemical and chlor-alkali.
Fertilizer industry
The fertilizer industry, particularly the nitrogenous fertilizer, is highly energy-intensive. It is estimated that manufacture, packing, transport and application of 1 kg of nitrogenous fertilizer requires about 2 kg of fossil fuel. The fertilizer industry is also one of the largest consumers of petroleum-based fuels. The rapid increase in fertilizer production in the eighties was attributed to the addition of new capacities of gas-based plants due to the then newly found reserve of natural gas in the Bombay High and South Basin.
The increase in capacity utilization of the nitrogenous fertilizer industry from 52.8 per cent (1980/81) tc 87.3 per cent (1992/93) was mainly due to higher capacity utilization of gas-based plants
. There was a significant re duction in imports of nitrogenous fertilizer, from 41 per cent in 1980/81 to 13.4 per cent in 1992/93 which was attributed to higher capacity utilization of gas-based plants and large number of new plants which were commissioned during the same time. The entire consumption of potash fertilizer is met by imports as there are no sources of potash in the country.
The Indian ammonia-industry during the last four decades has witnessed many changes in the form of feedstock, technology, which resulted in a substantial improvement in overall energy-use efficiency. The share of different feedstocks in ammonia production during 1992/93 was natural gas 54.2 per cent, naphtha 26.1 per cent, fuel oil 18.21 per cent and coal 1.54 per cent. In terms of calorific content, natural gas is the largest source of energy in the fertilizer industry. The shift of new projects/expansion projects towards naphtha/natural gas-based fertilizer plants is attributed to the highly energy-consuming and polluting nature of fuel oil and coal-based fertilizer plants.
Recent advances in process technology and catalysts also resulted in lower energy intensity. For example, consumption of naphtha per tonne of ammonia has fallen from 0.9-1.0 tonne during 1970 to 0.8-0.85 tonne in 1990. Similarly, the consumption of ammonia per tonne of urea has dropped from 0.6 tonne to 0.58 tonne. Simultaneously, the stream sizes of urea plants have also grown, thus reaping the benefits of economy of scale.
Various factors that affect the specific energy consumption in a fertilizer plant are:- loading of the plant due to production limitations type of feedstock technology adopted engineering deficiencies vintage of plant, and catalysts used
Aluminium industry
The aluminium industry in India, which began in the thirties, has taken long strides forward during the past five decades. The installed capacity has increased from 4000 tonnes in 1950 to 62,5000 tonnes in 1993/94. At present, five companies (two in the public sector and three in the private sector) are producing aluminium:
BALCO (Bharat Aluminium Co. Ltd) at Korba in Madhya Pradesh; INDAL Ondian Aluminium Co Ltd.) at Belgaum in Karnataka, Hirakud in Orissa, and Alwaye in Kerala; HINDALCO (Hindustan Aluminium Co. Ltd) at Renukoot in Uttar Pradesh; MALCO (Madras Aluminium Co Ltd) in Mettur in Tamil Nadu; and NALCO (National Aluminium Co. Ltd) at Damanjodi in Orissa. smelters in Alwaye and Hirakud, the input is alumina, which is produced at INDALs alumina plant at Muri in Bihar.
Bauxite is the basic raw material used for the Production of aluminium. India possesses nearly 8.3 per cent of the total known reserves of bauxite in the world (32,000 mt) amounting to about 2650 mt.
The two major energy-consuming steps are conversion of bauxite ore to alumina and production of aluminium from alumina.
The Bayer-Hall-Heroult (BHH) process has practically remained as the only viable commercial manufacturing process ever since the discovery of aluminium in 1886. At present, considerable R&D efforts are being made to improve the Hall-Heroult technology. and also to find out an alternative process route for aluminium production. Several organizations are experimenting with new reduction processes which they claim have significant advantages over the BHH process. However, these processes are either at the laboratory stage or under pilot operation and are not yet commercially established.
About 2.5 tonnes of bauxite are required to produce one tonne of alumina and about 2 tonnes of alumina are required to produce one tonne of aluminium. FUel oil is used for firing calcining kilns. Besides calcination, some units also use fuel oil to generate the steam required for digestion and evaporation. Coal is used c for steam generation whereas electricity is largely in smelting and grinding of bauxite.
Electrical power is the major source of energy lized in smelters for aluminium production. Though in recent years Indian companies have taken steps to reduce the specific power consumption, it is still sigr: cantly higher than international norms.
Reduction in excise duty from 20% to 15% as announced in the 1995/96 Union Budget will gener nedemand for the metal and will help in expand: the market in the country. The estimated demand: primarily aluminium in the year 2004/05 is 11.6 tonnes, indicating that there is adequate scope for crease in the capacity of aluminium production whi would involve modernization/ eXPansion of existi smelters and setting up of additional ones.
Textile industry
The Indian textile industry is the largest industry in the country. It accounts for 20% of the total industrial production and contributes 30% to the total value of exports. The textile industry comprises cotton textile wool, silk, synthetic fibre textiles, and jute textile Cotton textile manufacture, which is the predominant sub-sector in the textile industry consists of the organised sector and unorganised sector
Power looms and hand looms.
The organized cotton textile sub-sector, which has about 700 mills, is facing financial problems, not only because it is labour-intensive, but also because it uses old, poorly-maintainec machinery. Recently, a change has been sweeplnl through the industry with several private sector mills OPting for modernization and expansion.
The industry consumes about 4 mt of coal, 0.5 mt of fuel oil and 8500 million kWH of electricity every year, accounting for 9% of the total commercial energy use in India. Fuel and power account for 12-25% of the to tal cost of production. Coal and furnace oil meet the process heat requirements. All textile mills, except those around Bombay, use coal in boilers. An estimated 80-90% of the electrlcity used is the motive pOFyer for drivlng pumps, motors, drives, etc The energy expenses of mosttextile mills accounts for 10-159b of the total PUt costs. However, this consumption can be substantially reduced.
Low efficiency boilers, with efficiency levels of 50-60%, are USed in many mills. These boilers may easily be retrofitted with suitable heat recovery equipment. Cogeneration ;s another possibility, because several mills use 60% Of the required steam below 60 psig (pounds/sq. inch gauge while their boilers generate steam at 150 psig or more.
