Chapter - 6
LPG Bottling Plants
Over 100 million LPG consumers in the domestic sector in India are serviced through a network of 9365 LPG distributors who are getting supply from 181 LPG bottling plants located across the country. In 2007-08, India consumed a total of about 1170 TMT of LPG which is around 10% of the consumption of total petroleum products in the country. Out of the total LPG consumption during the year 2007-08, almost 75% was used for cooking, 17% as auto LPG and the remaining 8% for industrial use. Of the total supply of 11.7 Million Tonnes of LPG during 2007-08, the indigenous production was 8868 TMT from crude oil and natural gas fractionation (3:1). Imports by PSUs and private entrepreneurs accounted for 2156 TMT and 673 TMT respectively. LPG is transported from production installations i.e. Refineries, Fractionation plants and Import terminals to the bottling plants through pipelines, Bulk LPG Wagons or Bulk LPG Tank Trucks. This LPG, subsequently, is bottled in 19 Kg, 14.2 Kg and 5 Kg cylinders and is then delivered to commercial consumers and individual households. Bottling operation of LPG is very critical, as LPG is a highly inflammable product and the systems are required to be intrinsically safe. The systems also require very comprehensive fire safety arrangements. A typical LPG bottling plant has the following major energy consuming equipment:1. 2. 3. 4. 5. 6. 7. 8. 9. LPG pumps LPG compressors Conveyors Blowers Cold repair facilities including painting Air compressors and air drying units. Transformer, MCC & DG sets Fire fighting facilities Loading and unloading facilities
Some of the LPG bottling plants use a comprehensive monitoring technique for keeping track of energy / fuel Consumption on per tonne basis. PCRA's energy audit studies in various LPG plants have found 20-25% energy saving potential in the LPG Plant operations. The following are major energy conservation opportunities in a LPG Plant: 6.2 Energy Conservation Opportunities in Air Compressors
Compressed air system is one of the most inefficient operation for conversion and storage of energy. Typically, efficiency from start to end-use is around 10%. In any compressed air system with a saving potential of upto 30%. This saving potential is mainly, towards efficient compressed air generation system, efficient compressed air transportation system, maintenance of optimum pressure levels and reducing misuse and leakages.
Compressor Air Pressure Level
On overhauling the compressor, the Annual saving in energy Annual saving Investment required Payback Period
: 15120 kWh : Rs.71000.00 : Rs.25000.00 : 4 months
In a bottling plant, compressed air is used as instrument air and service air. The pressure level of 5 Kg/cm 2 is sufficient for all the operations in a bottling plant. The requirement of air pressure for various devices is as under: Remote Operated Valve(ROV) Deluge valve Stopper/pushing/pulling of cylinders Instrumentation Painting gun Hydrostatic testing of cylinders 5.0 Kg/cm2 3.5 Kg/cm2 5.0 Kg/cm2 2.0 kg/cm2 4.0 kg/cm2 5.0 Kg/cm2
Leakage of Compressed Air & Wastage:
Avoiding leakage is the largest opportunity of saving energy in a compressed air system. The leakage in compressed air system in a plant can be quantified by adopting the following process Raising the receiver pressure to the designed pressure and stopping the air usage with all intermediate valves open. b) Keeping the complete line including pneumatic circuit pressurised c) Recording loading and unloading duration of the compressor % leakage can be calculated by % Leakage = Load Time Load Time + Unload Time x 100 a)
Case Study 1 : Air Pressure Level Optimization Brief Air pressure level in the plant is fixed by setting the loading and unloading pressure through pressure switch provided in Air Compressor. Energy Savings Generally, the air pressure maintained in a LPG bottling plant is...