Rate:
 
Soap

Sector highlights

Soap is a basic material necessary for cleaning and sanitary purpose. Technically, soap is a metallic salt of a fatty acid, often made with calcium, aluminium and lithium. Production of Soap in Nepal is mainly in the solid form that is made by a reaction of Sodium Hydroxide reacting with the fatty acid from animal or vegetable oil. By 2006 the number of manufacturing of Soap and other Preparation was 31 with employment of 1,704 persons with the value of output of NPR 3.78 Billion with the inputs of NPR 2.43 Billion and value added of NPR 1.35 Billion (CBS, 2007).

Soap industries in Nepal mainly produce laundry soap. Only around 15 percent industries manufacture toilet soap along with the laundry soap. The average installed capacity of the plant is 27.7 TPD and average production is 15 TPD. Production is hampered by load shedding in soap and chemical industries. During load shedding, the industries generate electricity themselves with Diesel gensets that are installed within the factory premises to carry on the production. Thus, the cost of production is high due to high energy cost of diesel fuel based backup systems (GIZ/NEEP, 2012).

Process

Soap manufacturing can be classified into two types. The small units have open pan boiling of oil and caustic with fire wood without any washing system, whereas the larger units have steam generation system and washing process.

Major process involved for soap production in medium and large units are

  1. Oil Melting,
  2. Saponification (Mixing and cooking),
  3. Washing,
  4. Fitting,
  5. Mixing (Crutcher),
  6. Filtration,
  7. Vacuum Drying,
  8. Plodding, Cutting, Stamping, Wrapping, and
  9. Packing.

Process flowchart - Soap industry with washing unit

Process flowchart - Soap industry without washing unit

Energy Use

Soap and Chemical industries consume both electrical and thermal energy in their processes. All the units are installed with boiler for steam generation except small scale pan boiling laundry soap manufacturing units. Electrical energy is mainly used for the drives, compressed air generation, refrigeration and lighting. Thermal energy, mainly rice husk, is used for the generation of steam from boiler. All the industries installed with boiler use rice husk as boiler fuel. The pan boiling units use firewood as source for thermal energy in its boiling (saponification) process.

Figure 2: Energy use by resource in Soap industry (GIZ/NEEP 2012)

Energy supplier to the industries is Nepal Electricity Authority through 11 kV supply in large and medium scale industries with time of day (TOD) metering and a 3-phase 400 V supply in the small scale industries with ordinary metering. All the large and medium scale units have their own Diesel gensets to supplement the power in their production during power failure from the central grid. Only about 25 percent of industries have installed capacitor banks to improve the power factor. Combustion efficiency in boiler is not checked by the industries. Leakages of steam are observed in the units. Insulations are not adequate in the steam distribution system in the units. About 50 percent of the industries lack proper insulations of steam supply pipes, flanges and valves.

According to GIZ/NEEP baseline study conducted in 19 soap industries, the total production capacity of these units is 157,920 tons per annum and these units are found to be producing only 85,407 tons of soap and chemicals in fiscal year 2010/11. They consumed 9.501 million units of electricity (kWh) and total thermal energy equivalent to 288,587.66 GJ worth NPR 333.68 million. The average SEC is found to be 111.25 kWh of electricity and 3,378.97 MJ of thermal energy per metric ton. CO2 generation is estimated to be 27,389 tons equivalent to 320.70 kg/ton.

Table 1: Specific energy consumption in Nepalese Soap industries (GIZ/NEEP, 2012)

Table 2: Energy use in 19 surveyed soap industries (GIZ/NEEP, 2012)

Major energy consuming sections in Nepalese Soap industries are listed below:

Thermal equipment

  • Oil-melting
  • Saponification
  • Mixing
  • Vacuum Drying
  • Plodding

Electrical equipment

  • Electrical Distribution transformer & Power systems
  • Electrical drives
  • Diesel Generating Sets
  • Compressors
  • Lighting system
  • Boilers
  • Refrigeration plant
  • Material handling equipment

References

  • GIZ/NEEP, 2012: Baseline Study of Selected Sector Industries to assess the Potentials for more efficient use of energy.
  • Central Bureau of Statistics (CBS), 2007: Census of Manufacturing Establishments carried out in the fiscal year 2006/07.
 

Energy Saving potential

The soap industry stands on rank 7 in Nepal’s energy intensive industries. More than 5 % of product value accounts for energy cost (GIZ/NEEP, 2012). Energy saving potential for electrical and thermal are estimated to be 10% and 39%, respectively.

Figure 1: Energy cost on product value in % for different industrial sectors in Nepal (GIZ/NEEP, 2012)

It is estimated that soap units could save around 1,210 MWh of electricity and 149,334 GJ of thermal energy. By implementing energy efficiency the sector could achieve monetary savings of about 421 Lakh Nepalese Rupees annually (GIZ/NEEP, 2012).

Table 1: Energy Saving potential in Energy-intensive industrial sectors in Nepal  (GIZ/NEEP, 2012)

Experience from the past have identified many options for improving energy efficiency in soap and other chemical industries that are highly profitable, most of them with payback periods of investment of less than 1 year. The following table shows some implemented examples option with the respected payback period (Danida/ESPS, 2005).

Table 2: Energy saving options for soap industry and payback period of investment (Danida/ESPS, 2005)

Energy Saving Tips

Huge saving opportunities in soap and other chemical industries can be achieved in the following areas:

Electrical System

  • Install delta to star convertors for lightly loaded motors
  • Install maximum demand controller to optimise maximum demand
  • Optimization of capacitor banks for maintaining the Power Factor at optimum level
  • Replace rewound motors with energy efficient motors
  • Install energy efficient motors as a replacement policy
  • Replace V-belts with synthetic flat belts
  • Minimising overall distribution losses, by proper cable sizing and addition of capacitor banks
  • Adoption of the Load Management System
  • Installation of Variable Frequency Drive (VFD) wherever applicable.
  • Load Optimization of Drive Systems (Shuffling of Drive System)

Lighting

  • Use translucent sheets to make use of day lighting
  • Install timers for automatic switching ON-OFF of lights
  • Install timers for yard and outside lighting
  • Grouping of lighting circuits for better control
  • Replace 40 Watts fluorescent lamps with 36 Watts fluorescent lamps
  • Replace conventional ballast with high efficiency electronic ballasts in all discharge lamps
  • Install LED lamps for panel indication instead of filament lamps
  • Install CFL’s for lighting in non-critical areas, such as, toilets, corridors, canteens etc.
  • Optimise voltage in lighting circuit by installing servo stabilisers

Air Compressors

  • Ensure air compressors are loaded to a level of 90%
  • Set compressor delivery pressure as low as possible
  • Monitor pressure drop across suction filter and after filter
  • Segregate high pressure and low pressure users
  • Avoid/ minimise compressed air leakages by vigorous maintenance
  • Replace old and inefficient compressors with screw or centrifugal compressors

DG System

  • Use cheaper fuel for high capacity DG sets
  • Increase loading on DG sets (maximum 90%)
  • Increase engine jacket temperature (max. 85 o C) or as per engine specification
  • Take turbocharger air inlet from outside engine room
  • Installation of steam coil preheaters for DG set fuel in place of electrical heaters
  • Replace multiple small size DG sets with bigger DG sets

Boiler and steam distribution Systems

  • Monitor excess air levels in boilers
  • Arrest air infiltration in boiler flue gas path, particularly economiser and air preheater section
  • Plug steam leakages, however small they may be
  • Always avoid steam pressure reduction through PRVs.
  • Insulate all steam and condensate lines
  • Monitor and replace defective steam traps on a regular basis
  • Monitor boiler blow down; use Eloguard for optimising boiler blow down
  • Installation of flash vessels for heat recovery from hot condensate vapours
  • Monitor the blow-down quantity of water in cooling towers and the quality of water
  • Install automatic combustion control system/ oxygen trim control system in steam boilers and soda recovery boilers
  • Install economiser/air preheater for boilers
  • Use of cheaper fuels, like bamboo dust, wood barks, pith etc.
  • Install boiler air preheater based on steam to enhance cogeneration
  • Install heat recovery from boiler blow down

HVAC

  • Clean chillers and condenser coils regularly
  • Close doors to outside and unheated or un-cooled areas
  • Establish routine maintenance procedures
  • Regular cleaning and maintenance of condenser pipes
  • Regular cleaning of cooling tower to prevent algae formation.
  • Improvement of the Chiller
  • Minimization of refrigerant leakage
  • Preventive/ Scheduled Maintenance of the Plant and Machinery
  • Replacement of old traditional refrigerator system with efficient direct drive compressors and inverter based refrigeration system.
  • Installation of de-icing system in evaporators.

Miscellaneous

  • Replacement of Aluminium blades with FRP blades in cooling tower fans
  • Install dual speed motors/ VSD for cooling tower fans
  • Solar water heating for canteen and guest house
  • Avoiding pump operation by utilization of gravity head
  • Optimize capacity of vacuum pumps by RPM reduction.
  • Install high efficiency fans & blowers in boiler

References

  • GIZ/NEEP, 2012: Baseline Study of Selected Sector Industries to assess the Potentials for more efficient use of energy.
  • Danida/ESPS, 2005: Cleaner Production report of Soap industry.
  • Confederation of Indian Industry: Investors manual for Energy Efficiency.
  • Central Bureau of Statistics (CBS), 2007: Census of Manufacturing Establishments carried out in the fiscal year 2006/07.

 

 
 

EEC Factsheet: Energy Efficiency for Soap industry in Nepal - This fact-sheet summarizes energy saving potentials in Nepalese Soap industry. It also give information on monetary savings by implementing energy audit and energy efficiency options in the industries. The fact-sheet is based on the findings of "Baseline Study of Selected Sector Industries to assess the Potentials for more Efficient use of Energy in Nepal" conducted by GIZ/NEEP Program in 2012.