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The economic relevance of condensate reuse in steam generation

Condensates are the result of the condensation of steam after its use in industry. They are usually wasted, but there is a way to reduce water consumption and electricity demand through the process of reusing condensate in steam generation. In industry, steam generation is a fundamental process in sectors such as food, pharmaceuticals, chemicals or […]

Reutilizar condensados en la generación de vapor

Condensates are the result of the condensation of steam after its use in industry. They are usually wasted, but there is a way to reduce water consumption and electricity demand through the process of reusing condensate in steam generation.

In industry, steam generation is a fundamental process in sectors such as food, pharmaceuticals, chemicals or manufacturing, among others, where steam is used for heating, sterilization, cleaning or power generation.

One of the key aspects to optimize the efficiency of a steam generation system is the recovery and reuse of condensate, that is, the process of reusing the water that results from cooling the steam after it has been used.

Did you know that for every ton per hour of steam supplied to a unit, the same amount of condensate is discharged (1 ton per hour)? That’s why solutions like the condensate receiver are so important in an efficient steam generation facility.

What are steam condensates and how are they generated?

Steam condensates

Condensates are the result of the transformation of steam into liquid water after having given up its useful heat in a process.

During the transfer of thermal energy, the vapor cools and returns to its liquid state, maintaining a high temperature and retaining a significant amount of thermal energy that can be harnessed back into the steam generation system.

In a standard steam generation system, the process that water follows is as follows:

  1. Steam generation: the feed water is heated in the boiler to steam.
  2. Steam distribution: steam is directed to industrial processes where thermal energy is required (heating, sterilization, drying, etc.).
  3. Steam use and condensation: steam transfers its thermal energy to the equipment or products with which it comes into contact and, upon cooling, becomes condensate.
  4. Condensate recovery (optional with a condensate tank): in optimized systems, such as those in this success story, condensate is collected and returned to the system.
  5. Condensate discharge (in non-optimized systems): if condensate is not recovered, it is discharged through the drainage system, which implies a loss of water and heat.

How does the condensate tank work?

Condensate reservoir

The condensate tank is an equipment for the recovery of the condensate produced in the process to be returned to the boiler.

The operation of the reservoir begins with the collection of condensate through pipes and steam traps.

Once inside, non-condensable gases such as oxygen or carbon dioxide, which can cause corrosion in the system, are separated.

Finally, the stored condensate is sent back to the boiler by condensate pumps, ensuring a stable supply of hot water for steam generation.

Economic benefits of reusing condensate in steam generation

Steam generator

The reuse of condensate in steam generation reduces operating costs.

Reduced water consumption, reduced energy demand and less need for chemical treatment make condensate recovery a key strategy for improving the profitability of a process:

Savings in water consumption

By recovering condensate, the amount of water required to feed the boiler is reduced, reducing the costs of acquiring and treating this key element in steam generation.

2. Electricity savings

The condensate returns to the boiler at a much higher temperature than the water that normally feeds the system, which reduces the amount of energy required to convert it back to steam.

By reducing the demand for thermal energy, electricity costs are reduced. It can reduce fuel consumption by up to 2/3.

3. Reduction of chemical treatment costs

Boiler feedwater must be treated to avoid problems such as corrosion and scaling of equipment. When condensate is reused, the amount of feedwater requiring treatment is reduced, reducing the need for specialized chemicals.

4. Increased operational efficiency

By recovering condensate, the steam generation system operates with greater stability and efficiency.

The reuse of hot water improves the thermal regulation of the process and reduces the load on equipment, which reduces wear on valves, pumps and piping.

5. Other advantages of vapor recovery

Condensate recovery contributes to the reduction of CO₂, NOx and SOx emissions by reducing fuel consumption.

In addition, it minimizes the generation of vapor clouds, reduces the noise level and prevents the accumulation of puddles in the plant, creating a safer working environment.

Example of economic savings from condensate reuse

As mentioned above, condensate recovery not only offers benefits in terms of water savings, but also has a significant impact on the cost of electricity. This aspect is particularly relevant considering that condensates usually return to a temperature of around 60°C.

Compared to the use of cold water (at about 10°C), the energy required to heat the condensate to boiling point is more than 50% less.

To illustrate these savings, let us consider an example:

  • Temperature of recovered condensate: 60°C
  • Cold water temperature: 10°C
  • Boiling point of water: 100°C

The temperature difference to be covered is:

  • With condensates: 100°C – 60°C = 40°C
  • With cold water: 100°C – 10°C = 90°C

This means that, by using condensate, the water needs to be heated only 40°C instead of 90°C, which represents a 55.5% reduction in the energy required.

In economic terms, this translates into the following example: let’s assume an industrial plant that consumes 1000 kg/h of steam and recovers 70% of condensate:

  • Electricity consumption for cold water heating: 100 kWh
  • Electricity consumption for condensate heating: 44.5 kWh
  • Savings: 55.5 kWh

Assuming an electricity cost of 0.15 €/kWh:

  • Savings per hour = 55.5 kWh * 0.15 €/kWh = 8.33 €.

Considering 8,000 hours of operation per year:

  • Annual savings = 8,33 € * 8.000 h = 66.640 €.

This significant savings in electricity costs is in addition to the benefits already mentioned in terms of reduced fuel and water consumption.

From Giconmes we want to invite you to know our steam generators for industrial use, which will allow you to achieve greater cost savings and better energy efficiency, using a renewable and natural source such as steam and electricity for the generation and transfer of heat for different industrial uses and at different pressures.