Today, demand for energy is increasing unprecedented. So you can’t just go about traditional methods of electricity generation anymore. The important question is: Can electricity be generated without harming the environment and with greater efficiency? This is where the organic Rankin cycle, or ERC, enters the field. Many countries, especially those with low-grade heat sources, have moved towards using this technology. Because it is less polluting and produces usable energy from the heat that has been considered wasted so far.If you’re looking for an answer to which system works best in the current situation and how to optimally use waste heat or low temperature sources, don’t miss out!
How do traditional steam power plants work?
Traditional steam power plants have been one of the main foundations of electricity generation in the last century. These power plants use fossil fuels such as gas, oil or coal to heat water to high temperatures and produce steam. This Steam is transferred to the turbines at high pressure and generated electricity by turning them. Although this method is very common, it has significant limitations. High fuel consumption, high water requirements, low efficiency at moderate temperatures and high greenhouse gas emissions are among the challenges of this type of power plant.
Another disadvantage of traditional steam systems is the need for equipment resistant to very high temperatures and high pressure. These equipment are expensive and cost money to maintain. Also, in many parts of the world where water resources are limited, the widespread use of water to produce steam becomes a serious challenge. Along with these, environmental pressures and restrictive carbon emissions laws have led to a focus on more fuel-efficient and cleaner alternatives.
What is ERC and how is it different from classic thermal systems?
The organic Rankine Cycle is similar in appearance to the traditional steam cycle, but has fundamental differences from it. The most important difference is the type of working fluid. In ERC, organic fluids are used instead of water, which boil at much lower temperatures than water. This feature allows the system to generate useful energy from low-temperature heat sources such as industrial waste heat. This makes ERC very useful for areas without high temperature resources or limited access to fossil fuels.
Unlike traditional steam power plants, ERC does not require high pressure or extremely high temperatures. This reduces operating costs and reduces mechanical and environmental risks. In addition, because organic fluids are more thermodynamically efficient, efficiency is maintained at low temperatures. In fact, this system is a practical solution to optimize the use of latent energy in industrial and natural environments.
Comparison of ERC efficiency and classic steam power plants at different temperatures
One of the most important indicators of the evaluation of power generation systems is their efficiency. At temperatures below 150 degrees Celsius, the efficiency of steam power plants is greatly reduced and become almost unusable. Whereas the ERC system is able to generate electricity with acceptable efficiency even at temperatures below 100 degrees. The reason for this is the physical property of organic fluids, which perform better than water at these temperatures.
On the other hand, although at very high temperatures the efficiency of steam power plants can be higher, this advantage is associated with a significant increase in costs and technical complexity. In contrast, ERC is a low-cost solution for electricity generation in many industries with lower cost and the ability to use waste heat sources. This feature has led many industrial units to consider ERC as a complement or even an alternative to traditional power plants. Below is a complete comparison of the two methods:
Temperature range of heat source (°C) type of medium efficiency system ( % ) description
80 to 120 UTC 8 to 12 suitable for very low heat sources such as waste heat or poor solar
120 to 180 UTC 10 to 18 high efficiency relative to steam at this temperature ideal for the food and textile industries
180 to 250 UTC 15 to 22 very good performance; affordable option for geothermal and biomass
250 to 350 UTC 18 to 24 close to classic steam; energy recovery capability in industrial processes
250 to 350 classic steam power plants 20 to 30 higher efficiency but require high pressure and special equipment
350 to 600 classic steam power plants 30 to 40 very high efficiency but with the need for fossil fuel and the cost of equipment
Important points:
* ERC has a noticeable advantage over the steam system at temperatures below 250 degrees, especially in projects with waste or renewable heat sources.
• At high temperatures (over 300 degrees) classic steam power plants continue to have higher efficiency, but are not always the first option due to the complexity, cost and consumption of fossil fuel.
* The combined use of ERC and traditional steam (hybrid systems) is also recommended in some advanced industrial projects.
Comparison of pollutants and environmental impacts of ERC and thermal power plants
Can Electricity be produced without producing harmful pollutants? This fundamental question is important when traditional thermal power plants are recognized as one of the main sources of air pollution in the world. These power plants, using fossil fuels such as gas, oil or coal, introduce large volumes of greenhouse gases, including CO2, NOx and SO2, into the atmosphere. These gases contribute to global warming and lead to problems such as acid rain and respiratory diseases in humans. On the other hand, there is a need for large volumes of water to operate these power plants, which is a serious challenge in many areas with a water crisis.
By contrast, the organic Rankin cycle (ERC) has entered the energy production field. Unlike classic thermal systems, ERC does not require fossil fuel or abundant water. In many cases, this technology uses heat dissipated in industries or renewable heat sources such as geothermal or solar. The result is a significant reduction in greenhouse gas emissions and almost complete elimination of pollutants such as NOx and SO2. The use of organic fluids instead of water also saves water resources dramatically. From an environmental impact point of view, ERC is considered a green technology and plays a significant role in reducing carbon footprint in various industries.
Under what circumstances should ERC be used instead of a steam power plant?
The use of the ERC system instead of the steam power plant is recommended when the existing heat source has a low or medium temperature and it is not possible to achieve high temperatures (above 300 ° C). For example, in manufacturing industries such as cement, steel, glass or refineries where large volumes of waste heat are produced at temperatures from 80 to 200 degrees Celsius, the use of traditional steam power plants will not be very efficient, as these systems require higher temperatures to function effectively. In such a situation, ERC, which is able to generate electricity at lower temperatures, will be an optimal option for waste energy recycling.
Arvaj clean energy company, a pioneer in the design of ERC systems in Iran
Arvaj clean energy company, based on a team of experts and several years of experience in the field of clean energy technologies, is known as one of the pioneers in the design and implementation of ERC systems in Iran. We have been able to implement several projects in various industries in the field of waste heat and renewable resources. Arrowje manages from the conceptual design stage to the installation, commissioning and operation of ERC systems in full and offers solutions tailored to the needs of each industry. High technical capacity, accurate knowledge of the climatic conditions and infrastructure of Iran and the use of the latest simulation and engineering design software are key advantages of our complex.