Final project results

The Indus3Es Absorption Heat Transformer (AHT) technology.

In its final year, the Indus3Es project worked very hard on the AHT technology reaching many challenging goals in order to reduce the primary energy consumption of industries in order to increase their effectiveness and competitiveness. The project AHT is designed for recovering and revalorizing the industrial waste heat below 130°C and to revalorize almost the ~ 50% of recovered waste heat, boosting the temperature and becoming usable in the industrial process again.

The indus3Es Pilot demonstrator 200 kW revalued heat machine is equipped with an innovative non-condensable gasses (NCGs) purge system. This system requires no additional equipment, it is fully automated and has a negligible impact on the AHT performance. A very low-flow vapor bleed line delivers vapor and NCGs from the high-pressure vessel to the low-pressure vessel. And from there an additional line sucks vapor and NCGs to the adiabatic absorption chamber (AAV). The AAV attains the lowest pressure in the system by using portion of the strong solution, which is subcooled by the water-solution heat exchanger (WSHX). The removed subcooling heat is transferred to the refrigerant, therefore it is internally recuperated is not considered a loss. The NCGs which are collected in the AAV are trapped there and are periodically transferred to the evacuation vessel (EV). The EV is then isolated from the AHT, and its NCGs content is discharged into the atmosphere. No special ejectors are use and no vacuum pump is needed. For this procedure, only the opening and closing of valves in the correct sequence and timing is required. This is fully automated by the control system.

Indus3Es AHT beyond the State of the Art.

The Indus3Es will demonstrate the operation of a minimum scalable AHT in a real industrial environment. The knowledge of the absorption chillers ongoing development has been transferred to the AHT technology, implementing several innovations:

  • The implementation of two adiabatic absorption operation modes: Atomizing spray nozzles and a drip distribution system in which the liquid solution in the tray is exposed to the vapor – promoting adiabatic absorption. For demonstration and research purposes, the atomizing spray mode can be toggled on or off. Measurements from the Lab- and Breadboard-Scale high-pressure vessels have demonstrated that these modes perform as intended by increasing the maximum obtainable temperature within the absorber.
  •  Innovative motor-less non-condensable gases purge system: Presence of non-condensable (NC) gases critically reduces the absorption process which is critical for the AHT. The innovative system for removal of NCs developed in Indus3Es continuously gathers and traps NCs in a dedicated vessel, which are then periodically and automatically discharged to the environment. This solution is simple, inexpensive, and efficient, compared to other known options.
  • Indus3Es AHT behavior automatic control: The control system has been designed considering especially the “Characteristic Equation Method” approach. Apart from the desirable performance automatic adjustment procedures, an attention to anti-crystallization procedure has been considered, which is potentially riskier for AHTs, compared to absorption chillers. By the end of the project, a tested control system will have been installed and operated for several months. This will demonstrate the successful integration and automation of the technology and its innovations in a real industrial application.

Next to the AHT technology itself concepts for the implementation of the AHT technology into modern industrial environments were developed. In the Indus3Es case all challenges of the implementation in a refinery with the high security requirements especially in explosive environments were overcame.

 


 

System demonstration at real environment: TECNALIA’s latest results from the DEMO.

Tecnalia logoIndus3Es demonstrated the operation of a minimum scalable AHT in a real industrial environment.

The knowledge of the absorption chillers ongoing development has been transferred to the AHT technology, implementing several innovations:

  • The implementation of two adiabatic absorption operation modes: 
    Atomizing spray nozzles and a drip distribution system in which the liquid solution in the tray is exposed to the vapor – promoting adiabatic absorption. For demonstration and research purposes, the atomizing spray mode can be toggled on or off. Measurements from the Lab- and Breadboard-Scale high-pressure vessels have demonstrated that these modes perform as intended by increasing the maximum obtainable temperature within the absorber.
  • Innovative motor-less non-condensable gases purge system: 
    Presence of non-condensable (NC) gases critically reduces the absorption process which is critical for the AHT. The innovative system for removal of NCs developed in Indus3Es continuously gathers and traps NCs in a dedicated vessel, which are then periodically and automatically discharged to the environment. This solution is simple, inexpensive, and efficient, compared to other known options.
  • Indus3Es AHT behaviour automatic control: 
    The control system has been designed considering especially the “Characteristic Equation Method” approach. Apart from the desirable performance automatic adjustment procedures, an attention to anti-crystallization procedure has been considered, which is potentially riskier for AHTs, compared to absorption chillers. A tested control system have been also installed and operated for several months. This demonstrated the successful integration and automation of the technology and its innovations in a real industrial application.

Next to the AHT technology itself, concepts for the implementation of the AHT technology into modern industrial environments were developed. In the Indus3Es case all challenges of the implementation in a refinery with the high security requirements especially in explosive environments were overcame.

The AHT system has been installed at the power plant of the petrochemical facilities. In particular, the waste-heat source for the activation of the AHT system comes from the oily condensate flash steam tank. In order to recover the heat from the oily condensate flash steam, demineralized water sent to the boilers,which is considered constant throughout the year and equal to 65 °C, is first preheated by this waste source which is at about 100 ºC. The remainder of the waste-heat is used for powering the AHT, resulting in a stream at about 140 ºC, which upgrades the demin-water circuit to 135 ºC before this is sent to the boilers.

According to the first monitoring results the installation of the AHT could suppose, for 20 years using phase up to following consumption and economic savings:

  • Total Primary Energy Savings: 70,622,152 kWh primary energy;
  • Total CO2 emission savings: 9,974 tones CO2;
  • Total Economic Savings: 1,752,047 €.

With these results the calculated payback period would be concretely less than 10 years, really optimistic value for being the first prototype developed. By the “ready-to-market” costs, these indicators would result in a more attractive investment. The payback period would be about 5 years.


Scalability to other industries and processes of the Indus3Es technology: Repsol, Fertinagro and Tüpraş’ final updates on the replicability of the system.

Fertinagro logo“In the Indus3es project, the study and scaling of a heat recovery system has been carried out. This heat, until now, was not a useful heat. But with this project and with the designed and scaled of the absorption heat transformer, a solution was obtained.

With all this, Fertinagro Biotech positively evaluated being able to recover heat from a current that until now has not been used for the purposes of reducing energy costs and therefore economic.

The replicability of the study in Fertinagro Biotech has given the possibility of reducing natural gas consumption by a not too high percentage, because consumption is not high, but must be taken into account for future expansions and what can help reduce the energy consumption.

The concept of this project consolidates the idea of Fertinagro Biotech to support projects that can help reduce the carbon footprint of fertilizers and with it the products thus obtained”.


Repsol logo“AHT technology has a great potential in heat upgrading in most industries. The waste heat source temperature range fits well with industry requirements, as well as the revalorized heat temperature range. Indus3es project has been very helpful to assess possible problems during its implementation and start-up, and we hope that full scale equipment can be an interesting option to any industry concerned with energy efficiency and CO2 emissions in the industry decarbonization scenario.”


Tüpraş logo“Refinery industry is a highly energy intensive industry. Therefore, energy efficiency and energy integrity projects are crucial to minimize the energy  consumption and increase the efficiency of refineries. Energy is both produced and consumed in order to maintain the refinery processes, which are mainly  distillation, craking, hydrotreating.  These processes consume energy in the form of steam, fuel oil, fuel gas or electricity. For instance, crude oil needs to be heated up before entering the distillation process. On the other hand, products of distillation process such as gasoline and diesel are needed to be cooled down to the storage temperature before being stored. Therefore, the crude oil is heated up by  distillation products in heat-exchangers for the sake of heat integrity. This way, less fuel gas is consumed in the pre-heating furnaces to heat-up the crude oil. There are similar cases in the power generation units of refineries.  In power generation units, some waste heat sources are inevitably formed both in energy production and consumption phases. In the current state of the art, it is usually unfeasible to recycle such heat sources which are below 150 oC. At this point, AHT technology have great potential to enable reuse of such waste heats. After the successful demonstration of AHT system in power production unit at Tüpraş İzmit Refinery, investment options for AHT in refineries can be considered in much more explicit fashion.

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