Applications RA4

In Applications, we will:

  • Study applications of technology concepts that can lead to a 20-30 % reduction in specific energy use and/or minimum 10 % in CO2 emissions.
  • Study applications that will integrate basic research and concepts from the Research Areas (RAs) Methodologies, Components and Cycles into specific industry settings to generate more energy-efficient processes and improved heat capture and utilization concepts.
  • Investigate the exploitable potential in surplus heat found in partner industries. We will also look into the next generation surplus heat capture and utilization.
  • Using industrial examples, this RA will also develop further the potential of "green" industry clusters and local thermal grids on a Nordic scale. More specific the RA will identify potential and concepts for the possible use of process gas and develop a metal furnace concept with at least 20 % lower total energy use.

Potential innovations:

  • Improved understanding of the internal energy distribution inside a process and understanding how to reduce losses.
  • Business models for sharing energy and materials resources in closely located industries.
  • Methodology for optimizing cycle integration in plants and assessing the costs and benefits.
  • Self-cleaning dirty gas heat exchanger concepts in collaboration with SFI Metal Production and bring the technology further towards applications in heat-to-power conversion.

RA 4 Applications consists of the following Work Packages (WP)

RA4 Applications Aud Nina Wærnes SINTEF Industry
WP4.1 Process improvement Bernd Wittgens SINTEF Industry
WP4.2 Surplus heat recovery Vidar T. Skjervold SINTEF Energy Research
WP4.3 Industry clusters and technology integration Kristian Einarsrud  NTNU


 
   
   
 

 

2018 Results

Process improvements

Energy consumption and potential energy savings in power intensive industries such as ferro-alloy industries where the prime energy consumer is the sub- merged arc furnace (SAF) and potential reduction and/or utilization of energy recovered were the main activities in 2018. A literature review on auxiliary systems in ferro-alloy production processes with respect to reduced energy consumption, covers e.g. the utilization of the energy streams exiting the SAF through the furnace off-gases. Concepts for a cascading utilization of the energy in the temperature range from 800oC to approximately 150oC have been presented.

Starting from the energy cascading concept, a new task has been initiated to simultaneously reduce overall energy consumption, NOx-reduction and potentially facilitate CO2-capture from ferro-silicon furnaces. Currently, furnaces utilize fresh air for temperature control in the furnace hood, during the initial study a concept is developed where cleaned flue gas after energy recovery is recycled to the furnace, the study consist of (i) a CFD-model to evaluate the influence on the temperature profile in the furnace hood and thus NOx-formation and (ii) an evaluation of the potential energy savings and energy recovery through an improved temperature control which allows for higher temperatures into the energy recovery system.

In total three reports/papers on the technical and economical feasibility of simultaneously energy recovery and emission reduction have been presented linking activities within EnergiX-project "SCORE" to HighEFF. Two papers at Infacon considering the design and experimental verification of the SCORE concept; followed up by a technical and economical evaluation at SPIS/Flogen 2018.

Surplus heat recovery

The energy flow database was completed for Alcoa, Eramet, Hydro and Wacker's plants in Norway. The data provided by the industry partners was validated through mass and energy balances both on plant and sub-process level, revealing significant variations in the data quality. Exergy calculations were performed for some plants for additional validation. Process flow diagrams giving an overview of mass and energy flows as well as data validation have been completed for a selection of the plants. The diagrams and the database itself are available on the HighEFF eRoom.

A possible path for improving Al smelter off-gas heat exchanger design was explored. It was investigated whether changing tube geometry into a wavy cross-section would improve heat exchanger performance. Results were compared against the current state-ofthe- art, showing both advantages and disadvantages. 

Industry Clusters and Technology Integration

A methodology for modelling and optimization of energy exchange in industrial clusters and dynamic mathematical models for simultaneous exchange of energy and materials were developed. The description of barriers, whether they are physical, conceptual, technical or cultural, and understanding how thesecan be overcome are crucial in order to identify and implement future cross-industrial synergies and current activities will thus be extended to 2019.

2017 Results

Process improvements:

A comprehensive literature review has been made on finalized and on-going projects within The Norwegian Ferroalloy Producers Research Association (FFF) with respect to energy recovery. Processes with high potential for energy recovery (in terms of energy quality and quantity) are identified and selected for further analysis together with the industry. Recycling of flue gas into ferroalloy furnaces is the first activity.

A report/paper on the technical and economical feasibility of simultaneously energy recovery and emission reduction has been made by linking activities within EnergiX-project "SCORE" to HighEFF. Two papers are
prepared: 1) Experimental verification and operation presented at Infacon 2018, 2) a technical and economical evaluation submitted to SPIS/Flogen 2018.

Surplus heat recovery:

The framework for the database of thermodynamic potential in surplus heat sources has been developed, with extended scope compared to the initial idea. Work on data acquisition has begun for the metals and materials sector. So far, data from Alcoa, Hydro, Wacker Chemical, Eramet, and Elkem have been received.

The initial activity on "surplus heat database" has been tentatively extended to "Energy flow database", to also include energy and material input streams for each subprocess in the industry plants. This should enable the database to be useful for various activities in many RA's and WP's in HighEFF. Completed entries for individual plants in the "Energy flow database" has been presented as process flow diagrams showing energy and materials flows. Several site visits were arranged to observe authentic plant scenarios and conditions, and scrutinize the energy flow data on-site.

Industry Clusters and Technology Integration:

A Modelica-based modelling and optimization framework for coordinated exchange of surplus heat in industry clusters has been developed. Preliminary results have illustrated both advantages and challenges of using optimization-based control and intermediate storage as a means of leveraging varying surplus-heat streams and demands to improve utilization of surplus heat in industry clusters.

Aud Nina Wærnes

Senior Business Developer
Name
Aud Nina Wærnes
Title
Senior Business Developer
Phone
930 59 428
Department
Metal Production and Processing
Office
Trondheim
Company
SINTEF AS