Methodologies RA1

The main objective of Methodologies is to improve existing and develop new methodologies for improved energy efficiency in industrial plants. This requires close interaction with industry and the outcome will be disseminated and applied in other Research Areas.

Industrial processes, like converting raw materials into valuable products, require enormous amounts of thermal energy (heat), mechanical energy (power) and/or chemical energy (in fuels, raw materials and products). Because of the complexity of the processes, systematic and general tools and methods are required to analyze, design, optimize and control these systems. 

A holistic view is provided by the field of Process Systems Engineering, and the success of energy and resource efficiency will use exergy  as a standard KPI, since heat and power represent different energy qualities.

To improve energy efficiency in industrial plants we must innovate

In Methodologies, we believe that technological enhancements are better drivers of innovation than cost reductions. For that reason, solutions that are thermodynamically more efficient will serve as our main driver. Also, changes in the framework conditions related to energy, environment, new technologies and market will be closely considered in our work.

Potential innovations:

  • New software systems for innovative use of heating and cooling
  • New, systematic methodology using exergy to guide conceptual design.

RA 1 Methodologies consists of the following Work Packages (WP)

RA1 Methodologies Samuel Senanu SINTEF Industry
WP1.1 KPI's, energy & exergy analyses Olaf T. Berglihn SINTEF Industry
WP1.2 Process systems engineering Sigurd Skogestad NTNU
WP1.3 Future processes Asbjørn Solheim SINTEF Industry

 

 

Results 2019

KPIs, Energy and Exergy Analyses/ Process Systems Engineering

One important task for RA1 is to use relevant KPIs for energy and resource efficiency. Alternative Key Performance Indicators (KPIs) have been tested and evaluated for an industrial case at Mo Industripark (MIP). Process data has been collected to describe the energy flows between industrial clients located at MIP.

The annual energy flow (in GWh) has been visualised in the form of Sankey diagrams while the quality of the available energy is presented in the form of a grand composite curve which describes the amounts of latent energy available at different temperature levels. High temperature flue gas from ferrosilicon (FeSi) production at Elkem Rana represent the largest heat source available for utilisation. A theoretical assessment of potential applications for this energy is presented and includes:

  • electricity production via a steam Rankine cycle
  • biocarbon production, where surplus heat is utilised for drying of wood chips produced at MIP
  • carbon capture via amine-based post combustion technology, where surplus heat is utilized for amine solvent regeneration.

The theoretical studies indicate that the MIP ambition from 2016 of increasing the energy recovery from 400 GWh to 640 GWh is realistic and may contribute both to increasing the energy recovery and facilitate overall reductions in the carbon footprint of the activities at MIP.

PhD Vikse and PD Yu further developed Work and Heat Integration (WHI). Two review papers were published in 2019. WHI is now established as a new research field in HighEFF with considerable potential for industrial applications.

The main difference from established heat integration methods is that heat from compression and cooling from expansion are added to the basic heat recovery problem. Early results indicate considerable improvement to industrial energy systems. By making modest sacrifices in mechanical energy (work), significant savings can be obtained in thermal energy (heating and cooling). This has close connection to heat pumping, however, regular process streams are used as working fluids.

Considerable work was done on using Organic Rankine Cycles (ORCs) for power production from low temperature Waste Heat. The disadvantage with ORCs is their low efficiency in traditional applications, however, when combined with low temperature heat sinks (such as LNG regasification), the efficiency and economy can be quite good. The collaboration with Prof. Barton at MIT on developing a new paradigm for simulation and optimization has progressed. The methodology is referred to as Non-smooth Analysis and has been applied to LNG processes (multi-stream heat exchangers) and distillation columns.

Future Process Framework

Aluminium electrolysis by the Hall-Héroult process is energy intensive. In Norway, 18 TWh of electric power is consumed (12-13 % of the Norwegian production) for manufacturing about 1.2 Mton aluminium. The process emits around 2.1 Mt CO2-equivalents.

Earlier we evaluated alternative processes to today's Hall-Heroult (inert anode technology and chlorination route). We also intended to evaluate new concepts and solutions for use in today's HH- process, creating a basis for continued research on methods and means for decreased energy consumption and environmental footprint.

In 2019 we had a detailed study of recycling of flue gas in Al electrolysis cells. We want to recycle flue gas because this will give higher concentration of CO2 (today it is around 1 vol%), thereby enabling carbon capture technologies in the future. Another advantage is to increase the energy recovery potentials by introducing heat exchangers in the gas-system However, it is several challenges to be solved and therefore this will be followed up by a workshop in 2020 with industry partners and SINTEF.

2018 Results

All 6 PhD students are now recruited. One Post Doc (PD) (of two) finished the work from 1.7.2018. International collaboration is established with University of Manchester (UoM) and Massachusetts Institute of Technology (MIT) and one PhD student (Vikse) stays at MIT until summer 2019. 18 journal papers and 16 proceedings/papers for conferences was published and presented in 2018.

KPIs, Energy and Exergy Analyses/Process Systems Engineering

One important task for RA1 is to use relevant KPIs for energy and resource efficiency. PD Magnanelli fulfilled her work within KPI's and Exergy indicators for industrial practice during 2018. A workshop titled "RA1 + RA4 Workshop on KPIs, process improvements and surplus heat recovery" was arranged in Trondheim June 2018. From industry Elkem, Eramet and Mo Industripark were present together with SINTEF and NTNU researchers. Based on work performed earlier and discussions during this workshop a report "Definition of case studies" was delivered, giving the directions to further work in 2018 and 2019. A case study will be performed at Mo Industripark (MIP).

PhD Vikse and PD Yu are studying Work and Heat Exchange Networks (WHENs), Waste Heat Recovery by using ORCs and various Polygeneration concepts. Together with Prof. Truls Gundersen they received the Best Paper Award at the Escape conference in Graz, titled "Comparison of reformulations of the Duran-Grossmann model on Work and Heat Exchange Network Synthesis (WHENS)". Work and heat integration is established as a new field. Participating with MIT/Prof. Barton in development of a new paradigm for simulation and optimization is established. The work is non-smooth analysis for (hybrid)modelling and appliedto LNG processes.

Future Process Framework

Aluminium electrolysis by the Hall-Héroult process is energy intensive. In Norway, 18 TWh of electric power is consumed (12-13 % of the Norwegian production) for manufacturing about 1.2 Mton aluminium. The process emits around 2.1 Mt CO2-equivalents. The focus in HighEFF is to evaluate some alternatives to the traditional Hall-Heroult process.

The paper "Inert Anodes – the Blind Alley to Environmental Friendliness?" was presented in a large international conference (TMS) in March 2018 with good feedback and interest. A truly inert anode has not yet been developed, but the foundation of Elysis in Canada (Rio Tinto, Alcoa and Apple) shows willingness to develop a new process. The evaluation of the chloride process with less energy consumption and CO2-footprint, was finalized early 2018 with the report "Carbochlorination routes in Al production". This route is to be followed up by an industrial partner. New concepts and solutions for use in today's HH- process has also been evaluated, creating a basis for continued research on methods and means for decreased energy consumption and environmental footprint.

Advanced exergy analysis of the oil and gas processing on a North Sea platform is the key activities for a PhD study starting late 2018. This activity will be further planned with industrial partners and ongoing in 2019 with high focus.

2017 Results

Recruitments of PhD students (5) and PDs (2) is in place at NTNU. Together with SINTEF and MIT resources this has result in a very good and impressive publication production with 7 journal papers and 10 proceedings/papers for conferences. International collaboration is established with UoM and MIT and will be even more strengthen the coming years. Participating with MIT/Prof. Barton in development of a new paradigm for simulation and optimization is established. The work is non-smooth analysis for (hybrid) modelling and applied to LNG processes. Work and heat integration is established as a new field. A special session was organized at PRES'2017 in Tianjin and was appointed to be the "highest attended and best session of the conference."

KPIs, Energy and Exergy Analyses:

One important task for RA1 is to use relevant KPI's for energy and resource efficiency. Internal meetings, as well as the 3 workshops arranged by RA6 case studies, have been very useful to define and evaluate different methods. Discussions and work regarding KPI's and usage of exergy metrics is published in a journal (draft version for reviewing) as well as reported in a report. This work will be continued in closer co-operation with HighEFF members in 2018 and coming years. A workshop is planned to be arranged with industrial partners in 2018.

Future Processes:

Production of aluminium is a very energy intensive process and emits also huge amounts of CO2. Inert anodes (non-fossil carbon) have been evaluated as an alternative process. However, inert anodes will use 3 MWh/t Al more DC energy consumption than carbon anodes. Hence, the energy source for Al production will be essential for lowering the CO2-footprint. Only usage of renewable energy sources will give less CO2 emissions with inert anodes. Usage of carbon anodes with CCS technology consumes less power than inert anodes. A truly inert anode has not yet been developed. The paper "Inert Anodes – the Blind Alley to Environmental Friendliness?" will be presented in in a large international conference (TMS) in March 2018 with all the worlds Al producers present.

Egil Skybakmoen

Research Manager
Name
Egil Skybakmoen
Title
Research Manager
Phone
982 83 965
Department
Metal Production and Processing
Office
Trondheim
Company
SINTEF AS