Energy efficiency and cooling in large scale processing systems

Transcription

1 Energy efficiency and cooling in large scale processing systems Dr. Patrick Linke Qatar Shell Professor for Energy and Environment Chair, Chemical Engineering Program Executive Director, Office of Graduate Studies Presented at QNRF EU-GCC Conference on Energy Efficiency 3 May 2017

2 Increasing Demands Growing Population Growing Income Increasing Materials & Energy Intensity Degrading Environment Water Scarcity Soil Exhaustion Climate Change Depleting Resources In future we will need to support growth with much improved resource efficiency and reduced environmental impacts!

3 Local Situation in the State of Qatar No. 1 In per capita GDP and GHG emissions 90% of all food consumed in Qatar is imported 100% Dependency on seawater desalination for potable water supply 7 days of potable water reserve

4 Positives and negatives closely linked with process industries No. 1 In per capita GDP and GHG emissions Direct result of hydrocarbon resource monetization Significant energy and water footprints Silo approach to projects prevents efficiency at systems level Not integrated with other sectors of the economy (e.g. power/water)

5 Challenges for the process industries How to make more money with lower footprints? How to enable additional efficiencies across silos? How to benefit other sectors (esp. water/power)? Better processes, better integration!

6 How to turn problems into opportunities with integrated process systems solutions? An example from RLC : Once-through cooling seawater used for process cooling Dumping of many GW thermal energy into the sea Ignore it? Avoid/reduce? Reuse across processes / sectors,? How? Does regulation allow synergy options?

7 Why energy efficiency? Economics Reduce cost of fuel and/or opportunity cost Innovate technologies that can be exported Environment Reduce GHG emissions Reduce negative impacts on air quality Reduce impact on water resources (cooling water, )

8 Where to draw the boundaries? Heat / power centric view? How to reduce process energy requirements? How to utilize excess heat (power, water, )? How to replace offset fossil energy inputs (solar, )? Hydrocarboncentric view? How to best monetize hydrocarbon resources with minimum footprints?

9 More rigorous alternative Conventional approaches Approaches to Design - Trial & error - Brainstorming & Experience - Heuristics - Hierarchical approaches - Limited time to search - Relatively few options considered - Likely to miss good options - Limited room for innovation: Bias for conventional structures - Hope for ingenuity - Capture all design alternatives in one model - Search all options simultaneously - Identify highest performing solutions against selected performance criteria Process Systems Engineering approaches - Limited representations to capture design alternatives - Existing representations often simplistic - Optimal search of representations challenging (often MINLPs)

10 Research Track: Sustainable Industrial Clusters Optimal design, multi-period planning, simultaneous nexus integration Systematic minimization of footprints through integrated resources management Heat Water CO 2 Power Other materials Nat. Gas How to synergize within and across processes & plants? How to synergize within and across materials, energy? (W-E, E-CO2, )

11 Integrated process heat & water management Research under NPRP grant no from the Qatar National Research Fund Desalinated water can be co-produced in large quantities at very low cost and without additional GHG emissions by energy integration.

12 Research under NPRP grant no from the Qatar National Research Fund Water-Energy Nexus Industrial clusters have high energy and water footprints, esp. in the GCC Previous works have focused on water and energy integration independently Significant interactions and trade-offs exist across the Water-Energy Nexus Plant i Fuel Plant/Energy? Fresh Water Plant/Water Seawater Objective: To develop a representation to capture significant in-plant/inter-plant water and energy management options, initially focusing on Q, Cooling Net Power WW Streams Brine 1. Process cooling requirements and Cooling systems 2. Desalination and water treatment Each plant has a (minimum) cooling requirement which creates: Cooling costs associated with cooling (oncethrough seawater, cooling tower, air coolers) Plant ii Fuel Plant/Energy?? Fresh Water Plant/Water Seawater Opportunity to generate power/steam and use in industrial park or regionally/nationally (electricity is easier to transport ) Q, Cooling Net Power WW Streams Brine 12

13 Water-Energy Representation (one plant) Plant i Plant EMS / Utility System Seawater Desal / External Utility Net power can be exported or imported (subject to policies, regulations, and infrastructure ) Cooling requirement can be (partially) converted to power (efficiency depends on the grade of heat) Needs to be cooled down using one of the cooling systems option A C C S C T Sinks Sources Net Power Q, Cooling Seawater Dashed box shows cooling systems in water profil : Once through cooling sweater which has 1 source, 1 sink : Cooling tower: 1 source (blowdown), 1 sink (make-up) C S C T : Desalination plant: 1 sink (seawater), 2 sources (pot. water, brine) : Water treatment: 1 sink (WW), 2 sources (treated water, brine) : Process water sinks and sources : Offices sinks and sources which receives only potable water Cooling Systems: cooling towers, air coolers, or once-through seawater Cooling towers and seawater will have sources and sinks in water network; however, air coolers only need energy (power) Air coolers reduces water consumption but has the higher power requirement Both Cooling towers and Once-through cooling seawater requires water mainly but need power as well Q, cooling can be satisfied directly by using cooling system options or can be partially converted to power and be used in the plants (any cooling system, treatment or desalination unit) Freshwater generation from desalination (incl import) considered in terms of wnergy and brine

14 Illustration Two Plants; Ammonia & Refinery (6 sources & 7 sinks) Four Contaminants (TDS, Organics, Sulphate, Oil & Grease) Ammonia plant has a cooling requirement of 167 MW Scenario 1: Classical Water integration + Cooling syst. selection Selected Cooling System: Air Coolers Total Annual Cost: 4.30 (MM$/yr) Max water reuse: 372 ton/day Scenario 2: Enabling other options incl. waste heat to power, desalination of once-through seawater, and water export (which is currently not allowed in Qatar) Selected Cooling System: Once-Through Seawater Profit of 113 MM$/yr Exporting approx. 410,000m3/d desalinated water Less Water Re-Used: 302 ton/day Cheaper water compared to other external utility, reducing overall CO2 emissions by using power generated from waste heat instead of fuel burnt in desalination/power plant Total water input required (t/d) I Fresh water External Utility ($/m3) C T C S C T C S 1.5 Seawater Cost ($/m3) I Seawater Seawater Water Supply Seawater 14

15 Carbon Emissions Reduction through Systematic CCUS Source to Sink connectivity illustrated for one treatment technology CCU and CCS options (sinks) Which to feed? How much? Purity? Min Cost vs. net CO 2 reduction Emissions sources Capture or not? Purify or not? Which separation technology? Optimize CCUS network Transport options Compression, pipes, Now extended to simultaneously assess Renewable Energy options. See our 2016 Journal of Cleaner Production (JCLP) papers. I. DM Al-Mohannadi, P Linke, On the Systematic Carbon Integration of Industrial Parks for Climate Footprint II. III. Reduction. JCLP 112(5), DM Al-Mohannadi, SY Alnouri, SK Bishnu, P Linke, Multiperiod Carbon Integration, JCLP, 136B, R Hassiba, DM Al-Mohannadi, P Linke, Carbon Dioxide and Heat Integration of Industrial Parks. JCLP, DOI: /j.jclepro

16 Simultaneous exploitation of synergies across carbon and energy management Fuel input NG VHP GT HRSG Fuel Boiler Power Production and Heat Utilization in CCUS network Excess heat from processes / plants HP P1 P1 P2 P2 P3 Solar thermal / geothermal MP P1 LP

17 Transitions towards future targets: Significant cost differences between policies

18 Moving towards the hydrocarbons (the ultimate source of profits and footprints) The approach can synthesize integrated natural gas and carbon dioxide networks for industrial cities that can meet emissions constraints while maximizing the profitability of natural gas monetization Generic plant module Illustration of natural gas and carbon dioxide network superstructure with 3 generic production plants, NG-fired power plant, and renewable power plant.

19 Example No CO 2 footprint constraint Profit of the cluster: 3.4 billion usd/y CO 2 footprint constraint: 30% reduction of original emission Profit of the cluster: 3.4 billion usd/y (unchanged) Profit maintained due to EOR and methanol from CO 2 Renewable solar power used to max capacity (PV) PV saves methane from combustion in power plant (enables conversion into products to add value)

20 Outlook Continue to develop dimensions (heat, power, water, CO2, natural gas, intermediates) Develop & integrate nexus representations To optimize across dimensions (e.g. W-E-CO2) Incorporate other relevant objectives and aspects (sustainability metrics, reliability, uncertainty) Ultimate goal: Explore all dimensions simultaneously Link across scales & issues Design processes for performance in the big picture Link to micro and macro economic modelling to better understand policy implications Link across borders (national vs. multinational footprints)

21 Putting efficient solutions into practice OUTLOOK

22 Sustainable Industrial Systems Resource efficiency Economics Environmental footprints Global markets & environment National economy & environment Industrial Park Processing plant Production process Equipment Materials / Molecules Large & slow Rather: A System of Systems. Small & fast

23 The concerns are on the large scale Global markets & environment National economy & environment Industrial Park Processing plant Production process Equipment Materials / Molecules Large & slow Small & fast

24 but they build up over the scales Global markets & environment National economy & environment Industrial Park Processing plant Production process Equipment Materials / Molecules Large & slow PUBLIC PRIVATE Small & fast

25 Need to master the overall chain in light of stakeholder functions Government Understand resources Understand impacts Set policy & strategy Regulate Guide sustainable development Enable sustainable solutions Industry Be profitable Be good citizens Avoid problems Compliance Innovate as per business model Academia Research Community Educate, generate & disseminate new knowledge, serve / provide impartial advice Provide fundamental knowledge (across the scales!) to enable government & industry

26 What s needed? Holistic, evidenced-based policy making (GHG reductions including RE, CCUS) Win-win economic models (incentive schemes, pricing, ) Systems thinking! (the silos tend to be efficient)

27 Thank you.