Special Lecture on Energy & Environment Process Process Process, Energy and System Integration Energy Environment • Clean Process Technology (Ch. 28 in R. Smith) • Classes of Waste (Process & Utility) • Environmental Impacts from Energy Usage • Energy/Exergy & Component/System Efficiencies • Actions to mitigate Greenhouse Effects (Energy21) • How can TEP4215 Energy & Process (PI) Contribute Energy & Environment T. Gundersen E&M 01
Clean Process Technology – Some Ideas (Ref.: Robin Smith, Chemical & Process Integration, Ch. 28) • Environmental Issues (similar to Heat Integration) Process, Energy and System are often considered late in the Design Process • The Result is often “ End-of-Pipe ” Solutions • Clean Process Technology represents an Opposite Approach similar to Process Integration thinking: Minimize Waste at Source − Examples: u Choose Reactions Paths that avoid harmful Chemicals being produced as byproducts u Keep harmful Chemicals “inside the loop” by combining producing and consuming Reactions u Closing Processes as in Pulp & Paper Energy & Environment T. Gundersen E&M 02
Sources of Waste from the Process Industry Process, Energy and System R + S : Process Waste S H U R H + U : Utility Waste • Types of Process Waste: u Waste Byproducts, Purge Streams, etc. • Sources of Process Waste: u Reactors (byproducts, used catalysts, etc.) u Separation & Recycle Systems (inadequate recovery and recycle of valuable materials) u Process Operations (start-up, shutdown, product changeover, equipment cleaning, etc.) Energy & Environment T. Gundersen E&M 03
Sources of Waste from the Process Industry Process, Energy and System R + S : Process Waste S H U R H + U : Utility Waste • Types of Utility Waste: u Gaseous Combustion Products (CO 2 , SO x , NO x , Particles) u Aqueous Waste from BFW (Boiler FeedWater) Treatment u Waste from Water Systems • Sources of Utility Waste: u Hot Utilities (incl. Cogeneration) u Cold Utilities and Water Systems Energy & Environment T. Gundersen E&M 04
Sources of Waste from the Process Industry Process, Energy and System R + S : Process Waste S H U R H + U : Utility Waste • Our Focus in these Lectures: u Environmental Impacts from Energy Consumption • Remember to take a Systems Approach: u Local Emissions vs. Global Emissions u Producing or importing Electricity? Energy & Environment T. Gundersen E&M 05
Environmental Impacts from Processes including their Use of Energy • Various Kinds of Waste Material Process, Energy and System • Heavy Metals • CO and CO 2 • NO x and SO x • CH 4 , NH 3 and other volatile compounds • Particles (“Particulates”) • VOC (Volatile Organic Compounds) • Heat (or Cooling) • Wastewater • Using scarce Freshwater Resources Energy & Environment T. Gundersen E&M 06
Environmental Design for Atmospheric Emissions (Ref.: Robin Smith, Chemical & Process Integration, Ch. 25) • Urban Smog (Los Angeles, Mexico City, Lima, Shanghai) Process, Energy and System u Photochemical Reactions u VOCs + NO x + O 2 è O 3 (Ozone) + Other Photochemical Pollutants (Aldehydes, Peroxynitrates, etc.) • Acid Rain u Natural Precipitation is slightly acidic with pH around 5-6 § Carbonic acid from dissolved CO 2 § Sulfuric acids from natural emissions of SO x and H 2 S u Human Activity can reduce pH to 2-4 § Mainly caused by emissions of SO x § This is a primarily a local environmental problem § Can be a regional problem (from UK to Norway) Energy & Environment T. Gundersen E&M 07
Environmental Design for Atmospheric Emissions (Continued) • Ozone Layer Destruction Process, Energy and System u Lower Levels of the Atmosphere: Ozone is harmful! u Upper Levels: Ozone essential; it absorbs ultraviolet light! u Destruction is due to Oxides of Nitrogen and Halocarbons • The Greenhouse Effect u CO 2 , CH 4 and H 2 O present in low conc. in the atmosphere § Reduces emissivity and reflects some of the heat radiated by Earth. § Keeps the Earth warmer − a prerequisite for Life as we know it u This Balance can be disturbed è Global Warming § Burning Fossil Fuels (increased emission of CO 2 ) § Large Scale harvest of Forests (reduced absorption of CO 2 ) • The largest Volume of Atmospheric Emissions from Process Plants is due to Combustion Energy & Environment T. Gundersen E&M 08
Actions that reduce the Environmental Impacts from Energy Consumption • Statement: The most “Green” Energy is the Process, Energy and System Energy that is not used u Process Integration increases Energy Efficiency and results in Energy (in various forms) not being used u Investment in Equipment may cause use of Fossil Fuel based Energy elsewhere (considering LCA) • More comprehensive List of Actions u Use less Energy (vs. “Standard” of Living) u Increase Energy Efficiency u Increase Process Efficiency u Switch between Fossil Fuels u Switch from Fossil Fuels to Renewables Energy & Environment T. Gundersen E&M 09
“Energi21” − National Strategy for R&D, Demonstration & Commercialization − Energy in the 21 st Century Process, Energy and System • The Vision of Energi21 u Norway: Europe’s leading Energy and Environment- Conscious Nation − from a National Energy Balance to Green Energy Exports • To realize this Vision: 5 Priority R&D Areas u Efficient Use of Energy ( Industry /Transport/Buildings) u Climate-friendly Power u CO 2 -neutral Heating u An Energy System to meet the Needs of the Future u Desirable Framework Conditions for R&D Energy & Environment T. Gundersen E&M 10
Energy Consumption (TWh) in Norway by Sector in 2007 (Total: 813.5 PJ) Process, Energy and System Other Sectors: Private household (20.0%), Community Consumption (13.7%) and Fishing/Agriculture (3.6%) 35.1% 37.3% Industry & Mining Transportation 27.6% Other Sectors T(erra) = 10 12 The Course “Energy & Process” makes Sense !! Energy & Environment T. Gundersen E&M 11
Energy Consumption (TWh) in Norwegian Industry in 2007 (Total: 80.66 TWh) Process, Energy and System Aluminum 29.6% Chemical Pulp & Paper Petrochemical Food Industry Iron & Steel Minerals Wood Ware 12.0% 17.6% Mining 13.6% Others Discuss: Primary Application Areas for Process Integration? Energy & Environment T. Gundersen E&M 12
Main Focus in TEP 4215: Efficient Use of Energy • Saving Energy means Saving the Environment in Process, Energy and System one or more Ways (CO 2 , SO x , NO x , Particulates) • Process Integration provides Methods and Tools to improve Heat Recovery and Heat Integration • The Result is reduced Energy Consumption • With the current Energy Mix this also means reduced Emissions from Fossil Fuels • The Systems Approach in Process Integration can be used also to reduce Waste and other Impacts from the Process Industries Energy & Environment T. Gundersen E&M 13
What we’ve done in TEP 4215 Process Integration Process, Energy and System • Heat Recovery between Hot and Cold Streams to reduce Energy Consumption in the form of Hot and Cold Utilities • Heat Integration of Distillation Columns and Evaporators with the “Background Process” • Use of Heat Pumps to “lift” Thermal Energy (Heat) from below to above the Pinch by using Mechanical Energy (Power or Electricity) • Combined Heat and Power (Cogeneration) by using Backpressure Turbines and deliver Heat to the Process or District Heating System while producing Power/Electricity • Process Modifications to improve Scope for Heat Recovery guided by the “Plus/Minus” Principle Energy & Environment T. Gundersen E&M 14
Tools developed in Process Integration • The Composite Curves Process, Energy and System u Provides Insight and a Graphical Way to establish Energy Targets u Suggests Process Modifications (+/ − Principle) • The Grand Composite Curve u Based on the Heat Cascade − a Transshipment Model u Optimal Mix of Utilities (including Production) u Possible Integration of Reactors u Integration of Distillation Columns and Evaporators u Potential for and Correct Use of Heat Pumps u Combined Heat and Power Considerations Energy & Environment T. Gundersen E&M 15
A brief Discussion about Efficiencies • Energy vs. Exergy Efficiency Process, Energy and System u Exergy is defined as the Ability to produce Work u Exergy screens Energy Types w.r.t. Quality u Exergy does not reflect Cost − or better: The Cost of various Energy Forms does not reflect the 2 nd Law • Component vs. System Efficiency u “Local” vs. “Global” Considerations u Importing Electricity may improve Plant Efficiency and Emission Figures (inside Battery Limits) u With Process Integration, Systems Thinking and utilizing Synergies, Component Efficiencies become less Important and System Efficiency improves Energy & Environment T. Gundersen E&M 16
Basic Principle for Combined Cycle Plant 10% Ref.: Olav Bolland Process, Energy and System 30% 100% 20% 40% Energy & Environment T. Gundersen E&M 17
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