99540 - SISTEMI ENERGETICI PER L'AMBIENTE, AD IDROGENO E PER P2G M

Learning outcomes

The course aims to provide student with knowledge on design and operational issues of modern energy systems with reference to their impact on the environment, mainly in terms of pollutants formation and the advanced solutions for emissions removal. The student also acquires knowledge on hydrogen-powered systems and machines for the environment, required for the implementation of power-to-gas energy conversion strategies”

Course contents

Introduction.

Introduction on the international Energy Scenario based on latest statistical data. Energy resources, energy conversion and environmental impact. The need of quantitative performance indicators.

Air pollutants and formation mechanisms.

Main unit of measure of air pollutants from energy systems: concentrations, dilution and emission factors.

Formation mechanisms of NOx , CO, HC, SOx and PM form combustion; influence of operative parameters (fuel/air ratio, temperature, etc.).

Main effects of CO, HC, NOx, SOx, O3 and PM released in the atmosphere.

Combustion.

Basic definitions, ignition, equivalence ratio, flammability limits, rich and lean flames. The flame temperature. Classification of combustion processes: definition of premixed and non-premixed combustion.

Flame propagation in premixed flames. Laminar and turbulent premixed flames.

Turbulent diffusion flames.

Environmental impact of Gas Turbines and Combined Cycles.

Thermodynamic boundary conditions for a gas turbine combustor.

Main design elements and related functions of a gas turbine combustor. Diffuser and combustor pressure drop. Swirler and aerodynamics. Multi-burner combustor architectures. Conventional GT combustor and emission formation.

Techniques for emission reduction in gas turbine combustors and concentration performance.

NOx reduction with water/steam injection.

Design of dry low emission combustors: staging, rich-lean and lean-lean combustors.

Lean Premix concept and Dry Low NOx combustors.

Examples of advanced DLN combustor design.

Part-load emissions of gas turbine combustors.

Ultra-Low-Emission technologies: SCR and SCONOX systems and Catalytic combustors.

Use of H2 in Gas Turbines.

CH4-H2 mixtures properties: density, energy density, pressure for storage.

Impact of H2 on combustion: emission factor, Wobbe index, flammability, flame propagation, flame temperature, NOx; examples of advanced design of combustors.

Impact of H2 on turbomachinery.

Energy Systems for Power-to-Gas.

Examples of Power-to-Gas architectures of energy systems.

Impact of H2 on the gas network and energy consumption.

Environmental impact of power stations cooling systems.

Assessment of Thermal power released by power plants.

Water condenser cooling systems. Wet cooling tower. Water consumption. Concentration cycles.

PM emitted by cooling towers, Drift Rate. EPA and Reisman & Frisbie PM emission models.

Dry and wet/dry hybrid cooling towers. The plume.

Air condenser cooling system and comparison with water cooling systems.

Environmental impact of refrigeration plants.

Issues related with the use of CFC, HCFC. The Ozone Depletion Potential. The use of HFC fluids.

Environmental impact of CO2. Greenhouse effect; GWP and TEWI of refrigerant and cooling plants.

Cryogenic plants and energy/environmental issues.

Organic Rankine Cycle (ORC) for waste heat recovery applications.

Main architectures, applications and performance indexes.

Environmental impact of external combustion energy systems.

USC and conventional steam turbine plants.

Coal fired power plants. Pulverized coal combustion, burners and emissions; low emission techniques: air staging (OFA and BOOS), fuel staging, Flue Gas Recirculation, water/steam injection.

Post-combustion abatement systems: Wet Scrubber (layout and working principle), Dry Scrubber (layout and working principle), electrostatic precipitator (layout and working principle), fabric filters (layout and working principle), cyclone, SNCR.

The flue gas line with post-combustion abatement systems.

Fluidized bed combustors. Pollutant emissions of FBC. Limestone injection for abatement of SOx.

Coal gasification. Integrated Gasification Combined Cycle (IGCC) systems. The Air Separation Unit (ASU) as a cryogenic plant.

Clean Coal Technologies. Plant layouts.

Environmental issues of selected Renewable energy systems.

Geothermal energy and geothermal power plants. Steam and dominant water wells and steam turbine plants. Thermodynamic diagram of a geothermal power plant with double flash stage.

Geothermal/fuel based hybrid power plants.

Readings/Bibliography

Lecture notes and slides available after each lesson are the main source of information for the exam preparation.

Foreign students can ask the teacher for English readings, corresponding to the topics in this text.

Sistemi Energetici - Impatto ambientale, Vol. 3, Pitagora (in Italian).

 

Teaching methods

Class Lectures on all the Course Contents. The pc and projector are used.

Lectures attendance is recommended, but it is not mandatory to pass the exam.

Assessment methods

Individual oral exam, on the topics of the carried out lectures, with reference to:

1) functional aspects;

2) schemes of systems;

3) quantitative aspects and demonstrations.

The questions are aimed at the following main learning outcomes:

- knowledge of the main pollutants formation from energy systems;

- knowledge of the technologies to control pollutants formation from energy systems, mainly gas turbines, combined cycles, boilers of steam power plants and renewable energy systems.

Higher grades will be awarded to students who demonstrate an organic understanding of the subject, a high ability for critical application, and a clear and concise presentation of the contents.

To obtain a passing grade, students are required to at least demonstrate a knowledge of the key concepts of the subject, some ability for critical application, and a comprehensible use of technical language.

A failing grade will be awarded if the student shows knowledge gaps in key-concepts of the subject, inappropriate use of language, and/or logic failures in the analysis of the subject.

The exam will be grade over the 0-30 range, with 18 the minimum to pass, 30 the maximum. Honor can be assigned.

If the course is part of the integrated course COGENERATION, HYDROGEN AND P2G M (I.C.), the final grade, that will be recorded, will be given by the arithmetic average, rounded to the next whole number, of the marks that the student will have obtained in the courses which make up the integrated course. The final "30 e lode" (30 and honor) is awarded if the candidate has obtained 30 in both modules and the honor in at least one of them.

Teaching tools

The use of overhead projector and pc is considered in order to show the case of complex layouts of the plants and energy systems related with the course contents. All the lecture contents are shared at the end of each lecture.

Office hours

See the website of Andrea De Pascale