Online Plant Performance Improvement Solutions

Online Plant Performance Improvement Solutions

Suryaprakash DIGAVALLI

Owner and Principal Consultant

ENOPT Energy & Optimization Consultants Pte Ltd

EnOpt Energy and Optimization Consultants Pte. Ltd., #24-01, Regus Vision Exchange, 2 Venture Drive, SINGAPORE 608526 Ph: +65 6914 9127

PROFILE

Chemical Engineer with 17+ years experience

Operational experience with Refinery, Gas Plants and Petrochemical Plants

Mathematical model development

Certified Energy Auditor from Bureau of Energy Efficiency, India

Certified ISO 50001 – Energy Management Systems Lead Auditor

Advanced Diploma in Business Management

Key account management experience for large oil company in Middle-East

2EnOpt Energy and Optimization Consultants Pte. Ltd., #24-01, Regus Vision Exchange, 2 Venture Drive, SINGAPORE 608526 Ph: +65 6914 9127

SERVICES PROFILE

EnMS ISO 50001 implementation guidance

Detailed energy audits for asset performance improvement

Process and Utility optimization

Situational Analysis and Scoping studies

Benchmarking studies

Data validation and reconciliation services for production and yield accounting

Strategic sensor placement during FEED stage

Training on process operations and performance monitoring


Preamble

Management concern over energy efficiency

❑ “have we operated as well as we could?”

❑ “how can we improve ?”

Traditional energy reporting

❑ Monthly reporting of energy indices or specific energy consumption

❑ Fact reporting

❑ Does not often gives direction on action!

Our mantra – “Empower the Engineers and Operators”


Reducing EI – A Continuous challenge


Energy Savings

Energy Savings in plant are typically achieved in two ways:

❑ Optimization with no hard changes to the plant. Low investment and 2-5% reduction in overall energy consumption. UTILITY OPTIMIZATION

❑ Revamps and debottlenecking – where plant design is changed. High investment and 15+% reduction in overall energy consumption. PINCH ANALYSIS AND HEAT INTEGRATION

We advocate – “Rational Use of Energy and Resources”


Energy Savings






Objectives and Targets

Asset energy performance benchmarking

Unit-wise performance benchmarking

Optimize hot and cold utilities with a direction to reach the theoretically possible minimum energy requirements

Composite curves exploitation to deploy any possible heat and power systems

Minimize loading of penalty exchangers if not eliminating them for energy savings in operation

Validate the facility design for sustainable energy efficiency


Pinch analysis for heat integration

Energy Converters

Boilers

Waste heat recovery

CGTs

Etc.

Energy Consumers

Compressors

Pumps

Heat exchangers

Etc.


Minimum Energy Requirements and Targets

Graphical representation

❑ Composite curves

Pinch point divides the process into two sub systems

❑ Above pinch point : Energy deficit

❑ Below pinch point and above ambient T°: Energy excess

Gives guidelines for process improvements

❑ Actions are taken according to the pinch point location

❑ Column pressure, reaction temperatures, etc.

Energy saving technologies

❑ i.e. heat pumps, air preheaters, oxygen enrichment, etc.

Quality of the utilities

❑ Steam network, primary energy, refrigeration cycles

10


Conventional composite curves

11


ICC – better visibility

0

200

400

600

800

1000

1200

0 100 200 300 400 500 600 700 800

Adju

sted T

em

pera

ture

, deg F

Enthalpy, MMBtu/h

Integrated Composite Curves

12


Energy Savings





13


Long-term strategic planning (years)

budgeting

contract evaluation/negotiation

evaluation of future investments

Short-term tactical planning (months)

meet contractual commitments

observe equipment maintenance schedules

Operational optimisation

reduce daily costs

typical benefits:

2-3% reduction of energy consumption for well-managed plants

up to 10-15% reduction of energy consumption for other plants

Multiperiod – Utilities management


Dynamic demands, prices

Steam turbines

Heat recovery

Gas TurbinesBoilers

Power lines

Steam lines

Fuel lines

Electricity

Steam

Fuels

Chemical plants

External suppliesPlant demands

Plant generation

DRIVERS Pressure on energy cost & emissions

reductions

Impact of energy market deregulation – more contract flexibility

Increasing volatility in demand from client plants

COMPLEXITY (Potentially) large number of optimisation

decisions

fuel selection

device on/off status (boilers, turbines, …)

routing

Mixed continuous/discrete decisions

Site utilities management


Utility Optimization

Equipment Optimized

❑ Boiler steam production

❑ Cogen GT power gen / HRSG steam production

❑ Choice of steam turbine / motor driven pumps and compressors

❑ Steam desuperheating, letdown and venting

❑ Steam Turbine extraction or condensing mode

❑ Amount of export or import electricity, contracts etc.

Utilities Optimized

❑ Steam – all pressure levels

❑ Boiler feed water, Condensate and Demin

❑ Fuel gas, Imported gas

Optimized to Minimum Cost of Fuel, Water and Import Power 16


Utility Optimization Equipment constraints

Equipment Min and Max Constraints

❑ Pump flows

❑ Boilers loads

❑ GT / ST loads

Equipment Availability

❑ Mandatory(for operational reasons)

❑ Not available (in maintenance)

❑ Optimizable (free for the Optimizer to choose)

System Constraints eg

❑ Turndown capacity eg Boilers

❑ Min power export to grid (contractual)

❑ Min steam flows between production areas (process constraints)


Challenges

Measurement data availability

Inconsistencies in data

Operator action tracking

Changing contracts and utility prices

Multiple decisions to make with cross subsidies

❑ Steam – all pressure levels

❑ Boiler feed water, Condensate and Demin

❑ Fuel gas, Imported gas, LPG vaporization, H2 mains

Optimized to Minimum Cost of Fuel, Water and Import Power

18


www.belsim.com

DVR PrinciplesDVR Optimization & Calculation

10.16PenaltyPenaltyPenalty

)σ(y

yyMinPenaltyMinObjective

CB

i

2

i

*

ii

i

i

A=++=

−==

Mass balance:

35 – 21 – 10 = 4 0

A:35

B:21

C:10

M:35

σ:2.10

P:7.41

R:32.08

M:21

σ:1

P:1.68

R:21.66

R:10.42

M:10

σ:0.8

P:1.07

A

B

C


Utility Optimization


Typical results of Utility Optimization

1,0

1,2

1,4

1,6

1,8

2,0

2,2

2,4

1-Jan 8-Jan 15-Jan 22-Jan 29-Jan

Uti

lity

Co

st,

Millio

ns IN

R

Overall Utility Cost

Current

Optimized

Avg savings

around 7%

Est. Potential Benefit 30 Crores INR/ Annum


Differentiators

Data reconciliation as a precursor to optimization to ensure healthy values flow into optimizer eliminating GIGO scenario

MINLP solver usage to ensure the loading is globally optimal and not local optima

Robust automated structure with a few clicks for the solution

Full fledged training and inhouse maintaining capabilities imparted.


References

Saudi Aramco Gas plants Utility systems

Indian Oil refinery


Timelines

With full fledged reconciliation and utility optimization the project is normally around 6 months and 2 engineers

Without reconciliation and simple optimization algorithms for operational guidance would be around 6 months and 1 engineer


Operational frequency

Recommended to run the tool once per shift to get the valid set points for optimal operation

Reconciliation and calibration tool could run once every hour to automate performance monitoring and cater to the optimization algorithm with the corrected data.


Tool integration

The tool is supposed to interface with the plant historian system for its automated operation

This works on historical data and hence no DCS integration is envisaged.

This tool is intended to be decision support system and would be in the custody of technologist and operations supervisor

The operations supervisor could run and supply the set points for optimal operation

The technologist could run this tool to monitor performance of the big equipment and recommend operational changes. Further he could run what-if scenarios and arrive at profitable recommendations


BENEFITS…

❑ Sustainable energy savings

❑ Optimal plant loading to improve asset reliability

❑ Better operational picture of the plants and depiction of lost opportunity cost

❑ Energy awareness trainings for a motivated workforce

❑ Online running applications deployment with very low maintenance / intervention

❑ Lower carbon foot print

❑ Confident and profitable operations

27


HAPPY TO ASSIST

THANK YOU

FOR YOUR

TIME & ATTENTION

Phone: +65-911-718-25 [SG]

Email: [email protected]

Skype: surya18881


mailto:[email protected]

Documents

Online Plant Performance Improvement Solutions