Title: 29th Annual ENERGY BUYERS’ CONFERNCE
129th AnnualENERGY BUYERS CONFERNCE
- Combustion Turbines Alternate Fuels
- Mike Zampano
2Discussion Outline
- Fuel Selection
- Fuel Availability
- Product Specifications
- Quality Concerns
- Delivery Logistics
- Bottlenecks
- Delivery Example
- Working With Suppliers
3Fuel Selection
- Combustion turbines generally are designed to run
a primary fuel and a backup fuel - Most times the primary fuel is natural gas and
the backup fuel is a liquid distillate - Fuel choice is predicated on air permits and gas
turbine manufacturers specification - Initially most liquid fuel was either low sulfur
diesel or kerosene (500ppm max sulfur by weight) - Small aero derived jet packs ran kerosene
- Frame units usually consumed low sulfur diesel
- EPAs Clean Diesel Program mandated much lower
sulfur in road fuels, (from 500ppm max sulfur to
15ppm max sulfur) - Plan started to take effect mid 2006
- Refiners reduced production of 500ppm sulfur fuel
(80 of diesel output must be 15ppm max sulfur) - Many terminals shifted storage from low sulfur
diesel to ultra low sulfur diesel - Eventually all diesel, including off road diesel
will shift to 15ppm fuel
4Fuel Availability
- As suppliers/marketers shifted focus from LSD to
ULSD fuels power generators have faced shortages
of 500ppm fuel - Most cases 500ppm fuel was not available
- Forced generators to switch to ULSD fuels
- Forward timeline for sulfur reduction in NRLM
diesel (non-road locomotive marine) - 6/1/2012 Most LM diesel must meet 15ppm max
sulfur - 10/1/2014 Any wholesale purchasing/consumer
plants must be 15ppm max sulfur - 12/1/2014 All NR diesel must be 15ppm
- Essentially, at least in the northeast, there
will be two possible sulfur grades for
distillates - All diesels/on-road kerosene will be 15ppm max
sulfur - Heating oils which right now range from 2000ppm
to 5000ppm max sulfur - Two future outcomes are likely
- Elimination of 500ppm diesels will occur sooner
than deadline - Distillate heating oils will drop in sulfur
- There is a move among heating oil marketing
groups to move to an ultra low sulfur heating oil - Some states may also push for mandates for
inclusion of biofuels
5Product Specifications - Guidelines
- Generally speaking refiners of 15ppm distillates
are governed by ASTM D975-09 (the final 09
identifies the last year the specification was
modified.) - Combustion turbine manufacturers, power plants
with GTs, should be knowledgeable of both ASTM
D975-09 and ASTM D2880-03 - D2880-03 is the specification for gas turbine
fuel oils - D975-09 is mainly focused on the diesel product
specifications - D2880 is more concerned with product handling
contamination - D2880s No. 1 GT corresponds to kerosene as
defined by D975-09 - D2880s No. 2 GT corresponds to No. 2 diesel as
defined by D975-09
6Fuel Specifications Quality Concerns
- Sulfur levels
- Sulfur can precipitate out in the gas path
creating corrosive compounds - Should not be an issue anymore as fuel consumed
in turbines will contain a maximum of 15ppm
sulfur - Lubricity
- Fuel additives to meet minimum lubricity
standards - Approved tests have wide reproducibility results
- Viscosity
- Resistance to flow
- May be an issue with slippage through fuel
dividers pumps - Can be an issue if switching from 2 diesel to
1diesel or kerosene and a plants fuel system is
designed for a more viscous product (2 diesel)
7Fuel Specifications Quality Concerns
- Ash
- Can be evidence of formation of abrasive solids
or soluble metallic soaps (Basically non
petroleum constituents) - Can have a negative effect on buckets in the gas
path - Higher than normal ash levels can be an
indication of possible fuel contamination - Stability
- Today the distillate refining process is more
severe, (hydrocracking heavy fractions, catalytic
cracking, etc.), and negatively effects fuel
stability - Extended storage time, presence of oxygen, and
heat can also lead to instability - Unstable fuel is the enemy
- Premature filter plugging
- Deposits at high temperature injection points
during combustion - Additives can suspend further degradation but
does not improve fuel stability
8Fuel Specifications Changes to ASTM 975-09
- Biodiesel
- In 2009 the ASTM 975 diesel specification allows
up to 5 of biodiesel - All biodiesel blended in must meet ASTM 6751
- ASTM 6751 is the guiding specification for B100
(100) biodiesel - Since 5 or less biodiesel meets ASTM 975 there
is no requirement to report content - Once biodiesel is blended into fuel there is no
way to determine if the bio blend stock met the
ASTM 6751 specification - EN 14078 or ASTM D7371-07 can be run to determine
biodiesel - Uses Infrared Spectroscopy
- Identifies volume of Fatty Acid Methyl Esters
(FAME) in a middle distillate - Presence of Fatty Acid Ethyl Esters (FAEE) will
throw the test results off - Cannot be run in the field
- Takes about 20 minutes to obtain results in the
laboratory
9Biodiesel Quality Concerns
- Stability
- Like petroleum diesel unstable biodiesel can lead
to gum sediment formation - Stability is affected by biodiesel base stock
biodiesel - Different bio base stocks can affect stability
differently - Higher percentages of biodiesel, higher chance of
stability problems - 5 or less biodiesel should not adversely effect
stability - EN 14112 can be run to determine OSI, (Oil
Stability Index) - EN 14111 can be run to determine Iodine Index
- Iodine index measures the number of carbon double
bonds in the fatty acid - The number of double bonds are an indication of
the bio feed stock - Roughly the more double bonds, the less stable
the fuel stock - Can be a length of storage determinant
- Cold flow
- Biodiesels have higher cold flow properties
- Bio base stocks determine cold flow properties
10Delivery Logistics
- Acquiring the alternate fuel is half of the
solution to running delivering the fuel to the
plant is the other half of the equation - Understanding the delivery system
- Terminal configuration
- Capacity
- Inventory on hand
- Loading rack design
- Alternate terminal location
- Delivery
- Carrier
- Distance
- Reliability
11Supply Chain Bottlenecks
- Bottleneck factors
- Terminal configuration
- Carrier capacity
- Distance to plant
- Off loading capability
12Breaking Down Supply Chain Bottlenecks
- Terminal Configuration
- Loading positions for ULSD
- Configuration of loading rack
- Multiple products served through a bay can be a
limit on potential volume loaded - Carrier capacity
- Number of available trucks
- Dispatch reliability/efficiency
- Overall reliability
- Distance terminal to power plant
- Road(s) configuration
- Traffic congestion
- Average turn around time
13Breaking Down Supply Chain Bottlenecks contd
- Power plant configuration
- Number of off loading positions
- Stationary pump availibility
- Ease of ingress/egress
- Ability to pump out of tank into truck
- Length of hose required
- Hours of operation (for receiving fuel)
- Understanding the supply chain
- Evaluating bottlenecks allows one to estimate the
daily deliverable volume - Plant particulars allow one to determine daily
fuel requirement - Together they allow one to estimate reliance on
liquid fuel consumption
14Delivery Example 1
- Plant size 70mwh
- Plant type Combined cycle
- Liquid fuel ULSD
- Btu per gallon 125,000
- Overall gross heat rate 7,000 (on liquid fuel)
- Distance from terminal 50 miles
- Average round trip time 2.95 hours
- Hourly plant fuel burn 3,920
- Estimated trucks per 12 hour shift 3
- Hours run 8
- Total gallons burned 31,360
- Minimum trucks required 1
15Delivery Example 2
- Plant size 550 mwh
- Plant type Combined cycle
- Liquid fuel ULSD
- Btu per gallon 125,000
- Overall gross heat rate 7,000 (on liquid fuel)
- Distance from terminal 50 miles
- Average round trip time 2.95 hours
- Hourly plant fuel burn 30,800
- Estimated trucks per 12 hour shift 25
- Hours run 8
- Total gallons burned 246,400
- Minimum trucks required 8
16Selecting And Working With Suppliers
- Know your supplier
- Do they own or lease storage?
- How much storage do they have?
- Will they have sufficient fuel on hand and or a
backup supply source? - How is quality control handled?
- Does the supplier representative understand fuel
chemistry and quality control? - Do they do their own testing?
- What is their testing protocol?
- Do they understand the delivery requirements?
- Are they reliable?
- Does your representative understand power plant
operations?
17Conclusion
- A good supplier will understand power plant
operations power production/distribution - They will have a good understanding of combustion
turbines as well as the relationship between
natural gas oil consumption operations in these
plants - They will have a firm understanding of product
quality control - Provide adequate product testing
- Will be reliable
- On spec product
- Good delivery performance
- Remember its not just price!
18Sprague Owned Terminal Network
Spragues terminals hold over 300 million
gallons of liquid storage
19 20Appendix 1
21Appendix 2