DELAYED COKER UNIT (DCU)GROUP 9

Tarun Chadha (121) Hersh Kenkare (091)Ekta Poddar (087) Arnab Guha Mallik (074)Atul Sharma (075) Saurav Mishra (112)Surbhi Bhatia (119)

Introduction

Capacity Planning 2

1

3 Aggregate Planning

Scheduling 4

SUPPLY CHAIN MANAGEMENT 6

5 Advanced Statistical Process Control

7 Maintenance

Inventory Management 8

AGENDA

Broad Steps in DCU unit

Crude to AVU VR to DCU Distillation Heating

Coke formation

& extraction

• Fuel Gas• LPG• Naphta• LCGO• HCGO

Value added to otherwise low value heavy oils

Possible to process high sulfur crudes

Higher refinery margins

Benefits of DCU

Introduction

Significance of DCU

Whenever crude is processed, the heavy components cannot be broken down after a certain extent

The bottoms of Vacuum Distillation Unit is called Vacuum Residue (VR) and is around 20 % of crude processed

Earlier no technology was available to process it and it was simply used as fuel oil for internal consumption in the refinery

In 1960’s Delayed Coking process was developed to recover valuable middle distillates like petrol, gasoline, LPG from the VR

Batch cum continuous processThermal cracking process

Capacity Planning

Capacity Flexibility

Adjusting production levels

Switching between products

Throughput can be flexibly adjusted to balance flow with output of AVU

Limited flexibility (10%) of switching from HCGO to LCGO if demand for diesel increases

Present Capacity = 3 MMTPA (increased from 2.4 MMTPA in 2010)

Capacity management is done at refinery level and not unit level20 % of processed crude is VR; this is processed by DCU

Capacity design based on 8000 hours/year or 333 days/year (Best Operating Level)

Theoretical Capacity = 365 days/year

Capacity Utilization = 100%

Capacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

Aggregate Planning

PetroleumRefinery

State 1

State 2

State 3

State 4

State 5

State 6

The states around Panipat are demand centers for petroleum

Planning Department at Corporate Office of IOCL estimates demand of products for a period of 3 months. It calculates and procures required amount of crude oil. Software like RPMS and DRYA are used to determine optimum production levels at its 7 refineries

•Since IOCL is a PSU, the core team at IOCL follows a Level Strategy that maintains a stable workforce with stable work hours and adjusts inventory to meet demand

•The cycle time for crude oil was reduced from 24-18 hours at the IOCL refinery

•The maintenance team comprises of contract workers who work on chase strategy and more workers are hired to handle workload as a result of reduced cycle time

Capacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

Scheduling of Personnel

3 Officers per shift X 3 Shifts a Day X 7 days a week =63 1 Officer X 1 Shift per day X 6 days a week = 6No. of officers = 63/6 = 10.5 ~ 11 Officers

1 Panel Officer, 1 Shift-in-Charge, 1 Field-in-ChargeOfficers per Shift

Operators per Shift 7 Operators

7 Operators per shift X 3 Shifts a Day X 7 days a week =154 1 Operator X 1 Shift per day X 6 days a week = 6No. of officers = 154/6 = 25.55 ~ 26 Operators

Finite Loading Backward Scheduling

There is a detailed schedule of each activity being carried out and is based on forecasted demand

The output from the online analyzer is displayed to the Panel Officer who then takes corrective action

Pump Flow RateColumn ReactorHeater

Capacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

Scheduling of EquipmentCapacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

The only case of equipment scheduling is in the case of the reactors or coke drumsIn each block, one reactor (1A) is in “filling” mode while operations to extract coke from the filled reactor (1B) are carried outBatch Cycle time has been reduced to 18 hours from 24 hours to increase throughput from 2.4 MMTPA to 3 MMTPAAt the end of 18 hours, there is a switch between reactorsThis helps maintain continuity of the process

Liquid from Fractionator

Block 1

Reactor 1A

Reactor 1B

Block 2

Reactor 2A

Reactor 2B

Scheduling of EquipmentCapacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

Operation Time (hours)

Changeover 0.5

Steam Cooling 1.5

Water + Steam Cooling

1

Water Cooling 3.5

Draining 1

Preparation for coking

0.5

Cutting 4

Preparation for heating

1

Heating 5

• Equipment used for preparation and cutting for the “operating” reactor in both blocks is common

• Hence scheduling the batch process becomes critical to avoid wait time and queuing of equipment

• Rule of thumb is start operations on 2nd reactor after time “t”

• t = Cycle time / number of blocks• t = 18 / 2 = 9 hours

Advanced Statistical Process ControlCapacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

Given the product

parameters APC

uses the generated

algorithm to set

points to upstream

equipment

The APC system generates an

algorithm based on historic data

Engineers Enter Desired Product

Parameters into the APC system

Supply Chain Management

LPG –> Bottling

IOCL Oil Pipelines & StationsIOCL PR AVU

IOCL PR DCU

Kandla Port, Gujarat Crude Oil Import

Fuel Gas –> Internal Use

Naphthalene –> Blending Pool

LCGO -> DHDT -> Diesel Pool

Petroleum Coke Storage Yard

Conveyor Belts

Trucks

Customers

Capacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

• As Petroleum Coke is a dry product there are losses due to blowing wind during movement & storage.

• These losses are estimated to be 4-5% of the total production.• Water Sprinkler Systems at storage yard reduce these losses to about 1%. • These sprinklers are cheap to install & operate resulting in huge savings through

reduced pet-coke losses. These savings are estimated to be about Rs 29 Crores per year.

Total Pet-Coke Production (tonnes)

Price ( Rs/Ton)

Estimated Loss (%)

Total Loss (Rs ‘000)

Without Sprinklers

10,00,000 7400 5 3,70,000

With Sprinklers 10,00,000 7400 1 74,000

Water Sprinkler System – Petroleum Coke

Capacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

Capacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

Maintenance

Preventive

Pump wiring, windings, bearings every six months

Greasing, lubrication, oil

replacement, oil burners cleaning,

coke cutting system

Predictive

Change in frequency of Pump vibration,

signs of failure

Breakdown

Maintenance

Capacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

A major role of Maintenance is Planning and control.

In certain cases maintenance of an equipment needs more than one department. Hand over sequence is determined by production.

Multi-Department Coordination is the responsibility of production

Capacity planning

Aggregate Planning Scheduling APC SCM Maintenanc

e Inventory

Inventory Management

INPUT SIDE

4 feed tanks to store the crude oilRule of thumb < 10 days inventorySafety stock = 2 days inventory

PRODUCT SIDE

No storage required except for pet coke which has a storage yard

Other products directly transferred to units

THANK YOU