AL - ABBAS ENERGY LIMITED



SSJD BIOENERGY LIMITED

REQUEST FOR PROPOSAL

FOR

ENGINEERING, SUPPLY, ERECTION AND COMMISSIONING

OF

12MW BIOMASS POWER PROJECT

JANUARY – 2011

INDEX

Page No.

SECTION – 1 INSTRUCTION TO CONTRACTORS …………………………………..….… 02

SECTION – 2 GENERAL CONDITIONS OF CONTRACT …………………………..…….… 07

SECTION – 3 PROJECT SITE INFORMATION ……………………………………….…..…15

SECTION – 4 TECHNICAL REQUIREMENT AND DESIGN CONSIDERATIONS ...…….….. 17

SECTION – 4.1 TECHNOLOGY AND PLANT CONFIGURATION ...……………………….….17

SECTION – 4.2 STEAM BOILER & AUXILIARIES …………………………………………..….…17

SECTION – 4.3 STEAM TURBINE – GENERATOR & AUXILIARIES ………………………… 31

SECTION – 4.4 BALANCE OF THE PLANT EQUIPMENT (MECHANICAL) ……..………… 41

SECTION – 4.5 BALANCE OF THE PLANT EQUIPMENT (ELECTRICAL) ………………….. 56

SECTION – 4.6 INSTRUMENTATION & CONTROL SYSTEM (I&C)………………………… 67

SECTION – 4.7 GUARANTEES DATA ………………………………………………………...…… 73

SECTION – 5 CIVIL & STRUCTURAL WORKS ………………………………………..……… 75

SECTION – 6 COMMISSIONING AND TESTING …………………………………….……… 79

ANNEXURES - ……………………....... 84- 86

SECTION – 1: INSTRUCTIONS TO CONTRACTORS

Preamble

SSJD Bioenergy Limited, (“the Owner”) with its principal office located at Plot # 10-11, Hassan Ali Street, Karachi-Pakistan, under the Alternate Energy Policy, Alternate Energy Development Board (AEDB), Government of Pakistan, intend to construct and operate a power plant on multiple biomass of approximately 12MW in district Mirpurkhas, province of Sindh. The net electrical power will be exported to the nearest grid of Hyderabad Electric Supply Company (HESCO) electrical network.

Invitation for Proposals

The Owner is inviting proposal on turn key basis including civil works from the interested EPC Contractors for designing, manufacturing, furnishing, insuring, delivering to site, storing at site, erecting, commissioning, operating on a trial basis and testing of the equipments and materials for 12MW power generating unit (herein after called “the Project”).

The plant technical description and design considerations with scope of works contained in this document shall be a guideline to enable the Contractors to prepare and submit their proposal complete in all respect for a functional plant. Prior to preparation of this RFP, the Owner has conducted the preliminary site survey, assessed the site conditions, availability of land and water supply source for development of the project. A Letter of Interest (LOI) has been obtained from the relevant agency of the Government of Pakistan i.e. Alternate Energy Development Board (AEDB) to undertake the project on fast track.

The Contractors are advised in their own interest to have full understanding of the RFP, plant design consideration, specification of equipments, scope of works that are necessary for a complete functional biomass power plant prior to submission of proposal. Any explanation or clarification desired by the Contractors regarding the meaning or interpretation of the RFP may be requested by e-mailing to the Owner’s designated point of contact. If any explanation or interpretation is necessarily required by Contractors, it may be provided by the Owner subject to availability on best effort basis. No clarification or lack thereof will be a cause of contention at the time of submission of proposal or if and when the Contract is awarded.

An effort has been made to provide sufficient information/data for design, scope of works, services, materials, plant equipment, building and structure, and other essential facilities etc, described in the RFP. Nevertheless, the Bidder will solely be responsible for examination of its completeness and comply with all instructions. Failure to furnish complete information, or submission of a proposal not conforming to RFP, and found substantially non responsive may be rejected.

The Contractors shall submit a firm proposal for the entire EPC work, however the Owner reserve the rights to bifurcate the Contract at the time of contract award for, i)Supply Contract for supply of equipment and machinery together with all necessary items, ii)Service Contract for engineering, supervision, installation, commissioning and testing..

Owner's Rights to Accept any Proposal and to Reject Any or All Proposals

The Owner reserve the rights to accept or reject complete proposal or part of the proposal at any stage without assigning any reasons thereof whatsoever, without incurring any liability to the Contractors, or any obligation to inform the Contractors of the reasons for such actions. No conditional proposal shall be accepted.

Submission of Proposal

The firm technical and commercial proposal with two identical copies are required to be delivered in person or sent by completent courier services or by registered mail at the address of the Owner or by email, on or before the expiry of twenty (20) days period from the receipt of RFP.

The Contractor will submit the Commercial part along with the proposal and the EPC cost break down sheet.

To be addressed to Owner at the following address:

The SSJD Bioenergy Limited,

Plot # 10-11, Hassan Ali Street,

Off. I.I. Chundrigar Road, Karachi, 74000.

Phone: (92-21) 32631017

Cell # 0314 - 2357878

akhlaq@

Attention: Mr. Akhlaq Ullah

Vice President (Technologies)

SSJD Bioenergy Limited

Language

The proposal and all correspondence shall be written in English language.

Prices

The Contractors will quote firm EPC prices in detail breakdown as per format provided in Annexure, which shall remain valid up to the validity period. Proposal with escalable prices will be rejected as non-responsive. The quoted prices shall include the cost for entire scope as per the technical requirements and specifications provided in this document considering all items necessary for a complete functional plant.

Contractors Address

The Contractor shall give its full and proper address at which correspondence may be sent (electronically and by mail) and all notices may be served in connection with this RFP.

Clarification of Proposals

To assist in evaluation of the Proposals, the Owner may, at its sole discretion, require a Contractor to clarify its proposal. The request for clarification and Contractor’s response shall be in writing and no change in the price or substance of the proposal will be sought, offered or permitted.

Evaluation of Proposals

Owner will, in private, undertake a detailed examination and evaluation of proposals. To assist in the examination, and evaluation of proposals, the Owner may ask Contractors for clarification of their proposal, including breakdowns of quoted price. The Owner does not bind itself to award the Contract to lowest or any Contractor, but will take into consideration the quoted price and such other factors as are relevant for complete functional plant. After the Owner is satisfied with the proposal of a Contractor, the Owner will start clarifications/negotiation meetings.

Notification of Award

Following the proposals evaluation process the Owner will hold detailed discussion and make all good efforts to settle all technical, financial, and commercial matters to meet lenders requirement, and Power Purchaser that are necessary to incorporate in the Contract. Should such discussion not lead to signing of the contract between the Owner and the Contractor for any reason whatsoever, the Owner shall have all rights to reject such Contractor without any liability of any nature whatsoever. In case negotiations with one Contractor does not culminate in finalizing the contract for any reason, the Owner may, at its sole discretion, invite any other Contractor for negotiations or annul the process at any stage without any liability whatsoever.

The Owner shall at all time have the option and discretion to reject any or all proposals without assigning any reason thereof and without any liability whatsoever. The Contractor (s) shall not be entitled to claim any costs, charges, expenses or damages of any nature by reason of rejection of proposal (s) or annulment of the entire Bidding process.

Decisions conveyed by Owner in respect of its evaluation of the proposals, Award of Contract to a Contractor shall be binding. The Owner decision, in any manner whatsoever, shall not be challenged.

Signing of Contract

Upon finalization of the Contract document, the Contractor will be required to attend the office of the Owner within one (1) week from the date of receipt of notice to Award the Contract, with the power of attorney for signing the Contract Agreement in the form set out in the Contract documents with alterations or additions thereto as may have been mutually agreed upon.

Supplementary Information

(1) The following supplementary information shall be submitted with each copy of the proposal.

(a) An organization chart of the minimum supervisory staff the Contractor proposes to employ on Facility Site for the performance of the EPC Contract. This chart shall also show the distribution of work for each member of the staff and their respective duration of work at plant site.

(b) A list with complete description of all items of installation equipment and plant proposed to be used in carrying out the EPC Works, indicating the make, type and capacity of all equipment which shall be in complete detail to demonstrate fully that the equipment will meet all the requirements for carrying out the work according to specifications, drawings and the time schedule.

SECTION – 2: GENERAL CONDITIONS OF CONTRACT

General Instruction

The designing of the power plant on multiple biomass shall based on best steam power cycle, current state of-the-art technology, current industry trend, highly reliable equipments with built in redundancy and design margin and safety against unplanned outages, all equipments suitable for a thirty (30) years life period.

The Contractor is required to follow international designed approach to engineering and construction, all equipment to be designed and manufactured in accordance with the international applicable codes and standards, state regulations, and Pakistan Standards for environmental control are all adhered to in design, and complies with the emission levels during operation.

The plant design and steam power cycle shall be engineered for optimum thermal efficiency adopting high pressure and high temperature steam parameters, and design conditions specified in this document.

Contract Agreement

The Contractor shall enter into and execute a Contract Agreement to be prepared and submitted by the Contractor, however the Owner will have the full rights to review and negotiate the terms of the Contract documents and sign the Contract Agreement.

Compliance with Contract

Equipment, materials and services shall be complete in all respects and in strict accordance with the contract. The Contractor shall comply with the codes and standards specified in the Contract Documents which shall be latest revisions of international standards/codes.

Commercial Proposal

The Contractor shall submit commercial proposal in reasonable detail as per Annexure provided in this RFP.

Taxes

The Contractor shall be responsible for all Contractor’s corporate taxes payable under the laws of Pakistan. The tax payable in Pakistan will be in local currency.

Import Duties

Import duties, import permits fees and other charges applicable on import of equipment and materials will be the responsibility of and will be paid by the Owner for all items imported under the Contract. The freight and marine insurance cost on all equipment and materials shall be included in the price quoted by the Contractor.

Transportation and Insurance

The Contractor shall obtain all risk insurance for marine and inland transportation (in Pakistan and abroad) including coverage for custom duties without war risk to cover all loss and damage from Contractor’s (Manufacturer’s) warehouse to the site for imported material and equipment.

For the inland transportation of equipment and materials, the Contractor shall arrange and pay for transportation insurance with National Insurance Corporation or any other insurance company of Pakistan which shall cover all risks, i.e. fire, flood, theft, damage due to the exposure, breakages, loss in transit, or through riots, strikes, civil commotion, etc. from the manufacturer’s plant warehouse up to the site, plus ninety (90) days of storage after arrival of each consignment at site.

Subsequent to the obtaining of the custom clearance of the consignments at the sea port by the Owner, timely transportation of the said consignments to the site will be the responsibility of the Contractor. The Owner will not be liable for any demurrage on this account.

Sub Contractors

Except where otherwise provided by the Contract, the Contractor shall not appoint any sub-contractor for any part of the works without the prior written approval of the Owner.

Co-ordination with other Contractors

The Owner reserves the right to let other contractors in connection with the part of the works of this project. The Contractor shall provide reasonable opportunity for the storage of their materials and the execution of their works simultaneously, shall co-ordinate his work with their. On failure to meet this requirement the contractor shall be liable for any resulting damage and expenditure.

Performance Security

The Contractor shall within fifteen (15) days from the date of the issuance of Notice of Award of the Contract, furnish at his cost Performance Security in a sum of 15% of the total Contract price as a guarantee for the due and faithful performance of the Contract.

Guarantee for Material, Workmanship and Performance

The Contractor shall guarantee that the materials and workmanship incorporated into the project are brand new and the best of their respective kinds for the service intended and that all items will be free from inherent defects in design, workmanship and materials, and that all equipment in its several parts will operate successfully at all capacities up to and including the maximum specified load, specified noise levels, heating, stressing of parts, wear and vibration, and that an ample factor of safety is included in every design.

The Contractor’s liability shall not be limited only to the replacement of any defective part or equipment that may develop in the equipment or material of his own work or manufacture or those of his sub-contractor under power use and arising solely from faulty design, materials, or workmanship during the guarantee period but he shall also be responsible for replacement, erection and commissioning of such equipment/material which is damaged due to any mishap caused as a result of defective materials/equipment or inadequate workmanship of the Contractor.

Period and Extent of Guarantee

The period of guarantee on all equipment, material and workmanship shall be 12 Months starting from the effective date of provisional Acceptance by the Owner or as expressly stated elsewhere in the contract documents, including …

If during the guarantee period the services of the Contractor’s personnel are required for the rectification or replacement of any defective part of the work due to defective material, design or workmanship, such services shall be made available by the Contractor without charge to the Owner.

Qualification of Equipment/Manufacturers

Manufacturers for all major equipment shall be of international repute, shall have had at least 10 years previous experience in design, manufacture and installation of all major items of equipment and materials selected and proposed for the project in the proposal, and shall have built and placed in successful services not less than three similar size of unit prior to submission of proposal.

Inspection and Testing During Manufacture

The Owner will be entitled at all times during manufacturing to inspect examine and test in the manufacturer works the materials workmanship progress of manufacture and performance of all equipment and materials to be supplied under this Contract. All cost towards inspection by the owner authorized representative like cost of air fare, cost of accommodation; out of pocket expenses shall be borne by the Contractor. Provision of at least three (3) trips and fifteen (15) man-days is considered included in the Contract Price for such inspection.

Performance Guarantee Liquidated Damages

If the equipment is unable to ultimately meet its performance guarantees specified in the Contract document as set forth by the Contractor in the Contract Agreement, after the Contractor he has taken all steps to correct the deficiencies, the Contractor will be assessed liquidated damages in accordance with the provision of the Contract. The liquidated damages payable in respect of deficiencies in performance and delay in commissioning shall not exceed 15% of the Contract price.

Note: The Contractor must understand that timely completion of the Project and the performance guarantee level set forth in the Contract Agreement shall be complied in any case for successful operation of the plant over the term of Power Purchase Agreement (PPA).

Familiarization of Owner’s Personal (training)

The proposal price shall include on job training program of Owner’s personal in all aspects of plant operation and maintenance from the beginning of erection until provisional taking over of the plant. The program shall also include familiarization of the Owner’s personal in Contractor’s works and at works of Contractor’s sub suppliers.

The O&M personal required for safe and efficient plant operation and adequate maintenance of various types of equipments installed will be provided by the Owner in accordance with the recommendations to be made by the Contractor.

The O&M personal deployed are experienced and qualified for senior and middle levels and fresh graduates from engineering institutes. All persons will have to be trained through different training programs in similar operating plants etc., it is to be ensured that the persons are experienced and trained at the time of commissioning of the plant.

The training proposal should consist of several courses that are generally applied to the power plant personal, special training manuals in English describing all major plant system, maintenance procedures etc. shall be prepared for all trainees. The Contractor shall develop a comprehensive program for submission to the Owner for review and implementation.

About SSJD Group

SSJD group will be the leading independent energy supplier on indigenous fuel and renewable energy in Pakistan. Its aim is providing energy to Pakistan and helping the country to overcome the power crisis. The main focus of SSJD Bioenergy Ltd. is to generate electrical power from alternate energy sources and limit the dependency on foreign fuel resources. Its management team comprises of local and foreign professionals having vast experience of working in the power sector particularly in developing power projects on all kind of technologies. The professional team has also developed several IPP projects in Pakistan and abroad.

The group being principal sponsor of SSJD Bioenergy Limited has recently commissioned Pakistan’s first private coal-fired power plant of 15 MW and supplying electricity to Karachi Electric Supply Company (KESC) under Sale and Purchase Agreement.

SSJD Group has established a special purpose Company namely SSJD Bioenergy Ltd. (the “Company”) incorporated in 2010 under the laws of Pakistan as a Private Limited Company. The core activity of the Company is to install several multiple biomass based power projects through out Pakistan, produce and sell electricity to the respective distribution companies of the country.

The Company decided to construct its first biomass power generation facility on multiple biomass fuel in district Mirpurkhas, Province of Sindh, and intended to set up a 12MW power plant near Al-Abbas Sugar Mills on fast track basis.

Multiple biomass fuel (bagasse, rice husk, and other biomass) will be consumed as per requirement of the plant without any limitation of interchangeability. The proposed power plant will utilize maximum bagasse as main fuel available from sugar mills located within 50 km radius of the plant Site, and also the other biomass such as rice husk and cotton stalk abundantly available in the area.

About Hyderabad Electric Supply Company (HESCO)

HESCO is responsible for supply of electricity and operating the electrical network in the area of Sindh province except Karachi the largest city of Pakistan which is served by a private utility company. Currently about 1300MW power is being supplied to its consumers through the network. Power demand of Sindh province has a severe short fall in peak power demand as well as energy availability. This shortfall in peak power demand and energy demand will widen further in the subsequent years. The network thus requires a substantial addition in power generation capacity to meet the power demand of its rapidly growing industrial, agricultural and other sectors. Purchase of power from this plant will provide economical, eco-friendly power and contribute someway to bridge the gap between power supply and demand.

SECTION – 3: PROJECT SITE INFORMATION

Some information details of the site selected for biomass power plant is given in tabular form;

|Site |Project Site is located near Mirwah Gorchani town, Dist. Mirpurkhas, Province of |

| |Sindh, adjacent to Al-Abbas Sugar Mills. |

|Approach to Site | |

|Nearest town |Mirwah Gorchani Town (2 km from Site). |

|Nearest Grid |132 KV Mirwah Gorchani Grid (3 km from Site) |

|Nearest Railway Station |Mirpurkhas Railway Station: (28 km from Site) |

|Nearest Airport |Karachi, Port City (260 km from Site) |

|Access Roads |Super Highway up to Hyderabad, 145 km from Karachi, and then via the metallic road up|

| |to Site. Plant is located off the main road on way to Digri Town. |

| |All equipment and construction materials can easily be transported to Site by road. |

|Site Elevation |100.0 m above mean sea level |

|Geographical Location |Latitude : 69°,15’46* N |

| |Longitude : 25°,15’48* E |

|Climate |Tropical -Hot -Humid |

|Seismic Data |Zone-I |

|Seismic Intensity |Moderate |

|Metrological Data | |

|Ambient Temperature (Dry Bulb) | |

|a) Extreme Maximum |48 °C |

|b) Extreme Minimum |5°C |

|c) Average max. |34.5°C |

|d) Average min. |12°C |

|e) Annual Average |30°C |

|f) Design Wet bulb Temp. |27.5°C |

|Relative Humidity | |

|a) Maximum during monsoon (June to October)|84 % |

|b) Minimum Humidity during summer (February|28 % |

|to May) | |

|c) Design Relative Humidity |60 % |

|Rainfall | |

|a) Average per annum |200 mm |

|b) Tropical monsoon |June to October |

|Wind Velocity & Pressure | |

|a) Design Wind Speed |120 km/hr |

|Area of Land |16 acre |

|Soil Condition |EPC Contractor will carry out itself soil investigation for designing of civil |

| |structures and buildings. |

|Safe bearing capacity |14.6 t/m² (from data of adjacent sugar mills) |

|Sub soil water |Present |

|Source of water for construction |From existing water course of land |

|Nearest source of construction material |Stone clips - sand & bricks – Mirpurkhas city |

| |Cement - Direct from the factory |

| |Bricks - Hyderabad/Mirpurkhas city |

|Power supply during construction |Separate AC 220 volt, 3 phase connection from HESCO, or self generation by mobile |

| |Gen-set. |

SECTION – 4: TECHNICAL REQUIREMENT AND DESIGN CONSIDERATIONS

4.1– TECHNOLOGY AND PLANT CONFIGURATION

The power generation facility shall be developed on conventional steam turbine technology designed on multiple biomass fuel. The plant shall comprise of one (1) no. steam boiler with all auxiliaries including efficient flue gas cleaning and handling system, one (1) no. turbo-generator set with all accessories having a nominal gross capacity of 12MW. Balance of the plant equipment shall mainly comprise of steam condensing unit, feed heaters, multi cell cooling tower, circulating water, water treatment unit, and complete balance of mechanical and electrical system in all respect for a functional power plant.

4.2– STEAM BOILER & AUXILIARIES

The design, manufacturing, supply and installation of boiler on biomass shall be complete in all respects with accessories for safe and reliable operation for firing 100% bagasse as main fuel, and rice husk mix in the ratio of 80% bagasse – 20% rice husk, or 20% bagasse – 80% rice husk, and other biomass such as sugar cane leaf, rice straw, cotton stalk etc. The boiler shall be approximately 50tph evaporation capacity at pressure of 90 ±3% bar and temperature of 530 ±2% °C at superheater outlet and feed water temperature at economizer inlet depending on the design of steam power cycle to achieve final feed water temperature, but not less than 190°C.

The boiler will be single drum with natural circulation balanced draft, and water tube type suitable for outdoor installation. The drum will be fitted with all internals and attachments, nozzle connections and drum suspension/support. The boiler may be top or bottom support design, and provided with all supporting steel structure and platform and galleries staircases. Adequate weather protection is to be provided for instruments and operating personnel. Necessary insulation and cladding of boiler and ducting to limit outside surface temperature to a safe value will be provided.

Super heater section shall be of vertical convection and radiation type and suitably designed to maintain steam temperature of ≥ 530°C over the control range of 50% to 100% boiler load. For steam temperature control, attemperator with provision for spraying water tapped off from feed water piping shall be provided.

Tubular carbon steel air pre-heater (with gas flow through tubes) to pre-heat the combustion air complete with casing and support will be provided. Corten steel tubes will be provided at the low temperature block to avoid cold end corrosion during boiler start up and part load operation. Air-heater is also provided with air side bypass with motorized damper.

Adequate nos. of heating surface cleaning soot blowers with control shall be provided for superheater, evaporator, economizer and air preheater.

Steel structure and platform for boiler, economizer and air preheater. Grating and handrail platform. All gratings of stairways and platforms shall be galvanized; all structural steel for stairways and platforms as well as handrails, kicking plates and ladders will be painted. For all system equipment that are operated manually, either in normal operation or in the event of incidents/accidents, passages will have an inside height of 2.10 m. frequently used stairways, walkways, and escape routes will be 1m wide.

Biomass Fuel Specification

The analysis of biomass available for firing in the boiler is provided in the table below (for information only)

|Ultimate Analysis |Unit |Bagasse |Rice Husk |Cotton Stalk |

|Carbon |% |23.25 |36.70 |39.26 |

|Hydrogen |% |3.25 |03.00 |5.23 |

|Nitrogen |% |0.00 |00.40 |1.68 |

|Sulphur |% |0.00 |00.08 |0.00 |

|Moisture |% |50.00 |10.00 |10.00 |

|Ash |% |1.50 |18.80 |6.01 |

|Oxygen |% |22.00 |31.02 |37.82 |

|GCV |kcal/kg |2272 |3350 |3925 |

Design Fuel Mix Specification

The design fuel mix specification is provided in the table below.

|Mix 1: 80% Bagasse / 20% Rice husk |

|LHV |kcal/kg |1887 |

|Moisture |weight - % |46.5 |

|Ash Content |weight - % |2.3 |

|Mix 2: 80% Rice Husk / 20% Bagasse |

|LHV |kcal/kg |3205 |

|Moisture |weight - % |12.2 |

|Ash Content |weight - % |12.5 |

Biomass Handling – Storage System

The dry biomass storage shed shall be constructed for at least 3 days, RCC construction, steel roofing, open from two ends for movement of truck dumping, shall have biomass storage transfer conveyor with under ground hopper.

The design of biomass conveying system from dry biomass shed to the boiler bunker, fuel feed system including biomass fuel discharging system shall be designed for 20tph biomass handling.

Biomass Feeding System

The fuel feeding system may consist of arrangement to fire bagasse and/or rice husk fuel mix in the ratio specified above.

Fuel feeding system may comprise of nos. fuel dosing silos (15 minutes storage each) at the inlet of rotary drum feeder equipped with variable frequency drive motors, screw feeders with constant speed drives, pneumatic distributors, and rotary dampers with motor and necessary support structure, motorized isolation gates at the inlet of connecting chutes as per the respective design of the boiler manufacturer.

Furnace Draft System

Furnace draft system shall be designed to ensure a balanced draft with sub atmospheric pressure conditions in the furnace. The system to consist of:

1 x 100% (with 30% excess air) radial, backward curved, simply supported Forced Draft (FD) fans with variable speed drive motors and pneumatic power cylinder operated control mechanism through IGV, necessary base plates, foundation bolts, couplings, bird screen etc. Grease lubrication system for fans bearings.

1 x 100% radial, backward curved, simply supported Induced Draft (ID) fans with variable speed drive motors and pneumatic power cylinder operated control mechanism, necessary base plates, foundation bolts, coupling etc. Blades will be provided with replacement wear liners/hard facing. Grease lubrication system for fans bearings.

2 x 60% radial, backward curved, simply supported Secondary Air (SA) fan with motors suitable for variable frequency drives and pneumatic power cylinder operated control mechanism, necessary base plates, foundation bolts, coupling etc. Grease lubrication system for fans bearings.

Manually operated isolating damper at the outlet of FD, SA, and ID fans shall be provided.

Necessary air and flue gas ducting with required stiffeners, expansion joints, guide vanes, wherever required, dampers, insulation, cladding and supports. Expansion joints in flue gas ducting and hot air ducting will be of carbon steel. Non metallic bellows will be provided for the cold air ducting and in gas ducting to economizer.

Flue gas cleaning and handling system, ash silos and unloading system shall be designed for maximum ash content of the biomass.

Flue Gas Cleaning and Ash Handling System

Bagasse has maximum 2% ash while rice husk has maximum 18% ash.

Assume that during operation rice husk and bagasse blended in the ratio of 80: 20 will be fired, estimate the maximum ash generated for system design.

The system shall be such that bed ash generated due to combustion of bagasse/rice husk in the boiler is collected in front bed ash hopper and dropped on water submerged belt conveyor which will carry wet ash to the elevated silo. Ash from fine bed ash hoppers will be conveyed by screw conveyor and will be directed to bed ash submerged conveyors. This submerged conveyor will transfer wet ash to next conveyor which will convey ash to the discharge storage area, from where the ash to be removed by trailer/truck for further transportation.

Fly ash system design will be sized to handle 90% of the ash produced. The fly ash system shall comprise of flue gas cleaning system either installing ESP or bag filters, dry collection of fly ash shall be through vacuum system and to be discharged to the main fly ash conveyor or independent silos. The silos shall be sized for capacity to store approximate three (3) shift fly ash produced in worst condition. Fly ash collected in various economizer hoppers, air heater hoppers and ESP / bag filter hoppers is conveyed through vacuum conveying system to fly ash silos. Fly ash collected in ash silos will be unloaded into trucks after humidification through dust conditioner and can be transported to cement manufacturing plant or brick manufacturing plant or to ash disposal yard as the case may be.

Steam Piping

Boiler steam piping consisting of all interconnecting piping between the economizer inlet stop valve and the super heater outlet header etc. shall be provided. The design of the piping system shall be based on the international standard. The piping shall be properly supported and provided with necessary tapping for instruments. Necessary supporting materials to support the piping shall be supplied. The correct location of hangers and supports shall be considered for the flexibility analysis. Suitable expansion loops, restraints and anchors shall be provided to limit the stresses within the allowable values.

The material for the piping and fitting shall be properly selected for various services in the boiler integral piping. All integral piping shall be provided with valves, fittings, drains and vents, safety valves, exhaust piping, start-up vent with silencer, blow down system etc. Proper sampling facility shall be provided for feed water, super heated steam and blow down water. The system for sampling shall be complete in all respect for monitoring the satisfactory operation of the boiler.

The steam from the superheater outlet of the boiler will be conveyed through special alloy steel piping to a steam pipe of turbine-generator set.

Adequate stop valves, non return valves, drain valves; traps etc. shall be suitably placed in the piping and header. The piping shall be with necessary supports, hangers, etc. Steam flow meter shall be provided to measure the flow of steam from the boiler.

Feed Water Pumps

Two (2) 100% capacity Boiler Feed Pumps (multistage, barrel casing, centrifugal ring section type) with variable speed drive motors and accessories viz. base plates, coupling, coupling guard, automatic recirculation control valves, piping, suction strainer, suction manifolds, balancing leak off lines, foundation bolts, mechanical seals and lift off devices. The pumps will have their suction from the deaerator and deliver the feed water to the boilers, each pump will be provided with a self-contained forced lubricating oil system for supplying oil to the bearings, couplings etc.

Feed Water Control Station shall consist of 1 x 100% pneumatically operated control valve, 1 x 30% pneumatically operated start up valve and 1 x 100% motor operated bypass valve. Motor or manually operated isolating valves for control valves shall be provided, drain valves as required.

Accessories

One (1) no. continuous blow down (CBD) tank and one (1) no. intermittent blow down (IBD) tank for collecting the continuous and intermittent blow down from the boiler with necessary drain and vent piping, drain valves, level gauges, level control valve including motorized blow down valves, flash steam from CBD tank to deaerator.

Chemical dosing system (mounted on individual skids) with SS mixing tanks, motorized agitators, plunger type pumps, SS piping, valves and fittings. Dosing system will include 2 x 100% dosing pumps, one number SS mixing tank with motorized agitator, SS dosing piping up to steam drum. Dosing system will include 2 x 100% dosing pumps, one number SS mixing tank with motorized agitator, SS dosing piping up to deaerator outlet feed water piping.

Safety Valves

Boiler to be equipped with necessary valves, mountings and fittings including spring loaded safety valves (total 3 nos.) and remote water level indicator, motor operated startup vent valve with motorized isolation valve and one (1) no. electromatic safety valve. Silencers for superheater safety valves and start up vent valve will be provided to limit noise level to 90 dBA at 1 meter distance.

Drains System

Drains should be provided for all pressure stages of the boiler. These drains should be designed to be sufficient for normal operation of the boiler, as well as startup, steady loads up to 100% MCR and shutdown of the boiler.

All drains and vents should be routed separately to central stations, cascading lines to other pressure stages will not be used to avoid transferring impurities and high mineral concentrations into a lower pressure stage. The nominal diameter for the drain and vent system valves standardized to min. (25mm) or larger.

All drains required for operation of the boiler including those associated with the steam drum level gauges, level alarms and those from each of the economizer and evaporator bank manifolds will be routed to the blow down vessel.

Actuators shall be mounted on all valves which have to be operated during startup, shutdown and normal operation of the boiler. All drain control valves used for normal operation shall be doubling isolated, and are to be installed in the immediate vicinity of the flash tank or its inlet header.

Boiler Stack

The stack should be designed and constructed at site for at least 50 m height and manufactured in carbon steel with weather resistance coating.

Welds on Pressure Parts

All pressure parts welds are to be mandatory examination according to ASME code preferably 100% radiographic test.

Codes and Standards

The boiler shall be designed and manufactured in accordance with ASME Boiler and Pressure Vessel Code (BPVC) or Equivalent code. For the design of electric motors IEC standard or Equivalent shall be followed.

Painting

All steel components which are not provided with thermal insulation and are not galvanized will be given several coats of paint. The colors of the top coats will be agreed upon with the Owner.

Design Conditions

Particulars Units Data

Steam evaporation at superheater outlet tph 50

Peak evaporation tph 55

Steam pressure at superheater outlet bar (a) 90 ±3%

Steam temperature at superheater outlet °C 530 ±2%

Steam temperature control range % 50-100% MCR

Feed water temperature at economizer °C 180-200

inlet

Excess air % 20 - 30

Flue gas temperature °C ................
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