Connecticut Resources Recovery Authority, Mid-Connecticut Waste-to-Energy Facility

Posted on July 29, 2010

Client: Connecticut Resources Recovery Authority
Location: Hartford, CT
Project Type: Mid-Connecticut Waste-to-Energy Facility

Project Description

CRRA-facility_webThe Connecticut Resources Recovery Authority (“CRRA”) is the owner of the Mid-Connecticut Waste-To-Energy Facility (“the Facility”). The Facility consists of a Waste Processing Facility (“WPF”), a Power Block Facility (“PBF”), and an Electrical Generation Facility (“EGF”). The Facility began operations in 1987.

The WPF includes two (2) processing lines for the preparation of Refuse Derived Fuel (“RDF”) from raw waste. Each processing line operates at approximately 100 tons per hour. The WPF includes a scalehouse, vehicle maneuvering, and waste storage areas with Municipal Solid Waste (“MSW”) feed conveyors and picking stations, an MSW processing area with primary and secondary shredding, ferrous separation and ferrous and residue loadout areas, and an RDF storage facility. The two (2) processing lines produce the required RDF for the existing PBF boilers.

The PBF includes three (3) Waterwall RDF boilers. Each boiler is a CE Systems Model #VU-40, spreader stoker type with traveling grate. Each boiler has a permitted capacity to combust up to 326 million btu’s per hour of RDF based on 28.15 tons per
hour at a heating value of 5,785 btu’s per pound. Each boiler is also permitted to combust up to 9.85 tons per hour of coal and 20,000 cubic feet per hour of natural gas and may burn any combination of these fuels.

The EGF includes Turbine Generator #5 and Turbine Generator #6. Each turbine generator system includes a General Electric 45,000 kilowatt-condensing turbine with a design steam inlet temperature of 825 degrees F and pressure of 850 psig. Each steam turbine drives a General Electric 50,000 kva, 3,600-rpm, 11,500-volt generator. The EGF also shares portions of the above-listed systems with the PBF.

The CRRA also owns the Mid Connecticut Materials Recovery Facility (“MRF”). The MRF is privately operated under a service agreement between the private operator and the CRRA. The Facility processes single and dual stream recyclables originating from communities within CRRA’s service area.

D&B Engineers and Architects, P.C. (“D&B”) has carried out four (4) major assignments for CRRA regarding the Facility and the MRF:

  • In the first assignment, during 2005, CRRA sought to conduct technical and economic analyses of the feasibility of expanding the Facility. The need for the analyses was based upon two factors: (1) additional solid waste processing capacity was needed in order to match the region’s waste generation rates and expected growth and (2) the Facility’s waste processing (WPF) and combustion systems (PBF) were undersized in comparison to its power generation capacity (EGF).
  • The second assignment, during 2008, addressed the efficiency and cost of the operation of the WPF, under its contract operator. After several years of poor performance, CRRA has undertaken a program to increase the production and availability of the WPF while reducing costs.
  • The third assignment, during 2009, addressed the future of the RRF following the expiration of the Service Agreement with Covanta in 2012. D&B was assigned to conduct technical and economic assessments of several options for the future of the RRF. These options ranged from continued operation as-is, to expansion and shutdown
  • In the fourth assignment, during 2012, D&B carried out an independent audit of the MRF and prepared a Comprehensive Audit Report. The purpose of the Audit Report was to assess the physical condition of building and site features; to assess and report upon the operating condition and performance of the material processes, including single stream and separate container processing lines; and inspect major equipment associated with each processing line.  D&B compiled and reviewed MRF operating, maintenance, and production records, and performed on-site inspections and observations of material receiving, sorting, and baling operations, as well as overall Facility cleanliness.  D&B documented its observations with a detailed photographic record.  The Engineering Audit Report provided evaluations of the condition and adequacy of equipment and processing performance.  The Report provided an overview of the private operator’s organization, staffing, supervision and training, utility utilization, and compliance with service agreement requirements, and provided the CRRA with suggestions for improving the Facility and its operations.

Project Responsibilities 

Feasibility Study for Facility Expansion – 2005

The firm reviewed the design of the Facility and its operating records. These reviews included assessments of the existing equipment and expansion opportunities in the WPF and PBF, as well as the potential for developing new RRF structures on-site. Also reviewed were RDF production and combustion rates, steam production, and turbine-generator capacities. D&B conducted the following key analyses:

  • Capacity to generate additional electrical power.
  • Existing heat balance.
  • Additional refuse processing and combustion capacity required in order to utilize spare electrical generation capacity.

On the basis of these analyses, three (3) expansion alternatives were identified and analyzed as follows:

  • Two (2) new mass burn units in a new RRF structure on-site.
  • One (1) new RDF unit in a new RRF structure on-site.
  • One (1) new RDF unit in the existing PBF.

Layouts, equipment lists, construction costs, operating budgets, and power sales revenue estimates were developed by D&B. These were incorporated into models that projected the net costs of operation for the three (3) alternatives over a twenty (20) year period.

In addition, scenarios were analyzed in order to project the effects of variations in tonnage, energy revenues, and inflation.

Evaluation of Waste Processing Facility Operating Alternatives – 2008

D&B evaluated the relative benefits and costs of operation of the WPF by public sector employees or a private operations contractor. The work was initiated by a thorough review of documents relevant to the study. The documents to be reviewed included those listed below, as well as others that the CRRA deemed necessary for the work.

  • Operating records, operating reports, and invoices to CRRA for the previous five (5) years.
  • The Agreement for the operation of the WPF.
  • Correspondence associated with operations, including disputes.
  • Reports prepared for CRRA on the condition of the WPF.
  • Annual WPF operating budgets, showing projected and actual expenditures for the previous five (5) years.
  • Budgets for the CRRA associated with WPF administration and oversight.
  • Documentation of capital repairs and improvements to the WPF for the previous five (5) years.
  • Requests For Proposals/Bids issued by CRRA for private contractor operation of the WPF.
  • Correspondence received by CRRA from potential proposers.
  • Proposals received by CRRA for operation of the WPF.
  • Permits issued by the State of Connecticut and United States Environmental Protection Agency (“USEPA”) for the operation of the WPF.
  • Union agreements.

D&B visited the WPF in order to review its general layout, operating practices, and conditions.

D&B prepared an operations and economic model of the WPF using Excel software. The model included annual processing rates, capital improvements, major maintenance, debt service, staffing, labor costs, maintenance and repair, utilities, residuals disposal, recovered metals sales, insurance, supplies, subcontractors, and CRRA administration and permit compliance costs. The model allowed the comparison of operations and costs for public versus private sector operations. Information regarding current operations was utilized for the public sector evaluation. D&B utilized information in its files and obtained additional information regarding privately operated facilities similar to the WPF. The information was obtained by means of contacts with the public solid waste management agencies that own or use the facilities and with private facility operations companies.

A comparison of public versus private operations was prepared using the model. Operating results were projected for twenty (20) years. Gross and net operating costs were estimated for each year. D&B reviewed the results of the modeling as they were obtained and identified alternatives to be analyzed, as necessary to fully evaluate the comparative costs.

D&B also reviewed the agreement between the CRRA and the operator and prepared a comparison with agreements for private sector operation of similar facilities. This included the general agreement provisions, allocation of risks, performance incentives,
and performance guarantees. Recommendations were made for provisions that should be included in an agreement with an operations contractor in order to maximize the potential benefits of private operation, recommendations for improvements to the agreement with the current operator.

Assessment of Options for Future Operations – 2009

D&B prepared Program Operations and Economic Models (“POEMs”) of options for the future design configurations and processing capacities for the Mid-Connecticut RRF. The POEMs included annual processing rates, capital improvements, debt service, staffing, labor costs, maintenance and repair, utilities, residuals disposal, recovered metals sales, insurance, supplies, subcontractors, CRRA administration, and permit compliance costs.

The options evaluated and modeled are as follows:

  • Option 1 – Continuation of Current RDF Configuration and Processing Capacity Using One Operator for the WPF, PBF, and EGF.
  • Option 2 – Continuation of Current RDF Configuration and Processing Capacity and Add Mass Burn RRF Capacity for Process Residue from the RDF-Waste Processing Facility and Other Solid Wastes.
  • Option 3 – De-rate the WPF, PBF, and EGF Based Upon Processing 560,000 Tons Per Year; Transfer Excess Solid Waste to Disposal Facilities Via Off-Site Transfer Stations.
  • Option 4 – Shut Down Existing RDF Production and Combustion; Develop New Mass Burn Capacity On-Site for 500,000 Tons Per Year; Excess Solid Waste to Disposal Facilities Via Off-Site Transfer Stations.
  • Option 5 – Shutdown Existing RRF; Transfer-Haul All Solid Waste to Off-Site Disposal.

Independent Engineering Audit of the Mid Connecticut Materials Recovery Facility – 2012

D&B evaluated the performance of the private facility operator in complying with its obligations under the service agreement with the CRRA. D&B included the following as part of the independent MRF audit and its preparation of the MRF Audit Report:

  • Assembled MRF historical operating and performance data and maintenance records.
  • Prepared a flow diagram defining the processes and material flows within the MRF.
  • Prepared a comprehensive inspection checklist, including inspection requirements for:
    • Conveyors.
    • Optical Sort Systems.
    • Balers and Compactors.
    • Magnetic separators.
    • Trommels and Screens.
    • Bins and Bunkers.
    • Infeed Pits.
    • Rolling Stock.
    • Platforms and Stairs.
    • Electrical Power and Controls.
    • Building Facilities, including Offices, Lunch Rooms, etc.
    • Facility site conditions.
  • Reviewed material receiving and processing rates and current marketing data, including material prices and markets.

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