The Canadian Environmental Assessment Agency and British Columbia’s Environmental Assessment Office are taking comment on a liquefied natural gas (LNG) export project that will have a major power plant component.
The agencies are inviting the public to comment on the ongoing environmental assessment of the Pacific NorthWest LNG Project. The 30-day public comment period is from April 2 to May 1.
Pacific NorthWest LNG LP (PNW LNG) is proposing a project to construct and operate an LNG facility on Lelu Island. The project will be located primarily on federal lands and waters under the jurisdiction of the Prince Rupert Port Authority (PRPA). The project would be located within the District of Port Edward, British Columbia.
The natural gas would be transported to the project via a new pipeline from northeast BC. The pipeline is a separate project proposed by a third party (TransCanada Pipelines Ltd.) and assessed independently as the Prince Rupert Gas Transmission project pipeline.
At full build-out, the facility will receive approximately 3.2 billion standard cubic feet per day of pipeline grade natural gas, and produce up to 19.2 million tonnes per year of LNG. Two phases of construction are expected for the project with the first phase having a design capacity of two trains producing 12.8 million tonnes per annum of LNG; the second phase will include an additional 6.4 million tonnes per annum of capacity to be developed after the first two trains are operational. Construction is expected to take approximately four years and the first phase of the proposed project is expected to be operational by early 2019.
Pacific NorthWest LNG is principally owned by PETROLIAM NASIONAL BERHAD (PETRONAS). Japan Petroleum Exploration Co. (JAPEX) and PetroleumBRUNEI are minority shareholders in Pacific NorthWest LNG and its associated natural gas supply. PETRONAS is a top-ranked integrated oil and gas business which is wholly owned by the government of Malaysia.
Both onsite and offsite generation being looked at
In the LNG industry, heat from gas turbine exhaust is usually recovered for in-facility use to the extent possible. Even though this requires specialized heat recovery units to be inserted into gas turbine exhaust ducting and complex heat integration, it will improve overall facility efficiency, the February project application noted. For the project, heat from gas turbine exhaust will be recovered for heating, for example to supply heat to reboilers of distillation columns, and to supply heat to regenerate drier beds.
Until recently, few LNG projects were built using aero-derivative gas turbines. These turbines are more efficient than the more commonly used industrial gas turbines, the application noted. PNW LNG has decided to use aero derivative gas turbines as the main compressor drivers, as well as for power generation, to achieve better environmental performance.
To further enhance emission performance, PNW LNG is evaluating the use of the latest combustor technologies including dry low NOx (DLN) and dry low emission (DLE) systems.
The electrical power requirement is up to 500 MW for three trains, at full build-out (with the addition of Phase 2). The power plant will be designed to accept connection to an external utility power supply, in the event that renewable energy production capacity becomes available in the future, the application said.
Electrical power is required to operate equipment in the facility such as pumps, smaller compressors and air coolers, as well as lighting and space heating. The extent of electrical power generation depends on the choice of main refrigerant drivers as well as the final configurations. Total electrical power demand is up to 500 MW due to the selection of gas turbines as main drivers. If the electrical motor option were selected, the electrical power demand would be increased to 1,100 MW for three trains.
Onsite power generation would involve installation of generators and a power distribution and control network. All baseload LNG plants globally have power generation capacity onsite, the company noted. Offsite generation is being explored by PNW LNG through discussions with BC Hydro on the pace of electricity development in the province.
“Several conversations and a conceptual electricity supply study were undertaken with BC Hydro,” the application said. “Another option being explored is natural gas-fired co-generation facilities operated by third party entities. Third party supplied electricity would require the construction of a new co-generation facility and the accompanying transmission lines to the Project. Environmental considerations indicate that GHG emissions from co-generation plants and from natural gas–fired mechanical turbines are similar. Electricity supplied from BC Hydro and the nearby Port Edward sub-station remains under consideration as a potential power supply for the Project during the construction phase. A system impact study is underway.”