Gas transmission companies are sometimes disappointed with the results of efforts to control noise from reciprocating and centrifugal compressor packages, including new compressor station designs and retrofit programs. In an effort to begin to standardize noise control equipment specifications and performance testing procedures, the PRC I undertook a project to develop a series of “ Guidelines ” for implementing engineering noise control designs for compressor station equipment. The project was sponsored by the PRC I nternational (PRC I ). The project report consists of eleven stand-alone Guidelines that can be used by gas transmission companies to develop their own noise control specifications for major compressor station equipment. The intent of the Guidelines is to maintain traditional vendor/sub-vendor roles between compressor packagers and component manufacturers while maintaining the practice of vendor design - vendor guarantee. The noise control requirements can be verified by pre-establishing field performance testing methods. Specific field performance testing methods for various typical mechanical equipment are provided in each Guideline. The Guidelines are structured to draw a distinction between mechanical equipment components which are noise generators, sound attenuators or acoustic radiators, as each requires a different specification format. To fulfill this aspect, a high temperature microphone probe was researched, developed and tested. This piece of hardware, along with the developed measurement methodology, allows optional diagnostical testing of the engine exhaust noise component of compressor station noise. These diagnostics can assist in isolating the noise generated by the engine versus the attenuation provided by the exhaust silencer. The measurement procedures do not require silencer removal from the package or equipment shutdown to test, which thus reduces testing costs.

Increasingly stringent regulations by the EPA and state air quality agencies in the U.S., as well as new regulations by Environment Canada, are making the reduction of exhaust emissions from industrial engines and gas turbines ever more important far their operators. Not only are these regulations getting increasingly strict with time, but there will be both substantial fines and possible criminal penalties for non-compliance in the future. This presentation describes how harmful exhaust emissions are formed during the combustion process, what the current regulations are in various areas of North America and where they are probably headed in the foreseeable future. It then discusses possible emission reduction strategies in two broad categories, combustion modification and post-combustion treatment, using catalytic converters. The three types of catalyst substrates are discussed, with the advantages and disadvantages of each, as well as the relative advantages and disadvantages of the four possible catalyst locations.

Environmental noise has become a significant concern for compressor station operations. Typical compressor buildings provide limited attenuation of the noise from the compressor package. In addition, ventilation openings, windows, doors and explosion panels can significantly downgrade the building’s potential acoustical performance. Similarly, exterior equipment such as aerial coolers, yard piping and exhaust silencers are noise contributors that cause challenging design constraints towards achieving practical noise control solutions. Integration of all of these aspects means that the economic retrofit of existing compressor station noise sources, particularly the compressor buildings themselves, has proven to be a difficult challenge. Consideration of construction complexity and cost in the “Balanced Design” process ensures that the final design is practical, economical and expedient. This paper discusses in detail the components of an approach that has been successfully used to provide cost effective noise control at existing compressor stations.

The primary purpose of this paper is to provide a broad overview of Solar’s low emissions combustor development and how it is being shaped by emissions regulations that are continually changing. Discussed in this paper is a description of the development and present status of SoLoNOx ; a discussion of how increasingly restrictive emissions regulations impact industrial gas turbine production; and a review of new combustion technologies with the potential to achieve lower emissions levels. Solar continues to explore combustion technologies in the belief that clean combustion is a more cost-effective path to low emissions than exhaust gas cleanup.

Noise is generated at gas turbine-based compressor stations from a number of sources, including turbomachinery (gas turbines and compressors), airflow through inlet ducts and scrubbers, exhaust stacks, aerial coolers, and auxiliary systems. Understanding these noise sources is necessary to ensure that the working conditions on site are safe and that the audible noise at neighbouring properties is acceptable. Each noise source has different frequency content, and the overall sound pressure level (OSPL) at any location in the station yard or inside the compressor building is the result of a superposition of these noise sources. This paper presents results of multiple-point spectral noise measurements at three of TransCanada’s compressor stations on the Alberta System. A method is described to determine the overall noise map of the station yard using Delaunay Triangulation and Natural-Neighbour Interpolation techniques. The results are presented in OSPL maps, as well as animated pictures of the sound pressure level (SPL) in frequency domain which will be shown on a video at the conference. The latter will be useful in future work to determine the culprit sources and the respective dominant frequency range that contributes the most to the OSPL.

Government policies currently in place or in development will require the reduction of greenhouse gas emissions from industry, including gas transmission systems. Most of the natural gas transmission systems are powered by gas turbines of sizes up to 30 MW per unit. A typical gas turbine of this size can emit 6 ktonnes of CO 2 per MW-year, equivalent to about 180 ktonnes per year. Reduction in greenhouse gas emissions can be accomplished through post-combustion systems (separation of CO 2 from flue gases through chemical absorption, physical adsorption, membrane or cryogenic systems) or through oxy-fuel combustion, where fuel is combusted in pure O 2 leading to sequestration of CO 2 by compression and dehydration of the exhaust gases. The purpose of the current work is to explore the application of the latter concept, simplify and enhance the cycle, and to provide an economic valuation of the cost per tonne of CO 2 abated. Innovations explored for enhancement include elimination of excess power production, simplification of capital equipment requirements, and optimization of the power to the booster produced from the gas turbine and steam turbine. The paper presents various innovation options arrived at, detailed thermodynamic parameters, and a cost and economic evaluation of these options. Particular emphasis was placed on the application of this technology to a typical compressor station on a natural gas transmission system as this application is vastly different than a typical power plant contemplating or employing carbon capture and storage (CCS) systems, most notably from the small power size, the remote location, and the self-containment perspectives.

Automated, variable volume unloaders provide the ability to smoothly load/unload reciprocating compressors to maintain ideal operations in ever-changing environments. Potential advantages provided by this load control system include: maximizing unit capacity, optimizing power economy, maintaining low exhaust emissions, and maintaining process suction and discharge pressures. Obstacles foreseen include: reliability, stability, serviceability and automation integration. Results desired include: increased productivity for the compressor and its operators, increased uptime, and more stable process control. This presentation covers: (1) system design features with descriptions of how different types of the devices were developed, initial test data, and how they can be effectively operated; (2) three actual-case studies detailing the reasons why automated, hydraulically controlled, variable volume, head-end unloaders were chosen over other types of unloading devices; (3) sophisticated software used in determining the device sizings and predicted performance; (4) mechanical and field considerations; (5) installation, serviceability and operating considerations; (6) device control issues, including PC and PLC considerations; (7) monitoring of actual performance and comparison of such with predicted performance; (8) analysis of mechanical reliability and stability; and (9) preliminary costs versus return on investment analysis.

Gas turbine users increasingly seek to install equipment in remote and harsh operating environments. Experience has shown that the cost of performing work in such an environment can be an order of magnitude greater than the cost of similar work performed in the manufacturer’s workshop. For this reason, gas turbine users have requested manufacturers to create package designs that minimize installation time. This paper describes changes made to aero-derivative gas turbine package design over the past seven years that achieve reduced installation time. Package changes have been permitted by advances in component technology affecting air inlet, exhaust, and control systems. Advances have also been made in piping, cable and baseplate designs. Component and package changes are described via a comparison of today’s standard aero-derivative gas turbine package to the standard package provided five to seven years ago. The comparison is made for a pipeline compressor application.

Liquefied Petroleum Gas (LPG) is a mixture of light hydrocarbons, gaseous at normal temperature (15°C) and pressure (101.329 kPa) and maintained in the liquid state by increased pressure or lowered temperature. LPG is the generic name for “commercial butane” and “commercial propane”. Because of its high heating values, high purity, cleanness of combustion and easy of handling, LPG finds very wide application in a large variety of industrial, commercial, domestic and leisure uses. The history of LPG goes back to the early 1900s. The first car powered by propane ran in 1913 and by 1915 propane was used in torches to cut through metal. Current global LPG consumption is over 200 million tonnes/annum. Transportation of LPG by pipelines is environmentally friendly in that it entails less energy consumption and exhaust emissions than other modes of transportation. Worldwide, there are over 220,000 miles (350,000 kilometers) of petroleum, refined products and LPG pipelines. The majority are in the United States. Some refined products pipelines carry LPG in batch form. However, there are only about 8000 kilometers of single phase pipelines, of various diameters, that transport LPG (propane or butane) fluids (Mohitpour et al, 2006). There are a number of codes that industry follows for the design, fabrication, construction and operation of LPG facilities. However, there are no regulations or legislation that specifically cite the pipeline transportation of the product. From a safety point of view, although LPG is non-toxic, it can be very dangerous if not handled properly. A partial or complete rupture of an LPG pipeline, resulting in an accidental release, will cause issues related to evaporation, vapor cloud propagation and dispersion. Response to emergencies such as rupture and leak in LPG pipelining is thus critical and must ensure rapid action with respect to containment, control, elimination and effective maintenance/repair. This paper provides an overview the code and regulatory requirements and summarizes the more significant aspects of the design, construction and safe operation pertaining to LPG pipeline systems. It covers the timeline and statistics of the global LPG business; the type of facilities that make up the industry; and the LPG properties pertinent to pipeline design. It also addresses the significant safety issues of LPG pipelining including a discussion on emergency response and associated equipment needs and repair techniques.