New technologies have soon revolutionized the detection and monitoring of fugitive emissions. One technology, known as Differential Absorption Lidar (DIAL), can be used to remotely measure concentration profiles of hydrocarbons in the atmosphere up to several hundred meters from a facility. DIAL has been used for refinery surveys in Europe for over 15 years. A pilot study carried out in 2005 using DIAL found that actual emissions at a refinery were 10 to 20 times greater than the amount estimated using standard emission factors. The fugitive emissions were equivalent to 0.17% of the refinery throughput.

新技术很快就已经革新了对无组织排放的探测和监控。其中之一，称为差分吸收光遥感法 (DIAL)，可被用作在距生产设施几百米距离上遥测大气中烃类(碳氢化合物)浓度分布。DIAL在欧洲用于炼化企业调查已有十五年以上。2005年进行的一项试点研究发现炼化厂的实际排放量比用标准排放因子估算的量大10到20倍。无组织排放量相当于炼化企业产量的0.17%。  

An identified problem with emission factor calculations is that they assume all equipment is operating as designed, they do not include some major release areas, and the leak detection and repair (LDAR) programs typically do not measure tanks and difficult to access plant areas. Whole plant measurements can identify problem areas that are not being monitored and allow them to be addressed. Direct measurement of plant emissions is a way to identify areas for improvement, not necessarily a replacement for emission factor estimations. The issue should not be framed in an either/or fashion.

排放因子计算法已知的问题在于，其假定所有设备都按设计运行，且不包括某些主要的泄放区域 – 泄漏检测修复LDAR工作一般不检测储罐，以及难以进入的工厂区域。全厂域监测可以发现尚未监控的问题区域，并加以指正。直接测量厂域泄放是识别待改进领域的一个方法，但不一定可以取代排放因子估算法。这个问题不能以非此即彼的方式看待。

The DIAL technique has been used extensively in Europe and more recently in Canada. As currently configured it uses both ultraviolet (UV) and infrared (IR) lasers to measure criteria pollutants (NOx, SO2, and O3) and light aromatic (benzene, toulene, ethylbenzene, and xylene) in the UV, and methane and total hydrocarbon plumes in the IR. DIAL is capable of providing a 2-dimensional contour of concentrations across a scanning plane. By combining this concentration contour with separately obtained wind speeds, a contaminant flux can be calculated. The DIAL system has been validated in European studies for hydrocarbon emissions. Estimated fluxes obtained by the DIAL system are generally assumed to be conservative.

DIAL技术在欧洲已被广泛应用，近来，在加拿大也逐步推广。按目前配置，使用紫外与红外激光，用紫外谱段测量关键污染物(氮氧NOx, 硫化物SO2, 和臭氧O3)，以及轻烃 (苯、甲苯、乙苯和二甲苯)，用红外测量甲烷及总烃。DIAL能够生成所扫描平面上两维浓度分布图。通过综合此浓度分布图及另行获取的风速值，可以计算污染流。DIAL系统在欧洲研究中已验证可用于烃类排放。通过DIAL系统获得的污染流估算值，一般认为还比较偏保守。

Portable gas leak imaging cameras are also a new technology that can be used to improve leak detection and repair, leading to reduced fugitive emissions. The cameras use infrared imaging technology to produce video images in which invisible gases escaping from leak sources can be clearly identified.

便携式气体泄漏成像仪也是一项新的技术，可用于改进泄漏检测及维修，有助于减少无组织排放。成像仪采用红外成像技术产生视频图象，使泄漏点无形的气体逸漏一目了然。

The camera has been very effective in locating large hydrocarbon releases from hard to access places. It does not detect all chemicals, nor does it speciate or quantify them. Releases under 500 ppm are generally not detectable. The camera can be combined with a passive FTIR system that together provide a visual of where the release originated as well as its chemical composition and concentrations.

成像仪用于确定难以进入区域的超量烃类泄漏很有效率。但其无法探测所有种类的化学品，也不能区分或对化学品泄放定量。小于500ppm的泄漏一般难以测得。成像仪如果与被动式傅利叶变换红外仪(FTIR)协同使用，就可以既判定泄漏源位置，又确定泄漏成分及浓度。

By the late 1990s, the U.S. Environmental Protection Agency determined refineries were under-reporting emissions by a significant amount, thus indicating that LDAR programs were not achieving the desired results. As such, a need was identified for enhanced programs that proactively seek out and eliminate leaks. Between 1998 and 2008, non-compliant facilities were required to institute formal LDAR programs with dedicated management. Today they are required to implement enhanced LDAR programs that call for the use of certified low-leak valves and sealing technologies.

1990年代后期，美国环保署EPA判定炼化企业显著地低报了无组织排放量，表明泄漏探测检修LDAR项目没有取得期望的结果。基于此，已经认识到需要引入加强型项目更主动地寻找并消除泄放。1998至2008年间，要求未达标厂区建立配备专职管理的LDAR项目。目前，还要求它们实施加强型LDAR项目，要求采用经认证的低泄阀门和密封技术。

Monitoring requires the use of Method 21, with a toxic vapor analyzer and data logger, and varies with the type of equipment – monthly for pumps and agitators, quarterly for valves and closure devices on open-ended lines, and annually for piping and equipment connectors. Levels of leakage requiring remedial action also vary – 250 PPM for valves, closure devices and connectors, 500 PPM for pumps, and 2,000 PPM for agitators. To quickly detect large leaks well in excess of allowable levels, the EPA adopted the Alternative Work Practice, which employs optical imaging technology such as handheld infrared cameras that allow users to see fugitive emissions. However, this technology does not quantify leaks, so annual Method 21 surveys are still required.

要求采用21号方法Method21进行监控，采用气体检漏仪和数据记录仪，按不同设备种类进行 – 泵和搅拌器，每月检测；阀和管线盲板，每季检测；管线和设备接口，每年检测。要求安排补救措施的最低泄漏量值也各为不同 – 阀、盲板、接口，为250ppm；泵为500ppm，搅拌器为2000ppm。为快速侦测大的泄漏点以防其严重超标，EPA允许替代工作法，即采用光学成像技术比如手持式红外成像仪，以便用户直观无组织排放点。但，此技术不能确定泄漏量，21号方法Method21巡检还是需要的。

Initial attempts to repair such leaks must be made within five days of detection, and final attempts within 15 days. If a component cannot be immediately repaired or removed from service, it may be put on a delay-of-repair list subject to EPA inspections.

对如此发现的泄漏点的首次检修必须在五日内进行，末次必须在十五日内完成。如果设备部件不能立即修理或从生产流程中撤除，可以记入缓修清单，以备EPA检查。

Equipment Factors

As noted, Enhanced LDAR programs mandate equipment upgrades, replacement and improvement, and also require the use of certified low-leak valves and sealing technologies. With these requirements comes a dramatic reduction in acceptable emission levels from 500 PPM under conventional LDAR to 100 PPM under Enhanced LDAR.

如前所述，加强型泄漏检测维修项目LDAR强制要求设备升级、更换和改进，其也要求采用低泄阀门和密封技术。伴随这些要求的还有可允许排放量从常规LDAR中的500ppm量级大幅降低到加强型LDAR规定的100ppm。

With the EPA estimating 60% of fugitive emissions from pipe networks being attributed to valves, emissions control products have become a primary focus for valve and valve packing manufacturers. Recent consent decrees are requiring emission limits for valves and packing to remain below 100 ppm for five years.

基于EPA的估计，密闭管路的60%无组织排放来源于阀门，减排型产品就成为阀门及阀门盘根制造商的基本着眼点。最新的法规要求，阀门及盘根的泄放上限需在五年内保持低于100ppm。


The terms we must all become very familiar with are “Certified Low-Leaking Valves” and “Certified Low-Leaking Valve Packing Technology” as defined by the EPA in many consent decrees.  And most recently the term “Low E Technology” has been added to this list. These definitions not only define performance parameters, but, require a written guarantee to be provided by the valve manufacturers and packing manufacturers, that the valve or packing will not leak above 100 ppm for five years;.  

人们需要尽量熟悉的术语，是EPA在很多法规指令所定义的“获证低泄阀门”和“获证阀门盘根技术”。最近，另一术语，“低逸Low-E技术”，也加入这一名单。这些定义不仅指定了性能参数，还要求阀门及盘根制造商出具书面质保证明，确认阀门或盘根泄放率在五年内不高于100ppm。

New “Low E Technology” includes the above with the added requirement that the manufacturer has test documentation based on accepted engineering practices that documents life cycle and emissions performance.

最近的“低逸Low-E技术”则在上述基础上增加要求制造商出具按公认的技术方法获得的测试文件，详列产品的循环使用寿命及泄放性能。

Enhanced LDAR calls for valve stem packings leaking in excess of 250 PPM to be replaced with low-leak technology within 30 days or at the next scheduled maintenance outage. If leaking between 100 PPM and 250 PPM, they must be repaired or repacked annually per a set of equations.

加强型LDAR要求阀杆盘根泄漏率大于250ppm者，在30天内以低泄放技术予以更换，或者下次计划停车检修时进行。如果泄放率在100至250ppm，则必须按给定的减排公式逐年修理或维护。

Enhanced LDAR programs also address leaking flanged, threaded, compression, cam-lock and quick-connect connectors. These components do not require warranties and test reports, but like valves are subject to repair and replacement. Connectors found to be leaking at or above 250 PPM must be brought under 250 PPM within 30 days of detection.

加强型LDAR项目也针对法兰、螺纹、压插式、快锁式、快接式等接头的泄漏。这些器件不要求保证书和测试报告，但与阀门一样也需要维护和更换。接头泄漏量一旦发现大于或等于250ppm，需在发现后30天内更换。