Fugitive emissions account for approximately 50% of total hydrocarbon emissions from process plants. Federal and state regulations aiming at controlling these emissions require refineries and petrochemical plants in the United States to implement a Leak Detection and Repair Program (LDAR). The current regulatory work practice, U.S. Environment Protection Agency Method 21, requires designated components to be monitored individually at regular intervals. The annual costs of these LDAR programs in a typical refinery can exceed US$1,000,000. Previous studies have shown that a majority of controllable fugitive emissions come from a very small fraction of components. The Smart LDAR program aims to find cost-effective methods to monitor and reduce emissions from these large leakers. Optical gas imaging has been identified as one such technology that can help achieve this objective. This paper discusses a refinery evaluation of an instrument based on backscatter absorption gas imaging technology. This portable camera allows an operator to scan components more quickly and image gas leaks in real time. During the evaluation, the instrument was able to identify leaking components that were the source of 97% of the total mass emissions from leaks detected. More than 27,000 components were monitored. This was achieved in far less time than it would have taken using Method 21. In addition, the instrument was able to find leaks from components that are not required to be monitored by the current LDAR regulations. The technology principles and the parameters that affect instrument performance are also discussed in the paper.
Oil prices are notoriously hard to predict, but they are an important input in many energy and economic models. This paper explores the effects of different oil price assumptions on natural gas markets (production, consumption, prices in different regions) in the International Natural Gas Model (INGM). Three cases from the INGM are presented: a reference case, a high oil price case and a second high oil price case, where gas-to-liquids (GTL) capacity additions are constrained. The results show that regardless of constraints on GTL capacity additions, higher oil prices lead to higher production and consumption of natural gas. However, when GTL capacity is allowed to expand, higher oil prices generally lead to higher natural gas prices and to less gas consumption in the electric power and industrial sectors as they switch to cheaper fuels and more natural gas is diverted to the production of GTLs.
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