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Matt Halsey, Servomex, UK, explains how hydrocarbon processing plants and refineries can implement cleaner air strategies using gas analysis.
ncreasingly stringent environmental regulations, along with international action to reduce the impact on climate, such as the 2016 Paris Agreement, have made plant operators more aware of their contribution towards greenhouse gas emissions. Gas analysis systems provide an effective solution for plants looking to reduce their emissions and operate in an ecologically responsible way. Servomex operates a clean air strategy that focuses on three key process areas: combustion efficiency, gas clean-up, and emissions monitoring. Analytical solutions for these areas will support plants in their clean air goals, while also optimising processes to deliver reduced fuel consumption and higher yields.
Stage one: effective combustion control There are no realistic alternatives to combustion when it comes to creating the high temperatures needed for many hydrocarbon processing applications. Achieving an efficient reaction is therefore key. The reaction of oxygen (from air) with fuel typically generates harmful emissions, while also using a significant
amount of fuel and creating potential safety hazards. Obtaining an efficient reaction means optimising the ratio between the air and fuel. Before gas analyser technology was developed, fired heaters were typically run in high excess air conditions. This avoided the creation of unsafe conditions that could lead to an explosion, but was inefficient and increased the level of fuel consumption. Additionally, excess oxygen (O2) will combine with nitrogen and sulfur in the fuel to produce unwanted emissions such as oxides of nitrogen (NOX) and sulfur (SOX). By accurately measuring O2 and combustibles such as carbon monoxide (CO), plant operators are better able to balance the air-to-fuel ratio, controlling the combustion reaction. This produces a number of benefits, particularly where plants are looking to improve environmental standards. It reduces fuel consumption, resulting in fewer emissions, lower NOx, SOX, and CO generation, and a decrease in the greenhouse gas carbon dioxide (CO2). As a solution for monitoring O2 in combustion, Zirconia sensing is a long-established technology. It delivers reliable, accurate results with a fast response to changing conditions. HYDROCARBON 71
ENGINEERING
August 2021
