Liquid Hydrocarbon Applications

APPLICATION: MERCURY REMOVAL FROM LIQUID HYDROCARBONS

MERSORB® LH mercury removal adsorbent is used to achieve low outlet mercury concentrations in Liquid Propane, Light Hydrocarbon Condensate (C5-C10), and Naphtha. This mercury removal adsorbent is a high surface area (1,000 m2/g) activated carbon pellet (extrudate) that is impregnated with a sulfur compound by a proprietary method. This sulfur compound is insoluble in liquid hydrocarbons. Our impregnation method creates a high level of dispersion of the sulfur compound molecules inside the micropores of the activated carbon substrate. High dispersion means that the impregnant is more available to remove mercury.

MERSORB® LH mercury removal adsorbent performs well at temperatures of 15 - 85 °C (60-185 °F). When the temperature of hydrocarbon liquid increases, its viscosity decreases, so mercury diffuses more rapidly. As the feed liquid temperature is increased, dissolved mercury reacts faster with the sulfur compound impregnant in the mercury adsorbent. Both of these effects of higher feed liquid temperature increase the mercury removal efficiency.

MERSORB® LH mercury adsorbent pellets of 1.5mm & 1.0mm diameter are used in liquid hydrocarbon treatment. These small pellets provide up to 99+% Hg removal efficiencies at a low pressure drop. The pellets have high crush resistance, wet & dry, and are low in dust.

Because MERSORB® LH mercury adsorbent pellets are uniform in size and very low in dust, they do not require backwashing. With our pellets, the Pressure Drop Remains Low during the service life of the adsorbent. Granular carbons, however, require frequent backwashing and are often replaced before their contaminant capacity is used up, due to high pressure-drop. Thus, MERSORB® LH mercury adsorbent pellets are a low-maintenance product.

Particle filters before the mercury adsorbent are an essential part of The AntiMercureTM HC Process. The mercury adsorbent removes Hg atoms, Hg ions, & organo-Hg molecules, but not particles. Particles that contain mercury must be removed upstream of the adsorber vessels. Lab tests can be used to determine the optimum sub-micron-size PreFilter for a particular installation. A wire-mesh screen can NOT be used instead of the PreFilter. A sub-micron size PostFilter will catch any small quantity of particles shed by the mercury adsorbent, thus insuring that the treated hydrocarbon liquid stays within the required outlet Hg concentration limit.

With hydrocarbon liquid streams that have unavoidable upstream upsets that cause free water to enter the stream, we use MERSORB® CR mercury adsorbent pellets. MERSORB® CR mercury adsorbent pellets contain a mercury removal impregnant that is insoluble in liquid hydrocarbons and has the same high-efficiency mercury removal and mercury capacity as MERSORB® LH pellets