A spacer array including a plurality of spacers. Each spacer defines a longitudinal axis and includes a main body, a leading pin, and a trailing pin. The main body has a main body cross-sectional dimension. The leading pin extends from the main body and is upstream of the main body. The leading pin has a leading pin cross-sectional dimension. The trailing pin extends from the main body and is downstream of the main body. The trailing pin has a trailing pin cross-sectional dimension. The main body cross-sectional dimension is greater than the leading pin cross-sectional dimension and the trailing pin cross-sectional dimension.

Disclosed are embodiments of a filter unit containing a water adsorbent material in the form of water adsorbent particles in a packed bed and a gas adsorbent material in the form of gas adsorbent particles in a packed bed. In embodiments, the gas adsorbent material is downstream from the water adsorbent material in a direction of operation. Further disclosed are methods of preparing and using the filter units.

A process for separating 1-butene from a C4 raffinate gas composition includes introducing the C4 raffinate gas composition to a reactor containing an adsorbent material and passing the C4 raffinate gas composition through the adsorbent material; adsorbing the 1-butene from the C4 raffinate gas composition onto the adsorbent material to separate the 1-butene from the C4 raffinate gas composition and form a residue gas composition; and desorbing the 1-butene by heating the adsorbent material after the adsorbing to form the 1-butene and regenerate the adsorbent material. The adsorbent material is at least one of a zeolite adsorbent and an alkali-modified zeolite adsorbent having at least 99% by weight selective towards 1-butene for adsorption in comparison to iso-butene and iso-butane.

The present invention describes a method to remove metals present in a mixture comprising one or more organic amines comprising the step of contacting the mixture with a silica-polyethyleneimine adsorbent.