Abstract: A dual function material is provided that captures carbon dioxide from ambient air, i.e., direct air capture, and converts the CO2 to a desired product such as methane. The material includes a high surface area carrier such as Al2O3 upon which catalysts and alkaline adsorbents are positioned proximate each other. In the presence of reactive gas such as hydrogen, the catalysts reduce the adjacent adsorbents to generate additional active sites and enhance the amount of CO2 captured by the material. Once the material becomes saturated with CO2, hydrogen is reintroduced to reduce the catalyst, such as ruthenium, at which time the adsorbed CO2 can migrate from the adsorbent to the catalyst for catalytic conversion to methane. The materials can be employed in isothermal, cyclic reactor systems where target species are bound and then desorbed to reactivate the material, e.g., bind more target species for desorption and/or conversion to additional product.

Abstract: A gate valve (10) has an expanding gate assembly (34) mounted in the valve chamber (14) for movement between open and closed positions. The gate assembly (34) includes a gate (44) connected to a valve stem (28) and a segment (52) is carried by the gate (44). The gate (44) and segment (52) each have wedging surfaces (46 and 54) which permit a wedging action to provide lateral expansion therebetween at the open and closed positions. A rocker arm (80) is pivotally mounted to a side (49) of the gate (44). The rocker arm (80) has a slot (102) with a bearing block (104) slidably received therein. A bearing pin (110) extends from a side (57) of the segment (52) and is journaled in the bearing block (104). A seat skirt (60) is contained within the valve chamber (14) and engages the rocker arm (80) so as to control the ability of the rocker arm (80) to pivot about the gate (44) thereby allowing the gate (44) and segment (52) to expand from each other at a preselected position in the travel of the gate assembly (34).