Abstract: A method for separating a raw feed gas stream using a plurality of membrane module stages. The raw feed gas stream may be from a biogas process. Off-gas from another unit process in the system, such as a temperature swing adsorption unit or liquefaction unit, may be used as a low pressure sweep gas on the low pressure side of at least one of the membrane module stages. In one example, the sweep gas is used in a first membrane module stage. In another example, a stripping membrane module stage is provided and the sweep gas is used in the stripping membrane module stage. Optionally, portions of the off-gas could be directed to other streams in the system for the purpose of balancing compressor power requirements.

Abstract: Recovery of hydrogen from an ammonia cracking process in which the cracked gas is purified in a PSA device is improved by using a membrane separator on the PSA tail gas.

Abstract: A process for separating carbon dioxide from a feed gas comprising carbon dioxide may comprise compressing the feed gas in a feed gas compressor to produce a compressed feed gas. The process may also comprise separating the compressed feed gas by an adsorption process comprising: using a plurality of adsorbent beds to produce a carbon dioxide-enriched product stream and a carbon dioxide-depleted stream, and a blowdown step. A blowdown gas may be removed from the adsorbent bed. The process may also comprise compressing the blowdown gas in the feed gas compressor and combining the blowdown gas with the compressed feed gas.

Abstract: A biogas upgrading system can include a multiple stage membrane system that is configured to remove oxygen so that the biogas is upgraded to have a higher concentration of methane, a pre-selected oxygen (O2) concentration (e.g. less than or equal to 0.2 mol %, etc.), and a pre-selected carbon dioxide (CO2) concentration (e.g. less than or equal to 5 mol %, etc.). The membrane system can be configured to reject O2 by utilizing a low CO2/O2 selectivity that is within a pre-determined range (e.g. less than 5 or less than 4.5). In some embodiments, the upgraded biogas that is output from the system can be entirely made up of methane, carbon dioxide, and oxygen. In other embodiments, the biogas can be almost entirely composed of these components along with a small amount of nitrogen and a trace amount (e.g. less than or equal to 0.2%-0.1%, etc.) of other components.

Abstract: A method for separating a raw feed gas stream using a plurality of membrane separation stages includes separating a pressurized feed gas stream into a first nonpermeate stream and a first permeate stream, compressing the first permeate stream to form a compressed first permeate stream, separating the compressed first permeate stream into a second nonpermeate stream and a second permeate stream, separating the second permeate stream into a third nonpermeate stream and a third permeate stream, combining the third nonpermeate stream with a raw feed gas stream to form a combined feed stream, compressing the combined feed stream to form a compressed combined feed stream, and combining the second nonpermeate stream with the compressed combined feed stream to form the pressurized feed gas stream.

Abstract: A method for separating a raw feed gas stream using a plurality of membrane separation stages includes separating a pressurized feed gas stream into a first nonpermeate stream and a first permeate stream, compressing the first permeate stream to form a compressed first permeate stream, separating the compressed first permeate stream into a second nonpermeate stream and a second permeate stream, separating the second permeate stream into a third nonpermeate stream and a third permeate stream, combining the third nonpermeate stream with a raw feed gas stream to form a combined feed stream, compressing the combined feed stream to form a compressed combined feed stream, and combining the second nonpermeate stream with the compressed combined feed stream to form the pressurized feed gas stream.

Abstract: Process and apparatus for producing helium, neon, or argon product gas using an adsorption separation unit having minimal dead end volumes. A second separation unit receives a stream enriched in helium, neon, or argon, and a stream is recycled from the second separation unit back to the adsorption separation unit in a controlled manner to maintain the concentration of the helium, neon, or argon in the feed to the separation unit within a targeted range.

Abstract: Described herein is a first method of forming a hole in a workpiece, having a first surface and a second surface opposite the first surface. The method includes forming a first hole, having a first diameter, in the workpiece by passing a first cutter through the workpiece from the first surface to the second surface. Additionally, the method includes forming a chamfer in the second surface of the workpiece concentric with the first hole using a second cutter. The chamfer has a second diameter larger than the first diameter. The method further includes forming a second hole, having a third diameter larger than the first diameter, in the workpiece concentric with the first hole by passing a third cutter through the workpiece from the first surface to the second surface.

Abstract: Process and apparatus for producing helium, neon, or argon product gas using an adsorption separation unit having minimal dead end volumes. A second separation unit receives a stream enriched in helium, neon, or argon, and a stream is recycled from the second separation unit back to the adsorption separation unit in a controlled manner to maintain the concentration of the helium, neon, or argon in the feed to the separation unit within a targeted range.

Abstract: Described herein is a first method of forming a hole in a workpiece, having a first surface and a second surface opposite the first surface. The method includes forming a first hole, having a first diameter, in the workpiece by passing a first cutter through the workpiece from the first surface to the second surface. Additionally, the method includes forming a chamfer in the second surface of the workpiece concentric with the first hole using a second cutter. The chamfer has a second diameter larger than the first diameter. The method further includes forming a second hole, having a third diameter larger than the first diameter, in the workpiece concentric with the first hole by passing a third cutter through the workpiece from the first surface to the second surface.

Abstract: A go/no-go gauge for hole tolerance measurement incorporates a handle, a first pin having a first diameter extending from a first end of the handle and a second pin having a second diameter extending from a second end of the handle. A force measurement element is disposed between the ends of the handle and configured to provide an indication upon exceeding a predetermined force level when attempting to insert one of the pins into a hole.

Abstract: A process control system for controlling a set of outputs according to a multiplicity of inputs. The process control system analyzes the condition of the inputs as though they were arranged in a hypothetical ladder diagram which is a representation of the circuitry that would be required to control the loads if simple switches were interconnected, by wires, in the conventional way to control the loads. The hypothetical ladder diagram includes a plurality of hypothetical horizontal rows of circuit elements in which the circuit elements are also located in hypothetical vertical columns. All of the hypothetical vertical columns, except the last, are "input" vertical columns since they represent input circuit elements. The last vertical column contains the loads (or outputs) and is an "output" vertical column.

Abstract: Process and apparatus for conditioning whole-cell-containing physiological specimens such as those comprising mucous as a thickening agent. The specimen is made homogeneous, i.e. transformed into a single-cell suspension, and reduced markedly in viscosity by repeatedly being forced or sucked into and out of a small and relatively sharp-edged conduit positioned in a sample-holding container.