Abstract:
Embodiments relate generally to systems and method for processing tars to produce benzene, toluene, and xylene (BTX). A method for processing tars may comprise distilling the tars to separate creosotes and pitch; and processing the pitch via hydropyrolysis, including both hydrogenation and hydrocracking functions, to remove heteroatoms and break down polyaromatics in the pitch and produce monoaromatics, such as BTX. A system for processing tars may comprise one or more of the following: an input stream comprising tars feeding into a column; the column configured to separate the tars into one or more creosote streams and a pitch stream; and a reactor (or a series of reactors, or beds within a single reactor), wherein the pitch stream is fed to the reactor along with a stream of hydrogen, wherein the reactor is configured to break down the pitch to produce BTX.
Abstract:
A LNG liquefaction plant includes a propane recovery unit including an inlet for a feed gas, a first outlet for a LPG, and a second outlet for an ethane-rich feed gas, an ethane recovery unit including an inlet coupled to the second outlet for the ethane-rich feed gas, a first outlet for an ethane liquid, and a second outlet for a methane-rich feed gas, and a LNG liquefaction unit including an inlet coupled to the second outlet for the methane-rich feed gas, a refrigerant to cool the methane-rich feed gas, and an outlet for a LNG. The LNG plant may also include a stripper, an absorber, and a separator configured to separate the feed gas into a stripper liquid and an absorber vapor. The stripper liquid can be converted to an overhead stream used as a reflux stream to the absorber.
Abstract:
A method of producing syngas comprising receiving raw syngas from a gasification unit; introducing the raw syngas and water to a syngas scrubber to produce unshifted syngas; introducing a first portion of unshifted syngas to a first cooling unit to produce cooled unshifted syngas and a first aqueous condensate comprising cyanide in an amount of 5-200 ppmw; recycling the first aqueous condensate to the syngas scrubber; introducing a second portion of unshifted syngas to a water gas shift unit to produce shifted syngas; introducing the shifted syngas to a second cooling unit to produce cooled shifted syngas and a second aqueous condensate comprising cyanide in an amount of less than 2.5 ppmw; contacting the cooled shifted syngas with the cooled unshifted syngas to produce modified syngas; and introducing the second aqueous condensate to a sour water stripper to produce stripped water and an acid gas comprising H2S, CO2, and ammonia.
Abstract:
A contiguous duct assembly has first and second ducts that share at least one common wall element. An expansion joint is formed at the end of the contiguous duct assembly using a connector element that extends with respective portions into the internal spaces of the first and second ducts. First and second expansion fabrics are coupled to the respective portions from the inside of the ducts using fasteners that are accessible from and disposed within the internal space of the first and second ducts.
Abstract:
A method of treating sour water from industrial processes such as coal gasification. The method includes injecting a polysulfide into a sour water stream to convert cyanide to thiocyanate, thereby reducing the corrosiveness and toxicity of the sour water stream. The method also includes the step of mixing the sour water stream with a reactant to remove CO2 in its various forms in a reaction tank and subsequently routing the stream to a solid settler. The method further includes adjusting the pH of the sour stream in a pH correction tank before sending the sour water stream through a stream stripper for H2S and/or NH3 removal. After passing through the stripper, the treated sour water stream is sent to a biological treatment process for thiocyanate and formate removal. Subsequent treatment steps can be applied, such as multi-grade filters and activated carbon filters, to prepare the treated sour water for reuse.
Abstract:
Variable N2 content in feed gas ranging from 3 mol % to 50 mol % can be rejected from the process using a feed exchanger that is fluidly coupled with a cold separator and a single fractionation column to produce a nitrogen vent stream and streams that are suitable to be further processed for NGL recovery and LNG production.
Abstract:
A friction stir welding (FSW) tool tip is described. The tool tip comprises a pin portion and a body portion that meet to form a shoulder. The tool tip has a graduated change in composition along its length. In some embodiments, the alloy composition near the end of the pin differs from the alloy composition of the body by at least 0.5% by wt of at least one element. A method of manufacturing a FSW tool tip having a gradual compositional change is also described.
Abstract:
Friction Stir Welding (FSW) devices and methods for simultaneously welding both sides of an arcuate joint are described. The FSW method includes the step of operating a FSW tool and an anvil on the exterior surface of the joint and simultaneously operating another FSW tool and anvil on the interior surface of the joint. The anvils are positioned in a juxtaposing manner to the FSW tools, and move in tandem with the FSW tools, thus providing a supporting force to the FSW tools during their operation.
Abstract:
A natural gas liquids plant uses a demethanizer and a deethanizer in a two-column or single column configuration that can be used for ethane recovery and ethane rejection. During ethane recovery, 95% ethane recovery and 99% propane recovery are achieved, while during ethane rejection the sales gas Wobbe Index requirement is maintained while maintaining 95% propane recovery. A residue gas recycle exchanger is most preferably configured to use the demethanizer overhead product to either cool a portion of the residue gas and a portion of the feed gas during ethane recovery, or to cool a portion of the feed gas using two distinct heat transfer areas to produce a feed gas reflux at significantly lower temperature.
Abstract:
A method of diverting municipal solid waste (MSW) from a landfill that includes receiving, at a MSW processing system, a quantity of MSW, gasifying the quantity of MSW in a gasification unit to yield a syngas stream and biochar stream, converting at least a portion of the syngas to mixed alcohols in an alcohol synthesis unit, separating the mixed alcohols into one or more alcohol products, and determining a carbon offset for diverting the MSW from the landfill to the MSW processing system.