Abstract: A highly effective liquid-liquid extraction process to remove nitrogen compounds and especially basic nitrogen compounds from aromatic light petroleum oils with excellent recovery employs de-ionized water, which can be acidified, as the extractive solvent. The product is an aromatic hydrocarbon with ultra-low amounts of nitrogen poisons that can deactivate acidic catalysts. The extracted oils are suitable feedstock for the subsequent catalytic processes that are promoted with the high performance solid catalysts, which are extremely sensitive to nitrogen poison.

Abstract: A tray assembly is provided for improved gas/liquid contact when used in a large chemical process tower, resulting in better performance. Each tray assembly has two levels of tray decks and associated downcomers. Tray decks provide gas/liquid contact for mass transfer and the downcomers are required to clarify the liquid before entering the tray below. A novel downcomer configuration is provided for use in multipass trays. The shape of downcomer bottom chord is designed to allow for liquid to travel across any part of each tray deck at a similar distance between the inlet and the outlet weir. As a result, liquid on the tray deck travels in plug flow pattern. Benefits include a higher Murphree tray efficiency due to minimum liquid back-mixing, as well as minimum local entrainment due to uniform froth height.

Abstract: A highly effective liquid-liquid extraction process to remove nitrogen compounds and especially basic nitrogen compounds from aromatic light petroleum oils with excellent recovery employs de-ionized water, which can be acidified, as the extractive solvent. The product is an aromatic hydrocarbon with ultra-low amounts of nitrogen poisons that can deactivate acidic catalysts. The extracted oils are suitable feedstock for the subsequent catalytic processes that are promoted with the high performance solid catalysts, which are extremely sensitive to nitrogen poison.

Abstract: A multilevel LINC transmitter. The multilevel LINC transmitter comprises a multilevel signal component separator, a phase modulator block, and an RF block. The multilevel signal component separator comprises a multilevel scaler and converts a base band signal to constant envelope signals. The phase modulator block is coupled to the multilevel signal component separator. The RF block comprises a plurality of power amplifiers coupled to the phase modulator block and the multilevel scaler and a power combiner coupled to the power amplifiers.

Abstract: A method for performing a singular value decomposition (SVD) upon a matrix. The method includes the steps of: (a) simplifying the matrix to derive a simplified matrix; (b) performing an iterative matrix multiplication upon the simplified matrix to generate an iterated matrix; (c) extracting a vector of the iterated matrix according to an iteration number of the iterative matrix multiplication; (d) de-correlating the simplified matrix from the vector to update the simplified matrix; (e) repeating steps (b), (c), and (d) until a predetermined number of vectors have been derived; and (f) storing a first unitary matrix determined according to the predetermined number of vectors in the singular value decomposition.

Abstract: A process for recovering polar hydrocarbons from non-polar hydrocarbons, such as aromatics from non-aromatics, naphthenes from paraffins and isoparaffins, or olefins from paraffins and isoparaffins, in feed mixtures containing at least a measurable amount of heavier hydrocarbons. This improved extractive distillation (ED) process recovers aromatic hydrocarbons including benzene, toluene, and xylenes from the C6-C8 petroleum streams containing a measurable amount of C9+ hydrocarbons. The ED process also recovers benzene and toluene from the C6-C7 petroleum streams containing a measurable amount of C8+ hydrocarbons. The ED solvent utilized to recover and purify the aromatic hydrocarbons from the petroleum stream with a heavier than intended feedstock of hydrocarbons is also regenerated and recovered.

Abstract: An apparatus and process are described for recovery of a carboxylic acid by hydrolysis of an ester in a mixture comprising the ester, an alcohol and water. The apparatus comprises a catalytic distillation column containing an acidic catalyst and a distillation column. Simultaneously and interdependently the alcohol is catalytically dehydrated to the corresponding ether and water, and said water reacts with the ester to generate a carboxylic acid rich stream from the catalytic distillation column. The acid is recovered by distillation in the distillation column. The process requires no added water. A second embodiment of the apparatus and process has means to co-feed one or both of added methanol and/or water with the feed to maintain substantially optimum operation independent of feed composition.

Abstract: An apparatus is provided for improved gas/liquid contact in a chemical process tower, resulting in better performance. The apparatus includes a tower having a series of tray decks and downcomers. Tray decks provide gas/liquid contact for mass transfer and the downcomers are required to clarify the liquid before entering the tray below. In this invention, the trays have at least one downcomer and one adjacent active sump. The sump has at least one row of apertures for bubbling vapor through liquid flowing therein, and is separated from the downcomer by a baffle. The clarified liquid at the bottom of the sump is sent to the downcomer. The liquid entering the next tray can be assured to divide evenly for multiple-downcomer applications. Gas/liquid contact is thereby enhanced through the installation of these apertures, and clarification of the liquid from bubbles is thereby improved through the addition of the active sump. Benefits to the tower operation include higher tray capacity and efficiency.

Abstract: An energy efficient, high throughput process for aromatics recovery can be readily implemented by revamping existing sulfolane solvent extraction facilities, or constructing new ones, so as to incorporate unique process operations involving liquid-liquid extraction and extractive distillation. Current industrial sulfolane solvent based liquid-liquid extraction processes employ a liquid-liquid extraction column, an extractive stripping column, a solvent recovery column, a raffinate wash column, and a solvent regenerator. The improved process for aromatic hydrocarbon recovery from a mixture of aromatic and non-aromatic hydrocarbons requires transformation of the extractive stripping column into a modified extractive distillation column. The revamping incorporates the unique advantages of liquid-liquid extraction and extractive distillation into one process to significantly reduce energy consumption and increase process throughput.

Abstract: An efficient method for calculating the step-sizes for a frequency-domain equalizer of a discrete-multitone communications system using signal power estimation and tone grouping (SPE-TG) while on-line. The SPE-TG method is used to calculate a plurality of subchannel step-sizes which are then stored in a lookup table. When on-line, the method uses signal power estimation to select step sizes for each tone, and uses these step sizes for frequency domain equalization. The SPE-TG method simplifies the calculations necessary for frequency domain equalization, thereby saving significant hardware and/or processing resources. The SPE-TG method is reliable and robust, and does not depend upon assumptions about the line, location, or channel.

Abstract: The contact between, for example, ascending liquid droplets of lighter liquid, as the dispersed phase, and heavier liquid, as the continuous phase, flowing across perforated trays in a flooded liquid/liquid contacting column, is enhanced by providing upstanding baffles on lower trays, interspersed with depending baffles from the trays above. The baffles cause the heavy liquid to flow along an undulating path. Flow distributing partitions extend along the undulating flow path, between the baffles, to distribute liquid flow across the trays. The roles of the lighter liquid and the heavier liquid may be reversed as phases.

Abstract: A discrete multi-tone (DMT) communication system is provided herein, replacing the conventional inversed discrete Fourier transform (IDFT) and DFT with IDHT (together with the complex-to-real transformation) and a DHT alone respectively at the transmitting end and the receiving end. A DHT-based frequency-domain equalizer (FEQ) at the receiving end equalizes each of the 0-th to (N?1)-th DHT subchannels, where N is the number of point of the DHT. Finally, each of the 0-th to ( N 2 - 1 ) - th subchannels of the DMT system is obtained by combining the k-th and (N-k)-th subchannels of the DHT-based FEQ for k=0, 1, . . . , ( N 2 - 1 ) .

Abstract: Extractive distillation processes whereby water-soluble extractive distillation (ED) solvents are regenerated and recovered employ improved operations of the extractive distillation column (EDC) so that polar hydrocarbons are recovered and purified from mixtures containing polar and less polar hydrocarbons and measurable amounts of hydrocarbons that are heavier than intended feedstock and/or polymers that are generated in the ED process. The improved process can effectively remove and recover the heavy hydrocarbons and/or remove polymer contaminants from the solvent in a closed solvent circulating loop through mild operating conditions with no additional process energy being expended. With the improved process, the overhead reflux of the EDC may be eliminated to further reduce energy consumption and to enhance the loading and performance within the upper portion of the EDC, especially when two liquid phases exists therein.

Abstract: The present invention relates to a process for recovering polar hydrocarbons from non-polar hydrocarbons, such as aromatics from non-aromatics, naphthenes from paraffins and isoparaffins, or olefins from paraffins and isoparaffins, in feed mixtures containing at least a measurable amount of heavier hydrocarbons. According to the invention, an improved extractive distillation (ED) process is disclosed for recovering aromatic hydrocarbons including benzene, toluene, and xylenes (BTX aromatics) from the C6-C8 petroleum streams containing at least a measurable amount of C9+ hydrocarbons. The invention also relates to an improved ED process for recovering mainly benzene and toluene from the C6-C7 petroleum streams containing at least a measurable amount of C8+ hydrocarbons.

Abstract: The present invention provides a soft-threshold-based multi-layer decision feedback equalizer, including a feed forward filter for receiving a transmitted data, a feed backward filter, an adder and a soft-threshold-based multi-layer decision engine (STM engine). The adder is coupled to an output end of the feed forward filter and an output end of the feed backward filter, and generating an output of the equalizer. The STM engine includes a threshold detector, a data detector and a state machine. The STM engine detects whether or not the output of the equalizer is in a defined threshold value so as to determine the STM works as a slicer or delay decision.

Abstract: An energy-efficient extractive distillation process for producing anhydrous ethanol from aqueous/ethanol feeds containing any range of ethanol employs an extractive distillation column (EDC) that operates under no or greatly reduced liquid reflux conditions. The EDC can be incorporated into an integrated process for producing anhydrous ethanol used for gasoline blending from fermentation broth. By using a high-boiling extractive distillation solvent, no solvent is entrained by the vapor phase to the EDC overhead stream, even under no liquid reflux conditions. The energy requirement and severity of the EDC can be further improved by limiting ethanol recovery in the EDC. In this partial ethanol recovery design, ethanol which remains in the aqueous stream from the EDC is recovered in a post-distillation column or the aqueous stream is recycled to a front-end pre-distillation column where the ethanol is readily recovered since the VLE curve for ethanol/water is extremely favorable for distillation.

Abstract: A gas-liquid contactor baffle includes a body having a first portion, a second portion and a middle portion, the middle portion being positioned between the first portion and the second portion. The middle portion is a corrugated sheet having a first face and a second face. The corrugated sheet has alternating ridges and open ended channels extending across each of the first face and the second face between the first portion and the second portion. The first portion has a first collection channel adapted to collect liquids from the open ended channels of the middle portion when flow is along the first face in a first direction. The second portion having a second collection channel adapted to collect liquids from the open ended channels of the middle portion when flow is along the second face in a second direction.

Abstract: A tray assembly is provided for improved gas/liquid contact when used in a large chemical process tower, resulting in better performance. Each tray assembly comprises two levels of tray decks and associated downcomers. Tray decks provide gas/liquid contact for mass transfer and the downcomers are required to clarify the liquid before entering the tray below. In this invention, a novel downcomer configuration is provided for use in multipass trays. The shape of downcomer bottom chord is designed to allow for liquid to travel across any part of each tray deck at a similar distance between the inlet and the outlet weir. As a result, liquid on the tray deck travels in plug flow pattern. Benefits of this invention are higher Murphree tray efficiency due to minimum liquid back-mixing, as well as minimum local entrainment due to uniform froth height.

Abstract: An on-chip data transmission device. The on-chip data transmission device comprises a transmitter and a receiver. The transmitter transmits a control signal and a packet when a logic level of the control signal changes, wherein the logic level of the control signal changes every clock cycle, and the clock cycle is determined by an input signal clock A. The receiver receives the transmitted control signal and a clock B having a clock rate as same as clock A, generates a mixed clock having a phase substantially the same as the phase of the clock B, and receives one transmitted packet per clock B cycle.

Abstract: An apparatus is provided for improved gas/liquid contact in a chemical process tower, resulting in better performance. The apparatus comprises a tower having a series of tray decks and downcomers. Tray decks provide gas/liquid contact for mass transfer and the downcomers are required to clarify the liquid before entering the tray below. In this invention, the trays have at least one downcomer and one adjacent active sump. The sump has at least one row of apertures for bubbling vapor through liquid flowing therein, and is separated from the downcomer by a baffle. The clarified liquid at the bottom of the sump is sent to the downcomer. The liquid entering the next tray can be assured to divide evenly for multiple-downcomer applications. Gas/liquid contact is thereby enhanced through the installation of these apertures, and clarification of the liquid from bubbles is thereby improved through the addition of the active sump. Benefits to the tower operation include higher tray capacity and efficiency.