Abstract:
There is provided a process for recovery of lignin from a black liquor that contains either soluble or dispersed lignin, generating a "liquid lignin" at high yield. Soluble lignin at elevated pH is precipitated by reducing the pH of the black liquor stream by countercurrent reaction with carbon dioxide, at elevated temperature and pressure, creating two bulk fluid phases: a heavy lignin-rich phase and a light lignin- depleted phase. The heavy lignin-rich phase is separated and washed countercurrently with a strong acid to displace metal cations from the lignin, creating a low-salt lignin, which is then formed into a low-dust high-bulk-density lignin fuel pellet. If needed, especially for lignin recovered from kraft papermaking black-liquor streams, an oxidation step is included to eliminate negative odor for high-value green-chemistry applications.
Abstract:
A multivariate optical computing and analysis system includes a light source configured to radiate a first light along a first ray path; a modulator disposed in the first ray path, the modulator configured to modulate the first light to a desired frequency; a spectral element disposed proximate the modulator, the spectral element configured to filter the first light for a spectral range of interest of a sample; a cavity disposed in communication with the spectral element, the cavity configured to direct the first light in a direction of the sample; a tube disposed proximate the cavity, the tube configured to receive and direct a second light generated by a reflection of the first light from the sample, the tube being further configured to separate the first and second lights; a beamsplitter configured to split the second light into a first beam and a second beam; an optical filter mechanism disposed to receive the first beam, the optical filter mechanism configured to optically filter data carried by the first beam into at least one orthogonal component of the first beam; and a detector mechanism in communication with the optical filter mechanism to measure a property of the orthogonal component to measure the data.
Abstract:
A method of classifying information in an optical analysis system includes obtaning calibration data defining a plurality of data points, each data point representing values for two or more detectors when sampling a material [W] used to construct a multivariate optical element [38]. Based on the calibration data, one or more validation models can be developed to indicate one or more ranges of expected results. Validation data comprising the models can be used to compare data points representing values for two or more detectors when performing a measurement of a material to determine if the data points fall within an expected range. Classification data can be generated based on the comparison and, in some embodiments, one or more indicators, such as a confidence level in a measurement, can be provided.
Abstract:
A method of selecting components for a multivariate optical computing and analysis system to isolate a spectral region includes selecting a spectral region of interest; selecting a spectral element with a predetermined transmission characteristic to control a spectral range of an illumination source; illuminating a sample with the illumination source; and analyzing an optical frequency returned by the sample relative to the spectral region of interest.
Abstract:
A method of arranging and utilizing a multivariate optical computing and analysis system includes transmitting a first light from a light source; generating a second light by reflecting the first light from the sample; directing a portion of the second light with a beamsplitter; and arranging an optical filter mechanism in a normal incidence orientation to receive the portion of the second light, the optical filter mechanism being configured to optically filter data carried by the portion of the second light.
Abstract:
A process for making furfural using papermaking black liquor from the kraft pulping process as a feed material. First, the lignin is removed from the black liquor by carbonizing the black liquor to a pH below pH 10 to insolubilize the lignin, neutralize NaOH and other inorganic components of the black liquor. The next step is to treat the carbonated black liquor that contains the hemicellulose to remove the high molecular weight components. In a preferred embodiment the treatment uses multiple sequential steps. The first step of the treatment is to use ultrafiltration, centrifugation or dissolved- air floatation to separate the high molecular weight components. The second filtration is to pass the hemicellulose containing black liquor stream through a nanofilter to remove low molecular weight components. The conversion of xylans in the hemicellulose- containing mixture to furfural is accomplished using a catalytic process. The xylans are converted to pentose sugars and then converted to furfural. The furfural is formed at a low concentration and then further concentrated.
Abstract:
A method of using multivariate optical computing in real-time to collect instantaneous data about a process stream includes installing an optical analysis system proximate a process line, the process line being configured to move a material past a window of the optical analysis system; illuminating a portion of the material with a light from the optical analysis system; directing the light carrying information about the portion through at least one multivariate optical element in the optical analysis system to produce an instantaneous measurement result about the portion; and continuously averaging the instantaneous measurement result over a period of time to determine an overall measurement signal of the material.
Abstract:
This invention provides improvements to processes for making granular lignin from black liquor. One of the improvements is that the use of a pre-carbonation column reduces the CO2 flow into the sparger of a carbonation column. The pre-carbonation column is used to reduce the pH of the black liquor to about 12. Another improvement is that it has been found that coalescing droplets into a bulk liquid-lignin phase can be enhanced by placing the exit of the carbonation column at or slightly beneath carbonated black liquor/liquid-lignin interface. It has also been found that operating the carbonation settler at a low pressure and pumping the liquid- lignin from the carbonation settler to the acidification reactor operating at a higher pressure allows recycling the vent gas from the acidification reactor to the pre-carbonation column. The invention also provides for a vent gas absorber.
Abstract:
There are provided processes for recovering a "heart-cut" liquid-lignin fraction from a lignin-containing stream such as a black liquor stream from a paper making process or the crude lignin stream within a non-destructive biomass conversion process by carbonating, acidifying and recovering the liquid-lignin fraction. The processes generally include reacting black liquor with a carefully selected amount of carbon dioxide (C02), to decrementally reduce the pH of the black liquor and produce fractions of a dense liquid-lignin precipitate at each pH decrement to about a pH of 8. The sequential reduction in pH is less than or equal to about 1.5 in most embodiments, less than 1.0 in other embodiments, and less than 0.50 in still other embodiments. It has been discovered that lignin recovered from the dense liquid-lignin precipitate at the different pH decrements can have different molecular weight ranges and/or structures. This process provides an improved lignin with a more narrow distribution of molecular weight, melt point, and chemical structure that is more suitable for high- value polymer applications.
Abstract:
A process for recovery of lignin from black liquor that contains either soluble or dispersed lignin by generating a "liquid lignin" at high yield is disclosed. Soluble lignin at a high pH is precipitated by reducing the pH of the black liquor stream by countercurrent reaction with carbon dioxide, at elevated temperature and pressure, creating a heavy lignin-rich phase and a light lignin-depleted phase. The heavy lignin- rich phase is separated and washed countercurrently with a non-sulfur containing acid, such as acetic acid, to displace metal cations from the lignin, creating a low-salt lignin, which is then formed into a low-dust, high-bulk density lignin fuel pellet. If desired, an oxidation step may be used to eliminate odor for lignins having high value green chemistry applications.