Process for recovering carbon monoxide from catalytic fast pyrolysis product

#The present invention relates to an improved process for recovering carbon monoxide from a catalytic fast pyrolysis process product effluent.

#The needs for travel and consumer goods have driven the ever increasing consumption of fossil fuels such as coal and oil, typically obtained from deep underground. The extraction of fossil fuels by mining and drilling has often been accompanied by environmental and political costs. Furthermore, as the more accessible sources of fossil fuels are being used up; this has led to the pursuit of more expensive extraction technologies such as fracking and deep sea drilling. Additionally, the consumption of fossil fuels causes higher levels of atmospheric carbon, typically in the form of carbon dioxide.

#To reduce these problems, there have been extensive efforts made in converting biomass to fuels and other useful chemicals. Unlike fossil fuels, biomass is renewable and carbon-neutral; that is, biomass-derived fuels and chemicals do not lead to increased atmospheric carbon since the growth of biomass consumes atmospheric carbon.

#FIG. 1 is a schematic illustration of a process for converting biomass into aromatics and CO.

#FIG. 2 is a schematic illustration of a process for converting biomass into aromatics and CO.

#FIG. 3 is a schematic illustration of a process embodiment of the present invention.

#As a result of extensive research in view of the above, we have found that we can economically and effectively recover CO from a CFP process product effluent by separating and recovering at least a portion of the product of the CFP process into various phase fractions, and recovering CO by way of a series of sequential steps.

#The present improved process comprises steps of: a) providing a first vapor phase stream resulting from a CFP process comprising, on a water-free and solids-free basis, from 25 to 80% CO and at least 15% CO2, b) mixing the first vapor phase stream of step a) with solvent having an absorption capacity for CO2 that is at least 5 times the absorption capacity of the solvent for CO to make a mixed phase stream, c) separating the mixed phase stream of step b) into a second vapor phase stream comprising CO and a liquid phase stream, and d) recovering a product stream from the second vapor phase stream of step c) having a higher concentration of CO and a lower concentration of CO2 than the first vapor phase stream of step a); optionally followed by steps of: e) further separating the liquid phase stream of step c) to form a third vapor phase stream comprising CO2, and f) recovering a second product stream comprising at least 50% CO2 from the third vapor phase stream of step e); optionally followed by step: g) recycling at least a portion of the second product stream of step f) to the CFP process from which the first vapor phase stream comprising CO of step a) results.

#As used herein, the terms “aromatics” or “aromatic compound” refer to a hydrocarbon compound or compounds comprising one or more aromatic groups such as, for example, single aromatic ring systems (e.g., benzyl, phenyl, etc.) and fused polycyclic aromatic ring systems (e.g., naphthyl, 1,2,3,4-tetrahydronaphthyl, etc.). Examples of aromatic compounds include, but are not limited to, benzene, toluene, indane, indene, 2-ethyltoluene, 3-ethyltoluene, 4-ethyltoluene, trimethylbenzene (e.g., 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, 1,2,3-trimethylbenzene, etc.), ethylbenzene, styrene, cumene, n-propylbenzene, xylenes (e.g., p-xylene, m-xylene, o-xylene), naphthalene, methylnaphthalene (e.g., 1-methylnaphthalene), anthracene, 9,10-dimethylanthracene, pyrene, phenanthrene, dimethyl naphthalene (e.g., 1,5-dimethylnaphthalene, 1,6-dimethylnaphthalene, 2,5-dimethylnaphthalene, etc.), ethyl naphthalene, hydrindene, methylhydrindene, and dimethylhydrindene. Single ring and/or higher ring aromatics may also be produced in some embodiments. Aromatics also include single and multiple ring compounds that contain heteroatom substituents, i.e., phenol, cresol, benzofuran, aniline, indole, etc.