Patent · US Active

Methods and apparatus for recycling tail gas in syngas fermentation to ethanol

US11857923B2 · kind B2 · utility

1Cited by
2References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 1, 2021
Grant dateJan 2, 2024
Priority date
Expiry dateMar 23, 2042

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P20/59
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

The invention present provides a method (and suitable apparatus) to convert biomass to ethanol, comprising gasifying the biomass to produce raw syngas; feeding the raw syngas to an acid-gas removal unit to remove at least some CO2 and produce a conditioned syngas stream; feeding the conditioned syngas stream to a fermentor to biologically convert the syngas to ethanol; capturing a tail gas from an exit of the fermentor, wherein the tail gas comprises at least CO2 and unconverted CO or H2; and recycling a first portion of the tail gas to the fermentor and/or a second portion of the tail gas to the acid-gas removal unit. This invention allows for increased syngas conversion to ethanol, improved process efficiency, and better overall biorefinery economics for conversion of biomass to ethanol.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.