A MEMBRANE BASED PROCESS FOR THE UPGRADING OF BIOGAS TO SUBSTITUTED NATURAL GAS (SNG) AND RECOVERY OF CARBONDIOXIDE FOR INDUSTRIAL USE
Advancing the chemical engineering fundamentals
Membranes and Membrane Science - I (T2-8a)
Keywords: Carbon molecular sieve, gasseparation, gas upgrading, biohydrogen,
A low pressure carbon molecular sieve (CMS) membrane based process to upgrade biogas from anaerobic digestion of agricultural waste to a substitute natural gas (SNG) has been tested on a pilot scale. The data extracted from the pilot plant was used to estimate membrane permeance and ideal selectivity of the CO2/CH4 gas pair. Four semi-commercial modules were tested. The results show that by using a membrane cascade and by carefully choosing the CMS modules, it is possible to produce a stream containing at least 90 vol-% CH4 and a by-product containing at least 60 vol-% CO2. The substituted natural gas could be sold to the national grid and the latter by-product is intended for the production of liquified CO2, suitable for use in agricultural industries such as greenhouses. At a pressure level of 8-16 barg, this process could offer simplicity and less investment and maintenance than other technologies. CMS membranes are produced by pyrolysis of organic polymers, which is described in the presentation. The prospect of using CMS for gas separation can further be extended to separating hydrogen from gases made in an anaerobic process, the so-called biohydrogen process. In the presentation technologies for total separation of methane from carbondioxide will be presented together with a presentation of a combined anaerobic digester and a CMS membrane system for enhanced biohydrogen production.
See the full pdf manuscript of the abstract.
Presented Tuesday 18, 15:20 to 15:40, in session Membranes and Membrane Science - I (T2-8a).
