This document discusses the future of small scale biogas upgrading using membrane separation technology. Membrane separation is well-suited for small scale upgrading due to its compact size, simple on/off operation, low cost, flexibility, and high uptime with only biannual human interaction needed. New high selective membrane materials can further reduce methane slip to below 1% while achieving over 98% energy efficiency. DMT has developed a small containerized membrane upgrading system called Carborex MS that is low in capital and operating costs and well-suited for remote transportation of biogas or upgraded biomethane through a "virtual pipeline" system.

1. High selective membranes
Future of (small scale) biogas upgrading
R. Lems M.Sc. , R&D Manager
DMT Environmental Technology
Rlems@dmt-et.nl

2. Thema C- Biogas Utilization
Focus biogas upgrading + transportation
DMT: Development small scale upgrading
Clean Miles: Development virtual pipeline
Eneco: Case development
Hanze: Research and Support

3. Substance %
Methane, CH4 45-75
Carbon dioxide, CO2 25-45
Carbon monoxide, CO 0-0,3
Nitrogen, N2 1-15
Water, H2O Saturated
Hydrogen sulfide, H2S 0,1-0,5
Oxygen, O2
traces
Siloxane, R2SiO

4. Choice for (large scale )biogas upgrading?
PWS: Pressurized Water Scrubbing
+ Low investment and operational cost
+ Low methane slip 0.8 %
+ High energy efficiency >96%
+ Proven technology
+ No chemicals
- Complexity

5. Choice for small scale biogas upgrading?
Importance of
•Energy efficiency ?
=>Biogas utilization and running hours.
•Flow variations ?
=>Max flow is 200m3/hr
•Available manpower
=> None
•Methane emissions ?

6. Choice for small scale biogas upgrading?
MS: Membrane Separation
+ Compact
+ Simple on/off
+ Cheap
+ 100% biogas utilization/ flexibility
+ Highest operational up time
+ 2 times per year human interaction.
+ CO2 reuse
- High methane slip (conventional)

7. Why small scale biogas upgrading?
>90% of possible biogas production sites are <200m3/hr.
60-80% of possible biogas capacity is from small scale site.
50-200Nm3 biogas equals 35-150 l diesel
=> 170.000-1.450.000 euro/a

8. Small scale upgrading with membranes
CO2
Biogas Green gas

9. Membranes separation
J= (k . D . Δp ) / l
J= Flux
k= Solubility of CO2 in the polymer
D= Diffusion coefficient of CO2
through the polymer
Δp = The pressure difference
over the membrane
l = The thickness of the membrane

10. 60
HS Membranes

12. Multi stage

13. 200,0%
180,0%
160,0%
Competing
140,0%
Recylce Stream % membranes
120,0%
100,0%
80,0% High Selective
60,0%
membranes
40,0%
20,0%
0,0%
10 20 30 40 50 60 70
Membrane selectivity CO2/CH4

14. Biogas:
CH4 (53,3%) 35% recycle
CO2 (46%) Mixer
H2O (0,1%)
Recycle
N2 (0,5%)
O2 (0,1%) Stream
Membrane Cascade for
upgrading
Biomethane OFF Gas
CH4 > 97% < 0.5% CH4

15. Choice for (small scale) biogas upgrading?
MS: Membrane Separation
+ Compact
+ Simple on/off
+ Cheap
+ 100% biogas utilization
+ Highest operational up time
+ 2 times per year human interaction.
+ CO2 reuse
+ High methane slip ( Conventional ))
- Low High selective

16. DMT Carborex ® MS
+ 0,2 kWh/ Nm3
+ 0,3% CH4 slip
+ Energy efficiency > 98%
+ Operation reliability >98%
+ Plug and play
+ Containerized
+ Low in CAPEX and OPEX
- Price linear with membranes

18. SAT test at Acrres

20. Virtual pipeline
• For remote places and low flows (where pipeline are too expensive)
• Easy transport and utilization of gas @ 250 bar
• Transport of biogas and/ or greengas
• Alternative for local use of CBG (mobile CHP/ holiday houses)

21. Case Ameland

23. High selective membranes Future
of (small scale) biogas upgrading
R. Lems M.Sc. , R&D Manager
DMT Environmental Technology
Rlems@dmt-et.nl