FAQ

1. What are process strengths?

Our biggest assets are robustness towards impurities and poisons and intermittent operation. We manage to to produce methane of natural gas quality under intermittent, frequently changing feed composition switching between extremes (“gas in”, max. feed flow and “gas off”/0 feed) within minutes.

Our response from zero feed to full operational load is in the range of seversal minutes (see Fig. 1).

During stand-by no energy is needed (no heat, no stirring, no pumps) which minimizes operating cost (see Fiig. 1).

Fig. 1 Intermittency of Krajete® Process with instant methane production and no energy consumption during transition periods in stand-by (follow the blue curve, H2, which symbolizes electrolytic H2 and therefore stored electricity and compare to black curve (methane production).
Our process is simple, robust, highly economical, selective and it highly responsive to fast operational changes. Our process is tailored to the storage of excess electricity.

Our process is therefore tailored for all applications that need intermittend operation. It combines a fast response to changing feed conditions while minimizing energy consumption in periods of transition where little/no methane is produced. It is ideally suited for instant storage of electricity as methane.

Our process can extract and convert H2 and CO2 from gas mixtures in presence of other gas components (inerts, poisons, impurities; see application 2) without gas separation and without gas purification. This massively reduces process complexity.

„Intermittency“ and „selectivity“ can be combined in a „power to gas“ scenario with industrially available CO2 (application 3).

Fig. 1 Intermittency
Fig. 1 Intermittency

2. What is the product purity?

Our goal is to convert CO2 and H2 based feed gas into a product using a single step approach. This implies that all feed gas is converted to methane. We reach > 95 vol. % methane purity. In case higher purity level are needed, a simple and economically attractive purification step would be necessary.

This high product purity differentiates our process from others.

3. What can be done with the product „methane”?

Our product methane can be used in a number of applications:

  • Thermal: e.g. heater
  • Mechanical: e.g. CNG cars
  • Electric: e.g. combined heat power
  • Chemical: synthetic building block or intermediate on the way to higher value products

4. Which CO2 sources can Krajete® Process employ?

Our process can directly convert a big variety of CO2 sources. This is one of the main advantages we offer. We have already successfully demonstrated the feasibility of our process with different industrial (real) gas sources through on site feed sampling.

Our CO2 sources are:

  • Combustion gas based on petrol, Diesel as fuel
  • Syngas from steel industry
  • Syngas from waste incineration
  • Raw biogas
  • Purified biogas
  • CO2 from biogas

In 90 % of all cases industrial feed could be directly utilized without purification.
This is based on unprecedented selectivity and robustness using an ancient metabolic process of Archaea microorganisms which has been further optimized in Krajete process. These assets can be quantified and directly translated into a tangible economic customer benefit. It is our competitive advantage!

Please contact us at info@krajete.com in case you have different CO2 sources for methanation as stand alone component or in a wider context, e.g. within a “power to gas” frame.

5. What are preferred CO2 sources?

Our process can cope with different CO2 sources independent of the CO2 concentration. CO2 can be the major but also a minor component in corresponding gas mixtures.

This circumstance massively reduces the upstream efforts (gas upgrading), consequently a major CAPEX driver can be saved. Nevertheless economic implications of the CO2 concentration in the feed gas are significant. As a rule of thumb it can be stated that higher CO2 concentrations in the feed gas enable economically more viable process solutions. Byproducts in the feed gas which are not CO2, H2 or CH4, need to be removed from the product gas at a later stage unless product purity demands are low.

Therefore best CO2 candidates stem from following sources:

  • CO2 from fermentation (food industry, chemical industry)
  • Biogas (independent of its purity, native biogas or cleaned biogas)
  • Pyrolysis/Gasification Gas mixtures with both CO2 and H2
  • Combustion (high air concentration)
  • Combustion (low air concentration)

6. Which experience do you have with industrial gases (real gases)?

We are experienced in sampling, handling and evaluation of real industrial gases. Since 2012 we have been evaluating various industrial CO2 and H2 containing streams. We are familiar with the impurity tolerance of our process, and we can therefore provide the right gas source and composition depending on your needs.

7. Which H2 sources can Krajete® Process cope with?

Our process can cope with a variety of H2 sources. We have tested pure hydrogen and synthetic H2 containing mixtures. From today`s perspective hydrogen is no issue. In analogy to CO2 it can be stated: the higher the H2 purity the more economical the overall process becomes.

8. What are preferred H2 sources?

a) Electrolytic hydrogen. Hydrogen from water electrolysis is usually very pure, and it can be directly used for methanation purpose.

a) Syngas mixtures. Hydrogen in syngas and syngas like mixtures arising from pyrolysis or gasification is well tolerated in our process. Mot impurities are well handled in methanogenesis which is a key differentiating feature compared to chemical hydrogenation processes.

Hydrogen is usually a good process fit regardless of its origin and composition.

9. What is the process efficiency?

The process efficiency during methanation is close to 83 %. The overall efficiency in a wider context depends on periphery and overall process boundaries.

We have intentionally favored the biological methanation process over the chemical analog (“Sabatier”, CO2 hydrogenation). Biological processes are in general milder due to lower temperature and low pressure.

10. Are microbes dangerous?

No. Our microbes stem from a natural environment, they are not genetically manipulated.

11. What happens to biomass?

Our process does not require classic biomass as substrate for fermentation. Our biomass acts as “living catalyst”. This explains why our process yields comparably low waste biomass.
There are 2 ways of further biomass utilization.
Classic biomass disposal is based on a short air contact. Microbes turn into matter, and they are returned back to Nature.
In case further utilization is required, biomass can be used as biogas substrate or fertilizer which would provide synergies and alternative pathways for value creation.

12. What does your process need to produce natural gas?

The process is astonishingly sufficient, the only requirements are:

  • Microbes
  • Nutrients, simple
  • Temperature, redox, pH in the right regime
  • Bioreactor and periphery
  • Process automation, therefore little personnel involvement
  • Technical know-how to operate the process and exploit its advantages such as intermittent operation and selectivity for maximum performance

13. What do you provide microorganisms as nutrients?

Nutrients are usually components similar to fertilizer ingredients. They are simple, cheap and available in large scale. Price is stable, there are no supply shortages nor price fluctuations like in rare earth metal markets.

14. Who are your customers?

Our customers usually come from different industrial areas. Their main motivation is to store electricity, convert CO2 or generate CO2 neutral CH4.

Our customers have the following background:

  • Automotive (international)
  • Power production (international)
  • Mechanical (national, international)
  • Engineering (national)
  • Steel (international)
  • Biogas Production (national)
  • Energy Providers on Municipality Level (national)
  • Municipalities (national)

15. Since when have you been operating the process?

We started conceptual work in 2007, and we started to produce methane end 2009.