**3.3 Value-added materials**

Likewise for the above-mentioned and further chemicals that can be obtained from methane by fermentation, there is a sound market. Like SCP and biopolymers, they can be produced virtually without requiring (agricultural) land. Decoupling manufacturing from both crude oil and farming activities is attractive as it relieves pressure on existing feed and food value chains. When we estimate that between 500 and 1000 million tons of chemicals are to be made from other sources than oil, at again a rough value of 1 g methane per g of product, we end up with 16–32% of natural gas consumption per year.

#### **Figure 7.**

*Graphical depiction of annual natural gas demand for theoretically meeting the entire feedstock demand for SCP, plastics, and chemicals, compared to the natural gas production figures in IEA's scenarios STEPS, APS, and NZE, which span 3300–4500 billion m3 /year annual demand between 2010 and 2030 (compare Figure 7).*

## **3.4 Scenario of methane as sole feedstock**

So if we were to produce "all" global demand for protein, plastics, and chemicals from natural gas, which for sure is an exaggerated assumption, we would require approximately 1/3 to 1/2 of the annual natural gas production of today. Let us revisit briefly **Figure 7** and add the above estimations to it:

Also, biogas could cater to that raw material need. Production volumes are not yet close to 2000 billion m<sup>3</sup> per year, but several studies suggest that that potential is within reach.

The authors are firmly convinced that methanotrophic gas fermentation is the key enabling technology to succeed in abandoning crude oil as universal feedstock, by allowing cost-effective and scaleable production of protein, plastics, and chemicals, in a sustainable way, by avoiding the need for immense agricultural and associated production factors, such as water, fertilizer, and pesticides. As Liew et al. have started in their review article [49]—gas fermentation offers a flexible platform for large, industrial-scale production of low-carbon-fuels and chemicals from various feedstocks. This view is shared by other researchers, see Ref. [176].
