Food without agriculture: high-tech food solutions

The chemical synthesis of food from carbon dioxide (CO2) offers an interesting nonbiological pathway for producing essential nutrients. Carbohydrates such as glucose, glycerol, and propylene glycol can be synthesized from CO2, water, and electricity through electrochemical and thermochemical reactions. While current power-to-food efficiencies range from 10-21%, with a theoretical maximum of 31-73%, these processes are feasible due to the widespread availability of CO2, water, and electricity. The cost of producing artificial carbohydrates varies depending on energy costs, with a nominal cost of at least $1.15/kg.

Recent advancements in the formose reaction have enabled the selective synthesis of digestible sugars from CO2-derived formaldehyde. The process, developed by Air Company, uses CO2 and hydrogen gas from water electrolysis, combined with a chiral catalyst, to produce primarily digestible sugars like d-glucose and d-ribose. This method, which won the 2021 NASA CO2 conversion challenge, shows potential for scalable sugar production, though further optimization is needed. 

Glycerol can also be synthesized from CO2 and water through electrochemical methods, though food safety and scalability remain unproven. As systems for converting CO2 to formic acid reach pilot scale, additional research is needed to establish its viability as a resilient food technology. 

Recommended Research Areas

Study and develop neglected pathways for affordable food synthesis from CO2.

Single Cell Protein (SCP) is a nutritious food source produced through fermentation technologies. Gas, liquid, and solid fermentation can be used to produce food from inedible plants, fossil fuels, industrial and agricultural byproducts, and even CO2 from the air as carbon substrates. The protein is nutritionally complete and can be incorporated into various food products. 

Solid-state fermentation involves using a solid substrate with minimal or no water, enabling the production of SCP from materials like lignocellulosic biomass. For instance, enzyme-producing fungi can saccharify sugarcane bagasse — the material leftover from crushing sugarcane to extract their juice — converting it into sugar for further fermentation. A more unconventional approach has explored growing SCP on plastic substrates like polyethylene terephthalate (PET). The team working on this estimated that “If all PET waste (32 million tonnes per year) was converted with 100% efficiency into human food, we could supply ~4% of the global carbon consumption [of food]”.

In terms of photosynthetic microorganism cultivation, microalgae are particularly relevant. They are single cell photosynthetic organisms which grow in water using CO2 as a carbon source. Microalgae grow naturally in aquatic environments, but can be cultivated in either closed photobioreactors or artificial open ponds, or a hybrid of both. They are an excellent source of protein, fatty acids, and essential vitamins. Microalgae have very fast growth rates, are more efficient than plants at converting sunlight into energy, and have minimal biomass waste. Spirulina, a well-known type of microalgae, has been consumed for centuries.

Recommended Research Areas

Advance research into solid-state fermentation and improve cost-efficiency of microalgae cultivation.

Single Cell Protein (SCP) is a nutritious food source produced through fermentation technologies. Gas, liquid, and solid fermentation can be used to produce food from inedible plants, fossil fuels, industrial and agricultural byproducts, and even CO2 from the air as carbon substrates. The protein is nutritionally complete and can be incorporated into various food products. 

SCP can be produced through liquid fermentation using a variety of materials: methanol, formate, acetate, lignocellulosic biomass, and petroleum-derived products.

In the past, ICI developed methanol-based SCP (Pruteen™). Currently, companies like Farmless aim to commercialize SCP from methanol sourced from renewable feedstocks. This process has significant potential, especially as methanol offers a viable carbon source for large-scale production.

Quorn™, the major SCP product being commercialized directly as food today, is a direct descendant of the historical ICI industrial process for methylotrophic SCP production. The most notable difference is that Quorn™ uses agricultural sugar as the main feedstock rather than methanol, so it is not independent from agriculture and thus less resilient to loss of agricultural function, such as in an ASRS. Instead, SCP from lignocellulosic sugar would work better, as it can be sourced from wood and agricultural residues, bypassing dependence on traditional farming. 

SCP from petroleum-derived products, primarily from paraffin wax, was historically produced by companies like British Petroleum but was abandoned due to environmental permit issues and high input costs.

Recommended Research Areas

Generate open source front-end engineering design packages. 

Generate rapid deployment plans and operational guides.

Perform a 24/7 repurposing pilot of a liquid fermentation SCP factory.

Single Cell Protein (SCP) is a nutritious food source produced through fermentation technologies. Gas, liquid, and solid fermentation can be used to produce food from inedible plants, fossil fuels, industrial and agricultural byproducts, and even CO2 from the air. The protein is complete and can be incorporated into various food products. 

Two notable types of SCP are derived from gases like methane (CH4) and carbon dioxide (CO2) combined with hydrogen (H2), demonstrating high potential as resilient food solutions.  

SCP from methane utilizes organisms that convert methane, sourced from natural gas or biogas, into high-protein microbial biomass. This process shows great promise as methane is abundant and underutilized. Companies like Calysta Inc. and Unibio A/S are advancing this technology. While challenges remain, including high energy use and capital investment, recent models suggest methane-based SCP could fulfill the protein requirements for the entire global population within 2.5 to 4.5 years.

SCP from CO2 and H2, often called "Air Protein," relies on microorganisms that use CO2 as a carbon source and H2 for energy. This process is particularly resilient as CO2 is widely available and virtually inexhaustible. However, it is potentially less feasible than methane SCP due to higher capital costs and a considerable electricity requirement. Companies like Solar Foods, Air Protein, and others are working on developing this technology. 

Recommended Research Areas

Generate open source front-end engineering design packages. 

Generate rapid deployment plans and operational guides.

Perform a 24/7 construction pilot of a gas-based SCP factory.

Lignocellulosic biomass is derived from plant dry matter like corn stalks, wheat straw, and wood, which humans cannot naturally digest due to its complex structure—cellulose, hemicellulose, and lignin. However, through processing with steam or biological catalysts (enzymes), the biomass can be broken down into simple sugars (mainly glucose), which can be used as food, animal feed, or fermented into proteins and other nutrients.

Although large-scale lignocellulosic sugar production has not yet been established, companies like Renmatix and Comet Bio have developed efficient sugar production from this biomass, achieving theoretical yields of 85-90% through patented technologies. Existing industrial facilities, such as pulp and paper mills, sugarcane biorefineries, corn biorefineries, and breweries, could be repurposed for sugar production with reduced setup costs, as they already possess much of the necessary equipment.

In the event of an ASRS, if the entire global pulp mill factory capacity were rapidly repurposed for sugar production, it would produce the equivalent of ~9% of the caloric requirements of the global population, and the current global sugar demand could be fulfilled within 1 year after a catastrophe if this technology was deployed en masse. The resulting sugar mixture would be affordable in catastrophe conditions, with daily caloric needs costing between $0.55-0.91 per person.

Recommended Research Areas

Perform a cellulosic sugar repurposing pilot (of a paper mill, biorefinery, brewery, etc.) as it helps immensely with ASRS response.

Generate open source front end engineering design packages. 

Generate rapid deployment plans and operational guides.

Chemical synthesis of food from hydrocarbons offers an alternative pathway to food production, relying on nonbiological processes to create essential nutrients and fats. Vitamins, such as A, B1, B5, B6, and E, are synthesized from widely available petrochemicals. Nonbiological production methods for amino acids, such as methionine, glycine, and aspartate, are also well-established, with vast quantities being produced annually. These amino acids can be directly consumed or used to supplement other food sources.

Synthetic fats, produced through processes like paraffin oxidation, can serve as substitutes for agricultural fats. These fats are made by converting hydrocarbons from sources like petroleum or natural gas into fatty acids, which are then esterified into products resembling butter or oil. This method offers a promising resilient food solution, with low production costs and potential for reduced environmental impact compared to traditional agricultural fats. However, it currently only produces saturated fats, which should be consumed in moderation.

Glycerol, a carbohydrate, can be synthesized from propylene, a mass-produced petroleum product, and it is commonly used as a food additive in processed foods or even vegan cakes. Additionally, common carboxylic acids, such as acetic, citric, and lactic acids, can be synthesized nonbiologically, although biological methods are still more economical.

Recommended Research Areas

Generate open source front end engineering design packages. 

Rapid deployment of plans and operational guides for vitamin and amino acid production factories from hydrocarbons.

In vitro BioTransformation (ivBT) is a method for producing biocommodities using synthetic enzymatic biosystems. It consists of combinations of natural or artificial enzymes, coenzymes, and artificial membranes or organelles. ivBT utilizes artificial enzymatic pathways and electron transfer chains to enhance product selectivity and yield, overcoming limitations found in natural biological systems.

One key application of ivBT in food production is the synthesis of starch and glucose from cellulose, which was first demonstrated over a decade ago. Recent innovations have led to cost reductions, and a novel method now enables the one-pot conversion of lignocellulosic biomass into both artificial starch and single-cell protein (SCP). Notably, starch has even been synthesized from CO2 via ivBT. The first industrial use of ivBT involves the synthesis of inositol, a micronutrient, at a scale of 10,000 tonnes per year by Sichuan Bohaoda. This process highlights ivBT’s potential for food production.

Despite promising developments, ivBT-based food production from lignocellulosic materials faces challenges, particularly in scaling up and reducing costs. 

Recommended Research Areas

Economic analyses are needed to assess the feasibility of large-scale ivBT food production, especially in comparison with other approaches like lignocellulosic sugar production.

Microbial cell factories can be utilized for food production by harnessing microorganisms to synthesize essential nutrients without being consumed themselves. This approach has the potential to upcycle waste products and convert renewable resources into valuable food compounds.

One key method is precision fermentation, where microorganisms synthesize essential nutrients from sugars, such as lignocellulosic glucose. This type of process is already used at industrial scales to produce vitamin C and lysine from glucose, with lysine production exceeding 100,000 tonnes per year. Research is underway to explore alternative, non-food feedstocks like algae-derived mannitol, which could enhance food security in disaster scenarios.

Another interesting approach is the biosynthesis of food from CO2. Hydrogenotrophic bacteria can produce lipids, amino acids, and other essential compounds via gas fermentation in bioreactors. This method has yet to be commercialized as a food source but is being developed by companies like Arkeon Biotechnologies. 

Recommended Research Areas

Model the production of vitamin factories based on lignocellulosic biomass and other non-agricultural feedstocks.