The New Meat

“We shall escape the absurdity of growing a whole chicken in order to eat the breast or wing, by growing these parts separately under a suitable medium”. This prediction of growing meat in a lab was made in 1931, surprisingly not by any scientist, but by Winston Churchill, who was not so famous at that time. Lab-grown meat, which goes under various appellations like “cultured meat” or “cultivated meat” is currently one of the hottest emerging technologies. Cultivated meat is grown in a controlled environment out of a small sample of animal cells and the results have shown that it is possible to reproduce the taste, texture, smell, appearance and nutrition of conventional meat. Many start-ups are betting big on lab-grown meat and one estimate values the market for this novelty at $ 25 billion by 2030.

The starting material for cultivating meat is stem cells from the animal. These cells are grown in large bioreactors in a cell culture medium that is rich in oxygen, amino acids, glucose, salts, vitamins and other growth supplements. As the stem cells grow, they get differentiated into skeletal muscle, fat and connective tissues that together constitute the meat. Depending upon the meat that is being grown, the process can take up to 8 weeks.

Though the production process itself is fairly standardised there are some technical challenges related to scale-up, which is important from the perspective of lowering the cost. Even supplying 1% of the global demand for meat would require building a fermentation capacity that is 10 to 15 times more than the installed capacity of the entire biotechnology industry. The numbers are staggering. Researchers need to figure out how to improve the rate of cellular metabolism and reduce the amount of nutrients, so that more cells can be grown in the same volume. Another challenge is to lower the cost of the culture medium, which accounts for more than half the cost of the cultivated meat.

Lab-grown meat offers several advantages on the sustainability and health fronts. It would require significantly lesser land and water. A recent lifecycle analysis says that the reduction in land usage will be as much as 95%, while the water reduction can be up to 78%, when compared to conventional animal husbandry practices. Also livestock contribute nearly 15% to the global emission of greenhouse gases. Cultivated meat is expected to mitigate agriculture related deforestation and biodiversity loss. Since the meat is cultivated under sterile conditions, it is expected to significantly lower incidences of foodborne illnesses. Not having to eat slaughtered animals will please the more ethically inclined segment of the population.

The biggest challenges facing lab-grown meat are government regulations and consumer acceptance. At present, only Singapore allows commercial sale of cultivated meat. But more and more countries are opening up for tasting sessions in niche restaurants.

Squeezing Toothpaste

I am one among those millions of people who squeeze the tube of toothpaste harder and harder towards the end, trying to extract the last nanogram of paste before switching over to a fresh tube. Toothpaste is not the only stuff to be meted out this ignominious punishment in millions of households. There are hundred other gooey things like ketchup and mayonnaise which endure the same fate, as they try to cling like leeches to the inner walls of their containers. While this behaviour begs a serious study by sociologists, it is also a problem that strikes deep at the core of sustainability. Sticky gels, creams and pastes worth hundreds of millions of dollars are discarded every year, still stuck to the insides of their packaging. 

Stuff adhering to the walls of plastic packaging and metal cans also slows down their recycling and makes it more expensive. The problem extends to the equipment and pipelines in which these sticky materials are manufactured and processed. Cleaning chemicals and hundreds of gallons of water are required to expel the clingy stuff at periodic intervals and the resulting effluent also needs to be disposed of safely. So, can something be done to expel all the toothpaste leaving behind a squeaky clean tube?

LiquidGlide, a MIT-based start-up, seems to have solved the problem. The founders of the company have developed a robust superhydrophobic surface that will help all of the toothpaste to glide out of the tube. Inspired by the lotus leaf, the technology creates a liquid impregnated surface with non-wetting properties. Previously, nano-engineered textures have been used to produce hydrophobic surfaces with water-repellent and self-cleaning properties. Superhydrophobic surfaces are created by engineering nanoscale roughness on an intrinsically hydrophobic coating.

Hydrophobicity is the result of air-water interface within the nano-surface textures. The air entrained within the surface textures are displaced by impingement of liquid droplets, thereby diminishing the non-wetting property. LiquidGlide’s innovation lies in overcoming this vulnerability and creating a very robust superhydrophobic surface. The novelty essentially consists of impregnating a liquid within the matrix of the nano-engineered surface topography.

Different types of liquids have been successfully used for impregnating the surface textures. This makes it possible for the technology to be customised for a wide variety of applications. The innovation has implications beyond revolutionising toothpaste and ketchup packaging. It can be used to reduce viscous drag in oil and gas pipelines. It can prevent icing on aircrafts and powerlines. It has the potential to enhance heat transfer in condensers and to improve lubrication in compressors and engines. It will eliminate occlusions in medical devices. Losses during manufacturing can be substantially reduced. 

This innovation is yet another fine example of manipulating material properties through clever engineering to achieve miraculous results. LiquidGlide’s technology has already been lapped up by Colgate. My morning routine of exercising the fingers on the toothpaste tube will have to cease soon

Responsible Flying

On Wednesday, 1^st December, a United Airlines flight 737 MAX8 with more than 100 passengers took off from Chicago’s O’Hare International Airport to Washington DC. What was remarkable about this flight was that it used 500 gallons of Sustainable Aviation Fuel (SAF) in one of its two engines. The other engine used the same amount of conventional jet fuel to establish that there are no operational differences between the two fuels. Currently airlines are allowed to carry only a maximum of 50% SAF. United Airlines will go down in history as the first commercial carrier to operate a full passenger flight using 100% sustainable fuel. 

SAF is made from renewable biomass and waste resources. It has properties that are similar to conventional jet fuel, but a significantly smaller carbon footprint. Depending on the feedstock used, the reduction in GHG emissions from use of SAF can be as much as 80% compared to traditional jet fuel. Typical feedstocks for SAF are cooking oil, animal waste fat, agricultural residues, municipal solid wastes and animal manure. Other potential sources are forestry waste such as waste wood and fast growing crops and algae.

In order to maintain the same level of engine performance, SAF should have an identical molecular composition as that of traditional jet fuel, which is made up of n-alkanes, iso-alkanes, cycloalkanes and aromatics. The emission profile of an engine operating on SAF would thus be same as that with conventional fuel. However, SAF is almost carbon-neutral over its lifecycle because it is derived from renewable feedstocks.

SAF can be produced in many ways, which are broadly classified under two heads – thermochemical process and biochemical process. A typical thermochemical process is the well-known Fischer-Tropsch synthesis, in which carbon-rich biomass is gasified to produce syngas which is then catalytically converted to liquid fuel. The requirement of high pressure and temperature together with the need for a catalyst makes this an expensive process. Another thermochemical process is pyrolysis, in which the biomass is heated up to 600 degrees C in the absence of oxygen to yield among other things pyrolysis oil. Pyrolysis oil is converted to jet fuel by hydrotreating to eliminate the oxygenated molecules which are detrimental for the fuel. In a typical biochemical route for SAF, alcohols are produced first by fermentation of biomass which are subsequently converted into long-chain hydrocarbons that have similar properties as jet fuel. In another biochemical pathway, sugars are directly transformed to hydrocarbons without the alcohol intermediary.

Presently, ASTM has certified eight processes for producing SAF of acceptable quality. However, only the HEFA (Hydrogenated Esters and Fatty Acids) process has been successfully commercialised as of now and accounts for almost 95% of SAF production. In the HEFA process, waste oils and fats are hydrogenated and then isomerised to yield long-chain hydrocarbons, which are then selectively cracked to produce aviation fuel. The production of SAF is currently not economically favourable. However, SAF is becoming increasingly imperative if the aviation industry has to meet its 2050 target of cutting down emissions by 50%. In USA, the department of energy is working with the department of agriculture and other agencies to develop a strategy for scaling up technologies to produce SAF on a commercial scale.

BECCS (BioEnergy with Carbon Capture and Storage)

China, the world’s largest emitter of CO2, plans to become carbon neutral by 2060. EU, UK, Japan and South Korea have announced their intent to go carbon neutral by 2050. Many big corporations too have declared that they will be carbon neutral by middle of this century or even earlier. Amazon plans to achieve this goal by 2040. Microsoft is even more ambitious and hopes to become carbon negative by 2030.

Becoming carbon neutral means achieving “Net Zero Emission” of CO2. This requires removal of CO2 equivalent to amount emitted. One way of achieving this is to grow more forests or improve land management though better farming practices and thus enhance the natural sinks for carbon. But natural processes cannot achieve carbon neutrality and technological interventions are necessary.

The most practical and scalable technological solution consists of disrupting the carbon cycle by capturing the CO2 released while using biomass as fuel and locking it away permanently in a secure geological formation. The CO2 that is absorbed by the growing biomass thus does not get back into the atmosphere.

There are 3 techniques to capture the CO2: post-combustion, pre-combustion and oxy-combustion. The post-combustion approach uses well proven solvents like potassium carbonate and amines to scrub out the CO2 from the flue gases. In the pre-combustion approach, the fuel is subjected to partial oxidation and the resulting syngas is processed in a shift reactor to produce a mixture of H2 and CO2. The higher CO2 concentration makes the capture easier and cheaper. The oxy-combustion technique uses pure air for burning the fuel and results in flue gas that is nearly pure CO2, thus making capture simpler.

BECCS is not without critics. The land required for cultivating biomass for use as fuel is a serious limitation. Achieving carbon neutrality only via BECCS would require land equivalent to the area currently used for agriculture – 1.5 billion hectares.

Carbon Capture

Elon Musk, who became the richest man at the beginning of the year, has announced $100 million towards a prize for the best carbon capture technology.

CO2 concentration in the atmosphere has increased from 280 ppm at the start of the industrial revolution in 1760 to 417 ppm in 2020, a 49% jump. This is believed to be the highest since 3 million years ago, when the earth was significantly warmer and the sea levels were 15-25 meters higher than today. In the last few years, we have been adding 2.5 ppm each year.

With CO2 continually building up in the atmosphere, more carbon capture and sequestration (CCS) projects are necessary. Without CCS, net-zero emission is practically impossible to be achieved. Currently about 40 million tonnes of CO2 are captured and stored annually. This has to increase more than 100 times to 5.6 giga tonnes by 2050 if we have to meet the IPCC guidelines on limiting the global warming to 1.5 degrees C above preindustrial levels.

CCS capacity increased by 33% last year and currently there are 26 CCS facilities in operation. 65 projects are under various stages of development. The slew of projects currently in pipeline will take the CCS capacity to 110 million tonnes by 2026, a pitifully low value. ExxonMobil recently announced the formation of a new business unit to build as many as 20 CCS projects across the world. 

CCS projects are highly capital intensive and are not presently viable without fiscal support and incentives from governments. CCS technology is rapidly evolving and larger capture volumes will drive down costs and spur the much needed competition and innovation.

Many environmentalists are not too happy with CCS projects, because as much as 80% of CO2 captured so far has been used to pump out more oil in Enhanced Oil Recovery (EOR) projects. The irony of this is all too evident.

Green Hydrogen

Action on “Green Hydrogen” is heating up following Linde’s announcement of building a 24 MW electrolyser, to start production in second half of 2022. To be located in Germany, this will be the largest Proton Exchange Membrane (PEM) electrolyser in the world overtaking the 20 MW electrolyser recently built by Air Liquide in Canada. In contrast, the largest alkaline water electrolyser, the competing technology for Green Hydrogen, is 10 MW at Fukushima, Japan.

Green Hydrogen is the term used to denote Hydrogen produced by water electrolysis exclusively using renewable power. It is interesting to note that the capacities of electrolysers are stated in terms of power consumed and not Hydrogen produced. This is only appropriate because Hydrogen in this case acts essentially acts as a carrier of energy generated from renewable resources like hydro, solar and wind. Bulk of the Green Hydrogen will be used to power fuel cells, the competitor for batteries, to be deployed in EVs.

Linde’s announcement is also a clear indication that PEM technology is pulling away from the older alkaline water electrolysis. One of the important advantages of PEM electrolyser is that it is much more responsive to fluctuations in power, which is a typical characteristic of renewables like solar and wind. But PEM electrolysers are expensive because they require platinum.

A 3^rd technology, Anion Exchange Membrane (AEM), is rapidly emerging from the shadows. A consortium funded generously by EU is developing this technology, which claims to be cheaper because it operates in alkaline conditions and hence does not need the precious metals used by PEM. At the heart of this technology is a breakthrough development in membranes, which are reshaping and redefining many chemical processes. The developers of AEM technology are targeting to halve the cost of PEM electrolysers.

Perovskites

 

There is a new buzzword in the photovoltaic market – Perovskite. It may be the holy grail that the solar power industry has been seeking. 90% of the photovoltaic cells today are Silicon based and they have already reached the theoretical maximum efficiency postulated by the Shockley – Quiesser limit.

Recently, Oxford PV, a start-up spawned by Oxford University, announced a record efficiency of 29.5% for a solar cell, compared to 15-25% for today’s commercial solar cells. The researchers achieved this incredible success by coating Silicon cells with a thin film of Perovskite.

Perovskite was originally a mineral discovered in the Ural Mountains of Russia in 1839 and named after the Russian mineralogist, Lev Perovski. Today it is synthesised in the laboratories and refers to a class of materials that have the same crystal structure as Calcium Titanate, the original mineral. A typical Perovskite structure is ABX₃, where A is an organic cation, B is a metal (usually lead) and X is a halide anion.

Oxford PV is boosting the cell efficiency by capturing more of the energy available in solar radiation. The thin Perovskite layer absorbs shorter wavelengths and Silicon absorbs the longer ones.

Perovskite has many other advantages. It is more tolerant of defects unlike silicon which is required in very high purity. Also it is needed in much smaller quantities. The Perovskite solar cell is thus likely to be much cheaper.

There are question marks on the stability of Perovskites in hot and saline environments and also their environmental compatibility. Besides Oxford PV, at least a dozen other start-ups are working on the Perovskite technology. Commercial rollout is likely in 2022.