From plastic waste to green hydrogen, profitably

Torstai 5.10.2023 klo 14.50 - Mikko Nikinmaa

In recent past, plastics have been only considered as a waste, which one should diminish as much as possible. Most of the everyday plastic is polyethylene, and exciting new avenue for its recycling has recently been reported. Wyss et al. (https://doi.org/10.1002/adma.202306763) have written in Advanced Materials how one can produce hydrogen and graphene by rapid heating of polyethylene without any carbon dioxide emissions. By selling graphene, which is needed in increasing amounts, the production of a major energy source for future, hydrogen, becomes highly profitable.

So, a vision for a hydrogen production emerges which simultaneously nearly abolishes plastic problem. First, consumers are paid a small sum of money per kg of polyethylene returned to recycling stations. This is done, because while environmentally concerned people recycle plastics anyway, many people who are now throwing plastic bags to the environment would probably keep them if they knew that some money is given when the plastic is taken to recycling station. Second, the collected plastic is taken to hydrogen production facility. Hydrogen and graphene are produced, and hydrogen becomes, in fact, an energy source with no cost, as the produced graphene can be sold to any interested party at a price that is below today’s market price.

At the moment, the method for the production of hydrogen and graphene from waste plastics is at the lab scale, so scaling it up to commercial scale needs some time. However, in about five years the vision may become reality. It amounts to combatting climate change and plastic problem simultaneously, and doing it profitably. This shows again, how innovative new solutions can make green shift profitable, opposite to what the conservative, oil-loving populists say.

Kommentoi kirjoitusta. Avainsanat: plastic pollution, green energy, climate change, recycling

Steel Production without Carbon Dioxide Emissions

Sunnuntai 29.8.2021 klo 20.22 - Mikko Nikinmaa

One of the forgotten players in carbon emissions is steel production. It accounts for nearly 10 % of the total global emissions. Thus, steel production is 4-5 times greater emitter than air traffic, which has received a lot of attention. Further, current steel production is still largely based on iron extracted from mined ore, and not on effective recycling of used steel products.

The technology for carbon-free steel production is available. However, as with making all environmentally friendly products, making steel without carbon dioxide emissions is currently more expensive than the traditional steel production. Traditionally, steel is made from iron ore using coal as reductant. As a result, carbon dioxide emissions are high. The environmentally friendly way of producing steel would first make directly reduced iron (DRI) from iron ore using green hydrogen (hydrogen extracted from water with energy from renewable sources). The DRI and recycled steel scrap is then melted in Electric Arc Furnace (again with energy from renewable sources) and steel is produced.

As I said above, steel produced without carbon dioxide emissions is currently much more expensive than traditional coal-using production. The cost is, however, dependent on the proportion of production without carbon need. This is illustrated by the change in paper production. In 1970’s paper industry said that it would never be economically plausible to produce paper without chlorine-based bleaching. Yet, today all paper is chlorine-free and none of the paper mills have gone bankrupt because of that. Thus, once the carbon-free steel production is mainstream, the methods for such production certainly become more economical. Also, since the increased cost of steel production is directly associated with environmental actions, shouldn’t we accept it without reservations, if we say that we want sustainable economy.

Kommentoi kirjoitusta. Avainsanat: climate change, recycling, mining

Plastics in the Environment

Sunnuntai 14.4.2019 klo 14.51 - Mikko Nikinmaa

When one thinks about durable, light, easy-to-use and mouldable material, plastics certainly come to mind. It is hard to image that the plastic age is only 50-60 years old. One can hardly image life without plastic containers, plastic-insulated wires, plastic parts in household appliances and cars, and artificial fibres in clothing. This plastics era has produced and is producing so much of the useful materials that the world is choking to them. A very useful, detailed review about plastics, their use and environmental problems generated is written by CJ Rhodes in Scientific Progress 101: 207-260 (https://journals.sagepub.com/toc/scia/101/3).

In a way, lumping many different materials under one common name, plastics is wrong, because the foam used in insulation, fibres of clothing, and plastic packaging of food are very different. However, two things are common: First, most of the plastics are oil-based – more than 90 % of plastics are made of oil. In addition to oil-based products, plastic-like materials can be tree- or other plant material-based. However, these materials are exactly as problematic as oil-based ones except for not being fossil fuel-based. Second, the materials degrade slowly. The average life length of plastics is tens to hundreds of years. This means that virtually all plastics ever produced can still be present. The persistence is the major reason for the environmental problems generated by plastics.

Of the different plastics only less than ten percent are recycled, a little more than ten percent are burned and 80 % are currently ending up in the environment or in garbage dumps. This distribution of the fate of used plastics is the second major reason for the environmental problems. The most visible plastic pollution is that of the oceans, especially the Pacific Garbage Gyre in North Pacific, but virtually all major seas and beaches have significant amounts of trash. The waste problem is most pronounced in Asia, as all of the countries with most environmental plastic waste are there: China, Indonesia, Philippines, Vietnam and Sri Lanka. These countries contribute more than 55 % of world’s total waste. Because recycling is so limited, factories, which would use recycled plastics in their production, have an eternal material supply problem.

About 40 % of all the plastics is used in packaging. This has also the shortest half-life of use, less than a year. Thus, packaging is by far the most extreme case of single-use attitude. The second most important plastics user is building and construction industry with about 20 % proportion. However, the material is turned over in 35 years, decreasing the yearly amount of waste. A much bigger problem is textile industry, as the proportion is 20 %, and the turnover time is less than 5 years. Much of the rest is used in machines and electronics, and the material is turned over in 5-20 years.

The plastic waste can be macro-, micro- or nanosized. The macro-sized, visible material slowly degrades, but can disturb animal life up to hundreds of years. The materials are especially problematic, when they cause strangulation of animals or block their intestine thus inhibiting normal digestion. In addition, animals may feed on plastic materials, which naturally cannot be digested. Also, plastic trash affects the visibility of water. Micro-sized plastic is characterized as material of less than 5 mm but more than 100 nm in any dimension. Next to nothing is known about its appearance in soils, but an increasing number of studies has demonstrated its presence in water. It is notable that much more than 95 % of micro-sized plastic is removed in wastewater treatment plants. Much of the microplastics is ingested by animals. The lack of digestibility is a problem, and can cause starvation, when the alimentary canal is filled with material that cannot be digested. However, very little is actually known about if and how microplastic particles affect organisms. One of the possibilities is that it is not the particles themselves, but dissolved toxic chemicals initially adsorbed on microplastic particles that cause problems. The role of microplastics would in this case be increasing the surface area whereby all the toxic chemicals adsorbed to plastics can diffuse or otherwise be absorbed into the cells. However, the actual mechanisms by which microplastics affect animal functions are poorly known. In fact, one reviewer recently pointed out that the ingestion and egestion of microplastics have been extensively studied, but next to nothing is known about their toxic effects if any. The same is true for nanoplastics, materials with at the most one dimension 100 nm. Their cellular uptake and effects at environmental level are virtually unknown. This is a general problem in nanotoxicology: one has repeatedly shown that nanomaterials can be toxic at high concentrations, but their effects at environmental or predicted environmental level are unknown. One possibility is that they cause inflammation in any tissue they come in contact with.

Since the most important proportion of plastic waste is packaging, and single-use products largely associated with food and drink, it is were nice to know that the amount of trash can easily be decreased immensely by reducing overpackaging and by recycling. Effective plastic collection would be cheap and could be implemented anywhere in the world. Virtually all plastic material used in packaging needs to be recyclable and most of the plastics can minimally be burned. This would be equivalent to burning the same amount of oil. One can say that the major way of combatting plastic waste is to increase the effectiveness of plastic collection. At the moment, out of all trash found in the environment, more than 3/4 is plastics. Finally, replacing plastics by less “eternal” material where possible is needed. This, as reducing packaging, would be something that the production side needs to do. However, the consumers can affect, what is produced, by choosing the products so that overpackaging does not sell any more. The consumers can, on the other hand, do much on the recycling side.

Kommentoi kirjoitusta. Avainsanat: recycling, waste collection, trash, plastic pollution

Plastics - use as fuel component

Tiistai 24.7.2018 klo 19.57 - Mikko Nikinmaa

Plastics are made of oil. Thus, they could be utilized as components of fuel instead of generating massive garbage gyres in the oceans. And let's face it -since getting rid of the use of fossil fuels takes time, plastics should be used in energy production rather than just be destroyed by burning (without using the energy generated) which increases our carbon dioxide production.

This simple conclusion has now been advocated by the Finnish national oil company Neste. The company will start collecting plastic, and break it down to fuel components. The aim is to have 10-20 % of all petrol made of plastic garbage. This will mean savings in oil import, reduction in carbon dioxide generation and decrease in plastic garbage.

Although the solution does not make us fossil energy-free, it is a step in right direction. And at the present state of affairs anything done in right direction should be done as soon as possible, because it is getting hot in here, and a dop in the ocean must be done in the middle of plastic trash

Kommentoi kirjoitusta. Avainsanat: fossil fuels, plastic pollution, recycling

Plastics should not end up as trash in the environment

Keskiviikko 8.2.2017 klo 7.11 - Mikko Nikinmaa

Plastics are a major component of the present day "use once and throw away" culture. Plastic thrash ends up in the wayside and oceans. However, plastics should not end up in the environment.

Plastics are made of oil. Currently, most plastics do not have the acutely toxic oil components. Thus, they could be used in energy production instead of oil itself. It is an immense waste to use oil to make plastics which are then thrown away instead of even been used for producing energy.

However, a better solution would be to recycle plastics. Since a lot of work has gone to produce the material, it is an immense waste that it is thrown way and not reused. The biggest problem for recycling is the small number of collection places. They should be as common as paper recycling boxes. This is something that could easily be done, and in the name of savings, which is presently a catch word. As an analogy to paper - since having paper recycling units in Finland is very common, hardly any paper ends up in the environment.

So let's demand that we increase get the possibility to recycle plastics to help the environment.

Kommentoi kirjoitusta. Avainsanat: fuel, recycling, marine pollution