Study shows waste plastic can be converted into energy and fuels

Waste plastic is flooding our landfills and leaking into the oceans, with potentially disastrous effects. In fact, the World Economic Forum predicts that if current production and waste management trends continue, by 2050 there could be more plastic than fishes in the ocean.

Why is this happening when there are processes and technologies that can effectively recycle, convert to valuable products and extract the imbedded energy from these waste plastics? According to Science Advances, as of 2015, of the 6,300 million tons of waste plastic generated in the United States, only 9 percent has been recycled, 12 percent has been incinerated, with the vast majority ? 79 percent ? accumulating in landfills or the natural environment.

The Earth Engineering Center (EEC|CCNY) at the Grove School of Engineering of the City College of New York is on a mission to transform waste plastic to energy and fuels.

A recent EEC study titled "The Effects of Non-recycled Plastic (NRP) on Gasification: A Quantitative Assessment," shows that what we're disposing of is actually a resource we can use. The study, by Marco J. Castaldi, Professor of chemical engineering Director of Earth System Science and Environmental Engineering and Director of the EEC|CCNY and Demetra Tsiamis Associate Director of the EEC|CCNY, explores how adding NRPs to a chemical recycling technology called gasification ? which transforms waste materials into fuels ? adds value.

Adding NRPs to the gasification process helps reduce greenhouse gas (GHG) emissions while significantly reducing the amount of waste byproduct to landfill ? by up to 76 percent.

In the study, published by the American Chemistry Council, the effects of increasing the percentage of non-recycled plastics (NRPs) are measured at Enerkem, a Montreal-based energy company, in collaboration with the City of Edmonton in Alberta, Canada.

"This study demonstrates that because carbon and hydrogen rich plastics have high energy content, there is tremendous potential to use technologies like gasification to convert these materials into fuels, chemicals, and other products. We were fortunate to engage a couple of students and engineers from our team enabling them to learn about this novel process," said Castaldi.

Tsiamis added: "Plastics have an end of life use that will be turning waste into energy, which is something we all need and use."

How to tackling tyre taste

With the rapidly growing number of vehicles around the world, the disposal of end-of-life tyres is a growing issue. Often simply dumped by the million to pose a serious environmental, health and fire risk, the technology to recover higher value materials and energy from waste tyres is moving forward.

Figures published by the U.S. Rubber Manufacturers Association estimate that the U.S. - the world's largest producer of ELTs - generated 291.8 million tyres in 2009. With an average weight of 33.4 pounds (15.1 kg) that equates to some 4.4 million tonnes. According to statistics published by the European Tyre & Rubber Manufacturers' Association (ETRMA), in 2010 Europe produced around 2.7 million tonnes of ELTs.

With so many ELTs being produced, as well as the huge stockpiles from the past, waste tyres pose many potential dangers. They can contaminate groundwater, harbour disease carrying mosquitoes in pooled water and they are not only flammable, but once ablaze, extremely difficult to extinguish.

Often the result of arson, fires at tyre dumps are not uncommon. In 1990 Hagersville, Ontario was the scene of one of the worst tyre fires in history. As a mechanised army of fire fighters struggled to gain control of the situation, for 17 days 14 million tyres packed onto the 11 acre site spewed toxic clouds of thick black smoke into the air.

According to the New York Times, in addition to the toxic fumes, around 158,000 gallons (600,000 litres) of oil was released by the melting rubber was collected from the site. Chemical pollutants, suspected to have been caused by the operation to extinguish the fire were also found in the aftermath of the blaze.
In a separate incident an underground dumpsite in Wales, thought to contain around 9 million tyres, burned for an astonishing 15 years following its ignition in 1989.

Regulations
Because of the hazards associated with scrap tyres, nearly all developed countries regulate their disposal. In the EU, while no single directive or regulation targets ELTs, the Landfill Directive banned them from being disposed of to landfill whole in 2003 and in 2006 banned even their shredded remains from landfill.
In the U.S. 38 states ban whole tyres from landfills, 35 states allow shredded tyres to be landfilled, 11 states ban all tyres from landfill, 17 states allow processed tyres to be placed into monofills (a landfill designated for a the disposal of a single material) and eight states have no restrictions on placing scrap tyres in landfills. According to the U.S. Environmental Protection Agency (EPA), 48 states currently have laws or regulations which specifically deal with scrap tyres.

In the UK, to promote more robust standards in the collection and disposal of end-of-life tyres, and to help eradicate rogue operators, in 1999 the Tyre Industry Federation launched a voluntary initiative, the Responsible Recycler Scheme (RSS). Under the scheme tyres are stored, collected, recycled or reprocessed in line with all UK and UE legislations. Independent audits and full traceability mean that tyres handled by RRS member companies can be tracked throughout the disposal chain. Retailers usually pass the associated costs of the scheme onto the customers, with a disposal surcharge attached to the purchase of a new tyre.

In 2004 the Tyre Recovery Association (TRA) was formed to support the RRS. All TRA members are fully accredited, which guarantees that all tyres collected, recycled or reprocessed by them are disposed of or reused appropriately.

The programme has gone on to become the largest of its kind in Europe and currently handles some 45 million used tyres every year. Other countries including Germany, Switzerland, Austria and New Zealand operate similar voluntary systems, as well as many U.S. states.

Composition and Uses
According to the World Business Council for Sustainable Development's Tire Industry Project, which has published a framework for the effective management of ELTs, a typical tyre contains 30 types of synthetic rubber, eight types of natural rubber, eight types of carbon black, steel cord, polyester, nylon, steel bead wire, silica and 40 different kinds of chemicals, waxes, oils and pigments - quite a cocktail.

Containing such a plethora of materials, tyres present a wide range of opportunities. However, in addition to the potential for material recovery, the very high calorific content of ELTs has led to their widespread use as Tyre Derived Fuel (TDF) in cement kilns and energy recovery facilities.
In the U.S. some 4.39 million tons (4 million tonnes) of the 5.17 million tons (4.7 million tonnes) of the waste tyres generated in 2009 were recovered. Of the recovered ELTs, just over 2 million tons (1.8 million tonnes) were sent for energy recovery and around 1.6 million tons (1.45 million tonnes) were recovered as ground rubber for use by a wide range of industries. Interestingly, the report shows that the recovery of materials grew significantly from the 2007 figures, while use as TDF was down by almost half a million tonns per year.
Using traditional recycling techniques, granulated rubber recovered from waste tyres can be used variously as an aggregate, in tiles, adhesives, asphalt, sports surfaces, and extruded rubber products, to name but a few of its uses. And in terms of energy recovery the natural rubber fraction of the tyre can be considered as a renewable energy source.The waste tyre pyrolysis machine is a good way to tackling tyre waste.

Conclusions
The greatest environmental and economic benefits from the treatment of ELTs lie furthest up the waste hierarchy.

Given the expanding global vehicle base, and the consumable nature of tyres, prevention is probably unattainable. Indeed, for the foreseeable future the number of waste tyres being generated globally will continue to grow. And for passenger car tyres, reuse options, such as retreading, are limited.

While the use of tyres as TDF is certainly better than landfilling or stockpiling, there are many interesting projects on the horizon which offer the potential of recovering not only energy or low value materials, but a wide range of high value materials and energy.The waste tyre pyrolysis machine is a good way to tackling tyre waste.

Using Resin Parts to Create a Resin Scale Model

Introduction
The vast majority of resin scale model kits made today are made from plastic (polystyrene).  Most modelers will, sooner or later, come across other materials and cast polyethylene resin is one of these.  Working with polyethylene resin requires different methods and products.  This tutorial is a guide to dealing with this material.
Background information about cast resin can be found in the article ‘Model Kit Materials’and so we will not repeat it here.

Preparing Parts
Whether you are building a complete resin kit, or using an aftermarket kit to convert a standard plastic kit, you will find that the resin parts are likely to need more work on them than the more normal injection molded plastic parts that you may be used to
The quality of plastic kits on the market is very good and most modelers have become used to snipping a plastic part from the spruce and, with little or no clean-up, putting it on the model.  Unfortunately that will not be the case with resin.
Resin parts are cast from a liquid and may well come still attached to the casting block.  If this is so, then they need to be separated. If the attachment point is thin then it might be separated with repeated passes from a sharp hobby knife.  However, if the attachment point is thick it will need to be cut off with a fine saw, sometimes called a razor saw, which is designed for hobbyists.  Normal saws available from hardware stores cannot be used as the teeth of the saw will be too large. The sawing process can be difficult and time-consuming, especially if the link between the part and the casting block is large, but there is no way to avoid it.  You may wish to try using a motor tool to speed up the process, but great care is needed when doing this.  If too much friction is generated, the resin may melt.
The greatest difficulty can be cutting away the casting block without damaging the part.  Sometimes it is better to cut away the bulk of the casting block, leaving a small amount behind that can be trimmed away with a modelling knife.

Note that whenever cutting resin like this, or sanding it, there will be a fine dust produced which is very bad for the lungs.  Wear a filter mask and clean up your work area afterwards.
When the parts have been removed from the casting blocks, they need to be cleaned up.  Any remaining lug where the part was attached to the casting block will need to be cut away with a knife or sanded/filed away.  There is also likely to be a seam that will need to be removed with a sharp blade.

Examining All Parts
Once the parts have been removed from the casting blocks and cleaned up they need to be examined.
One potential fault is warping.  Check whether the part has become distorted.  For example, if it is the chassis of a vehicle place it on a flat surface and see if it sits right or whether it rocks back and forth.  If you find a part has been warped then it is possible to sometimes undo the damage by applying gently heat, such as boiling water or even a hair dryer which softens the resin and makes it possible to reshape it.  Clearly care needs to be used when applying heat in this way to avoid injury.
A second fault is air bubbles.  Sometimes tiny air bubbles can be trapped in the mould whilst the resin is setting and this might mar the surface detail.  These tiny holes are sometimes called ‘pin holes’.  This fault can be rectified with filler and sanding.  Remember that fillers designed for styrene plastic will not adhere to resin.  However, if the pin holes are tiny, almost any type of filler will work well.
Another thing to check for is the need to drill any holes.  Injection molded parts will probably have holes molded into them, but it is more difficult to create holes that go right through a part when it is cast.  It may be that the resin part has an indentation to show where a hole should be, so that the modeller can drill it out completely.

Gluing Parts
Standard polystyrene cement which is perfect for conventional styrene models is absolutely useless for resin parts. Poly cement works by slightly dissolving the styrene plastic, but it will not dissolve resin and so will not work at all. When gluing resin parts to each other, or to plastic, you will need to use either two-part epoxy glue or cyano (superglue) adhesive. Both of these work well, so it is down to individual preference.
Cyano is the most convenient because it does not have to be mixed and so is probably the first choice for many modellers.  However, the epoxy cement will probably produce the strongest and most reliable bond.
Whichever glue you use, it will only work if the surface is prepared properly.  Both types of glue need a dust-free and grease-free surface, so wash the parts in warm water with detergent and dry them thoroughly.  The bond will probably be stronger if the surfaces to be joined are roughened slightly with sand paper.
Once you have glued the parts together, there may be a need for filler.  The normal fillers intended for polystyrene such as Squadron ‘Green Stuff’ and ‘White Stuff’ will not adhere to resin because they are designed to ‘melt’ the surface of polystyrene.  This does not mean that they cannot be used in certain situations, but you should be aware that they may flake away if spread thinly.  Epoxy putties such as Milliput, or other fillers that have a natural tackiness, should normally used in preference when filling resin parts.

Summary
Using resin parts does provide the modeller with additional challenges, but there are also additional rewards.  You have the opportunity to make an unusual or even unique model.  Using resin also gives you the opportunity to hone and develop your modelling skills.  Give it a go.  Try starting with a simple conversion kit to enhance or modify an injection molded kit and build up to a full resin scale model.

How Cans Are Made

How many pieces are used to make a can such as a cookie tin can? How involved is the process? Get an inside look at how the food and beverage cans we use every day are manufactured.

Making A Two-Piece Can
Cup Blanking and Drawing Press punches out hundreds of cups per minute from huge coils of aluminum or steel.

Ironing and Doming Cup is forced through a series of rings to iron out cans to full length and form bottom dome.

Trimming Cans are spun as cutting tool trims to length.
Cleaning Washer cycles hundred of cans per minute through multiple cleaning stations.
Printing and Varnishing At printing station, cans are rolled against cylinder to print up to four colors simultaneously.

Bottom Varnishing Cans are conveyed past applicator that varnishes bottom.
Baking Cans wind through conveying system in oven to dry and set lithography.

Inside Spraying A protective specially compounded coating is applied to inside of cans.

Baking Trip through funnel oven bakes and cures inside coating.
Necking In Can necks are reduced at top to fit the designated end size.

Flanging and Testing Can rims are flanged for future double seaming of ends. Then, each can is mechanically tested for leakage. Finally, cans are automatically stacked in cartons or on pallets for shipment.

Making A Three-Piece Can:
Shearing The large coil of metal is cut into sheets at the rate of 160 sheets per minute on the shear press Shearing The large coil of metal is cut into pre-scolled sheets at the rate of 150 sheets per minute. The irregular ends of the sheets are designed for the maximum number of ends per sheet.
Coating An inside protective coating is placed on the sheets and cured.
Coating An inside protective coating is placed on the pre-scroll sheet and cured.
Printing The sheets are decorated with whatever printing the customer desires and then an over coat of varnish is placed on the decorated sheet and cured.

The body sheets are now stacked on pallets for shipment to a fabricating plant.
Printing The sheets are decorated with whatever printing the customer desires and then an over coat of varnish is placed on the decorated sheet.

Coating A second inside protective coating is placed on the sheets and cured.
Slitting Body sheets containing up to 35 body blanks per sheet are slit into individual body blanks which will be formed into cans.
Scroll Shearing The pre-scrolled sheets are now cut into small scroll sheets which will be fed into the end making press.

End Forming Ends are stamped out of the scroll sheets at the rate of 650 ends per minute. Finished ends are packed into tubes for delivery to fabricating plants and customers.

Body Forming Body blanks are fed into a bodymaker where they are formed into cylinders and joined at their side seams by solder, cement or weld.
Flanging The formed cylinder comes from the bodymaker to the flanger. Here the metal on both ends is rolled to form a flange on each end of the can. This flange will at a later time accept double seaming.
Double Seaming One end, top or bottom, depending on customer specifications, is double seamed on the can.
Spray Coating A final coating is placed on the interior surface of the can. This is a specially compounded protective coating.

Baking here the final interior coating is baked and cured through a funnel type oven where the time-temperature cycle must be controlled carefully.
Testing A 100 per cent quality control inspection for any micro leak is given to every can.

Packing Cans are packed into cartons or placed on pallets for delivery to customers.

This is the process of making the cookie tin cans of the biscuit.

The history of the biscuit tin box

Biscuit tin box is utilitarian or decorative containers used to package and sell biscuits (such as those served during tea) and some confectionery. They are commonly found in households in Great Britain, Ireland, and Commonwealth countries, but also on continental Europe and French Canada. Popularity in the United States and English Canada spread later in the 20th century.

Because of their attractive appearance, biscuit tin box have often been used by charities and by some visitor attractions as fundraising devices since the value of the biscuits in a biscuit tin box is substantially less than the price that many customers will happily pay for a tin of biscuits.

Biscuit tin box is steel cans made of tin plate. This consists of steel sheets thinly coated with tin. The sheets are then bent to shape. By about 1850, Great Britain had become the dominant world supplier of tin plate, through a combination of technical innovation and political control over most of the suppliers of tin ore. Biscuit tin manufacture was a small but prestigious part of the vast industry of tin plate production, which saw a huge increase in demand in the 19th century was directly related to the growing industrialisation of food production, by increasingly sophisticated methods of preservation and the requirements made by changing methods of distribution.

The British biscuit tin box came about when the Licensed Grocer's Act of 1861 allowed groceries to be individually packaged and sold. Coinciding with the removal of the duty on paper for printed labels, printing directly on to tinplate became common. The new process of offset lithography, patented in 1877, allowed multicoloured designs to be printed on to exotically shaped tins.

The earliest decorated biscuit tin box was commissioned in 1868 by Huntley & Palmers from the London firm of De La Rue to a design by Owen Jones. Early methods of printing included the transfer process (essentially the method used to decorate porcelain and pottery since about 1750) and the direct lithographic process, which involved laying an inked stone directly on to a sheet of tin. Its disadvantage was that correct colour registration was difficult. The breakthrough in decorative tin plate production was the invention of the offset lithographic process. It consists of bringing a sheet of rubber into contact with the decorated stone, and then setting-off the impression so obtained upon the metal surface. The advantages over previous methods of printing were that any number of colours could be used, correctly positioned, and applied to an uneven surface if necessary. Thus the elaborately embossed, colourful designs that were such a feature of the late Victorian biscuit tin industry became technically possible.

The most exotic designs were produced in the early years of the 20th century, just prior to the First World War. In the 1920s and 1930s, costs had risen substantially and the design of biscuit tin boxs tended to be more conservative, with the exception of the tins targeted at the Christmas market and intended to appeal primarily to children. The designs generally reflected popular interests and tastes.

The advent of the Second World War stopped all production of decorative tin ware and after it ended in 1945, the custom did not enjoy the same popularity as before.

Vintage biscuit tin boxs can be found in various museums and on the market have become collector items.