Multiple chemical reactions take place sequentially in the catalyst: the substrate molecules pass through the large pores of a “porous ceramic sponge” for the first reaction, and then enter the slightly smaller pores for the second reaction.
The journal Nature Catalysis reported on October 26 that researchers from the Royal Melbourne Institute of Technology (RMIT) and the University of Western Australia have developed a new high-efficiency catalyst that can recycle waste cooking oil and agricultural waste into biodiesel, as well as convert food scraps and plastic waste into high-value products.
Existing commercial production methods can only process high-purity feedstocks with 1% to 2% contaminant content, and waste cooking oil must undergo an energy-intensive cleansing process before it can be used for biodiesel production. With the facilitation of the new catalyst, the researchers were able to make biodiesel from low-grade feedstocks with contaminant content of up to 50%.
RMIT researcher Professor Adam Lee said, “We have designed a new catalyst that can help people make the most of wasted resources by integrating rotten cooking oil, rice husks and vegetable peels into the circular economy. Using this catalyst for biodiesel production will significantly reduce environmental pollution and bring humans closer to green chemistry.”
To obtain a highly efficient catalyst, the researchers created a micron-sized “ceramic sponge” that is highly porous and contains multiple active ingredients. The substrate molecules enter the “ceramic sponge” through large pores for the first chemical reaction, and then enter slightly smaller pores for the second reaction. This is the first catalyst that can carry out multiple chemical reactions sequentially in a single particle, and it may have a huge impact on the global catalyst market.
RMIT professor Karen Wilson notes that the new sponge-like catalyst draws on the coordination of complex chemical reactions by human cellular enzymes.
Previously developed multi-reaction catalysts have been unpredictable and inefficient in their control of chemical reactions,” Wilson said. Inspired by biological enzymes, we wanted to design an ‘enzyme-like’ catalyst that would allow it to catalyze multiple reactions in a fixed sequence – it would be like cramming an entire miniature production line into a single catalyst particle.”
The sponge-like catalyst is inexpensive to manufacture and easy to use – technicians simply add the waste to a giant container, heat it and stir it to obtain biodiesel.
Wilson commented, “This is especially important for developing countries. In these countries, diesel is the primary fuel for household electricity generation. If we can help farmers produce biodiesel directly from agricultural waste, it will help address key issues such as energy shortages and carbon emissions.”
With further research and tweaking by the researchers, the catalyst may soon be used in the chemical process of producing aviation fuel from agricultural and forestry waste (and even algae).
Original from Science World
Compiled by Xinyu Lei
Reviewer: Simo
Editor: Zhihan Chen
Journal source: Nature Catalysis
Journal number: 2520-1158
Link to original article.
https://phys.org/news/2020-10-biodiesel-dirty-cooking-oil-easier.html
Copyright statement: This article is originally compiled by the Science Sector Platform, the Chinese content is for reference only, all content is subject to the original English version. Please indicate the source of the article in Science and Technology Worker’s Home – Science Community App.

In view of this, Prof. Ming-Yang Xing of East China University of Science and Technology reports the degradation of aromatic organic compounds in AOP by 3D-MoS2 sponges loaded with MoS2 nanospheres and graphene oxide (GO).

Key points of the article

(1) The researchers obtained 3D-MoS2 sponges by dipping blank melamine sponges into MoS2 and GO alcohol solutions sequentially through a two-step simple impregnation method. The 3D catalyst, called ” nSMG” (” n” stands for the number of times the sponge was dipped in the MoS2 solution), was then obtained after a simple heat treatment in an oven at 200 °C. Meanwhile, the samples without GO during the preparation process were denoted as ” nSM”.

(2) SEM images showed that the original network skeleton was completely preserved after loading the sponge with MoS2 and GO; meanwhile, a large number of MoS2 nanospheres were observed on the sponge surface. TEM images showed that the size of ultrathin MoS2 nanoflowers was about 200 nm. The laminar accumulation and irregular edges of MoS2 nanoflowers could improve their surface adsorption capacity and active surface area. In addition, the edges of the petals can provide more unsaturated sulfur active sites.

(3) The exposed Mo4+ active sites on 3D-MoS2 can significantly increase the concentration and stability of Fe2+ in AOP and keep a stable dynamic cycle of Fe3+/Fe2+, which can effectively promote the activation of H2O2/PMS. As a result, the degradation rate of organic pollutants in the system with 3D-MoS2 co-catalyst was 50 times higher than that without the co-catalyst. It maintained high efficiency and stable AOP activity even after 140 L of pilot experiments. After 16 consecutive days of reaction, the degradation rate of 3D-MoS2 for 120 mg/L antibiotic wastewater was 97.87%. Importantly, the operating cost of treating one ton of wastewater was only 0.33 USD, which indicates its great value for industrial application.

Good quality cotton wool is generally soft in color, white or milky white. Fibers fluffy and uniform, feel soft and elastic. Old cotton recycled cotton has a smell due to the use of sulfur bleaching or laundry detergent washing, while recycled cotton produced from clothing waste will have a medicinal smell, moldy smell and other odors.

1. In the selection of sponge, mainly to its touch and elasticity as the primary factor in determining. Touch should have a soft touch, and malleable; 2. In addition, one of the most practical way to identify the sponge is folded in half, rubbing one another. If you do not rub a few times to drop the sponge shavings, it should be eliminated.

At present, the production, the use of many types of sponge, there are foam cotton, styling cotton, rubber cotton, memory foam, etc..

Shaped cotton: this material cotton by polyurethane materials, by the foaming agent and other additives mixed, pressure agent into a simple mold temperature can be pressed out of different shapes of sponge, it is suitable for swivel sofa seat, back cotton, there are also a small number of armrests also use shaped cotton to do;

Foamed cotton: this material with polyether foam molding, like foamed bread. Available machinery and equipment foaming can also be manually surrounded by wooden boards foaming, foamed cotton seems to be a large square-shaped bread, the use of slicing machine after slicing process, according to different requirements cutting thickness, foamed cotton can also be adjusted for softness and hardness;

Rubber cotton: one of the sponge, it uses the main material is natural latex raw material foam, it has rubber characteristics, excellent elasticity, good resilience, will not be deformed;

Recycled cotton: recycled cotton is made of waste cotton, industrial offcuts and textile enterprises of cloth and yarn head recycling, especially raw materials may also contain medical waste cotton, therefore, recycled cotton can cause harm to human health, recycled cotton and civilian cotton placed together is easy to cause pollution.

And in the headset products used in general for shaped cotton and foam cotton, some high-end products will use rubber cotton.

Most of the headset products used in the ear stack is the more prominent stereotyped effect of stereotyped cotton, has a better hardness and life, but also due to the problem of hardness, resulting in a decline in wearing comfort.

The ear stack of Sides professional gaming headset is made of rubberized cotton foamed from natural latex materials. Rubber cotton has rubber characteristics, excellent elasticity, good resilience, will not be deformed, but the price is not expensive, than the foam cotton to 3 ~ 4 times higher. Nevertheless, Thaddeus chooses to use rubber cotton just to provide the most optimal wearing comfort to the user.

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