Why is gasification better than combustion?
As the volume of waste increases and the push for sustainable energy continues, producing energy from waste has the potential to be the perfect solution to both problems. However, not all technologies for generating energy from waste are created equal. They vary in terms of efficiency, environmental impact and economic viability. This article compares and contrasts incineration – by far the most widely used waste-to-energy technology – with gasification to highlight why the latter is the more sustainable and economically viable option.
What are combustion and gasification?
1.Incineration: The process of effectively burning garbage at high temperatures and oxygen to produce heat, ash, and flue gas. Before being released into the atmosphere, flue gas must be cleaned of polluting gases and debris.
2.Gasification: Thermochemical processing of waste materials without combustion at temperatures above 700 °C with tightly regulated oxygen or steam supply. Synthesis gas (syngas), which is the product of the process, is then employed in a range of applications.
Advantages and disadvantages of combustion：
1.Incineration is a tried-and-true technology that has been commercially successful. There are more than 500 incinerators in Europe, and the European Federation of Energy from Waste Plants represents 410 of the continent’s 23 nations. The amount of rubbish burned in Europe increased by more than twofold to 58 million tons between 1995 and 2018.
2.A straightforward trash management technique: incineration can burn up to 90% of solid waste, making it much more practical than landfills for waste management.
3.Reduced landfills: According to the European Environment Agency, between 2010 and 2016, the percentage of total trash disposed of in landfills decreased from 29% to 24%, and it has since continued to decline. The increase in incineration is partly to blame for this drop. For instance, as a direct result of government efforts to limit landfills, incineration will soon make up more than half of all garbage disposed of in the United Kingdom.
4.Energy production: The heat produced during incineration can be used as a source of energy and as a way to create electricity.
1.Expensive. The cost of building the infrastructure to operate the incineration plant is very high. In addition, incineration plants require trained personnel and dedicated staff to operate them. Incinerator plants also require regular maintenance, which adds to the already high operating costs.
2.Pollution of the environment. Incinerators produce smoke during the combustion process. The smoke produced includes acidic gases, carcinogens dioxins, particulates, heavy metals and nitrogen oxides. These gases are harmful to the environment. Studies have shown that dioxins produced in plants are a carcinogenic chemical.
3.Potential for long-term problems: Incineration does not encourage recycling and waste reduction. This is not a calculated strategy for any society. The focus should be on reducing waste and recycling most of the waste. Simply burning most of the waste without recycling some of it will only cause further environmental damage, as it may encourage more waste generation.
4.Ash waste can be hazardous to humans and the environment: Although the amount of ash remaining from the process is relatively small, it contains many toxins and heavy metals that require further treatment. If not properly configured, it may pose a serious hazard to the public and the environment.
Advantages and disadvantages of gasification：
(l) During pyrolysis gasification, the organic components in the waste can be converted into different forms of usable energy such as combustible gas and tar, and its economy is better.
(2) The air coefficient is lower during pyrolysis gasification, which greatly reduces the amount of smoke emission, improves energy utilization, reduces ammonia oxide emission, and reduces the investment and operation cost of flue gas treatment equipment
(3) Under the reducing atmosphere, metals are not oxidized, which is convenient for recycling, and Cu, Fe and other metals are not easily generated to promote the formation of dioxins catalyst
(4) The content of heavy metals, dioxins and other pollutants in the flue gas produced by pyrolysis gasification method is less, and the secondary pollution is smaller, so the pollution control problem is simplified and safer for the environment.
(1) It is a misunderstood technology, and a serious problem with gasification is that many people in the market do not understand it.
(2) Due to some of the failures of gasification projects – especially in the UK – some people believe that the technology is not applicable on a commercial scale or for certain types of waste materials. Others believe that the technology is not viable.
Why choose gasification?
Gasification is the best choice for future-proofing your energy from waste projects, depending on your waste management and energy requirements.
Plants may be developed more quickly and with reduced capital costs thanks to its flexible, modular implementation. In terms of the different waste kinds that can be treated and the variety of products, it gives a lot of versatility. Due to all of this, it can manage a wide range of waste kinds and generate a number of high-value revenue streams.
Gasification is a more environmentally friendly method of waste disposal than incineration or landfilling. This is crucial to take into account because, in the upcoming years, there may be restrictions on new projects and stronger emission standards for incineration.