Gasification and Gasifiers

An Old Technology brought up to date!

Gasifiers convert carbonaceous feedstock (coal, wood, cornstalks, most any biomass) into gaseous products. The process usually takes place at high temperatures and pressures and with a carefully controlled amount of oxygen.

Gasification can be used to create many products (electric power, liquid fuels, hydrogen, synthetic gas) and provides great opportunities for pollution control, especially sulfur, nitrous oxides, and mercury.

Garbage Gasification - Watch it now! (from Google)

Underground coal gasification (UCG) is an example of a gasification process which converts coal in-situ into a synthesis gas through the same chemical reactions. Gasification can also begin with materials that are not otherwise useful fuels, such as biomass or organic waste. In addition, the high-temperature combustion refines out corrosive ash elements such as chloride and potassium, allowing clean gas production from otherwise problematic fuels.

Gasification is in use throughout most of the world already but the scope for increasing its use is huge. The technology ranges from fully commercialized for certain feedstocks and technologies to scientific exploration for other feedstocks and more advanced technologies.

A gasification system basically consists of a gasifier unit, purification system and energy converters - burner or engine. This internet article will give you an insight into gasification technology.

Gasification has been around for over a hundred years, but the true benefits of biochar are only newly being discovered, it's a wide-open field. It is also a process which for example, can be used for burning wood where the gases from the wood are burned at very high temperatures. Downdraft produces extreme heat up to 2000 degrees igniting all gases including smoke and creosote therefore giving almost 100% efficiency!

It is a technology which is well proven. For example, there are more than 100 plasma gasification plants around the world and a similar number of gasification plants. Gasification itself is a century-old technology that flourished before and during the Second World War. The technology disappeared soon after, as liquid fuel again became readily available.

Gasification use for fertilizer and chemical production will grow dramatically (particularly in China).

The process uses extreme heat, in the form of plasma arcs, to reduce matter to its basic elements. Gasification of wood and wood-type residues and waste in fixed bed or fluidised bed gasifiers with subsequent burning of the gas for heat production is state of the art. The wood gasifiers employed primarily in the Scandinavian countries are used almost entirely for heat generation.

Gasifiers produce a gas which is commonly known as syngas. This gas is used mostly where it is created to power a gas turbine.

Gasification enables a wide range of energy sources including coal, biomass and residual oils to be converted into environmentally-friendly chemicals and fuels. Most of the effluents normally created in atmospheric burning plants are caught before combustion and converted into useful by-products, or captured for safe storage.

Gasifier throughput on one project has been demonstrated to be 150% of design. One gasifier which is fully operational is said to produced enough fuel to generate more than 200 MWh of electricity per day.

Gasifiers have been built for remote Asian communities using rice husk, which in many cases has no other use. One installation in Burma uses an 80 kW-modified diesel for about 500 people who are otherwise without power. Gasifiers cannot cope with these variations: they need consistent feedstocks, where the size of the feed particles, their moisture content and composition are more or less the same over long periods.

Steve Evans is enthusiastic about gasification of biomassgasification and other renewable energy sources from boimass. He also runs a great web site about gasification for energy.

Gasification Biomethane and Syngas

A green renewable energy scheme is best!

Gasification and Biomethane production is probably the most important and efficient energy-conversion technology for a wide variety of biomass fuels. The large-scale deployment of efficient technology along with interventions to enhance the sustainable supply of biomass fuels can transform the energy supply situation in rural areas.

Biomethane recovery, use and production generates "Greentags" or a "Renewable Energy Credits" for the owners as it is good for our environment and our governments wish to encourage its use. The production and use of the natural gas sold by your gas supply company does not generate these incentives and new revenue streams and is not good for our environment because it is sourced from mineral gas fields which are finite in their size and contribute to global warming when burnt.

Watch this YouTube video -The Hybrid Stove Two Cooking With Biomass

By careful renewal of the biomass source (such as by replanting forests) biomethane does not contribute to global warming when created and burnt. This may seem hard to believe, but as long as the biomass burnt is replaced by re-growing another crop, it is a fact. Whether it be forest wood or corn-stubble, the human intervention whereby we use the energy and heat through burning that organic material for our purposes as part of the natural circulation of carbon driven by the sun’s light energy, the net level of carbon dioxide in the atmosphere will not rise.

For global warming to occur it matters not how much carbon dioxide man creates, it only matters that what he does create is re-absorbed the next summer by the re-growth of plants.

The magic of gasification comes both from the cleanness of the burn from gasification, but most importantly also from the gas it produces, which is called syngas.

Syngas can be used as a fuel to generate electricity or steam, or as a basic chemical building block for a multitude of uses.

When mixed with air, syngas can be used in gasoline or diesel engines with few modifications to the engine. Syngas is a mixture of hydrogen and carbon monoxide and it can be converted into fuels such as hydrogen, natural gas or ethanol.

Syngas (which in one example) leaves the converter at a temperature of around 2,200 degrees Fahrenheit) is fed into a cooling system which generates steam.

Syngas can be used as a fuel to generate electricity and steam or as a chemical building block for the petrochemical and refining industries. The gasification process converts feedstock such as coal, crude oil, petroleum-based materials or gases into marketable fuels and products.

Collaborative research now reportedly underway aims to convert synthesis gas (syngas), that can be derived from abundant resources such as coal or biomass, to "building block" chemicals in a more efficient and economical process. For example Dow Chemical, America's diversified chemical company and Shemie, a Munich-headquartered specialty chemical company, have announced an agreement to research alternative routes to produce chemicals to help reduce dependence on traditional sources of oil and gas by April 2009.

So, to round this article off our point is that gasification conserves the chemical energy of waste in the syngas produced. The syngas is than a very versatile energy or raw material source.

One technology giving good results has been developed by Thermoselect of Switzerland. The process accepts a wide range of waste, and better than an ash, it produces, in addition to purified syngas, well as granulated metals and minerals that can be used in industry and construction.

Steve Evans is enthusiastic about gasification and other renewable energy sources from biomass. He also runs a great web site about agricultural anaerobic digestion homesite.