Biomass, combined with coal

Bio-briquettes (biomass briquettes) are a biofuel substitute to coal and charcoal. They are used to heat industrial boilers in order to produce electricity from steam. The most common use of biobriquettes is in the developing world, where energy sources are not as widely available. There has been a move to the use of briquettes in the developed world throngh the nse of co-firing, when the briquettes are combined with coal in order to create the heat supplied to the boiler. This reduces carbon dioxide emissions by partially replacing coal used in power plants with materials that are already contained in the carbon cycle. 

Carbon dioxide neutral production and utilization of methanol as an automotive fuel for the transport sector integrated with production of electric power and district heat could be achieved with biomass combined with natural gas or coal as a raw material. An amoimt of CO2 corresponding to the carbon in the fossil fuel then has to be captured and disposed into, e.g., an aquifer. Examples of a few such options... 

The CO2 emissions firom the transport sector could be reduced by combining CO2 capture with the production of automotive fuel (methanol), electric power, and heat from biomass combined with natural gas or coal. Optimization work is needed to find the most favorable process configurations. 

Using hydrogen to produce electrical energy from fossil fuels in large centralised plants will contribute positively to achieving important reductions of C02 emissions, if this is combined with C02 capture and sequestration processes. Such plants will also help to increase the diversification of resources, since a variety of fossil feedstocks can be used, including resources such as coal and waste that otherwise cause major impacts on the environment, as well as biomass. 

Future widespread use of anthropogenic C02 in combination with renewable hydrogen as well as the implementation of coal, biomass, and other nonconventional sources of synthesis gas will lead to suboptimal synthesis gas compositions. Efficient incorporation of these synthesis gas mixtures into the current methanol synthesis infrastructure will necessitate the redevelopment of catalysts to perform stably under high concentrations of C02, water, and impurities. To that end, advanced characterization methods must be implemented to discriminate between surface area loss by... 

For CTL plants, CCS can be a low-cost method of addressing carbon dioxide concerns and may result in greenhouse gas emissions. Where coprocessing of coal and biomass is undertaken, and combined with CCS, greenhouse gas emissions over the full fuel cycle may be as low as one-fifth of those from fuels provided by conventional oil. 

The use of tire-derived fuel as a cofiring feedstock in power generation has many advantages. Hrst, because of the high calorific value of TDF, particularly the wire-free TDF, the cost of TDF in GJ (ot /10 Btu) is lower than that of any fossil fuel - with the possible exception of Powder River Basin coal delivered locally or to a mine-mouth plant - and is competitive with even the lowest cost biomass fuels. This, combined with the lower ash content of TDF (without steel) makes it a viable blending fuel. In addition, the sulfur content of TDF is less than most eastern bituminous coals and conq>arable to medium-sulfur coals throughout the world. 

FIG. C-16 CO2 neutral production of methanol, power and district heat by co-gasification of biomass and coal combined with CO2 capture. (Source Vattenfall Utveckling AB.)... 

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