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Nowadays attention is focused on biomass as a renewable energy source, but still one of the remaining drawbacks to be solved is the elimination of the high level of tar present in the syngas from the gasification process of the biomass. The objective of this work is to perform experimental measurements of liquid–liquid equilibria that will be used for the operation of tar removal from the gasification process. With this aim, the liquid–liquid equilibrium of water + solvent (p-xylene or methyl hexadecanoate) + model molecules of tar (thiophene, or pyridine, or naphthalene, or phenanthrene, or anthracene) were studied at 303.2, 323.2, and 343.2 K. The obtained data were correlated with the nonrandom two-liquid and universal quasi-chemical models.

The sequestration of carbon dioxide fumes from oxyfuel combustion is used to reduce significantly the carbon dioxide emissions from coal‐fired power plants. Impurities like nitric oxide, present in the fumes, can cause technical difficulties during the capture, the treatment, the transport, and the storage steps of the CO2 fumes. The purpose of this study is to better understand the oxidation of nitric oxide under pressure in the presence of carbon dioxide and in the experimental condition of flue gas treatment. This reaction is known to be a third‐order reaction, two order in nitric oxide and first order in oxygen. To examine the effect of the temperature, the pressure and the volume fraction of oxygen on the rate constant of oxidation, k1, an autoclave is used. The first experiment studies the influence of the temperature between 288 and 323 K. The results found are in the form of an Arrhenius‐type equation: k1 = 810 exp(620/T) and are in agreement with the literature. Carbon dioxide does not seem to have an influence on the rate constant, whereas our experimental measurements indicate an influence of the volume fraction of oxygen. The rate constant decreases when the oxygen volume fraction increases by up to 10%. Then the rate constant remains constant. This observation allows us to conclude that the mechanism involving the mechanism with a dimer of NO as an intermediate is more likely to be the mechanism involved in the nitric oxide oxidation in our experimental conditions: high pressure and ambient temperature. The rate constant k2, k–2, and k3 were also estimated in these conditions.

Biomass is known as a potential renewable energy source which can be used in the gasification process in order to produce biomethane gas. One of the major challenges encountered is the elimination of the high level of tar found in the syngas issued from the gasification process. The main purpose of this work is to conduct experimental measurements of liquid−liquid equilibria that will be used for tar removal from the biomass gasification process which is the important step before the distribution and the industrialization of the biomethane gas. In the present work, we propose an experimental and modeling study of liquid− liquid equilibrium of ternary systems of water + solvent (methyl oleate) + model molecules of tar (benzene, toluene, phenol, thiophene, and pyridine) at 303.2 K, 323.2 K, and 343.2 K. The experimental results were correlated using the nonrandom two-liquid (NRTL) and UNIQUAC models and are used to feed the industrial needs for thermodynamic modeling.