Abstract: The invention concerns steps in a process for the synthesis of at least one alkyl tertiobutyl ether, preferably respectively MTBE or ETBE, from at least one alcohol and from isobutene, each synthesized at least partially from natural gas. The alcohol, preferably methanol or ethanol respectively, is synthesized at least partially from synthesis gas, a portion of said synthesis gas being prepared in a natural gas steam prereforming zone. The isobutene is synthesized in a series of processes which includes direct transformation of natural gas to ethylene, known as oxidative coupling of methane (OCM), dimerisation of ethylene to normal butene, isomerisation of n-butene to isobutene, and the separation units associated therewith.

Abstract: The invention concerns a process for the synthesis of at least one alkyl tertiobutyl ether, preferably respectively MTBE or ETBE, from at least one alcohol and from isobutene, each synthesized at least partially from natural gas. The alcohol, preferably methanol or ethanol respectively, is synthesized at least partially from synthesis gas, a portion of said synthesis gas being prepared in natural gas steam prereforming zone. The isobutene is synthesized in a series of processes which includes direct transformation of natural gas to ethylene, known as oxidative coupling of methane (OCM), dimerization of ethylene to normal butene, isomerization of n-butene to isobutene, and the separation units associated therewith.

Abstract: The polysulphide is heated with a substance capable of dissolving elemental sulphur. After cooling, the polysulphide reduced to a lower numbver of S atoms is separated from the substance, which can be recovered.An important use consists in converting the polysulphide to the form of dimethyl disulphide, the solvent used for the dissolution of sulphur deposited in conduits, particularly those used for natural gas.

Abstract: A process to produce sulphur from two acid gases both containing hydrogen sulphide and one of which contains ammonia, using a modified Claus technique.The acid gas containing ammonia is burnt in the presence of air under substoichiometric conditions in a first heat-reaction chamber, while the ammonia-free acid gas is burnt in a second heat-reaction chamber, forming a series with the first chamber, with the right quantity of air to provide a molar ratio of H.sub.2 S to SO.sub.2 of approximately 2/1 at the catalytic reaction stage inlet. The mixed effluents from both heat-reaction chambers may pass through a high-temperature residence chamber before being conveyed to the heat-recovery stage.Gas effluents from the heat-reaction stage contain H.sub.2 S and SO.sub.2 in the right ratio for the catalytic reaction stage, and no hydrocarbons or harmful quantities of NH.sub.3 and NO.

Abstract: A process to produce sulphur from two acid gases both containing hydrogen sulphide and one of which contains ammonia, using a modified Claus technique.The acid gas containing ammonia is burnt in the presence of air under substoichiometric conditions in a first heat-reaction chamber, while the ammonia-free acid gas is burnt in a second heat-reaction chamber, forming a series with the first chamber, with the right quantity of air to provide a molar ratio of H.sub.2 S to SO.sub.2 of approximately 2/1 at the catalytic reaction stage inlet. The mixed effluents from both heat-reaction chambers may pass through a high-temperature residence chamber before being conveyed to the heat-recovery stage.Gas effluents from the heat-reaction stage contain H.sub.2 S and SO.sub.2 in the right ratio for the catalytic reaction stage, and no hydrocarbons or harmful quantities of NH.sub.3 and NO.