Liquid hydrogen processing development

The main contributions to liquid hydrogen processing development, from small liquefiers to large tonnage plants have been ... 

The Bio-FGD process converts sulfur dioxide to sulfur via wet reduction (10). The sulfur dioxide gas and an aqueous solution of sodium hydroxide are contacted in an absorber. The sodium hydroxide reacts with the sulfur dioxide to form sodium sulfite. A sulfate-reducing bacteria converts the sodium sulfite to hydrogen sulfide in an anaerobic biological reactor. In a second bioreactor, the hydrogen sulfide is converted to elemental sulfur by Thiobacilh. The sulfur from the aerobic second reactor is separated from the solution and processed as a sulfur cake or liquid. The process, developed by Paques BV and Hoogovens Technical Services Energy and Environment BV, can achieve 98% sulfur recovery. This process is similar to the Thiopaq Bioscrubber process for hydrogen sulfide removal offered by Paques. 

A three-step process developed hy Snamprogetti is based on the reaction of acetylene and acetone in liquid ammonia in the presence of an alkali metal hydroxide. The product, methylhutynol, is then hydrogenated to methylhutenol followed hy dehydration at 250-300°C over an acidic heterogeneous catalyst. 

A gas-liquid-particle process termed cold hydrogenation has been developed for this purpose. The hydrogenation is carried out in fixed-bed operation, the liquefied hydrocarbon feed trickling downwards in a hydrogen atmosphere over the solid catalyst, which may be a noble metal catalyst on an inert carrier. Typical process conditions are a temperature of 10°-20°C and a pressure of 2.5-7 atm gauge. The hourly throughput is as high as 20-kg hydrocarbon feed per liter of catalyst volume. 

The present economic and environmental incentives for the development of a viable one-step process for MIBK production provide an excellent opportunity for the application of catalytic distillation (CD) technology. Here, the use of CD technology for the synthesis of MIBK from acetone is described and recent progress on this process development is reported. Specifically, the results of a study on the liquid phase kinetics of the liquid phase hydrogenation of mesityl oxide (MO) in acetone are presented. Our preliminary spectroscopic results suggest that MO exists as a diadsorbed species with both the carbonyl and olefin groups coordinated to the catalyst. An empirical kinetic model was developed which will be incorporated into our three-phase non-equilibrium rate-based model for the simulation of yield and selectivity for the one step synthesis of MIBK via CD. 

Detal [Detergent alkylation] A process for making detergent alkylate, i.e., alkyl aromatic hydrocarbons such as linear alkyl benzenes, as intermediates for the manufacture of detergents, by reacting C10-C13 olefins with benzene in a fixed bed of an acid catalyst. Developed by UOP and CEPSA as a replacement for their Detergent Alkylate process, which uses liquid hydrogen fluoride as the catalyst. Demonstrated in a pilot plant in 1991 and first commercialized in Canada in 1996. Offered by UOP. 

KLP [Dow K Catalyst liquid phase] A selective hydrogenation process for removing acetylenes from cmde C4 hydrocarbons from ethylene cracking, with no loss of butadiene. The catalyst is based on either copper metal or alumina. Developed by Dow Chemical Company and first commercialized at its plant in Temeuzen, The Netherlands. The KLP licensing business was sold to UOP in 1991. 

Kombi [Kombinations-Verfahren] A liquid-phase petroleum hydrogenation process which combined hydrogenation with hydrorefining. The catalyst contained molybdenum and tungsten on an aluminosilicate. Developed by BASF. 

Liquid acid-catalyzed processes are mature technologies, which are not expected to undergo dramatic changes in the near future. Solid acid-catalyzed alkylation now has been developed to a point where the technology can compete with the existing processes. Catalyst regeneration by hydrogen treatment is the method of choice in all the process developments. Some of the process developments eliminate most if not all the drawbacks of the liquid acid processes. The verdict about whether solid acid-catalyzed processes will be applied in the near future will be determined primarily by economic issues. 

A modification of the pyrolysis process, developed by Hoppe-Seyler in 1871, involved the addition of water and alkali to biomass which was converted into oil, gas, water-soluble components, and carbonaceous material. " The addition of carbon monoxide and hydrogen in the liquefaction process allowed the production of liquid fuels from biomass. Asphalt substitutes have also been prepared from biomass under liquefaction conditions. ... 

The butane isomerization process developed by the Universal Oil Products Co. is shown in Figure 4. In this process (3), the feed is maintained essentially in the liquid phase under pressure. Part of the feed is by-passed through a saturator, where it dissolves aluminum chloride. The feed later picks up hydrogen chloride and passes through the reactor, which is packed with quartz chips. Some insoluble liquid complex is formed, and this adheres to the quartz chips. The aluminum chloride in the feed is preferentially taken up by the complex, which thus maintains an active catalyst bed. The complex slowly drains through the reactor, losing activity en route. It arrives at the bottom in essentially spent condition and is discarded. Aluminum chloride carried overhead in the reactor products is returned to the reactor from the bottom of the recovery tower. The rest of the process is the same as in the vapor-phase processes. 

C3 Hydrorefining. The aim of C3 hydrorefining is to hydrogenate methylacetylene and propadiene present in the cut. Efficient liquid-phase processes were developed by Bayer314-316 (cold hydrogenation process carried out at 10-20°C) and IFP,317 but hydrogenation in the gas phase is also practiced. 

A somewhat similar hydrogenation problem arose in a different approach to 1,4-butanediol and tetrahydrofuran.345 In the process developed by Mitsubishi, 1,3-butadiene first undergoes Pd-catalyzed diacetoxylation to yield 1,4-diacetoxy-2-butene. To avoid the further transformation of the diol as in the abovementioned process, l,4-diacetoxy-2-butene is directly hydrogenated in the liquid phase (60°C, 50 atm) on traditional hydrogenation catalysts to produce 1,4-diacetoxybutane in 98% yield, which is then hydrolyzed to 1,4-butanediol. 

The best-developed method of solar electricity storage is to send it to an electrolyzer that splits water into Oz and H2. In this process, the 02 is released (used or sold), and the H2 is stored either as high-pressure gas or as a cryogenic liquid. This process will be described in the discussion of hydrogen processes after the forthcoming description of various solar collector designs in Section 1.5. 

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