Routes to hydrogen

Specifications for reformulated gasoline have meant less aromatics and olefins and constraints on light hydrocarbons and sulphur. New legislation for diesel requires deep desulphurisation to 10-50 ppm S. This is done by reacting the sulphur compounds with hydrogen into hydrogen sulphide (hydrotreating), which is removed from the hydrocarbon stream. The requirement for sulphur removal may be accompanied by a wish to remove aromatics. 

In general, these trends result in an increasing atomic ratio H/C of the fuels approaching two [161], while available oil resources become heavier with higher contents of sulphur and metals. This has created a large requirement for more hydrotreating (HDS, HDN, HDM) and hydrocracking. 

Traditionally, a major part of the hydrogen consumption in refineries was covered by hydrogen produced as a by-product from other refinery processes, mainly catalytic reforming ( plat-forming ). However, there is 

Plants supplying hydrogen for the build-up of a future hydrogen infrastructure are faced with a dilemma when based on fossil fuels [418]. Centralised large-scale hydrogen production is penalised by significant costs for compression and transportation. 

it might appear more feasible to manufacture hydrogen decentralised at gas stations, but CO2 sequestration (refer to Section 

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Figure 3.3 Direct gasification routes to hydrogen conversion from biomass.

Ewan BCR, Allen RWK (2005) A figure of merit assessment of the routes to hydrogen. Int J Hydrogen Energy 30 809-819... 

Hydrogen cyanide is an important building block chemical for the synthesis of a variety of industrially important chemicals, such as 2 hydroxy-4 methylthiobutyric acid, adiponitrile, nitrilotriacetic acid, lactic acid, and methyl methacrylate. The primary commercial routes to hydrogen cyanide are the reaction of methane and ammonia under aerobic (Andrussow Process) or anaerobic conditions (Degussa Process), or the separation of hydrogen cyanide as a by-product of the ammoxidation of propylene < ) The ammoxidation of methanol could represent an attractive alternate route to HCN for a number of reasons. First, on a molar basis, the price of methanol has become close to that of methane as world methanol capacity has increased. However, an accurate long term pricing picture for these two raw... 

Fig. 26. Possible routes to hydrogenation and ring-opening reactions.

The direct route to hydrogen peroxide from hydrogen and oxygen is described in Chapter 5.4.1 (page 238). 

The problem then is the route to hydrogen peroxide in the present case. Insertion of ozone into a carbon—hydrogen bond has been postulated by White and Bailey (14) to explain the ozonation of benzaldehydes, by Price and Tumolo (15) in the ozonation studies of ethers, and by Batter-bee and Bailey (16) in their studies on the ozonation of anthrone. We postulate a similar intermediate to explain the formation of hydrogen peroxide and subsequently the diaminoperoxide VII. 

The yields depend on the size of the ring formed, decreasing in the order 3>5>6 >4 i7. Formation of five-membered rings is inhibited in the presence of a proton donor (dimethyl malonate) and cyclization to four-, six- and seven-membered rings is completely prevented. However, these conditions have little effect on the formation of the three-membered rings [221]. The authors interpret the results of their preparative studies as a competition between protonation and intramolecular Sn2 reaction on the radical anion stage. However, it seems more likely that the competition is between protonation and cyclization of the /S-carbanion formed en route to hydrogenation. 

Muradov N, Smith F, Huang C, Raissi AT (2006) Autothermal catalytic pyrolysis of methane as a new route to hydrogen production with reduced CO2 emissions. Catal Today 116 281-288... 

New routes to hydrogen peroxide new methods for direct synthesis of hydrogen peroxide (from hydrogen and oxygen) in a controlled, safe manner could provide a lower cost oxidant that reduces the use of chlorine. For example, in situ generation of hydrogen peroxide can be used to produce propylene oxide in place of the chlorohydrin route and... 

For an overview of H2O2 production processes, see W.R. Thiel (1999) Angewandte Chemie International Edition, vol. 38, p. 3157 - New routes to hydrogen peroxide Alternatives for established processes ... 

High-temperature Thermochemical Potential route to hydrogen with no Highly speculative prospects - both techni-... 

Bertrand A, Lortie F, Bernard J (2012) Routes to hydrogen bonding chain-end functionalized polymers. Macromol Rapid Commun 33(24) 2062-2091... 

Hydrogen from biological wastes is the sustainable route to hydrogen economy, but there is not currently an industrial production of biohydrogen because of the low hourly productivity and yield. 

The potential for carbon capture and sequestration (CCS) and precombustion decarbonization expand possibilities for the sustainable use of conventional fossil energy carbonthis area during the 2009-2015 term may be gasification related. Currently, Task 27 - Near-Term Market Routes to Hydrogen by Co-utilization of Biomass as a Renewable Energy Source with Eossil Euels addresses many of these issues. This task seeks to advance the development... 

Near-term market routes to hydrogen by co-utilization To identify and evaluate the most attractive process pathways towards a large-scale demonstration of biomass co-gasification with fossil fuels and for renewable-based H2 2008-2011... 

Methanol from biomass may represent a sustainable route to hydrogen [485] (see Section 2.2). 

Thiel WR. New routes to hydrogen peroxide alternatives for established processes Angew Chem Int Ed Engl. 1999 38 3157-8. 

Scheme 9.4 Route to hydrogen-bonded polymers by combining ROMP and azide/alkyne click chemistry, (a) Direct polymerization approach [13, 17], ONBEs with thymine and Hamilton-receptor functionalities, 22a and b via azide/alkyne click reaction, followed by polymerization...

Abstract This chapter examines the role of the fuel in the operation, performance and degradation of fuel cells. The range of fuels and impurities that are of relevance to low-temperature fuel cells are discussed and the performance from a thermodynamic perspective is analysed. As a route to hydrogen, various fuel processing options are considered along with an overview of the major storage techniques. Issues associated with alternative fuels are covered along with the deleterious properties of fuels and their impurities. 

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