Thomas G. Kreutz

A comparison of hydrogen, methanol and gasoline as fuels for fuel cell vehicles: implications for vehicle design and infrastructure development

All fuel cells currently being developed for near term use in electric vehicles require hydrogen as a fuel. Hydrogen can be stored directly or produced onboard the vehicle by reforming methanol, or hydrocarbon fuels derived from crude oil (e.g., gasoline, diesel, or middle distillates). The vehicle design is simpler with direct hydrogen storage, but requires developing a more complex refueling infrastructure. In this paper, we present modeling results comparing three leading options for fuel storage onboard fuel cell vehicles: (a) compressed gas hydrogen storage, (b) onboard steam reforming of methanol, (c) onboard partial oxidation (POX) of hydrocarbon fuels derived from crude oil. We have developed a fuel cell vehicle model, including detailed models of onboard fuel processors. This allows us to compare the vehicle performance, fuel economy, weight, and cost for various vehicle parameters, fuel storage choices and driving cycles. The infrastructure requirements are also compared for gaseous hydrogen, methanol and gasoline, including the added costs of fuel production, storage, distribution and refueling stations. The delivered fuel cost, total lifecycle cost of transportation, and capital cost of infrastructure development are estimated for each alternative. Considering both vehicle and infrastructure issues, possible fuel strategies leading to the commercialization of fuel cell vehicles are discussed.

Co-production of decarbonized synfuels and electricity from coal + biomass with CO2 capture and storage: an Illinois case study

Energy, carbon, and economic performances are estimated for facilities co-producing Fischer–Tropsch Liquid (FTL) fuels and electricity from a co-feed of biomass and coal in Illinois, with capture and storage of by-product CO2. The estimates include detailed modeling of supply systems for corn stover or mixed prairie grasses (MPG) and of feedstock conversion facilities. Biomass feedstock costs in Illinois (delivered at a rate of one million tonnes per year, dry basis) are

Fuels for fuel cell vehicles

3.8/GJHHV for corn stover and

Preliminary Economics of Black Liquor Gasifier/Gas Turbine Cogeneration at Pulp and Paper Mills

7.2/GJHHV for MPG. Under a strong carbon mitigation policy, the economics of co-producing low-carbon fuels and electricity from a co-feed of biomass and coal in Illinois are promising. An extrapolation to the United States of the results for Illinois suggests that nationally significant amounts of low-carbon fuels and electricity could be produced this way.

A time domain photoacoustic study of the collisional relaxation of vibrationally excited H2

The issue of fuel choice impacts both fuel cell vehicle design and infrastructure development. In general, there is a trade-off between simpler vehicle design (hydrogen vehicles are inherently simpler than those with onboard fuel processors) and simpler infrastructure issues (liquid fuels such as gasoline or methanol are easier to store and handle, and are more compatible with the existing refueling infrastructure). In this article we compare fuel cell vehicle characteristics and infrastructure requirements for four possible fuel option compressed hydrogen gas, methanol, gasoline and synthetic liquids derived from natural gas. The advantages and disadvantages of various fuels are discussed, and possible fuel strategies leading towards the commercialisation of fuel cell vehicles are explored.

Black Liquor Gasifier/Gas Turbine Cogeneration

Black liquor, the lignin-rich byproduct of kraft pulp production, is burned in boiler/steam turbine cogeneration systems at pulp mills today to provide heat and power for onsite use. Black liquor gasification technologies under development would enable this fuel to be used in gas turbines. This paper reports preliminary economics of 100-MW e scale integrated black-liquor gasifier/combined cycles using alternative commercially proposed gasifier designs. The economics are based on detailed full-load performance modeling and on capital, operating and maintenance costs developed in collaboration with engineers at Bechtel Corporation and Stone & Webster Engineering. Comparisons with conventional boiler/steam turbine systems are included.

Combined biomass and black liquor gasifier/gas turbine cogeneration at pulp and paper mills

Abstract We report the first direct measurement of the vibration-to-vibration (V-V) and vibration-to-translation (V-T) rates for vibrational relaxation out of the ν=2 vibrational level in hydrogen gas. Time domain photoacoustic spectroscopy was used to monitor the collision dynamics after excitation into ν=2 through overtone stimulated Raman pumping. The V-V relaxation rate is found to be (1–4) × 10−14 cm3 s−1 molecule−1 and the V-T rate constant is (0.6–2) × 10−15 cm3 s−1 molecule−1 for normal hydrogen at 298 K.

Coal and Biomass to Fuels and Power

The kraft process dominates pulp and paper production worldwide. Black liquor, a mixture of lignin and inorganic chemicals, is generated in this process as fiber is extracted from wood. At most kraft mills today, black liquor is burned in Tomlinson boilers to produce steam for on-site heat and power and to recover the inorganic chemicals for reuse in the process. Globally, the black liquor generation rate is about 85,000 MW fuel (or 0.5 million tonnes of dry solids per day), with nearly 50 percent of this in North America. The majority of presently installed Tomlinson boilers will reach the end of their useful lives during the next 5 to 20 years. As a replacement for Tomlinson-based cogeneration, black liquor-gasifier/gas turbine cogeneration promises higher electrical efficiency, with prospective environmental, safety, and capital cost benefits for kraft mills. Several companies are pursuing commercialization of black liquor gasification for gas turbine applications. This paper presents results of detailed performance modeling of gasifier/gas turbine cogeneration systems using different black liquor gasifiers modeled on proposed commercial designs.

Mass effects and channel coupling sensitivity in vibrational energy transfer

Kraft pulp and paper mills generate large quantities of black liquor and byproduct biomass suitable for gasification. These fuels are used today for onsite cogeneration of heat and power in boiler/steam turbine systems. Gasification technologies under development would enable these fuels to be used in gas turbines. This paper reports results of detailed full-load performance modeling of pulp-mill cogeneration systems based on gasifier/gas turbine technologies and, for comparison, on conventional steam-turbine cogeneration technologies. Pressurized, oxygen-blown black liquor gasification, the most advanced of proposed commercial black liquor gasifier designs, is considered, together with three alternative biomass gasifier designs under commercial development (highpressure air-blown, low-pressure air-blown, and low-pressure indirectly-heated). Heavyduty industrial gas turbines of the 70-MW e and 25-MW e class are included in the analysis. Results indicate that gasification-based cogeneration with biomass-derived fuels would transform a typical pulp mill into a significant power exporter and would also offer possibilities for net reductions in emissions of carbon dioxide relative to present practice.

Sensitivity analysis of mass effects in rotational energy transfer

Systems with CO(2) capture and storage (CCS) that coproduce transportation fuels and electricity from coal plus biomass can address simultaneously challenges of climate change from fossil energy and dependence on imported oil. Under a strong carbon policy, such systems can provide competitively clean low-carbon energy from secure domestic feedstocks by exploiting the negative emissions benefit of underground storage of biomass-derived CO(2), the low cost of coal, the scale economies of coal energy conversion, the inherently low cost of CO(2) capture, the thermodynamic advantages of coproduction, and expected high oil prices. Such systems require much less biomass to make low-carbon fuels than do biofuels processes. The economics are especially attractive when these coproduction systems are deployed as alternatives to CCS for stand-alone fossil fuel power plants. If CCS proves to be viable as a major carbon mitigation option, the main obstacles to deployment of coproduction systems as power generators would be institutional.