Synthesis gas generation on-board a vehicle: Development and results of testing

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    The present work is focused on the development of energy-efficient internal combustion

    engines with minimized CO, CO2, CH and NOx emissions. In frame of this concept,

    increasing fuel demands and mass emissions of harmful

    tive emission regulations. The world leading car manufac-

    tures have been focusing intensive efforts on improving

    spark-ignited internal combustion engines, including

    changeover to gaseous fuels [1].

    based catalysts raise the car price and worsen engine effi-

    hydrocarbon fuel combustion in spark-ignited engines, in

    particular, on lean-combustion approach. In city driving, a car

    engine frequently runs in idle and partial load regimes,

    emitting large amount of harmful combustion products. For

    * Corresponding author. Boreskov Institute of Catalysis, Pr. Akademika Lavrentieva 5, Novosibirsk 630090, Russia. Tel.: 7 383 3306187.

    Available online at www.sciencedirect.com

    w.

    i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n en e r g y 3 7 ( 2 0 1 2 ) 1 6 3 5 9e1 6 3 6 6E-mail address: vak@catalysis.ru (V.A. Kirillov).substances into the atmosphere. At present, motor transport

    is the main source of urban air pollution in the world. Current

    levels of specific fuel rates and exhaust cleanup remain

    insufficient that provokes continuous tightening of automo-

    ciency. In other words, traditional approaches to reduce car

    exhaust emissions address consequences rather than prin-

    cipal shortcomings of fuel combustion in the engine. It seems

    reasonable to concentrate attention on new principles of1. Introduction

    Large-scale vehicle production in the developed countries and

    high concentration of vehicles in large cities caused

    Traditionally, reduction of harmful emissions in automo-

    tive exhausts is reached by using three ways catalytic

    neutralizers which provide simultaneous conversion of CO,

    CH, NOx [2]. But expensive three-component platinum metalArticle history:

    Received 15 November 2011

    Received in revised form

    17 April 2012

    Accepted 20 April 2012

    Available online 17 June 2012

    Keywords:

    Hydrogen

    Onboard synthesis gas generator

    Internal combustion engine

    Natural gas

    Electronic control system

    Catalytic reaction of partial

    oxidation0360-3199/$ e see front matter Copyright doi:10.1016/j.ijhydene.2012.04.106a method for hydrogen-rich gas generation onboard a vehicle and, in particular, its

    application as an additive to the engine fuel was suggested and tested experimentally. For

    practical realization of the method, the catalysts for hydrocarbon fuel reforming to

    synthesis gas were created, compact under-hood mounted synthesis gas generator was

    designed, and integrated ICE-synthesis gas generator control system was developed. The

    tests proved fuel economy in city cycle and considerable decrease of CO, CO2, CH and NOxemissions. The prospects of the technology for the development of energy-efficient envi-

    ronmentally benign engines are analyzed.

    Copyright 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rightsreserved.a r t i c l e i n f o a b s t r a c tbNovosibirsk State University, Ul. Pirogova 2, Novosibirsk 630090, RussiacRussian Federal Nuclear Center VNIIEF, Ul. Jeleznodorojnaya 4/1, Sarov 607188, RussiaSynthesis gas generation on-band results of testing

    V.A. Kirillov a,b,*, V.A. Sobyanin a,b, N.A. KuaBoreskov Institute of Catalysis, Pr. Akademika Lavrentieva 5, Nov

    journal homepage: ww2012, Hydrogen Energy Pard a vehicle: Development

    a, O.F. Brizitski c, V.Ya. Terentiev c

    irsk 630090, Russia

    elsevier .com/locate/heublications, LLC. Published by Elsevier Ltd. All rights reserved.

  • development of new type structured catalysts for theconversion of hydrocarbon fuels to synthesis gas;

    development of compact, under hood-mounted synthesisgas generators;

    development of microprocessor-based control system ofsyngas generator, integrated with vehicle control system;

    technical problems associated with practical operation andcontrol of ICE integrated with SGG;

    lab, bench and road trials; evaluation of technology perspectives for the developmentof energy-efficient ecologically benign engines.

    Analysis of these tasks is the aim of the present report.

    2. Results and discussion

    i n t e rn a t i o n a l j o u r n a l o f h y d r o g e n en e r g y 3 7 ( 2 0 1 2 ) 1 6 3 5 9e1 6 3 6 616360example, an engine of 50e100 kW nominal power demon-

    strates in city cycle an average power not exceeding 10 kW

    and efficiency below 15% (instead of 30% nominal) [3]. In view

    of hydrocarbon fuel economy, reduction of CO2 emissions and

    minimization of internal combustion engines (ICE) impact on

    urban environment, the use of lean fuel mixtures shows

    obvious promises. One of the problems related to application

    of lean fuels is to provide stable ICE operation without power

    losses. Promising approach is to use hydrogen as an additive

    to the lean fuel combusted in ICE.

    However, the use of even small amounts of cylinder

    hydrogen in vehicles is problematic because of high explosion

    and fire risks as well as the absence of developed hydrogen-

    supply infrastructures. A practical solution consists in the

    production of hydrogen-rich gas mixture (synthesis gas,

    syngas) in situ onboard a vehicle. This concept is especially

    attractive in view of large territories and lack of hydrogen-

    refueling stations in Russia. It combines the advantages of

    engine fuelling by hydrogen-enriched lean fuel mixtures and

    hydrogen risk reduction.

    Application of hydrogen as an additive to fuel mixtures is

    not a new problem. As far back as 1980s, a cycle of extensive

    studies on hydrogen engines was performed in USSR [4,5].

    Changeover to fuelling automotive engines with hydrogen in

    combination with traditional motor fuels was proved prom-

    ising. At the same time, the problems of hydrogen storage,

    blending and risk management were unveiled that suspended

    activities towards practical application of hydrogen as fuel

    additive.

    Investigations carried out in 1973e1975 in USA with

    Chevrolet car with an engine (5.75 L in volume) equipped with

    synthesis gas generator demonstrated a decrease in petrol

    consumption by 26% when driving according to the Federal

    Drive Cycle CVS-3 [6]. However, the development was not

    commercialized because of low lifespan of catalysts and

    tightening of NOx emission standards.

    In the following years, investigations on using hydrogen as

    a fuel for ICE were reported periodically [7e13]. The results of

    the studies allow conclusion that addition of hydrogen to

    natural gas in the amount not exceeding 20% reduces CO, CH

    and NOx concentration in the exhausts, but worsens thermal

    efficiency of an engine owing to lower volumetric energy

    density of hydrogen. Reduction of emissions may be attrib-

    uted to homogenization of the fuel mixture with hydrogen

    additives that provides more uniform spatial ignition in the

    ICE cylinders where hydrogen serves as a spatial combustion

    initiator.

    Further increase of hydrogen concentration leads to

    increasing formation of NOx and provokes other critical

    effects such as back-fire of the fuel. To neutralize these

    effects, recycling of the exhaust gases is recommended.

    Clearly, the use of variable composition fuels and optimum

    combustion of lean fuel mixtures represented a complex task

    which needed novel approaches and technical solutions.

    Mostly for this reason, the realization of this obviously

    advantageous concept remained kept within laboratory bench

    bounds.

    For practical realization of hydrogen-rich gas generationonboard a vehicle and its application as an additive to

    conventional fuel, the following tasks are to be solved:2.1. Catalyst for partial oxidation of the natural gas

    Catalytic reaction of partial oxidation of natural gas is one the

    most preferred processes for hydrogen-rich gas generation.

    The following gross reactionsmay proceed at partial oxidation

    of natural gas:

    CH4 2O2 CO2 2H2O DH0298 803kJ=mole

    CH4 H2O CO 3H2 DH0298 206kJ=mole

    COH2O CO2 H2 DH0298 41kJ=mole

    Since the reaction of methane partial oxidation is highly

    exothermic, it is reasonable to support a catalyst ontometallic

    materials in order to prevent hot spot formation and improve

    mechanical strength. In the present work, we used nickel

    catalysts reinforced with stainless steel gauze and nickel

    catalysts supported onto porous nickel strips (Fig. 1). To

    prepare gauze-reinforced nickel catalysts, a mixture of Ni

    powder PNE-1 (84.0e85.5 wt.%), a

  • SGG and ICE configurations and control systems should be

    As the flow rates of natural gas and air was 2 m /h and 5.5 m /

    h, SGG generated 9.6 m3 of hydrogen-rich gas. The tempera-

    ture of hydrogen-rich gas at SGG outlet was 150e200 C; theflow rate of cooling agent did not exceed 100 L/h. According to

    test results, the SGG hydrogen-rich gas productivity ranged

    within 5e30 m3/h.

    i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n en e r g y 3 7 ( 2 0 1 2 ) 1 6 3 5 9e1 6 3 6 6 16361maximally integrated and operated according to control

    algorithm. Depending on the integrated operation mode, SGG

    performs the following functions: cold start mode; all modes

    of operation (except of clo