Elsevier

Bioresource Technology

Volume 135, May 2013, Pages 292-303
Bioresource Technology

States and challenges for high-value biohythane production from waste biomass by dark fermentation technology

https://doi.org/10.1016/j.biortech.2012.10.027Get rights and content

Abstract

Hythane (H2 + CH4) has attracted growing attention due to its versatile advantages as, for instance vehicle fuel. Biohythane consisting of biohydrogen and biomethane via two-stage fermentation is a potential high-value solution for the valorization of waste biomass resources and probably an alternative to the fossil based hythane. However, the significance and application potential of biohythane have not yet been fully recognized. This review focuses on the progress of biohydrogen and subsequent biomethane fermentation in terms of substrate, microbial consortium, reactor configuration, as well as the H2/CH4 ratio from the perspective of the feasibility of biohythane production in the past ten years. The current paper also covers how controls of the microbial consortium and bioprocess, system integration influence the biohythane productivity. Challenges and perspectives on biohythane technology will finally be addressed. This review provides a state-of-the-art technological insight into biohythane production by two-stage dark fermentation from biomass.

Highlights

Hythane (H2 + CH4) has attracted growing attention as clean vehicle fuel. ► We review the progress of bioH2 and bioCH4 fermentation in the past ten years. ► We discuss the feasibility of biohythane output from bioH2 and bioCH4. ► This review is intended to provide a state-of-the-art insight to biohythane.

Introduction

Hydrogen and methane are the two main gaseous energy carriers and also are widely used in the chemical industry. Each has independently attracted broad commercial interest and is highly valued. Hydrogen is regarded as the cleanest fuel. The hydrogen-based economy is described as a developing trend of future society with zero carbon emissions (Turner, 2004), as it is clean and sustainable compared with the current fossil fuel-based economy. However, the development of a hydrogen-based society has been restricted mainly by its cost-intensive processes and operations. Methane is being commonly used, not only in the chemical industry but also in transport as compressed natural gas (CNG), which has been regarded as the clean energy carrier in comparison to gasoline or diesel. Based on data from NGV (Global NGV, 2011), CNG-powered vehicles have been rapidly developed throughout the past decade, particularly in China. To satisfy the huge demand in east China, several projects, for instance the west-east natural gas transmission, have been established (Xinhua, 2004).

A mixture of hydrogen and methane is called hythane, which was trademarked by Eden (2010), HCNG or methagen (Ljunggren and Zacchi, 2010). Typically, the suggested hydrogen content in hythane is 10–25% by volume (Fulton et al., 2010). By combining the advantages of hydrogen and methane, hythane is considered one of the important fuels involved in achieving the transition of technical models from a fossil fuel-based society to a terminal hydrogen-based society (Bauer and Forest, 2001, Das et al., 2000, Fulton et al., 2010). Hythane has been used commercially as vehicle fuel in the USA and India (Das et al., 2000, Eden, 2010) and has also received much attention from many individual companies such as Volvo, Fiat, Airproducts and others. Currently, the industrial chain of hythane is mainly limited by the production and instrumentation associated with hydrogen since methane is a kind of primary energy carrier with relatively abundant sources of diverse origins, such as natural gas, landfill gas, biogas, etc. At present, hydrogen is mainly produced by physical/chemical methods, for instance, via the reforming of methane or during the production of syngas. These approaches are mostly not sustainable due to their heavy dependence on fossil based energy. The ability of providing sustainable and environmentally benign hythane is a key factor that will allow applications of hythane to attain its potential respected market position. One method is to add clean hydrogen to natural gas. Two separate gas channels with quantitative control of the gas flow rates would be required to produce hythane with the desired H2/CH4 ratio.

Another approach is to biologically produce hydrogen and methane concurrently in one system, which can be realized through a two-stage dark fermentation using biomass as the substrate (Banks et al., 2010, Liu et al., 2012, Ljunggren and Zacchi, 2010, Lu et al., 2009). If the system can reach an H2/CH4 ratio suitable for hythane, a sustainable route for the generation of so-called biohythane can be expected. In fact, the nature of the biological method guarantees the H2/CH4 ratio because it can be easily regulated by adjusting the conditions of the microbial fermentations. Therefore, biohythane production from biomass via two-stage biological fermentation can be a sustainable win–win solution, as it provides an output of renewable biological hythane and the efficient utilization of waste biomass. However, the application potential of biohythane has not yet received the attention it deserves. In addition, a large body of work focused on independent biohydrogen or biomethane production from biomass. This paper firstly summarizes the status of investigations and applications of hythane, then reviews the progress in the coproduction of biohydrogen and biomethane via dark fermentation in terms of substrate, microbial consortium, reactor configuration, product yield as well as H2/CH4 ratio by focusing on the feasibility of biohythane generation in the past ten years. This review also covers how microbial consortium control, process control and system integration influence the performance of the two-stage system. Challenges and perspectives on the development of biohythane will finally be addressed. This review is expected to provide a state-of-the-art technological insight to the study and applications of biohythane production by two-stage dark fermentation from waste biomass.

Section snippets

Hythane and its significance

Hythane has received extensive attention as a vehicle fuel since the 1980s (Bauer and Forest, 2001, Ma, 2008, Nagalingam et al., 1983). The characteristics of hydrogen and methane are given in Table 1 (Bauer and Forest, 2001). Methane (CNG) is considered to be a clean fuel for vehicle use compared to gasoline or diesel. It is, however, limited by its narrow flammability range, slow burning speed, and high ignition temperature (Table 1), which result in poor combustion efficiency and an

Process description

The end use of hythane is quite straightforward with a clear business model. The production of biohythane from waste biomass can be achieved via two-stage dark fermentation if the H2/CH4 ratio can be feasibly controlled. The traditional anaerobic methane fermentation normally consists of four steps (Gerardi, 2003): hydrolysis, acidogenesis, acetogenesis, and methanogenesis. Microorganisms with different functions are incorporated together to establish a synthetic route for methane production

Key factors affecting the performance and application of two-stage fermentation for coproduction of hydrogen and methane

According to the published results (Table 2), the hydrogen content by volume (H2/(H2 + CH4), given that the gas mixtures are purified with the removal of CO2) via two-stage dark fermentation ranged from 0.01 to 0.75, depending on operating conditions and substrates used. The hydrogen content covered the suggested range (0.1–0.25) for hythane. A flexible and controllable H2/CH4 ratio afforded by two-stage fermentation is of great importance in making biohythane. This section will discuss the key

Challenges and possible solutions

Although there is an emerging potential technology for biohythane production from waste biomass, several challenges still need to be addressed:

Conclusions

This review linked the valorization of waste biomass and the generation of biohythane via two-stage dark fermentation and discussed the key issues affecting biohythane production. Based on its properties and the strong demand for hythane fuel, as well as the stringent requirement of treatment of biomass waste, the concept of simultaneous high-value biohythane production and valorization of waste biomass was proposed. The coproduction of hydrogen and methane from waste biomass would be a

Acknowledgements

This work was supported by the Project of the National Basic Research Program of China (973 Plan) (2011CB707404), NSFC-JST Cooperative Research Project (21161140328), NSFC project (21106080) and Chinese Universities Scientific Fund (2012RC030).

References (75)

  • L.M. Das et al.

    A comparative evaluation of the performance characteristics of a spark ignition engine using hydrogen and compressed natural gas as alternative fuels

    Int. J. Hydrogen Energy

    (2000)
  • T.D. DiStefano et al.

    Effect of anaerobic reactor process configuration on useful energy production

    Water Res.

    (2010)
  • E. Elbeshbishy et al.

    Comparative study of the effect of ultrasonication on the anaerobic biodegradability of food waste in single and two-stage systems

    Bioresour. Technol.

    (2011)
  • A. Giordano et al.

    Monitoring the biochemical hydrogen and methane potential of the two-stage dark-fermentative process

    Bioresour. Technol.

    (2011)
  • X. Gómez et al.

    The production of hydrogen by dark fermentation of municipal solid wastes and slaughterhouse waste: a two-phase process

    J. Power Sources

    (2006)
  • H. Hafez et al.

    An integrated system for hydrogen and methane production during landfill leachate treatment

    Int. J. Hydrogen Energy

    (2010)
  • T. Kanai et al.

    Continuous hydrogen production by the hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1

    J. Biotechnol.

    (2005)
  • P. Kaparaju et al.

    Bioethanol, biohydrogen and biogas production from wheat straw in a biorefinery concept

    Bioresour. Technol.

    (2009)
  • P. Kongjan et al.

    Performance and microbial community analysis of two-stage process with extreme thermophilic hydrogen and thermophilic methane production from hydrolysate in UASB reactors

    Bioresour. Technol.

    (2011)
  • E.C. Koutrouli et al.

    Hydrogen and methane production through two-stage mesophilic anaerobic digestion of olive pulp

    Bioresour. Technol.

    (2009)
  • Y.W. Lee et al.

    Bioproduction of hydrogen from food waste by pilot-scale combined hydrogen/methane fermentation

    Int. J. Hydrogen Energy

    (2010)
  • D.Y. Lee et al.

    Continuous H2 and CH4 production from high-solid food waste in the two-stage thermophilic fermentation process with the recirculation of digester sludge

    Bioresour. Technol.

    (2010)
  • D.B. Levin et al.

    Challenges for biohydrogen production via direct lignocellulose fermentation

    Int. J. Hydrogen Energy

    (2009)
  • W.W. Li et al.

    From wastewater to bioenergy and biochemicals via two-stage bioconversion processes: a future paradigm

    Biotechnol. Adv.

    (2011)
  • D. Liu et al.

    Hydrogen and methane production from household solid waste in the two-stage fermentation process

    Water Res.

    (2006)
  • Y. Liu et al.

    Hydrogen production from cellulose by co-culture of Clostridium thermocellum JN4 and Thermoanaerobacterium thermosaccharolyticum GD17

    Int. J. Hydrogen Energy

    (2008)
  • Z. Liu et al.

    Enhanced hydrogen production in a UASB reactor by retaining microbial consortium onto carbon nanotubes (CNTs)

    Int. J. Hydrogen Energy

    (2012)
  • M. Ljunggren et al.

    Techno-economic analysis of a two-step biological process producing hydrogen and methane

    Bioresour. Technol.

    (2010)
  • Y. Lu et al.

    Characteristics of hydrogen and methane production from cornstalks by an augmented two- or three-stage anaerobic fermentation process

    Bioresour. Technol.

    (2009)
  • G. Luo et al.

    Anaerobic treatment of cassava stillage for hydrogen and methane production in continuously stirred tank reactor (CSTR) under high organic loading rate (OLR)

    Int. J. Hydrogen Energy

    (2010)
  • G. Luo et al.

    Enhancement of bioenergy production from organic wastes by two-stage anaerobic hydrogen and methane production process

    Bioresour. Technol.

    (2011)
  • F. Ma

    Effects of hydrogen addition on cycle-by-cycle variations in a lean burn natural gas spark-ignition engine

    Int. J. Hydrogen Energy

    (2008)
  • B. Nagalingam et al.

    Performance study using natural gas, hydrogen supplemented natural gas and hydrogen in AVL research engine

    Int. J. Hydrogen Energy

    (1983)
  • X. Ou et al.

    Alternative fuel buses currently in use in China: life-cycle fossil energy use, GHG emissions and policy recommendations

    Energy Policy

    (2010)
  • O.M. Pakarinen et al.

    One-stage H2 and CH4 and two-stage H2 + CH4 production from grass silage and from solid and liquid fractions of NaOH pre-treated grass silage

    Biomass Bioenergy

    (2009)
  • M.J. Park et al.

    Comprehensive study on a two-stage anaerobic digestion process for the sequential production of hydrogen and methane from cost-effective molasses

    Int. J. Hydrogen Energy

    (2010)
  • K.R.J. Perera et al.

    Fermentative biohydrogen production II: net energy gain from organic wastes

    Int. J. Hydrogen Energy

    (2012)
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