A methodological study to structure liquid biofuel science and put its publication dynamics into perspective

Mirjam Schomaker 1, 2 and Ed Noyons 1

1 Centre for Science and Technology Studies, Leiden University2 African Studies Centre, Leiden

19th International Conference on Science and Technology Indicators

Leiden, the Netherlands

September 5, 2014

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Outline

• Context of this biofuel knowledge mapping project

• Data sources, tools and collection

• Structuring publications into clusters

• Analysis on publication dynamics

• Conclusions

• Next steps

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Context of this biofuel knowledge mapping project

• Geographer with background in integrated

environmental assessment and reporting: connecting

science and policy

• Dynamics in the science-policy interface remain

un-transparent and thus intriguing

• Decided to study inter-linkages in biofuel for transport

- Using a systematic approach to map biofuel knowledge

- Integrating scientific and grey literature

• Discovered CWTS and the magic of bibliometrics

• First paper: focus on methodology of structuring

scientific biofuel publications and their

dynamics

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Data sources and tools

• Web of Science (WoS) database

• CWTS global classification system of science(Waltman and Van Eck 2012)

- automated clustering of citation relations at publication level

- over 18 million publications between 1993 - 2012

- three levels (broad, intermediate, detailed)

- cluster size varies considerably

- each cluster contains both biofuel specific and surrounding publications

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Actual data collection

• Searched the WoS database: English only; 20 years;

titles, abstracts and keywords

• Long iterative process to define the search strategy

• Delineation problems: definitions, habits, different

contexts, and terminology changes over time

• Combined two sets of publications to arrive at a final set

for further analysis (21,422 publications)

Web of Scienceset_0not_set_0

set_0 and not_set_0

final_set

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Comparing renewable energy publications

0%

1000%

2000%

3000%

4000%

5000%

6000%

7000%

solar energy wind energy

modern solid biomass energy liquid biofuel for transport

Relative increase in publications in the entire WoS for some forms of renewable energy, 1993 – 2012

Indexed at 1993

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Structuring publications into clusters – 1

Final WoS set combined with CWTS science classification

Second level: position of biofuel, solar- and wind energy (colored) among the total of ± 800 science clusters in the WoS (blue)

Biofuel – 21 clustersSolar – 12 clusters

Wind – 5 clusters

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Structuring publications into clusters - 2

• Third level: 1689 biofuel clusters

– Each with at least one biofuel-specific core publication and

– surrounding pubs that do not match the biofuel search rules, but are relevant in a biofuel context

– The more biofuel publications compared to surrounding publications, the higher the biofuel coverage and the more biofuel relevant the cluster

• Number of clusters for analysis was limited to 40

– selected clusters with a coverage of at least 5 % and– at least 10 core biofuel publications,– while also applying some minor data cleaning

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Details for the 40 biofuel clusters - 1

Number of core biofuel pubs per year

from ± 2005 onwards

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Details for the 40 biofuel clusters - 2

Top ten scientific publishing countries in 1993 – 2012

All pubs in WoS All pubs in 40 clusters Biofuel core in 40 clusters

USA 28 % USA 21.2 % USA 24.1 %

Japan 7 % P. R. China 9.2 % P. R. China 9.8 %

Great Britain 7 % Japan 5.6 % India 6.3 %

P. R. China 6 % India 4.5 % Brazil 5.9 %

Germany 6 % Great Britain 4.1 % Japan 3.6 %

France 4 % Brazil 4.1 % Spain 3.6 %

Canada 4 % Canada 3.8 % Great Britain 3.3 %

Italy 3 % Spain 3.7 % Canada 2.9 %

Spain 3 % Germany 3.6 % South Korea 2.7 %

India 2 % France 3.5 % Turkey 2.6 %

Details for 10 selected clusters # cluster code N all

pubsN BF pubs cluster impression * cover-

age overall cluster age

biofuel cluster age

(a) 10 22 1 4916 4267 biodiesel blends - production and performance

86.8 % 2008.58 2009.01

(b) 10 8 1 3636 1788 ligno-cellulosic feedstock decomposition [for bioethanol]

49.2 % 2007.87 2008.92

(c) 6 7 8 1393 853 biofuel debate 61.2 % 2009.22 2009.86

(d) 10 22 2 2816 783 micro-algae [for large-scale biomass production]

27.8 % 2006.16 2010.74

(e) 6 7 3 1869 421 non-food [energy] crop yield improvement

22.5 % 2005.37 2008.16

(f) 20 4 1 3146 286 thermo-chemical biomass conversion (pyrolysis) [into bio-energy]

9.1 % 2006.71 2008.74

(g) 10 8 4 2486 257 ligno-cellulosic feedstock decomposition

10.3 % 2003.78 2009.50

(h) 1 55 7 919 253 [potential of bio-] butanol 27.5 % 2006.18 2010.31

(i) 10 16 4 1380 245 fermentation; beer, wine, bioethanol, …

17.8 % 2003.05 2006.75

(j) 10 22 4 771 153 re-use of glycerol [waste from biodiesel]

19.8 % 2009.19 2009.64

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* see last ppt sheet for an example of cluster annotations

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Publication dynamics – three examples presenting annual numbers in graphs gives additional insightdark = biofuel core; light = surrounding publications

(a) biodiesel production and

performance‘only’

more popular

(c) Biofuel de-bate

between more popular and new

(d) micro-algae biofuel - new

algae – become more popular

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Conclusions

• On biofuels for transport

– We obtained interesting initial clues on scientific publication structure and dynamics which is a nice incentive to continue

• On methodology

– Integration of quantitative bibliometric data with qualitative textual information provides additional insights

– Such cross-fertilization gives added-value for both communities (the subject experts and the bibliometrists)

– Visualizing annual publication numbers for each science clusters can provide additional information on publication dynamics

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Next steps

• A comprehensive mapping of the scientific biofuel landscape:– term map including all clusters pointing to multiple disciplines– term maps within specific clusters– classification cluster map of main topics – cluster- and author networks – ……….• Creation of a compatible database on grey literature, including official policy documents and legislation, and integrating it with the scientific core set (pdf format problems) • Analysis of the integrated biofuel for transport knowledge database, zooming in on linkages (or not) between science and policy, with a focus on Europe and Africa

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Thank you very much for your attention(see the paper itself for more details and reference to actual data via internet)

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The biofuel debate – an example of cluster annotations made

Cluster gives a comprehensive overview of the (liquid) biofuel debate, using a wide variety of arguments, applying different methodologies and tools to make ones point: life cycle- and sustainability assessments, vulnerability-uncertainty-risk modeling, footprint analyses, energy/green accounting, supply chain studies, national strategies and policies (on energy, economy, transport, sustainable development), and more political, philosophical, social or ethical reasoning (sustainability standards, new paradigms, smallholders, poverty, ...).

Potential and/or perceived impacts are discussed: (1) on the environment (changes in land use, greenhouse gas emissions, the nitrogen cycle, water

resources, biodiversity); (2) on social aspects (food security, social unrest due to unjust land allocation, gender issues); and (3) on economy and development (changes in e.g. the energy, transport and agricultural sectors and

policies, international trade, energy consumption, deteriorating livelihoods, inequality/poverty, ....).

Contradictions used in biofuel core titles are: good or bad; benefits versus risks; food versus fuel; constraints and potential; constraints and synergies; promises and perils; (landscape-scale) trade-offs; success story or cautionary tale; opportunities, challenges and pitfalls; realistic or foolish; biofuel-poverty-growth; authorities and controversies.

The surrounding non-biofuel pubs in the cluster are not far from biofuel issues. Some pubs are e.g. on biogas or combined heat and power (CHP) - usually in smaller scale (local) burners-, but even then often in combination with liquid biofuel. In some pubs the search terms are not used, but are relevant nonetheless (sugarcane/sugar footprint, Jatropha, renewable energy, bioenergy, soil sustainability).

Strangely enough the issue on land grabbing related to biofuel is hardly included in this cluster (is covered in cluster 6 20 11).