DOCSLIB.ORG

International Point of View on Natural Gas, Liquefied Natural Gas and Liquefied Petroleum Gas Adriaan M.H

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
International Point of View on Natural Gas, Liquefied Natural Gas and Liquefied Petroleum Gas Adriaan M.H International point of view on Natural Gas, Liquefied Natural Gas and Liquefied Petroleum Gas Adriaan M.H. van der Veen, G. Nieuwenkamp, E.T. Zalewska, A. Baldan International Awareness Forum on Environment, Energy and Public Health Santiago de Querétaro, Qro. Mexico, 11 October 2018 Metrology for LNG . Economic way of transporting natural gas . Composition as for natural gas, without − Helium − Carbon dioxide − C6+ hydrocarbons . Temperature -161 °C . Pressure up to 4 bar 11-10-2018 NIST-OAS Forum 2 Flow rate measurement: primary standard . Reference: gravimetry . Up to 25 m3/h Partly undefined direction of flow . Up to 5 bar during switch over . Uncertainty 0.08 % Supplying tank (for MUT 0.12 %) Weighing tank Fixed connection causing non- constant forces on scale Uncertainty in mass Pump Reference for collected between Flow meter to be calibrated calibrations MUT and Reference 11-10-2018 NIST-OAS Forum 3 Calibration and testing facility Designing, building and validating a mid-scale LNG mass and volume flow calibration facility 11-10-2018 NIST-OAS Forum 4 Composition standard Aims: . Produce an accurate, lab-based sampling and analysis reference method to test and calibrate commercially available sampling/ composition measurement systems . Develop methods to sample and vaporize LNG in a representative and homogeneous fashion . Validate Raman spectroscopy methods for composition analysis and compare the results obtained to those from GC methods . Study the effects of long-term storage on LNG composition 11-10-2018 NIST-OAS Forum 5 Application of the LNG sampling and composition measurement reference standard Reference Sampler &Vaporizer LNG based calibration gases LNG loop Measurement 1 (Reference) Measurement 2 (Result) Service Commercial Quantity (unit) Quantity Sampler &Vaporizer Reference Result 11-10-2018 Presentation at GAS2017, 13-15 JuneNIST-2017,OAS ForumWTC Rotterdam 6 LNG Density . Conversion between mass and volume . Specifications (RU Bochum) − T-range: 90 K to 300 K − p-range: 0.05 MPa to 12 MPa − Homogeneous + saturated liquid (incl. vapor pressure), hom. gas − Δρ/ρ < 0.05 % (incl. mix. unc.) 11-10-2018 NIST-OAS Forum 7 Natural gas substitutes: refinery, synthesis and coke oven gas . Growing demand of new energy sources Syngas Biosyngas Refinery gas Coke oven gas − flexibility of refining process causes varying composition of refinery gas Hydrogen − alternative methods producing synthesis gas or biosyngas Carbon dioxide . For fiscal purposes and to provide compliance to carbon emissions required by the European Carbon monoxide Emissions Trading Scheme. Challenging and maybe not perfect but worth Nitrogen to improve cost-effectiveness of the measurement Methane 0 10 20 30 40 50 60 70 80 . Development of a universal analytical method amount of substance fraction (%) for refinery and synthesis gas-type mixtures . Preparation of a suite of primary standard gas mixtures 11-10-2018 NIST-OAS Forum 8 Experimental FID1 A, Front Signal (2012\20120914\120914 2012-09-14 11-29-07\005F0502.D) TCD2 B, Back Signal (2012\20120914\120914 2012-09-14 11-29-07\005F0502.D) TCD3 C, Aux Signal (2012\20120914\120914 2012-09-14 11-29-07\005F0502.D) pA . Agilent 7890A Series GC CH4 250 . Four micro packed GC columns, two capillary 200 columns, three six port rotary valves, two ten port rotary valves, a split/splitless inlet, a flame 150 ionization detector (FID) and two thermal 100 50 conductivity detectors (TCD). CO . Equipped with three channels: 0 1. Aluminiumoxide plot ‘S’ column 25 m × 0.32mm × 8mm; FID, higher 5.2 5.4 5.6 5.8 6 6.2 min FID1 A, Front Signal (2012\20120914\120914 2012-09-14 11-29-07\012F1206.D) hydrocarbons. TCD2 B, Back Signal (2012\20120914\120914 2012-09-14 11-29-07\012F1206.D) TCD3 C, Aux Signal (2012\20120914\120914 2012-09-14 11-29-07\012F1206.D) pA 2. HayeSep Q (80/100 mesh) 0.25 m × 1/16'‘column (trapped higher hydrocarbons) + Hayesep N (80/100 mesh) 1 m × 1/16'' column 2000 H2 (CO2, C2H6, C2H4,H2S) + Molsieve 13X, 2 m × 1/16'' column, 1500 CO2 TCD (O2, N2, CH4, CO). 3. Combined HayeSepQ/Molsieve 5A column (1 m/2 m, 1/16'') TCD, 1000 N2 N carrier gas (He, H ). 500 CO 2 2 C2H4 CH4 CH4 C2H6 0 iso-Buteen -500 -1000 1 2 3 4 5 6 min 11-10-2018 NIST-OAS Forum 9 Results (full ranges) . Calibration function 2nd order polynomial . Uncertainties similar as for CCQM-K77 . Combination of high fraction methane and low fraction carbon monoxide problematic . For most compositions, method performs sufficiently well and is a low(er)-cost alternative to dedicated methods calibration range [%] Sr CMC component model low high low high low high Hydrogen parabola 5 46 0.06 0.01 0.08% 0.03% Methane parabola 1 40 0.2 0.09 0.20% 0.12% Nitrogen parabola 2 71 0.25 0.04 0.31% 0.04% Carbon monoxide parabola 1 70 2.1 0.03 1.73% 0.04% Carbon monoxide parabola 2.5 70 0.32 0.03 0.35% 0.04% Carbon dioxide parabola 0.2 37 0.19 0.07 0.24% 0.10% Ethene parabola 2 16 0.07 0.06 0.10% 0.07% Ethane parabola 0.2 20 0.09 0.04 0.28% 0.05% 11-10-2018 NIST-OAS Forum 10 Liquefied petroleum gas . Reference standards: − Gravimetric preparation, largely based on ISO 6142-1 − Verification done using ISO 6143, ISO 6974 − Challenge to keep the entire mixture in one phase (liquid, vapour) . At the brink of gas metrology and petroleum chemistry . One key comparison organized (CCQM-K119) − Most results agreed within ± 1 % − Expanded uncertainty typically 1 % or larger 11-10-2018 NIST-OAS Forum 11 Hydrogen-enriched natural gas . Development of a suite of reference gas mixtures for hydrogen in natural gas (3% - 20%) . Validation of the extension of the scope of ISO 6974 for this application . Expanded uncertainty in the order of 0.12 % on the natural gas analyser, 0.20 % on the refinery gas analyser . Results published in Int. J. Hydrogen Energy 40(46) (2015), pp. 15877-15884 11-10-2018 NIST-OAS Forum 12 European Metrology Network (EMN) for Energy Gases . European knowledge and metrological service centre for energy gases . Facilitate energy transition, with focus on metering of energy gases . Conventional fluids and fluids related to (emerging) renewable/ sustainable energy sources . Cross-cutting character: gas analysis, flow, humidity, pressure, density, material data and testing . Under EURAMET 11-10-2018 NIST-OAS Forum 13 Questions?.
Load more

Recommended publications
  • New Federal Law Addresses Excise Tax on LNG, LPG, And
    Multistate Tax EXTERNAL ALERT New federal law addresses excise tax on LNG, LPG, and CNG August 13, 2015 Overview President Obama recently signed into law the Surface Transportation and Veterans Health Care Choice Improvement Act of 2015 (H.R. 3236).1 Effective January 1, 2016, the new law equalizes the federal excise tax treatment of liquefied natural gas (LNG) and liquefied petroleum gas (LPG) and provides further guidance applicable to the taxation of compressed natural gas (CNG). This Tax Alert summarizes these federal excise tax law changes. The federal excise tax on alternative fuels Currently, under Internal Revenue Code (I.R.C.) §4041, the federal excise tax on “alternative fuels” is imposed when such fuels are sold for use or used as a fuel in a motor vehicle or motorboat.2 The term “alternative fuels” includes, but is not limited to, LNG, CNG, and LPG.3 LNG is currently subject to tax at the federal diesel fuel tax rate of 24.3 cents per gallon.4 However, LNG contains a lower energy content than diesel. According to the Oak Ridge National Laboratory, LNG has an energy content of 74,700 Btu per gallon (lower heating value), while diesel has an energy content of 128,450 Btu per gallon (lower heating value).5 Therefore, one gallon of LNG has the energy equivalency of 58 percent of one gallon of diesel fuel, although LNG is currently taxed as having the energy equivalency of 100 percent of one gallon of diesel fuel.6 Similarly, LPG is currently subject to tax at the federal gasoline tax rate of 18.3 cents per gallon.7 However, LPG contains a lower energy content than gasoline.
    [Show full text]
  • Final Report Study on the Potential of Increased Use of LPG for Cooking in Developing Countries
    Final Report Study on the Potential of Increased Use of LPG for Cooking in Developing Countries September 2020 TABLE OF CONTENTS Executive Summary ....................................................................................................................................................................... 2 List of Abbreviations ...................................................................................................................................................................... 6 Preface .......................................................................................................................................................................................... 7 1 Introduction.......................................................................................................................................................................... 8 1.1 General ................................................................................................................................................................................. 8 1.2 Background ........................................................................................................................................................................... 8 2 Purpose and Scope of the Study ............................................................................................................................................ 9 2.1 Purpose of the Study ...........................................................................................................................................................
    [Show full text]
  • Liquefied Petroleum Gas (LPG)
    Liquefied Petroleum Gas (LPG) Demand, Supply and Future Perspectives for Sudan Synthesis report of a workshop held in Khartoum, 12-13 December 2010 The workshop was funded by UKaid from the Department for International Development Cover image: © UNAMID / Albert Gonzalez Farran This report is available online at: www.unep.org/sudan Disclaimer The material in this report does not necessarily represent the views of any of the organisations involved in the preparation and hosting of the workshop. It must be noted that some time has passed between the workshop and the dissemination of this report, during which some important changes have taken place, not least of which is the independence of South Sudan, a fact which greatly affects the national energy context. Critically, following the independence, the rate of deforestation in the Republic of Sudan has risen from 0.7% per year to 2.2% per year, making many of the discussions within this document all the more relevant. Whilst not directly affecting the production of LPG, which is largely derived from oil supplies north of the border with South Sudan, the wider context of the economics of the energy sector, and the economy as a whole, have changed. These changes are not reflected in this document. This being said, it is strongly asserted that this document still represents a useful contribution to the energy sector, particularly given its contribution to charting the breadth of perspectives on LPG in the Republic of Sudan. Liquefied Petroleum Gas (LPG) Demand, Supply and Future Perspectives for Sudan Synthesis report of a workshop held in Khartoum, 12-13 December 2010 A joint publication by: Ministry of Environment, Forestry and Physical Development – Sudan, Ministry of Petroleum – Sudan, United Kingdom Department for International Development, United Nations Development Programme and United Nations Environment Programme Table of contents Acronyms and abbreviations .
    [Show full text]
  • Influence of the Use of Liquefied Petroleum Gas (LPG) Systems In
    energies Article Influence of the Use of Liquefied Petroleum Gas (LPG) Systems in Woodchippers Powered by Small Engines on Exhaust Emissions and Operating Costs Łukasz Warguła 1,* , Mateusz Kukla 1 , Piotr Lijewski 2, Michał Dobrzy ´nski 2 and Filip Markiewicz 2 1 Institute of Machine Design, Faculty of Mechanical Engineering, Poznan University of Technology, Piotrowo 3, PL-60965 Poznan, Poland; [email protected] 2 Institute of Internal Combustion Engines and Drives, Faculty of Civil Engineering and Transport, Poznan University of Technology, Piotrowo 3, PL-60965 Poznan, Poland; [email protected] (P.L.); [email protected] (M.D.); fi[email protected] (F.M.) * Correspondence: [email protected]; Tel.: +48-(61)-665-20-42 Received: 12 August 2020; Accepted: 3 November 2020; Published: 4 November 2020 Abstract: The use of alternative fuels is a contemporary trend in science aimed at the protection of non-renewable resources, reducing the negative impact on people and reducing the negative impact on the natural environment. Liquefied petroleum gas (LPG) is an alternative fuel within the meaning of the European Union Directive (2014/94/UE), as it is an alternative for energy sources derived from crude oil. The use of LPG fuel in low-power internal combustion engines is one of the currently developed scientific research directions. It results from the possibility of limiting air pollutant emissions compared to the commonly used gasoline and the lower cost of this fuel in many countries. By “gasoline 95” the Authors mean non-lead petrol as a flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines, whereas 95 is an octane rating (octane number).
    [Show full text]
  • 2002-00201-01-E.Pdf (Pdf)
    report no. 2/95 alternative fuels in the automotive market Prepared for the CONCAWE Automotive Emissions Management Group by its Technical Coordinator, R.C. Hutcheson Reproduction permitted with due acknowledgement Ó CONCAWE Brussels October 1995 I report no. 2/95 ABSTRACT A review of the advantages and disadvantages of alternative fuels for road transport has been conducted. Based on numerous literature sources and in-house data, CONCAWE concludes that: · Alternatives to conventional automotive transport fuels are unlikely to make a significant impact in the foreseeable future for either economic or environmental reasons. · Gaseous fuels have some advantages and some growth can be expected. More specifically, compressed natural gas (CNG) and liquefied petroleum gas (LPG) may be employed as an alternative to diesel fuel in urban fleet applications. · Bio-fuels remain marginal products and their use can only be justified if societal and/or agricultural policy outweigh market forces. · Methanol has a number of disadvantages in terms of its acute toxicity and the emissions of “air toxics”, notably formaldehyde. In addition, recent estimates suggest that methanol will remain uneconomic when compared with conventional fuels. KEYWORDS Gasoline, diesel fuel, natural gas, liquefied petroleum gas, CNG, LNG, Methanol, LPG, bio-fuels, ethanol, rape seed methyl ester, RSME, carbon dioxide, CO2, emissions. ACKNOWLEDGEMENTS This literature review is fully referenced (see Section 12). However, CONCAWE is grateful to the following for their permission to quote in detail from their publications: · SAE Paper No. 932778 ã1993 - reprinted with permission from the Society of Automotive Engineers, Inc. (15) · “Road vehicles - Efficiency and emissions” - Dr. Walter Ospelt, AVL LIST GmbH.
    [Show full text]
  • Liquefied Natural Gas/ Compressed Natural Gas Opportunities
    Liquefied Natural Gas/ Compressed Natural Gas Opportunities Fixed Gas and Flame Detection Applications While there are many solutions that can help meet our energy needs into the future, natural gas and its benefits are available now. The significant increase in the supply of natural gas, brought about by technical advancements in producing gas from shale deposits, has revolutionized the gas industry; opening up new sources of gas production in North America. Such increased production has escalated U.S. competitiveness, promoted job growth and bolstered the economy with lower, more stable natural gas prices.¹ ¹http://www.powerincooperation.com Because every life has a purpose... LNG/CNG Opportunites Liquefied natural gas (LNG) is natural gas that has been converted Total U.S. natural gas production, consumption, to liquid form for ease of storage or transport, and its use allows for and net imports, 1990-2035 the production and marketing of natural gas deposits that were (trillion cubicfeet) History 2010 Projections previously economically unrecoverable. This technology is used for 30 natural gas supply operations and domestic storage, and in Net exports, 2035 5% consumption such as for vehicle fuel. 25 Compressed natural gas (CNG) is natural gas under pressure Consumption which remains clear, odorless, and non-corrosive. CNG is a fossil 11% Net imports, 2010 fuel substitute for gasoline (petrol), diesel, or propane/LPG and is a 20 Henry Hub spot market more environmentally clean alternative to those fuels, and it is natural gas prices (2010 dollars per million Btu) much safer in the event of a spill. Domestic production 10 Interest in LNG and CNG has been rekindled and is expected to play 15 5 an important role in the natural gas industry and energy markets 0 over the next several years.
    [Show full text]
  • Quantifying the Potential of Renewable Natural Gas to Support a Reformed Energy Landscape: Estimates for New York State
    energies Review Quantifying the Potential of Renewable Natural Gas to Support a Reformed Energy Landscape: Estimates for New York State Stephanie Taboada 1,2, Lori Clark 2,3, Jake Lindberg 1,2, David J. Tonjes 2,3,4 and Devinder Mahajan 1,2,* 1 Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NY 11794, USA; [email protected] (S.T.); [email protected] (J.L.) 2 Institute of Gas Innovation and Technology, Advanced Energy Research and Technology, Stony Brook, NY 11794, USA; [email protected] (L.C.); [email protected] (D.J.T.) 3 Department of Technology and Society, Stony Brook University, 100 Nicolls Rd, Stony Brook, NY 11794, USA 4 Waste Data and Analysis Center, Stony Brook University, 100 Nicolls Rd, Stony Brook, NY 11794, USA * Correspondence: [email protected] Abstract: Public attention to climate change challenges our locked-in fossil fuel-dependent energy sector. Natural gas is replacing other fossil fuels in our energy mix. One way to reduce the greenhouse gas (GHG) impact of fossil natural gas is to replace it with renewable natural gas (RNG). The benefits of utilizing RNG are that it has no climate change impact when combusted and utilized in the same applications as fossil natural gas. RNG can be injected into the gas grid, used as a transportation fuel, or used for heating and electricity generation. Less common applications include utilizing RNG to produce chemicals, such as methanol, dimethyl ether, and ammonia. The GHG impact should be quantified before committing to RNG. This study quantifies the potential production of biogas (i.e., Citation: Taboada, S.; Clark, L.; the precursor to RNG) and RNG from agricultural and waste sources in New York State (NYS).
    [Show full text]
  • Scale Gas-‐To-‐Methanol Conversion by Engine Reformers
    System Model of Small-Scale Gas-to-Methanol Conversion by Engine Reformers By Angela J. Acocella B.S., Mechanical Engineering Rensselaer Polytechnic Institute, 2012 Submitted to the Engineering Systems Division in partial fulfillment of the requirements for the degree of Master of Science in Technology & Policy at the Massachusetts Institute of Technology June 2015 © 2015 Massachusetts Institute of Technology, All rights reserved Signature of Author............................................................................................................. Technology & Policy Program; Engineering Systems Division May 8, 2015 Certified by.............................................................................................................................. Daniel R. Cohn Research Scientist, MIT Energy Initiative Thesis Supervisor Accepted by............................................................................................................................. Dava J. Newman Professor of Aeronautics and Astronautics and Engineering Systems Director, Technology and Policy Program 2 System Model of Small-Scale Gas-to-Methanol Conversion by Engine Reformers by Angela J. Acocella Submitted to the Engineering Systems Division On May 8, 2015 in partial fulfillment of the requirements for the degree of Master of Science in Technology & Policy ABSTRACT As global energy demands grow and environmental concerns over resource extraction methods intensify, high impact solutions are becoming increasingly essential. Venting and flaring of associated
    [Show full text]
  • Natural Gas Liquids
    Brookings energy security initiative natural gas task Force natural gas BrieFing Document #1: Natural Gas Liquids march 2013 charles k. ebinger govinda avasarala Brookings natural g as task Force Issue Brief 1: Natural Gas Liquids 1 PREFACE n may 2011, the Brookings institution energy security initiative (ESI) assembled a task Force of independent natural-gas experts, whose expertise and insights provided inform its research on various issues regarding Ithe u.s. natural gas sector. in may 2012, Brookings released its first report, analyzing the case and prospects for exports of liquefied natural gas (lng) from the united states. the task Force now continues to meet pe- riodically to discuss important issues facing the sector. With input from the task Force, Brookings will release periodic issue briefs for policymakers. the conclusions and recommendations of this report are those of the authors and do not necessarily reflect the views of the members of the task force. members of the Brookings institution natural gas task Force JOHN BANKS, Brookings institution KELLY BENNETT, Bentek energy, LLC JASON BORDOFF, columbia university KEVIN BOOK, clearview energy Partners, LLC TOM CHOI, Deloitte CHARLES EBINGER, Brookings institution, task Force co-chair DAVID GOLDWYN, goldwyn global strategies, LLC, task Force co-chair SHAIA HOSSEINZADEH, Wl ross JAMES JENSEN, Jensen associates ROBERT JOHNSTON, eurasia group MELANIE KENDERDINE, massachusetts institute of technology energy initiative VELLO KUUSKRAA, advanced resources international MICHAEL LEVI, council on Foreign relations ROBERT MCNALLY, the rapidan group KENNETH MEDLOCK, rice university’s James a. Baker iii institute for Public Policy LOU PUGLIARESI, energy Policy research Foundation, inc. BENJAMIN SCHLESINGER, Benjamin schlesinger & associates, LLC JAMIE WEBSTER, PFc energy non-participating observers to task Force meetings included officials from the energy information adminis- tration and the congressional research service.
    [Show full text]
  • The Future of Gasification
    STRATEGIC ANALYSIS The Future of Gasification By DeLome Fair coal gasification projects in the U.S. then slowed significantly, President and Chief Executive Officer, with the exception of a few that were far enough along in Synthesis Energy Systems, Inc. development to avoid being cancelled. However, during this time period and on into the early 2010s, China continued to build a large number of coal-to-chemicals projects, beginning first with ammonia, and then moving on to methanol, olefins, asification technology has experienced periods of both and a variety of other products. China’s use of coal gasification high and low growth, driven by energy and chemical technology today is by far the largest of any country. China markets and geopolitical forces, since introduced into G rapidly grew its use of coal gasification technology to feed its commercial-scale operation several decades ago. The first industrialization-driven demand for chemicals. However, as large-scale commercial application of coal gasification was China’s GDP growth has slowed, the world’s largest and most in South Africa in 1955 for the production of coal-to-liquids. consistent market for coal gasification technology has begun During the 1970s development of coal gasification was pro- to slow new builds. pelled in the U.S. by the energy crisis, which created a political climate for the country to be less reliant on foreign oil by converting domestic coal into alternative energy options. Further growth of commercial-scale coal gasification began in “Market forces in high-growth the early 1980s in the U.S., Europe, Japan, and China in the coal-to-chemicals market.
    [Show full text]
  • Liquefied Petroleum Gas Specifications and Test Methods
    GPA Standard 2140-97 Liquefied Petroleum Gas Specifications and Test Methods Adopted as Recommended Procedures 1931 Revised 1940-1947-1948-1951-1955-1957-1959-1960-1962-1968 1970-1973-1975-1977-1980-1984-1986-1988-1990-1992-1996-1997 Reprinted 1998 Gas Processors Association 6526 East 60th Street Tulsa, Oklahoma 74145 TABLE OF CONTENTS Disclaimer ........................................................................................ ii Foreword ......................................................................................... ii GPA Specifications for Liquefied Petroleum Gases ....................................................... 1 ASTM D-1265-92: Sampling Liquefied Petroleum Gases .................................................. 2 ASTM D-1267-95: Vapor Pressure of Liquefied Petroleum Gases ........................................... 5 ASTM D-1657-89: Density or Relative Density of Light Hydrocarbons by Pressure Hydrometer ............................................................ 10 ASTM D-1837-94: Volatility of Liquefied Petroleum Gases ............................................... 14 ASTM D-1838-91: Copper Strip Corrosion by Liquefied Petroleum Gases .................................................................. 17 ASTM D-2158-92: Residues in Liquefied Petroleum Gases ................................................ 20 ASTM D-2163-91: Analysis of Liquefied Petroleum (LP) Gases and Propylene Concentrates by Gas Chromatography ........................................ 24 ASTM D-2713-91: Dryness of Propane (Valve Freeze
    [Show full text]
  • Methane Emissions from Natural Gas and LNG Imports: an Increasingly Urgent Issue for the Future of Gas in Europe
    November 2020 Methane Emissions from Natural Gas and LNG Imports: an increasingly urgent issue for the future of gas in Europe OIES PAPER: NG 165 Jonathan Stern, Distinguished Research Fellow, OIES The contents of this paper are the author’s sole responsibility. They do not necessarily represent the views of the Oxford Institute for Energy Studies or any of its members. Copyright © 2020 Oxford Institute for Energy Studies (Registered Charity, No. 286084) This publication may be reproduced in part for educational or non-profit purposes without special permission from the copyright holder, provided acknowledgment of the source is made. No use of this publication may be made for resale or for any other commercial purpose whatsoever without prior permission in writing from the Oxford Institute for Energy Studies. ISBN 978-1-78467-170-9 i Acknowledgements Colleagues at the OIES have been kind enough to read through the text and make helpful suggestions including: Alex Barnes, Mike Fulwood, James Henderson, Anouk Honoré, Martin Lambert, David Ledesma, Simon Pirani and Katja Yafimava. Special thanks are due to Marshall Hall who spent a great deal of his time discussing the subject with me, alerting me to many sources that I otherwise might have missed, filling in gaps in the text, and helping greatly by calculating methane intensity values. Outside the OIES I am grateful to: Tomas Bredariol, Christian Lelong, Christophe McGlade, Antoine Rostand and Peter Zeniewski for providing me with helpful comments and sources for many aspects of this extremely difficult subject. Thanks for John Elkins for his editorial suggestions and Kate Teasdale who did everything else with her customary efficiency I am solely responsible for all and any errors and omissions which remain, and all opinions and interpretations.
    [Show full text]