The industrial gas industry derives its core products from the Earth’s atmosphere: oxygen, nitrogen, argon and carbon dioxide, and therefore is vitally concerned about the rising levels of anthropologic emissions.
Recent efforts extending the level of commitment to sustainable industrial development have discovered interesting opportunities to enable customers to improve their environmental performance.
The cryogenic air separation units operated by the industry that produce an estimated 80% of the total volume of atmospheric gases consumed worldwide, depend almost exclusively on electric power. Greenhouse gas (GHG) emissions from fossil-fuelled power generation plants are thought to represent around 50% of the industry’s total indirect GHG emissions.
Reduction of the specific power consumption of their ASU’s is the obvious way for gas companies to reduce their indirect carbon footprint, but this goal has always been vigorously pursued in the interest of improved profitability and the potential gains here are likely to be minimal. Typically, goals of around 1% annual improvement are announced in sustainability reports.
Indirect contribution to GHG reduction
It is by assisting and encouraging their customers to apply sometimes pioneering innovations in process technology or operation, that the gas industry finds the largest scope for reducing the release of GHGs into the atmosphere.
Gas companies report that useful reductions in carbon release have been achieved through cryogenic recovery of volatile pollutants including fluorinated hydrocarbons and other solvents. Innovative heat-exchanger systems take advantage of waste heat or replace electric refrigeration when integrated with gas vaporizers at customer sites.
Facilitating the capture of carbon dioxide
A popular application for industrial oxygen is the enhanced combustion of fossil fuels including coal, oil and gas with the primary objective of increasing the output of a given furnace or smelter, reducing the operating cycle time and/or reducing the fuel consumption of the process.
Recent developments in the design of oxy-fuel burners, combined with the imperative of reducing carbon emissions, have created new impetus that will result in considerable growth in the use of oxy-fuel combustion.
The secondary benefit of replacing air with oxygen for combustion applications is that by eliminating the nitrogen that was previously carried through the process, the concentration of carbon dioxide in the exhaust stream is far higher. This facilitates the capture and sequestration of carbon dioxide and will play a significant role in the development of practical applications of this process.
The production of hydrogen from natural gas and the operation of cogeneration plants are the two activities that account for the vast majority of direct GHG emissions in the production of industrial gas.
Around 95% of hydrogen production is by the reforming of natural gas with steam and the unavoidable by-product of this process is carbon dioxide. The chemistry of methane dictates the ratio of hydrogen to carbon dioxide and although the carbon dioxide could be separated for disposal, this is not widely practised. It may be argued, of course, that were hydrogen not produced in this way, that volume of natural gas would end up as combustion fuel and the same volume of carbon dioxide released.
In terms of transport and logistics, the industry does operate large fleets of diesel-fuelled distribution vehicles and although these probably contribute less than 5% to their total of GHG emissions, they do represent a significant opportunity for improvement. Engine manufacturers have been required to comply with a series of revised standards that continually reduce the allowed levels of toxic pollutants released in vehicles exhaust gas.
Vehicle emission standards
Emission control standards were initially established in the major centres of Japan, the US, and the European Union (EU). These regions have similar approaches to emission reduction, although each set of regulations is tailored to specific requirements.
The US system has decreasing emissions limits and increasing durability requirements. The European regulations also define increasing restrictions. Currently Euro V sets limits to 2013, when Euro VI will take effect.
The most stringent emissions standards in the world are to be found in California, which has become the benchmark for worldwide environmental legislation. The rest of the world is following the emission standards and technologies of the vanguard nations, allowing them to adopt increasingly stricter standards at a faster pace.
Note that none of the pollutants regulated today are GHGs such as carbon dioxide, methane, nitrous oxide, or water vapour. On 2nd April 2007, Congress ruled that greenhouse gases are considered pollutants and as such the Environmental Protection Agency has the authority to regulate them.
Optimising fuel economy
Road transport contributes about one-fifth of the EU’s total emissions of carbon dioxide, the main greenhouse gas. While emissions from other sectors are generally falling, those from road transport have continued to increase since 1990.
Eager to tackle climate change, the European Commission has a comprehensive strategy designed to help the EU reach its long-established objective of limiting average carbon dioxide emissions from new cars to 120 grams per km by 2012.
Addressing the United Nations World Forum for Harmonization of Vehicle Regulation and Technological Innovations last year, the International Road Transport Union (IRUS) pointed out that that the road transport industry has already reduced its toxic emissions by up to 97% over the past 20 years and proposed a shift of legislative focus for heavy commercial vehicles from toxic emissions to CO2 emissions.
IRU Head of Technical Affairs, Jacques Marmy, reportedly called upon governments to, “strive, in principle, for globally harmonised emission standards and to develop a global certification procedure for CO2 emissions of heavy commercial vehicles.”
Speaking of plans to reduce greenhouse gas emissions from the freight sector, which include making eco driver training for LGV drivers a mandatory part of the EU Driver Certificate of Professional Competence, UK Transport Minister Paul Clark is attributed as saying, “With initiatives like this I am confident we will succeed in creating a greener and cleaner industry fit to meet the environmental challenges we face.”
The benefits of eco-driver training are estimated to save up to three million tonnes of carbon dioxide over five years and £300m in fuel costs.