Feature article
COâ‚‚energy assessment: Making optimal use of carbon emissions
16/08/2008
Andy Brittain, Managing Consultant, Shell Global Solutions International BV, The Hague, The Netherlands, for International Oil and Gas Engineer
Energy fuels economic activity and growth. Hydrocarbons are expected to provide the foundation of the world’s energy for the remainder of this century. Consequently, management of carbon dioxide (CO₂) emissions is a priority.
Shell believes that the CO₂challenge cannot be met by one company alone. Instead, the Shell Group is striving for public-private partnerships and a strong policy framework.
In addition, Shell has been one of the first energy companies to acknowledge the threat of climate change and believes that most businesses can take steps to reduce their energy consumption and carbon emissions. The company set aggressive, voluntary CO₂emissions targets, aiming to reduce emissions from Shell’s operations in 2010 to a level at least 5% lower than in 1990. Shell’s greenhouse gas (GHG) emissions fell to 92 million tonnes of CO₂equivalent in 2007, which is a 25 percent reduction since 1990.
Shell is pursuing research and development into leading-edge technologies to further improve energy efficiency, generate energy cleanly and mitigate CO₂emissions. Developing cost-effective technologies to capture carbon emissions from power plants and refineries and sequestering them underground. Several storage possibilities exist that are being explored through a range of projects.
For example, in Queensland, Australia, Shell and others are exploring sites that could potentially be used to store CO₂captured from a power plant. Shell is the preferred provider of gasification technology and is providing drilling and CO₂storage expertise. If the project goes ahead, it is thought that up to 420,000 tonnes of CO₂the majority of the demonstration plant’s CO₂emissions could be annually captured and stored. Commercial versions would have carbon emissions nearly 40 percent lower than those from a comparably sized conventional natural gas-fired power plant.
The Carbon Energy Management Consultancy (CEM), from Shell Global Solutions, brings together technology and expertise from across Shell’s operations, gained from reducing its own CO₂footprint, and also works with other companies facing the same challenges by saving energy, reducing costs and lowering CO₂.
The CEM programme examines current emission positions of clients and benchmarks them against optimal industry operating practices. Strategic options are proposed to improve the client’s emission position, such as energy efficiency programmes, carbon optimisation, CO₂sales and carbon-allowance trading.
Using Shell’s extensive technical and operating experience from its plants, the CEM programme is designed to be modular and builds upon Energise—the company’s energy efficiency programme, Energise, has helped large industrial sites save energy and cut emissions with minimum capital expenditure. This programme has delivered reductions in energy usage by between two percent and nine percent with minimal capital investment.
Strategies for energy efficiency could include best available technology assessments, hydrocarbon management reviews, asset reliability improvements and catalyst optimisation. The company’s own energy efficiency improvements are already delivering CO₂savings of about 1 million tonnes per year.
A company’s options for carbon optimisation can be explored through carbon abatement curves. These help to inform strategy through analysing different technologies that are available for mitigating greenhouse gas emissions and their costs. Switching to less carbon intensive fuels, introducing renewable fuels sources, make-or-buy decisions for power supply, CO₂mineralisation and storage can all be considered.
CEM also looks at the options for carbon allowance trading and offsetting, within the European Union Emission Trading Scheme (EUETS) and using the Kyoto instruments, such as the Clean Development Mechanism and Joint Implementation.
The CEM programme considers options against the parameters of feasibility and impact. Once a preferred implementation approach is identified, CEM can support its delivery and provide ongoing support to ensure that energy or carbon savings are sustained. Changes in management practices, operator training, monitoring tools and leadership focus play a role in preventing value erosion once consultants leave a client’s site.
Positive results from the CEM programme have already been seen. By focusing on better operational performance, the Fredericia refinery in Denmark achieved sustainable energy savings of nine percent. The refinery was Shell’s second most energy efficient refinery; yet, the CEM programme still managed to generate more savings. For example, the Fredericia refinery’s crude distiller changed the way skimming oil in the hydrodesulphurisation unit was managed. The refinery achieved more energy savings.
The energy-efficiency stream of the programme has also helped Malaysia LNG decrease the amount of feed gas used as fuel to run the LNG plant and reduce venting of hydrocarbons through flaring or incineration. The saved fuel is available as additional feed gas for conversion into LNG product.
One of Shell’s UK refineries identified energy savings worth five to six percent of the site’s energy bill through Energise, demonstrating the success of Shell Global Solutions’ Carbon and Energy Management Consultancy. Additionally, Shell Global Solutions Carbon and Energy Management Consultancy won the Petroleum Economist Cleaner Energy Initiative Award 2007.
Shell’s Energy Management System, a key tool to help ensure that value is sustained, is a combination of structured management processes and monitoring tools linked to real-time plant data systems. If implemented correctly, it can help develop a self-sustaining energy culture that enables continuous energy improvement. In exploring the potential for one Russian refinery, estimates suggested that operational excellence based on the energy management monitoring system could generate annual savings approaching US$250,000 on its most efficient crude unit, based on the preliminary assessment.
Another innovative approach to carbon management is also bringing results. For example, Shell’s Pernis refinery in The Netherlands has reduced emissions by using a pipeline to redirect CO₂from the plant to horticultural growers in the south of The Netherlands. The additional benefit is that pure CO₂accelerates crop growth (up to a 25 percent increase in production) and the growers now no longer need to run greenhouse heating systems during the summer just to maintain CO₂flow.
Shell Global Solutions has also facilitated the sale of CO₂for other industrial applications including the paper industry in which it is converted to precipitated calcium carbonate and used as a paper whitener. In addition, Shell actively supports carbon trading and it completed the first-ever trade of CO₂emission allowances in 2003. This was within the EUETS, on behalf of Nuon Energy Trade and Wholesale, to effectively open the European emissions trading market.
Jeroen van der Veer, Shell Chief Executive, has said, “Meeting the world’s growing energy needs in an environmentally responsible manner is a tremendous challenge. Technology is essential to answering that challenge.” Already, the technologies that are being developed are enabling major steps to reduce and to manage CO₂and to meet the mandates, which are being laid before the oil and gas sectors.
Success of Shell Global Solutions, Carbon and Energy Management Consultancy, includes:
- A US specialty chemicals plant reduced its energy bill by approximately 9% and realised savings of $1.17 million/yr.
- One of Shell’s UK refineries identified energy savings worth 5%–6% of the site’s energy bill through Energise.
These examples were achieved with commensurate savings in CO₂
- Energy management software developed by Shell Global Solutions was awarded “Highly Commended” in the IChemE AspenTech award for information technology.